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  • 1980-1984  (4,371)
  • Physics  (2,657)
  • Atomic, Molecular and Optical Physics  (1,301)
  • Gas chromatography  (412)
  • Nuclear reactions
Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 327 (1984), S. 260-265 
    ISSN: 1432-1912
    Keywords: Amitriptyline ; Imipramine ; Clomipramine ; Demethylated metabolites ; Free fractions ; Serum ; Equilibrium dialysis ; Gas chromatography ; Binding parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The plasma protein binding of amitriptyline, imipramine, clomipramine, and their primary demethylated metabolites were studied by means of a method combining dialysis and gas chromatography. Equilibrium in dialysis of serum containing amitriptyline and its metabolite nortriptyline was attained in about 0.5 h with the drug dissolved in the serum compartment, and in about 2 h with the drug passing from the buffer to the serum compartment. The calculation of free fractions was influenced by variations with dialysis time in the volumes of serum and buffer. Increase of pH in serum increased the protein binding of the weakly basic drugs studied, and made the Donnan distribution effects more pronounced. At pH 7.4, the Donnan effect was negligible. Binding parameters for the 6 tricyclic antidepressant substances studied were estimated for the binding to α1-acid glycoprotein and for total binding in serum. For α1-acid glycoprotein, the k-values ranged from 1·105 to 8·105 M−1, and for pooled serum from 0.4·105 to 8·105 M−1. The determined number of binding sites on the α1-acid glycoprotein was, on average 0.87 for the 6 substances. In serum, the binding capacity was 2–14 times the concentration of α1-acid glycoprotein.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 142 (1984), S. 165-169 
    ISSN: 1432-1076
    Keywords: Adrenal gland neoplasms ; Urine steroids ; Gas chromatography ; Mass spectrometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Steroid excretion in urine of 12 infants with virilising adrenal tumours has been determined using gas chromatography. In six children, (Group A, five female, one male) aged 2.8–5.3 years, very high urinary excretions of 17 oxosteroids (〉40 μmol/24 h) were largely accounted for by dehydroepiandrosterone (DHA). In one of the girls, the pattern of steroids excreted in urine was similar to that of newborn infants, with high excretions of 16-oxygenated derivatives of DHA. The histology of this tumour suggested a neoplasia of fetal-type adrenocortical cells. Very large tumours were found in three of the infants, two of whom have died and one has multiple metastases. From the other three children, small, well-encapsulated adenomas were successfully removed. Six children (Group B), had moderately elevated 17-oxosteroid exrretions (8–17 μmol/ 24 h). In five of these cases (four female, one male) aged 0.8–5 years, 11β-hydroxyandrosterone was a consistently prominent urinary steroid. In one boy, aged 7.7 years, 17-oxosteroid excretion was 15 μmol/24 h and the major steroids in urine were metabolites of pregnenolone. These six children have survived with no clinical evidence of recurrent tumour. The in vivo functional activities of the tumours can be deduced from the different profiles of steroids in urine. These have revealed heterogeneous patterns of steroid biosynthesis.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 55 (1984), S. 70-75 
    ISSN: 1432-0738
    Keywords: Soman ; Gas chromatography ; Mass spectrometry ; Cholinesterases ; Aliesterase ; Phosphorylphosphatase ; Toxicity ; Stereoselectivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The fate of the four stereoisomers of soman [0-(1,2,2-trimethylpropyl)-methyl-fluoro phosphonate] has been studied a) in vivo in mouse blood and liver after IP injection of 0.75 × LD50 Rc- and Sc-soman respectively, and b) in vitro upon incubation wih acetyl- und pseudocholinesterase, aliesterase and phosphorylphosphatase. The analytical method used is based on gas chromatography — mass spectrometry with deuterated internal standard. Most soman disappeared very rapidly from blood and liver. In liver, SCRP and RCRP, the two isomers that preferentially react with cholinesterase, could be detected. The level of SCRP, which was higher than that of RCRP, could be followed for 17–18 h. In blood only SCRP could be detected. The amounts found were fairly constant during the time period 2 min to 4h, and it could even be detected 17–18 h after soman administration.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 55 (1984), S. 272-275 
    ISSN: 1432-0738
    Keywords: 2-Ethoxyethanol ; Teratogen ; Adsorption ; Desorption ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A gas Chromatographic procedure for the determination of 2-ethoxyethanol (C2H5OCH2CH2OH) was developed by using the general principles of analysis of solvent vapors. 2-Ethoxyethanol was sampled by adsorbing on activated carbon. It was desorbed with carbon disulfide plus 2-propanol (0.5%). The analytical column was packed with 10% free fatty acid phase on Chromosorb-P AW. The analysis was conducted at 130° C isothermal using a flame ionization detector. Addition of 2-propanol (0.5%) to carbon disulfide improved (P≤0.01) desorption of 2-ethoxyethanol adsorbed on activated carbon. The mean desorption efficiency of carbon disulfide plus 2-propanol (0.5%) was 87.9±2.86% (n=15). Based on a 101 air sample and detector sensitivity of 2×10−10AFS, the calculated limit of detection of 2-ethoxyethanol was 0.1 ppm. The precision (coefficient of variation) for this analytical procedure was 3.34% (n=12). In conclusion, 2-ethoxyethanol adsorbed on activated carbon can be desorbed with carbon disulfide plus 2-propanol (0.5%). Subsequently the desorbed 2-ethoxyethanol can be analyzed by gas chromatographic identification on 10% FFAP using a flame ionization detector.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Cross-linked Stationary phase ; Immobilized Stationary phase ; Packed columns ; Trapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A coating of silicone SE-54 on Chromosorb W has been converted to an analytically stable, immobilized stationary phase layer by cross-linking with an organic peroxide. Up to 10% by weight has been applied in this manner. Excellent high temperature qualities are exhibited, such as low bleeding and good base line stability, during typical analyses. Poly (2,6-dimethyl-p-phenylene oxide) has also been crosslinked as a surface coating on Chromosorb W with an organic peroxide. From 3 to 4% by weight has been immobilized in this way. The resultant packing material, following high temperature conditioning, has been examined for use as an adsorbent of trace substances, similar to the applications to which such adsorbents as Tenax GC have commonly been applied, e.g. trace analysis of air. It appears to exhibit satisfactory properties for this analytical purpose.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 18 (1984), S. 21-22 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Isopropylidene-glucose ; Glucose ; GC of TMS-derivatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper describes the gas chromatographic separation of the mixture of di- and mono-O-isopropylidene-D-glucose and D-glucose as their trimethylsilyl derivatives. The use of OV-101 as liquid phase provides a complete separation for the all components in the mixture. Quantative analysis was performed using xylitol as the internal standard for di- and mono-O-isopropylidene-D-glucose, and sorbitol as the internal standard for α-and β-glucose.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Nuclear magnetic resonance ; Terpenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A procedure is described for recording1H NMR spectra of flowing gaseous GC fractions boiling as high as 200°C. The line width of the signals in the NMR spectra is smaller than 2.2Hz.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 18 (1984), S. 556-559 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid chromatography ; Tetramethrin ; Residues
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is described for the analysis of tetramethrin aqueous formulation and residues of tetramethrin on woolen cloth. The samples were extracted with acetonitrile and partitioned with benzene. Interferences were removed by liquid column chromatography with acid alumina and eluted with 10% ethyl acetate-hexane. Analysis was by gas chromatography with a 10% UCW98 (methylsilicone) column. Detection was made with the flame ionization detector to avoid the repeated dilutions necessary with use of the electron capture detector.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention index ; Electric parameters ; Physico-chemical relationships ; Structure-retention study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new equation is derived relating the retention index to the molecular polarizabilities, ionization potentials and permanent dipole moments of the stationary phase and the solute. Various implications of this equation to quantitative structure-retention relationships are discussed.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1612-1112
    Keywords: Aldehydes and ketones ; 2,4-dinitrophenylhydrazine-coated silica gel ; Gas chromatography ; Column liquid chromatography ; Pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary After a brief review of several methods described in the literature this paper discusses air-sampling on 2,4-dinitrophenylhydrazine-coated silica gel and identification requirements for aldehydes and ketones most commonly found in industrial pollution. Quantitative analysis of formaldehyde and acetaldehyde either by GC or by HPLC techniques is established using a dynamic system producing test atmospheres and compared with the usual colorimetric determinations.
    Type of Medium: Electronic Resource
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  • 11
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Esterification in aqueous solution ; n-Butyl esters of C2−C16 dicarboxylic acids ; Dicarboxylic acid analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary C2−C16 dicarboxylic acids were esterified in aqueous solution in the presence of sulfuric acid. Esterification in water/n-butanol mixtures with mole ratios between 0.02 and 2.53 can be utilized for the quantitative determination of the dicarboxylic acids by gas chromatography. The presence of water does not interfere at water/n-butanol mole ratios below 0.27. For mole ratios above 0.27 anhydrous sodium sulfate has been used for binding the water. The mole ratio range was 0.25–0.75 for anhydrous sodium sulfate/water, and 0.32–1.3 for sulfuric acid/anhydrous sodium sulfate.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 18 (1984), S. 202-204 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Polysiloxane stationary phases ; Heat of adsorption ; Heat of solution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The changes in the heat of solution of polar compounds and xylene isomers in methylsilicone fluid OV-101 deposited on Chromosorb W AW DMCS were studied. It was shown that the heat of solution increases with an increase of the percentage loading of the OV-101 up to 10%. Solution and adsorption thermodynamic characteristics of the studied system are briefly discussed.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 329-332 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Fused silica capillary columns ; Deactivation ; Polymethylhydrosiloxanes ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 338-339 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Pesticides ; Multidetection ; ECD-NPSD-SSD ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 332-333 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Polarity mixtures ; Reaction products ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 370-374 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Trace analysis ; On-column injection ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Large sample volume on-column injection (up to 250 μL) of n-pentane solutions of halogenated hydrocarbons has been employed for the direct measurement of both low-boiling and high-boiling compounds in what is essentially a single run. Two-bonded phase, fused-silica capillary columns are joined in series, through which the low-boiling compounds are first chromatographed and detected with an electron capture detector. High-boiling compounds are then trapped in a section joining the two columns, and subsequently chromatographed in the second column, using the same detector. This procedure permits analysis at the ppt level.
    Additional Material: 7 Ill.
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  • 17
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 404-410 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Multidimensional capillary columns ; Enantiomeric separations ; Intermediate trapping ; Mixed polarities ; Terpene alcohols ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 18
    ISSN: 0935-6304
    Keywords: Low and high resolution liquid chromatography ; Gas chromatography ; Capillary columns ; Alkali flame detection ; Chemical ionization mass spectrometry ; Nitro-PAHs ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An analytical procedure is described for the fractionation of organic compounds present in environmental samples and the determination of nitro polyaromatic hydrocarbons (nitro-PAHs). Both low and high resolution liquid chromatography are employed for the prefractionation of the soluble organic fraction (SOF) extracted from particulate matter or gaseous pollutants collected on adsorption traps. High resolution gas chromatography is used to analyze four fractions containing alkanes, PAHs, nitro-PAHs, and other polar PAHs. Nitrogen-containing species are separated by GC and detected specifically using an alkali flame (NPD) detector. Flame ionization (FID) detection, GC-MS of positive ions, and negative ion chemical ionization MS of the whole fraction is used for the identification and quantitation of the various components. The composition of SOF extracted from particulate matter emitted from diesel exhausts is elucidated and a large number of nitro-PAHs identified by the combination of the various techniques.
    Additional Material: 7 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 536-537 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column ; On-Column injection ; Vaporizing injection ; Decomposition ; α-Ferrocenyl carbinols ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 700-701 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Glass capillary columns ; Immobilization ; 60Co gamma radiation ; Medium-polarity phase ; OV-1701-Vi ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 21
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 142-143 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Solute focussing ; Solvent effect ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 22
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 215-217 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, fused silica ; Coupled columns ; Halogenated organic pollutants ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 23
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 222-224 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Interface ; Partition ; Adsorption ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 24
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 282-283 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Gas analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 25
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 306-311 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Thermodesorption ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A commercial thermodesorption and cold trap unit can be used as a large sample volume injection device in high resolution gas chromatography. Volumes of more than 100 μl can be injected. More than 97% of solvents, such as hexane, can be removed by a Tenax TA precolumn without any loss of compounds with volatilities comparable to naphthalene. Experimental conditions, recovery rates of polycyclic aromatic hydrocarbons, and the reproducibility of the method are described in detail. The method was successfully applied for the determination of PAH in air particulate matter extracts.
    Additional Material: 3 Ill.
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  • 26
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 334-335 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Fused-Silica columns ; Thermal stability ; Dibenzothiophene oxides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 27
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 477-479 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Glass capillary column ; Adsorbent ; Cold trapping ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 28
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 414-422 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Steroid analysis ; Sample pretreatment ; Sample introduction ; Separation speed ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantitative analysis of steroids and their metabolites in urine samples calls for increased speed of sample clean-up, of the derivatization procedure, and of separation. A fast procedure for sample pretreatment, which can be performed within 8 hours, is introduced and evaluated. It is shown that use of fast pretreatment in combination with narrow bore columns, which are compatible with existing instrumentation, can considerably increase, laboratory throughput. The effect of different sample introduction techniques (e.g. splitless, on-column, and moving needle) on column efficiency and resolution is demonstrated and discussed.
    Additional Material: 7 Ill.
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  • 29
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 492-494 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, glass ; Closed loop stripping analysis ; Filter extraction ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 30
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 137-139 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Deactivated fused silica tubing ; Zero dead volume union ; Capillary column GC/MS interface ; Test mixture for non-polar columns ; Test mixture of phenols ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 31
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 144-146 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column ; Cyclopentolate ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 32
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 185-190 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Mass spectrometry ; Dynamic headspace ; Deans switching ; Cold trap ; Reinjection ; Polymers ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An experimental method for the analysis of volatile organic compounds in polymers is described. The technique involves dynamic headspace sampling, collection, and concentration of the volatiles in a cold trap, followed by capillary column gas chromatography/mass spectometry. Flow switching is carried out by the Deans switching technique. Four technical polymers used as pharmaceutical packaging materials have been analyzed in order to demonstrate the method.
    Additional Material: 6 Ill.
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  • 33
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 212-214 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Trace analysis ; Solvent effect in GC ; Parts per trillion ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 34
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 270-273 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column ; Temperature-programmed analysis ; Retention indices ; Polychclic aromatic hydrocarbons (PAH) ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 35
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 340-342 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Sample preparation ; Closed loop stripping analysis ; Charcoal adsorbent filter ; Overcoming contamination ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 36
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 487-489 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column ; Multi-dimensional technique ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 37
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 533-536 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Fungicides and insecticides ; Sensitivity limits ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 38
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 140-141 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Narcotics: street samples ; Narcotics, adulterants and diluents: simultaneous determination ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 39
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    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 148-150 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; On-column injection/enrichment ; Milliliter sample volumes ; Trace analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 40
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    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 191-195 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Saturated hydrocarbons ; Retention indices ; Molar refraction ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kováts retention indices for a series of linear, branched, and cyclic alkanes on squalane at any temperature, and on other stationary phases of different polarity at a given temperature, are related to physicochemical properties of the solutes, such as boiling point and molar refraction, by multiple regression analysis. The equations found permit calculation of the Kováts retention index for all alkanes, with standard deviations close to experimental error. The same equations can also be used for calculating the physicochemical parameters they contain.
    Additional Material: 8 Tab.
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  • 41
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    Journal of High Resolution Chromatography 7 (1984), S. 209-210 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Solvent effect ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
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  • 42
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    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 274-276 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column, glass ; Liquid-liquid and liquid-solid extraction ; Serum lipids ; Fatty acids ; Cholesterol and cholesteryl esters ; Triglycerides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 43
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    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 280-281 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Reaction GC ; Iodination reactor ; Electron capture detection ; Trace analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 44
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    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 284-285 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Fruit juices ; Amino acids ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 45
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Thick liquid phase films ; Natural and refinery gases ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Capillary columns having a thick liquid phase film and a low phase ratio permit the separation of low molecular mass compounds which would have a very small capacity factor on columns with a classical thin film. At the same time, the increased sample capacity allows conventional hot-wire thermal conductivity detectors to be used with such columns. The analysis of natural and refinery gases, containing both inorganic compounds and light (C1—C7) hydrocarbons, utilizing a combination of hot-wire and flame ionization detectors, is demonstrated.
    Additional Material: 10 Ill.
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  • 46
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    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 7 (1984), S. 382-388 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; HETP equation ; Optimum column parameters ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An HETP equation for the capillary column is developed that takes into account the dependence of gaseous diffusion on pressure, the compressibility of the mobile phase, together with the unique relationship between mobile phase velocity, and the resistance to mass transfer in the stationary phase. The equation is used to develop a procedure for column optimization and expressions are derived that allow the optimum column radius and optimum column length to be calculated for a given fixed inlet pressure. It is shown that fast, simple separations are optimally achieved using relatively short small diameter columns. Conversely, optimum performance for the separation of complex mixtures requiring higher efficiencies requires the use of long columns with relatively large diameters.
    Additional Material: 5 Ill.
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  • 47
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    Journal of High Resolution Chromatography 7 (1984), S. 431-432 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Triglycerides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 48
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Packed and capillary columns ; Fungicides and insecticides ; Adsorption ; Length of column ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 49
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    Journal of High Resolution Chromatography 7 (1984), S. 504-508 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Fused silica capillary columns ; GC/MS/DS ; Cryotrapping and cryofocussing of organics ; Purgeable compound analysis ; Trace organic analysis ; Priority pollutants ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The purge and trap (P&T) method of analysis has been interfaced with fused silica capillary column gas chromatography. This interfacing has been accomplished without splitting the P&T trap desorption carrier gas. Thus, 100% of the purged compounds are transferred to the column. The analytes are cryofocussed on the column using whole column cryotrapping (WCC) at -80°C. The resulting P&T/WCC procedure is extremely well-suited to the analysis of trace purgeable aqueous organic compounds. Samples and standards containing a variety of aromatic standard compounds were analyzed. The standards included benzene, toluene, ethylbenzene, xylenes, C3-C4-benzenes, and naphthalene, as well as three P&T internal standard compounds. Chromatographic peak widths were uniformly less than 6 s at the base and excellent precision was obtained in the relative retention time data for all compounds. The chromatogram of a groundwater sample contaminated with aromatic gasoline compounds is also presented. Since P&T/WCC works well with fused silica capillary columns, the full sensitivity and chromatographic efficiency of capillary gas chromatography is made available to P&T analyses.
    Additional Material: 2 Ill.
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  • 50
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    Journal of High Resolution Chromatography 7 (1984), S. 542-544 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Fused silica (capillary) columns ; Bonded (cross-linked) phases ; Hydrocarbon analysis ; Olefinic hydrocarbons ; Retention index data ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 51
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    Journal of High Resolution Chromatography 7 (1984), S. 48-48 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, glass ; Carrier gas flow controller unit ; On-column injection ; Sample, loading onto column ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 52
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    Journal of High Resolution Chromatography 7 (1984), S. 89-92 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column ; Stationary phase ; Polysiloxane ; Autocrosslinkable ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methyl-2-phenylethylpolysiloxane polymers have been synthesized for comparison with methylphenylpolysiloxane stationary phases for gas chromatography. The 50% 2-phenylethyl polysiloxane was found to be autocrosslinkable at 260°C without addition of free redical initiator. Although the selectivity of this phase appears to be similar to the 50% phenyl polysiloxane, its thermal stability is not as high.
    Additional Material: 2 Ill.
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  • 53
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    Journal of High Resolution Chromatography 7 (1984), S. 92-94 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column ; Solute focusing ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 54
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    Journal of High Resolution Chromatography 7 (1984), S. 540-541 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary ; SDE enrichment ; Fatty acids ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 55
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Immobilized capillary columns ; Aqueous solutions ; On-column injection ; Split injection ; Multidimensional separations ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various methods of gas chromatographic analysis at high resolution and low detection limits in aqueous solutions are described with regard to sampling techniques, column technology, and the application of coupled pre-columns, also including multidimensional methods. Immobilized polyethylene glycol (Carbowax 20 M) columns have also been produced and used successfully.
    Additional Material: 11 Ill.
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  • 56
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    Journal of High Resolution Chromatography 7 (1984), S. 13-18 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Biphenyl polysiloxane ; Stationary phase ; Polarizable phase ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A crosslinkable biphenylmethylpolysiloxane stationary phase was synthesized for capillary column gas chromatography and compared with methyl, phenyl, and cyanopropyl polysiloxane stationary phases for the separation of isomeric polycyclic aromatic compounds. While the new phase gave similar separations of nonpolar isomers when compared to the nonpolar phases, separations of polar isomers were greatly improved because of the induced polarity of the biphenyl group of the stationary phase by the solute molecules. This polarizable stationary phase offers a unique selectivity which is not available in other stationary phases.
    Additional Material: 5 Ill.
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  • 57
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    Journal of High Resolution Chromatography 7 (1984), S. 19-24 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, fused silica ; Splitless injection ; Flash derivatization ; Quaternary ammonium compounds ; Acetylcholine ; Biogenic amines ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A conventional splitless injector is used as a pyrolysis chamber or chemical reactor for the N-demethylation of acetylcholine and other choline esters. The novel uses of 2-aminoethanol as a N-demethylation reagent in splitless injection and bonded-phase fused silica capillary columns in the separation of the tertiary amine derivatives of choline esters are described. A comparison is made between non-polar and moderately polar fused silica capillary columns in the separation of choline esters.
    Additional Material: 4 Ill.
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  • 58
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    Journal of High Resolution Chromatography 7 (1984), S. 25-32 
    ISSN: 0935-6304
    Keywords: Gas chromatography ; CGC-ECD, CGC-MS ; Chlorophenols ; Chlorophenoxyalkanoic acids ; Neutral chlorinated compounds ; Biological sewage treatment plant ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The environmentally hazardous organic substances in the waste water from the manufacture of chlorophenoxyalkanoic acids have been identified and semiquantified before and after passing through a biological treatment plant for municipal sewage, the secondary effluent of which is discharged into a marine ecosystem. The organics belong to three groups: (i) chlorophenols; (ii) chlorophenoxyalkanoic acids; and (iii) chlorinated neutrals. The removal of chlorophenols and phenoxyalkanoic acids was shown to be good, with a 90% overall reduction of chlorinated substances in the sewage passing through the treatment plant. The lowest reduction occurred for the polychlorinated compounds. Two chlorobenzofurans among the chlorinated neutrals were preliminarily identified.
    Additional Material: 2 Ill.
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  • 59
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Mass spectrometry ; Capillary GC ; Fused silica GC ; 6-Nitrobenzo[a]pyrene ; 3-Nitrobenzo[a]pyrene ; 1-Nitrobenzo[a]pyrene ; 3-Nitrobenzo[e]pyrene ; Nitro-PAHs ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 60
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    Journal of High Resolution Chromatography 7 (1984), S. 33-37 
    ISSN: 0935-6304
    Keywords: Chlorinated paraffins ; Gas chromatography ; Mass spectrometry ; Negative ion ; Chemical ionization ; Capillary column ; On-column injection ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Although chlorinated paraffins (CP) are produced in large amounts (300 000 tonnes per year), little is known about their occurrence in the environment due to the lack of specific and sensitive analytical methods. The present paper describes the GC/MS analysis of different CP's using capillary gas chromatography with on-column injection and negative ion chemical ionization (NCI) mass spectrometry. Chromatographic resolution of groups of isomers and homologues was obtained. The chromatograms and mass spectra are discussed. The suitability of this method for trace analysis of a CP sample using multiple ion detection (MID) is described.
    Additional Material: 3 Ill.
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  • 61
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    Journal of High Resolution Chromatography 7 (1984), S. 68-73 
    ISSN: 0935-6304
    Keywords: MS-MS ; Gas chromatography ; Capillary GC-ECD, GC-MS, GC-MS-MS ; Bleaching ; Chlorine compounds ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gas chromatography (GC) with electron capture detection (ECD), GC combined with mass spectrometry (MS), GC with multi-stage mass spectometry (MS-MS), and direct inlet MS-MS have been used to determine 1,1-dichlorodimethyl sulfone (DDS) in aquatic organisms in the receiving waters outside a pulp mill bleach plant. Both GC-MS-MC and direct inlet MS-MS of tissue extracts of fish and mussel appear to be sensitive, selective, and rapid analytical techniques for the determination of DDS.
    Additional Material: 8 Ill.
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  • 62
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary column ; HPLC prefractionation ; MS ; ECD ; Substituted PAHs ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is described which allows the determination of different substituted polycyclic aromatic hydrocarbons (PAH) such as NO2-PAH, carbazoles, keto-PAH, and aza-arenes in aerosol samples. Liquid CO2-extraction is used to minimize the loss of reactive compounds. High performance liquid chromatography on chemically activated silica is employed to prefractionate the samples into subfractions with a minimum of overlap between different PAH compound classes. Both electron capture detection and negative ion chemical ionization combined with capillary gas chromatography are used for identification and quantification. The latter method also allows distinction between isomers with different toxic properties when N2O/CH4 reaction gas mixtures are used. Selectivity for tetrachlorodibenzo-p-dioxins as against pesticides and polychlorinated biphenyls can be improved by this technique. The applicability of the method is critically discussed and different examples are given.
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  • 63
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    Chromatographia 18 (1984), S. 663-667 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Gas solubilities ; Enthalpies of solution ; Polar solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The gas-liquid chromatographic method has been used to determine the solubilities and partial molar enthalpies of solution of the gases H2S, CO2 and COS in four polar solvents. The results agree well with literature values obtained using conventional techniques, with the one exception of H2S in N-methyl-2-pyrrolidinone. In this case there is some evidence for the occurrence of adsorption at the gas-liquid interface.
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  • 64
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Esterification in aqueous solution ; n-Butyl esters of aromatic polycarboxylic acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The direct esterification and gas chromatographic analysis of aromatic carboxylic acids as n-butyl esters is described. Derivatization is performed in aqueous solution with n-butanol in the presence of sulfuric acid. The butyl esters of benzoic, phthalic, hemimellitic, trimellitic, trimesic and pyromellitic acids permit their gas chromatographic separation from each other and from fatty acids and alipatic dicarboxylic acids. At mole ratios of [H2O]/ [n-BuOH]≤0.04 the water present does not interfere with the esterification reaction. At mole ratios above 0.04 anhydrous sodium sulfate is used for binding the water, at mole ratios of [Na2SO4 anh.]/[H2O]=0.25–0.75.
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  • 65
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Metal complexes ; Chemically bonded phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Packings consisting of diphenylphosphine complexes with CoCl2 and CoBr2, chemically bonded to the silica surface, were synthesized and their retention parameters determined. The packings are capable of specifically interacting with electron-donating compounds by forming π-complexes. The interaction is considerably stronger in the case of CoBr2-containing packing than in the case of CoCl2-containing packing.
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  • 66
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    Chromatographia 18 (1984), S. 234-238 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open-tubular columns ; On-column injection ; Stopped-flow operation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple, inexpensive, on-column injector of the septum moving-needle kind is described for quantitative analysis using open-tubular columsn. when operated in the stopped-flow mode an improvement incolumn efficiency is observed combined wit a diminished tendency to produce split-top peaks, particularly for late eluting peaks. Using electronic integration a relative error of about 2.7% was observed for peaks spanning a wide range of sample concentrations and volatilities.
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  • 67
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    Chromatographia 18 (1984), S. 243-248 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Carrier gas ; Viscosity ; Influence of temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The vicosity-temperature relationship of the three gases (helium, nitrogen and hydrogen) most frequenly used as the carrier gas in gas chromatography is studied. Based on available data, equaitions are derived to describe this relationship. Using these equations viscosity data are tabulated for the chromatographically important temperature range.
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  • 68
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    Chromatographia 18 (1984), S. 260-264 
    ISSN: 1612-1112
    Keywords: Parabens and their dissolution ; Pharmaceutical dosage forms ; Derivatization ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A specific, sensitive and general applicabla gas chromatographic method is described for the determination of parabens in various liquid pharmaceutical preparations: propylparaben and butylparaben in a liquid antacid dosage form (I); methylparaben, ethylparaben and propylparaben in a syrup (II); methylparaben and propylparaben in a solution for injection (III). Each time one of the parabens is used as internal standard. The parabens are extracted with diethylether and derivatized by silylation. Different columns are used for the analysis of the parabens: 3% SE-30 column, a 3% QF-1 column for different selectivity, a 2% OV-1 column for isothermal operation. Special attention is attributed to the standard: the parabens are dissolved in a minimal amount of 0.1 M sodium hydroxide and extracted in the same way as the pharmaceutical dosage form.
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  • 69
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Configuration ; Resolution ; Alcohols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The study of the resolution of sixteen secondary aliphatic alcohols by gas chromatography on (+)-dodecyl (2R, 3R)-tartrate, trapping the ascending part of the peak from a conventional filled column, has allowed the determination in a single operation of the sign and order of emergence of enantiomers. A correlation between the configuration of these secondary alcohols and their order of emergence has been established.
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  • 70
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    Chromatographia 18 (1984), S. 309-312 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Carboxylic acids ; Acetonyl derivatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The preparation of the acetonyl esters of nine aliphatic carboxylic acids is described, the general formula of the derivatives being RCOOCH2COCH3 where R=alkyl or H. The derivatives show good chromatographic properties on both packed and capillary columns. The electron impact and chemical ionisation mass spectra of the derivatives are discussed.
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  • 71
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    Chromatographia 18 (1984), S. 367-368 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open tubular (capillary) columns ; Variation of film thickness ; Thick-film columns ; Mass transfer terms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The factors characterizing the influence of the variation of the liquid phase film thickness on the mass transfer terms in the Golay equations describing the performance of open tubular columns are investigated and numerical values are given.
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  • 72
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Thermodynamic relationships ; Retention index ; Peak identification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A thermodynamic criterion, ΔQ, is suggested which permits to estimate the difference in the functional group energy of interactions for two different stationary phases. The linear dependence of ΔQ on the homolog number m of any series Rm X can be used as the thermodynamic criterion for the identification of substances by GC analysis.
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  • 73
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    Chromatographia 18 (1984), S. 477-488 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open tubular (capillary) columns ; Sample capacity ; Column comparison ; Film thickness ; Column diameter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Wall-coated, open-tubular (capillary) columns prepared from different diameter tubing, with different liquid phase film thickness, are compared with each other and with packed and support-coated open-tubular columns. The comparison is based on the variation of the phase ratio and the capacity factor, and includes column efficiency (HETP, theoretical plate number), resolution, retention time, and sample capacity. Problems associated with the evaluation of the sample capacity are outlined. The influence of temperature on column performance is discussed in detail. Finally, the possibilities of short, wide-bore open-tubular columns prepared with a thick liquid-phase film are demonstrated.
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  • 74
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The singlet-triplet energy difference in para-, meta-, and ortho-xylylenes is studied as the interaction of two radical centers through the benzene ring. An SCF perturbative procedure adapted to open-shell systems leads to two benzyl-like nonbonding molecular orbitals (NBMOS) and to benzene-like occupied and vacant MOS whatever the xylylene isomer. The superposition of these NBMOS in para-, meta-, and ortho-positions and their interaction with the benzene-like MOS lead, at the configuration interaction level, to the following results: The exchange energy (which favors the triplet state) and the charge transfer energy (which favors the singlet state) are important only in the meta-xylylene; the dynamic (or double) spin polarization favors the triplet in meta and the singlet in para and ortho-isomers; the super-exchange energy (which favors the singlet) is important only in para- and ortho-isomers. The above results are independent of the chosen geometry.
    Additional Material: 6 Ill.
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  • 75
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    International Journal of Quantum Chemistry 25 (1984), S. 347-354 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The recently proposed method of using momentum densities for interatomic interactions is applied to the long-range force between the ground-state hydrogen atom and the proton, and the results are compared with those from using the position density based on the electrostatic Hellmann-Feynaman theorem. A new physical interpretation of the long-range force is obtained, which is complementary to that in position space. It is found that some perturbative changes in the position density do not accompany changes in the momentum density.
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  • 76
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    International Journal of Quantum Chemistry 25 (1984), S. 391-410 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: With the aid of a method similar to the one we used in an earlier work (part I) a new Schrödinger-type field equation with logarithmic nonlinearity can be derived from a Fokker-Planck equation for a distribution function. This nonlinear field equation describes the frictinally damped motion of a system under the influence of a magnetic field and can be interpreted in the same way as the nonlinear Schrödinger-type equation (NLSE) derived in part I, where no magnetic fields were taken into account. The NLSE for the two-dimensional motion of a charged material system in a homogeneous magnetic field is solved exactly. The solutions are compared with the quantum-mechanical solutions of the corresponding undamped problem. The method is extended to include also anisotropic conditions; i.e., in the Fokker-Plank equation the diffusion constant has to be replaced by a diffusion matrix, as different diffusion constants may be possible for different space directions. We regard the three-dimensional motion under the combined influence of magnetic and electric fields according to K = (q/c)(v × B) + qE - mγv with Ey = (m/q)ωt2y, Ez = -(m/q)ωt2z, B = (0, 0, B) as an example. This is an approximation of the conditions existing in an ion cyclotron resonance spectrometry cell, neglecting an additional drift motion in the x direction which could be taken into account by Galilean transformation and gauge transformation. The corresponding NLSE for the coupled three-dimensional motion is specified and solved exactly.
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  • 77
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    International Journal of Quantum Chemistry 25 (1984), S. 211-221 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The concept of the equalization of atomic electronegativities accompanving molecule formation is applied to a study of the electronic structure of polyhedral clusters of main-group atoms such as Ge, Sn, Pb, Tl, and Bi. Emphasis is placed upon charged clusters such as Sn9-x Pbx4-(x = 0 → 9), Sn9-xGex4-, Sn8-xPbx Tl5-, Sn2Bi22-, SnTe44-, etc. The role of the relativistic spin-orbit splitting of an np shell into np1/2 and np3/2 subshells in modifying atomic and hence molecular electronegativities is discussed. Correlations are made between calculated charge distributions and observed199 Sn NMR chemical shifts for clusters of a given size and charge. It is concluded that a useful picture of charge distributions in these clusters may be obtained from electronegativity equalization considerations.
    Additional Material: 4 Ill.
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  • 78
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    International Journal of Quantum Chemistry 25 (1984) 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 79
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    International Journal of Quantum Chemistry 25 (1984), S. 493-502 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have carried out a computational study of the reactive properties of chlorooxirane, the metabolically produced epoxide of vinyl chloride that is believed to be a direct-acting carcinogenic form of this molecule. An ab initio SCF-MO procedure (GAUSSIAN 70) was used to compute the energy requirements for stretching the C—Cl and both C—O bonds (SN1 reactivity) and to determine the course of the epoxide's possible SN2 reactions with ammonia, taken as a model for nucleophilic sites on DNA. The epoxide was assumed to be protonated; both the oxygen- and chloro-protonated forms were considered. At each step along the various reaction pathways, the structure of the system was reoptimized. For the oxygen-protonated epoxide, the C1—O bond has a significantly lower energy barrier to stretching than does the C2—O. (The carbon bearing the chlorine is designated C1.) However, both are very much higher than that of the C—Cl bond in the chloro-protonated form, confirming our earlier finding of the relative weakness of this bond. In the SN2 processes involving ammonia, intermediate complexes are formed with both carbons of the oxygen-protonated epoxide, the C2-complex being the more stable. However, the most stable ammonia complex occurs at C1 of the chloro-protonated epoxide. Our calculated results, both the energies and also the geometry changes, allow us to propose two possible mechanisms for the formation of the 7-N-(2-oxoethyl) derivative of guanine that has been observed to be the major in vivo DNA alkylation product of vinyl chloride and has been suggested as possibly being responsible for its carcinogenicity. One of these mechanisms is SN1 and starts with the chloro-protonated epoxide; the other is SN2 and involves the oxygen-protonated form.
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  • 80
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    International Journal of Quantum Chemistry 25 (1984), S. 543-552 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio SCF as well as pseudopotential calculations were performed for determining equilibrium structures and relative stabilities of several disilyne isomers. For the singlet state there are only two structures, the bridged and the silavinylidene carbene, which correspond to minima on the energy hypersurface. The most stable of the six isomeric structures investigated is the bridged conformer in the 1A1 electronic state, followed by the silavinylidene carbene in the 1A1 and 3A2 electronic states. Inclusion of electron correlation by MRD-CI calculations has no qualitative influence on the relative stabilities found in the SCF calculations.
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  • 81
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    International Journal of Quantum Chemistry 25 (1984), S. 535-542 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The vertical ionization potentials (IPS) of B2H6 are calculated by means of the ΔESCF procedure, within the scheme of ab initio LCAO-MO-HF-SCF. The basis set used is LEMAO-3G. The scaling factors of the various atomic orbitals for the ground state and for the various hole states are optimized independently. The iteration procedure is specially designed to avoid the changes of the symmetry of the remaining occupied orbitals. The 1 ag (B1s) hole is found to be localized. The vertical IP of the 1 ag electron is calculated to be 196.5 eV, in fair agreement with experimental value. The D2h symmetry is thereby broken and reduced to C2V symmetry. The valence holes are found to be delocalized. The calculated vertical IPS are: 21.781, 16.974, 14.842, 14.389, 13.599, and 12.380 eV for the 2ag, 2b1u, 1b3u, 1b2u, 3ag, and 1b3g electrons, respectively. The agreement with experimental values is much better than the Koopmans' values. All these results are in favor of the concept that the nature of the convelent bond should be considered as a result of the mutual interactions and mutual conditioning between the wave nature of the electronic motion on the one side and the various attractive and repulsive factors on the other side.
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  • 82
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    International Journal of Quantum Chemistry 25 (1984), S. 637-644 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The relations based on an external one-electron operator V(r) are examined from two view-points, i.e., from the Hohenberg-Kohn approach and the four-dimensional density concept introduced by Wilson and Frost, and extensively studied by Parr and Politzer. The object being to obtain, with the help of the Hellmann-Feynman theorem, new formulas for the energy of atoms and molecules, and to discuss the construction of the universal energy density functional on the basis of the four-dimensional density.
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  • 83
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    International Journal of Quantum Chemistry 25 (1984), S. 653-666 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The unitarily invariant decomposition of Hermitian operators is performed by means of Lie algebra.
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  • 84
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    International Journal of Quantum Chemistry 25 (1984), S. 707-713 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new derivation is given for the Waller-Hartree-Fock double-determinantal spatial wave function. One starts from the single-determinant wave function in which a orbitals are doubly occupied, and decomposes it into a sum of products of spatial and spin functions. The spatial product of the first genealogical spin eigenfunction is a double-determinantal function. The derivation is based on the simple form of U1ƒ(P) when the representation matrix is obtained from the genealogical spin eigenfunction.
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  • 85
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    International Journal of Quantum Chemistry 25 (1984), S. 715-721 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Expressions for the second-row nuclei chemical shifts calculation using a CNDO-SCF wave function are outlined. In collating it with the Pugmire and Grant's equations, a term with a changed sign appears. Both sets of equations are applied to a study of carbon-13 chemical shifts in alkanes down to C7; results are interpreted with aid of the Lindeman-Adams' empirical equation. Expressions proposed are confirmed for an excellent agreement with experimental data.
    Additional Material: 1 Tab.
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  • 86
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    International Journal of Quantum Chemistry 25 (1984), S. 853-861 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Regularities observed in the variations of calculated energy components, for example, those of electronic and nuclear repulsion energies in the analysis of conformational changes and in studies of the propagation of basis set errors in ab initio calculations, are found to be related to the variational principle and to the boundedness of energy expectation value functionals. These relations are analogous to the le Chatelier principle of equilibrium thermodynamics, and may be formulated as a general “compensation principle” for two sets of general parameters of the molecular total energy functional.
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  • 87
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    International Journal of Quantum Chemistry 25 (1984), S. 869-879 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aim of this study has been to determine how the hydrogen bond between formaldehyde and ammonia is affected by the ring-opening interaction of protonated ethylene oxide with the ammonia nitrogen. Our purpose is to gain insight into the possible effect of carcinogenic epoxides upon the hydrogen bonding within DNA base pairs; it is known that such epoxides react with nucleophilic sites in DNA, including amine nitrogens that are involved in hydrogen bonds to carbonyl groups. We have used an ab initio self-consistent-field molecular orbital procedure to compute optimized structures, interaction energies, and other properties of interest. The H2CO·HNH2 system and the protonated epoxide were found to form two stable complexes, with syn and anti orientations. Their formation is accompanied by a significant overall strengthening of the H2CO·HNH2 hydrogen bond, as indicated by both calculated force constants and bond lengths. An analysis of these and other properties, such as atomic charges, suggests that the interaction is leading to the formation of N-protonated ethanolamine, which is linked to the formaldehyde through the proton on the nitrogen. If carcinogenic epoxides have a similar strengthening effect upon some of the hydrogen bonds in DNA, it could interfere in the replication and transcription processes.
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  • 88
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    International Journal of Quantum Chemistry 25 (1984), S. 891-914 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The leading term in the asymptotic expansions of the three-center contributions to the exchange matrix elements for a system of three hydrogen atoms is derived. The approximations are used to estimate the importance of three center interactions in “spin-aligned hydrogen”.
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  • 89
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    International Journal of Quantum Chemistry 25 (1984), S. 929-940 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The singularities of the quantum-mechanical electron current density induced in a molecule by an external magnetic field are analyzed via the theory of the real autonomous systems of differential equations. Group-theoretical techniques, based on the idea of color symmetry, are developed, which predict the occurrence of singularities about molecular symmetry elements. Plots of induced electron current density have been obtained for the ethylene molecule through accurate coupled SCF calculations. The theoretical magnetic properties of ethylene obtained through this investigation are the most accurate reported so far.
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  • 90
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The nodal structure of molecular momentum distributions is studied by considering the simplest case of the ground state of the hydrogen molecular ion. By examining the exact expansion of the H2+ momentum distribution, it is shown that an infinite sequence of nodes does exist along the pz axis (z axis parallel to the bond axis) but not nodal planes perpendicular to the pz axis (as is found for the simplest LCAO function). The nodes are those points where nonplanar nodal surfaces cross the pz axis. It is also shown that molecular systems with more than one electron cannot, in the ground state, have nodal surfaces in their momentum distributions. Implications for the directional Compton profiles J(q) are discussed.
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  • 91
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    International Journal of Quantum Chemistry 25 (1984), S. 1003-1021 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Valence bond (VB) diagrams form a complete basis for model Hamiltonians that conserve total spin, S, and have one valence state, φp, per site. Hubbard and Pariser-Parr-Pople (PPP) models illustrate ionic problems, with zero, one, or two electrons in each φp, while isotropic Heisenberg models illustrate spin problems, with only purely covalent VB diagrams. The difficulty of nonorthogonal VB diagrams is by-passed by exploiting the finite dimensionality of the complete basis and working with unsymmetric sparse matrices. We introduce efficient bit manipulations for generating, storing, and handling VB diagrams as integers and describe a new coordinate relaxation method for the ground and lowest excited states of unsymmetric sparse matrices. Antiferromagnetic spin-½ Heisenberg rings and chains of N ≤ 20 spins, or 2N spin functions, are solved in C2 symmetry as illustrative examples. The lowest S = 1 and 0 excitations are related to domain walls, or spin solitons, and studied for alternations corresponding to polyacetylene. VB diagrams with arbitrary S and nonneighbor interactions are constructed for both spin and ionic problems, thus extending diagrammatic VB theory to other topologies.
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  • 92
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    International Journal of Quantum Chemistry 26 (1984), S. 21-33 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Theoretical substituent effects upon the acidity of the title compounds were investigated using STO-3G basis sets augmented by diffuse functions for all oxygen atomic centers of the probe groups. The results are discussed in connection with the available gas-phase data within a novel conception of attractive and repulsive substituent effects.
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  • 93
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    International Journal of Quantum Chemistry 26 (1984), S. 145-149 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Simple density functional theory gives the following relation between the energy EZ, N of an ion of nuclear charge Z and N electrons, the potential V(0) created at the nucleus by the electronic cloud, and the chemical potential μ \documentclass{article}\pagestyle{empty}\begin{document}$$ E_{Z,N} = \frac{3}{7}(ZV(0) + N_\mu). $$\end{document}Using Hartree - Fock values for V(0) and μ, this equation has been tested in several isoelectronic series with 3 ≤ N ≤ 28. The importance of the term 3Nμ/7 increases as the degree of ionization increases.
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  • 94
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    International Journal of Quantum Chemistry 26 (1984), S. 167-181 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: With empirical and theoretical atom-atom potentials the GABA·nH2O, n = 25, 192 and GABA·Zn2+ · nH2O, n = 25, 50, 100 complexes are simulated at 298.15 K by the Monte Carlo technique. The results show that the carboxyl group of GABA coordinates six water molecules. Two geometries of the GABA·Zn2+ complex, corresponding to the “direct” and “through-water” interaction of Zn2+ with the carboxyl group of GABA were found. For the latter interaction a GABA·Zn2+ · 6H2O complex was found whereas the hydration of the former interaction leads to a GABA·Zn2+ · 5H2O complex. Here the carboxyl group of GABA displaces only one water molecule in the first hydration shell of Zn2+. Energetically the “direct” and “through-water” geometries seem to be competitive, the former being slightly favored.
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  • 95
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    International Journal of Quantum Chemistry 26 (1984), S. 223-230 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio calculations are performed with 6-31G basis set to study the geometry and binding of the H3O2-, H5O3-, H7O4-, and H9O5- complexes. The H3O2- complex is also investigated with the 6-31 G* basis set and MP2 (Moller-Plesset perturbation theory of second order).
    Additional Material: 1 Ill.
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  • 96
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    International Journal of Quantum Chemistry 26 (1984), S. 293-293 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 97
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    International Journal of Quantum Chemistry 26 (1984) 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 98
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    International Journal of Quantum Chemistry 26 (1984), S. 373-381 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new procedure for the Fock matrix operator construction is proposed. Its application for RHF calculations on diatomic molecules using Slater orbital basis sets shows that the computation time for the new SCF procedure is proportional to the square of the basis set size.
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  • 99
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    International Journal of Quantum Chemistry 26 (1984), S. 439-439 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 100
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    International Journal of Quantum Chemistry 26 (1984), S. 297-312 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The spinor representations for the groups forming the chains O ⊃ T ⊃ D2 and Td ⊃T ⊃ D2 are constructed as projective representations. The Clebsch-Gordan coefficients are then calculated using a standard method. Projective factor systems, irreducible representations, canonical bases, and tables of Clebsch-Gordan coefficients are given. The subduction from O to D3 is discussed.
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