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  • 1980-1984
  • 1975-1979  (600)
  • 1965-1969
  • 1920-1924
  • 1850-1859
  • 1975  (600)
  • Analytical Chemistry and Spectroscopy  (516)
  • Engineering  (84)
Material
Years
  • 1980-1984
  • 1975-1979  (600)
  • 1965-1969
  • 1920-1924
  • 1850-1859
Year
  • 101
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 133-136 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The urinary excretion by rats of predominantly 2-ethyl-3-deuterohydracrylic acid is a consequence of the intraperitoneal injection of 2-trideuteromethylbutyric acid. A significant fraction of the loading acid also is excreted unchanged. These results support the proposal of an alternate minor pathway of isoleucine catabolism and suggest that the corresponding catabolites in the minor and major pathways, 2-ethylhydracrylic and 2-methyl-3-hydroxybutyric acids, respectively, have significantly different subsequent metabolism.
    Additional Material: 2 Ill.
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  • 102
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. xi 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 103
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electron impact mass spectrum (70 eV) of 26-trimethylsilyloxy-4-cholesten-3-one shows a base peak at m/e 196, attributable to combination of the trimethylsilyl group with a fragment of m/e 123 produced by cleavage across ring B. 18O labelling confirms that the fragment of m/e 196 contains the 3-oxygen atom, and 2H labelling indicates retention of the trimethylsilyl moiety. Similar ions are observed from other Δ4-3-ketones with sidechain trimethylsilyloxy groups: abundances depend on the site of substitution. The corresponding enol trimethylsilyl ethers are readily separable from the keto forms by gas-liquid chromatography, and afford mass spectra in which the molecular ions are abundant, while ions of m/e 196 are of only moderate intensity.
    Additional Material: 1 Ill.
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  • 104
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 176-182 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ultraviolet irradiation of the methanoindene compounds chlordene, 1-hydroxychlordene cis- and trans-chlordane, trans-nonachlor and heptachlor using acetone as the sensitizing solvent yielded caged photoisomers. Electron impact spectra of twelve photoproducts are reported. Structural assignments based on nuclear magnetic resonance, infrared and gas chromatography data are reported for the major photoproducts.
    Additional Material: 14 Ill.
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  • 105
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A mass fragmentographic method for simultaneous measurement of unlabeled and deuterium labeled methadone in human plasma is described. This specific method has a lower sensitivity of about 16 pmol/ml with a coefficient of variation of less than 4%. The usefulness of the method was evaluated in studies on opiate dependent subjects undergoing methadone maintenance treatment. In one application methadone-d3 was given as a pulse dose during continuous treatment with unlabeled methadone and plasma levels of both species followed by mass fragmentography. The method will be of value in the study of methadone pharmacokinetics in the steady state and in other in vivo situations where multiple drug pools must exist.
    Additional Material: 3 Ill.
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  • 106
    Electronic Resource
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 201-203 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High resolution photoplate mass spectrometry has been used to examine crude goat urine extracts to determine the fate of organochlorine xenobiotics in these animals. Using a direct introduction temperature controlled probe the crude urine extracts were analyzed and the presence of oxygenated metabolites of 4-chlorobiphenyl and 4,4′-dichlorobiphenyl were confirmed in goats; analyses of urine extracts from goats injected with the commercial Aroclor mixtures 1254 and 5460 confirmed the formation of oxygenated penta-, tetra- and monochlorobiphenyl metabolites and an oxygenated dichloroterphenyl metabolite, respectively. This technique was particularly useful in the analysis of complex mixtures of metabolites.
    Additional Material: 1 Ill.
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  • 107
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 215-218 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several slightly volatile or nonvolatile organic compounds were transformed directly in the solid sample inlet system into more volatile compounds by addition of an appropriate reagent to the sample. In this way, in several instances free organic acids could be obtained from their salts. A similar method was used to transform some amino acids into derivatives of diketopiperazine or of phthalic acid.
    Additional Material: 4 Ill.
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  • 108
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 225-225 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 109
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method has been developed for quantification of phencyclidine [1-(1-phenylcyclohexyl)piperidine] in body fluids using gas chromatography chemical ionization mass spectrometry with selected ion recording. Pentadeuterated phencyclidine was synthesized and used as the internal standard. In developing the method it was discovered that phencyclidine thermally fragments to 1-phenylcyclohexene at elevated temperatures. The sensitivity and specificity of the method permits determination of 1 ng of phencyclidine in 1 ml of body fluid. The concentrations of the drug in blood samples from five individuals, who ingested unknown quantities of phencyclidine, were found to range from 50 ng/ml to 2.7 μg/ml. Following intravenous administration of 1 mg of phencyclidine hydrochloride to a 12.5 kg dog, the blood concentration of the drug peaked at 17.6 ng/ml and exhibited a half-life of approximately one hour. Two metabolities of phencyclidine were detected in human and dog urine after enzymatic hydrolysis. The metabolities were tentatively identified as 4-phenyl-4-piperidinocyclohexanol and 1-(1-phenylcyclohexyl)-4-hydroxy-piperidine by electron impact and chemical ionization mass spectral analysis of the metabolites and their trimethylsilyl derivatives. Structural confirmation was achieved by synthesis of the metabolities. A third metabolite was found in urine from rhesus monkeys and was tentatively identified as 1-(1-phenyl-4-hydroxycyclohexyl)-4-hydroxypiperidine.
    Additional Material: 13 Ill.
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  • 110
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. vii 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 111
    Electronic Resource
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975) 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 112
    Electronic Resource
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 229-253 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Publications from 1969 through 1974 reporting organic and spark source mass spectrometric studies on environmental samples have been compiled. Emphasis is placed on pollutants identified, but some methods and techniques are discussed. The 396 reports cited vary from those reporting hundreds of identified pollutants to those describing the analysis of only one sample containing one or a few pollutants. Reports concerning forensic, synthetic and standard samples, and analyses for drug residues, metabolites and degradation products are not included.
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  • 113
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Incubation of four common cannabinoids with vegetative cultures of the fungus Syncephalastrum racemosum yielded a number of polar metabolites. Major metabolites of Δ9-tetrahydrocannabinol, Δ8-tetrahydrocannabinol, cannabidiol and cannabinol were eluted from preparative thin-layer chromatographic plates and analyzed by gas-liquid chromatography mass spectrometry. The mass spectrum of each of the compounds examined showed a molecular ion corresponding to a monohydroxylated derivative of the parent cannabinoid. Identification of the major metabolite of each cannabinoid as the product of hydroxylation in the penultimate (4′) position of the n-pentyl sidechain was made by analysis of the mass spectra of underivatized and TMS derivatized metabolites and by comparison with model compounds. A number of prominent fragment ions in the mass spectra were identified as arising through known fragmentation pathways of cannabinoids.
    Additional Material: 4 Ill.
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  • 114
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 272-275 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Melatonin containing three deuterium atoms in the 5-methoxy position has been synthesized by methylation of N-acetylserotonin with dideuterodiazomethane. The deuterated product was characterized by mass spectrometry and found to contain 90.8% of maximum possible deuterium incorporation. The major fragmentation patterns of melatonin under electron impact ionization are discussed with the aid of high resolution, deuterium labelling and metastable transition data.
    Additional Material: 1 Ill.
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  • 115
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2,3,7,8-Tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzo-p-dioxin-13C12 parent ion isotope cluster abundances are calculated on a multinomial probability basis for all possible isotope combinations. Parent negative ions \documentclass{article}\pagestyle{empty}\begin{document}$ \left[{\rm M} \right]^{\mathop - \limits_. } $\end{document} at m/e 322 and m/e 334 were selected for dual ion monitoring in the isotope dilution technique. Calculations, according to the Jaech's Method, are given for optimizing dual ion monitoring dwell time in the pulse counting mode at the femtogram level.
    Additional Material: 3 Tab.
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  • 116
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methylphenidate undergoes partial thermal decomposition in the injection port of a gas chromatograph. This decomposition explains inconsistencies in some of the previously published mass spectra of the drug. The decomposition products were identified by gas chromatography mass spectrometry as methyl phenylacetate and a tetrahydropyridine. The extent of decomposition was found to be a function of the injector temperature and was also influenced by other factors, resulting in considerable variability. The ethyl ester analog behaved similarly. Derivatization with trifluoroacetic anhydride eliminates the thermal decomposition.
    Additional Material: 1 Ill.
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  • 117
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The field desorption mass spectra of eight rifamycins were obtained and compared with their electron impact mass spectra. All the compounds gave abundant molecular or quasimolecular ions, while no significant fragmentation was observed in the low mass region of the spectra. Therefore, field desorption mass spectrometry has been shown to be of great importance for the determination of the molecular weight of these antibiotics.
    Additional Material: 9 Ill.
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  • 118
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complex mixtures of O-trimethylsilylated polyamino alcohols, which have been generated by either acid or enzymatic hydrolysis of polypeptides and subsequent derivatization, are completely characterized by a gas chromatograph mass spectrometer computer system. These peptide derivatives possess excellent gas chromatographic properties; a wide range of derivatives from di- to hexapeptides may be separated in a single chromatographic experiment. The identification of these compounds, either manually or with the assistance of the computer, is based on three sets of data which are automatically generated after the g.c.m.s. computer experiment: (1) mass spectra, which exhibit sequence-determining ions of high abundance; (2) selected ion records, which allow efficient location of peptide derivatives in the gas chromatogram as well as resolution of incompletely separated fractions; (3) retention indices, which can be calculated from values which have been assigned to each amino acid residue.
    Additional Material: 7 Ill.
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  • 119
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975) 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 120
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A rapid, sensitive method of analysis for methylphenidate and ritalinic acid in blood and urine has been developed using gas chromatography mass spectrometry and selected ion monitoring for separation and detection. The methylphenidate is isolated by solvent extraction into chloroform and the ritalinic acid is isolated by salting out into isopropyl alcohol, followed by methylation and subsequent solvent extraction. The method has been applied to the study of methylphenidate metabolism and excretion in adults and hyperactive children under-going treatment with methylphenidate.
    Additional Material: 4 Ill.
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  • 121
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The use of thin-layer chromatography has demonstrated that incubations of indoleamines with 5-methyl[14C]tetrahydrofolic acid and an enzyme previously described as an N-methyltransferase, do not yield Nω, N1 or O-methylated products. Further elucidation by thin-layer chromatography, gas chromatography, mass spectrometry and selected ion monitoring enabled us to identify the reaction products as tetrahydroisoquinolines and tetrahydro-β-carbolines in mixtures incubated respectively with catecholamines and indoleamines in the presence of 5-methyl[14C]tetrahydrofolic acid and enzyme. The alkaloids have been shown to originate from a spontaneous condensation of the corresponding amines with formaldehyde, this latter being formed in the first stage of the reaction by enzymatic conversion from 5-methyltetrahydrofolic acid.
    Additional Material: 5 Ill.
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  • 122
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 31-35 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The advantages and limitations which quadrupole mass filters afford to the field desorption technique with respect to use for routine work are discussed and experimentally confirmed by the analyses of some drugs using a field desorption quadrupole mass spectrometer. The possibility of fast identification of drug intoxication is demonstrated by the analysis of the chloroform extract of urine in a case of overdose of hypnotics.
    Additional Material: 5 Ill.
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  • 123
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    Biological Mass Spectrometry 2 (1975), S. 59-62 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 124
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    Biological Mass Spectrometry 2 (1975), S. 63-64 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 125
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    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 64-64 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 126
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thin-layer chromatography and mass spectrometry were used to isolate and identify cyclophosphamide metabolites present in blood of mice. Blood was removed 5, 15, 30 and 45 minutes after intraperitoneal administration and extracted with chloroform followed by methanol. Thin-layer chromatography of the two extracts and the residual solid with or without prior methylation, collection of resulting alkylating components, determination of radioactivity and mass spectral analysis, served to identify cyclophosphamide, 4-ketocyclophosphamide, alcophosphamide, N-dechloroethylcyclophosphamide, carboxyphosphamide, phosphoramide mustard and nor-HN2. The absence of detectable levels of 4-hydroxycyclophosphamide or aldophosphamide in the blood of cyclophosphamide-treated mice suggests that cyclophosphamide is converted rapidly in the liver to carboxyphosphamide, 4-ketocyclophosphamide, phosphoramide mustard and nor-HN2. Direct administration of synthetic 4-hydroxycyclophosphamide to mice and extraction of blood with chloroform demonstrated the recovery of this metabolite in vivo. Analysis of extracts of blood from mice treated with phosphoramide mustard indicated the presence of nor-HN2, 3-(2-chloroethyl)-1,3-oxazolidin-2-one and unchanged drug. Consideration of blood levels, cytotoxicity and alkylating activity of metabolites identified in, or inferred from, this study, implicates phosphoramide mustard as a leading candidate for the biologically active form of cyclophosphamide.
    Additional Material: 1 Ill.
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  • 127
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    Biological Mass Spectrometry 2 (1975), S. 78-81 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Single and multiple ion monitoring is employed to evaluate whether deuteriomethylated allobarbitone or methylated quinalbarbitone is the better internal standard for quantifying methylated allobarbitone through a g.c.m.s. system based on a quadrupole mass spectrometer. It is shown that the coefficient of variation of the single ion monitoring method is substantially lower than that of the multiple ion monitoring method. Small quantities of a compound are therefore most accurately determined by adding a labelled version of the compound solely to act as a carrier, plus an internal standard giving an ion in common with the compound being measured. By this means 40 pg and 100 pg of methylated allobarbitone could be determined with coefficients of variation of 11.5 and 2.0%, respectively. Using only the labelled compound as internal standard, the corresponding values were 19.8 and 15.3% for the same quantities.
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  • 128
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    Biological Mass Spectrometry 2 (1975), S. 97-106 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass spectra and fragmentation pathways of some achiral and a number of chiral 1,4-benzodiazepine-2-ones, and those of their in vitro biotransformation products are reported and discussed. Various derivatives substituted in position 3 are shown to be useful for the determination of fragmentation pathways from low resolution spectra.
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  • 129
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    Biological Mass Spectrometry 2 (1975), S. 107-111 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The metabolism by rat liver microsomes of the 2,4,6-trideuterio derivative of aniline mustard [N, N-di-(2-chloroethyl)aniline] in admixture with unlabelled material, has been studied. The resulting p-hydroxy derivative was isolated and examined by mass spectrometry. The extent of migration of deuterium from the p- to the m-position, determined from the ratio of trideuteriated to dideuteriated product, was 46%, but the protium and deuterium forms were hydroxylated at the same rate (zero isotope effect).
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  • 130
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    Biological Mass Spectrometry 2 (1975) 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 131
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    Biological Mass Spectrometry 2 (1975), S. 117-120 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Five children deficient in growth hormone were treated with oxandrolone and human growth hormone. Average nitrogen retained was calculated from nine day balance data. During some balance periods, nitrogen retention was calculated by determination of 15N labeled glycine, as reported in this article. Twenty milligrams of 15N in excess of the natural abundance was administered orally. Urines were collected prior to, as well as after, administration of glycine-15 N and were analyzed for 15N by mass spectrometry. The percentage of 15N ranged up to 0.449% for collection over a 24 hour period, compared with 0.364% from control samples without excess 15N. These 15N data, like those from nitrogen balance, show the stimulating effects of oxandrolone and human growth hormone in the group as a whole.
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  • 132
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    Biological Mass Spectrometry 2 (1975), S. 137-141 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reported synthesis of N-hydroxyphenmetrazine from phenmetrazine by the action of m-chloroperbenzoic acid could not be repeated. When the synthetic procedure was modified N-hydroxyphenmetrazine was obtained in low yield. The product had different properties from those claimed previously, but was identical to metabolically produced N-hydroxyphenmetrazine. It was characterized by means of thin-layer chromatography, combined gas chromatography and mass spectrometry, preparation of a t-butyldimethylsilyl derivative and oxidation to a mixture of nitrones. Mass spectrometry was also used to characterize these derivatives.
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  • 133
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    Biological Mass Spectrometry 2 (1975), S. 156-163 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass spectrometry has revealed the sugar sequence of a new saponoside isolated from the bark of Colubrina arborescens Mill (Rhamnaceae). The branched trisaccharide moiety if this saponoside is shown to be and O-β-L-arabinopyranosyl (1 → 2gal)-O-β-D-glucopyranosyl (1 → 3gal)-galactopyranose located on an as yet unknown genin. Mass spectra are presented for the permethylated saponoside, a permethylated trisaccharide and a partially methylated disaccharide, i.e. 3-β-D-glucopyranosylgalactose (C2 — OH), derived by partial hydrolysis. Further characterization of the mono-, di- and trisaccharides involved NaBH4 and NaBD4 reduction of the 4,6-dimethylgalactose reducing sugar moiety, followed by acetylation or trimethylsilylation.
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  • 134
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low molecular weight volatile organics extracted from the plasma of patients before and after hemodialysis were analyzed by high resolution capillary gas chomatographic mass spectrometric computer methods. The volatile components were collected on a polyphenyl ether solid adsorbent prior to analysis. Identification of components was achieved by mass spectrometry. Quantitaive changes were observed in both the plasma and dialysate composition with time. The method described provides a new means whereby the 100 or so low molecular weight organic volatiles of plasma can be monitored during the dialysis procedure.
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  • 135
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    Biological Mass Spectrometry 2 (1975), S. 164-167 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chemical ionization mass spectra of eleven biomedically significant quaternary amimes are reported. The samples are converted to volatile compounds by known thermal decompositions. Chemical ionization of the compounds gives simple, easily identifiable spectra which are useful for the analysis of the original samples.
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  • 136
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    Biological Mass Spectrometry 2 (1975), S. ix 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 137
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    Biological Mass Spectrometry 2 (1975) 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 138
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    Biological Mass Spectrometry 2 (1975), S. 169-175 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The photodecomposition products of aldrin, dieldrin and endrin were investigated by means of gas chromatography mass spectrometry, nuclear magnetic resonance and infrared spectrophotometry. An alternate isomeric product of aldrin and four endrin analogs were encountered. The mass spectra of eight photoproducts are presented with direct inlet spectra of endrin aldehyde and endrin alcohol.
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  • 139
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    Biological Mass Spectrometry 2 (1975), S. 190-196 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectroscopic behaviour of prostaglandin A1 and its methyl ester has been studied. Mechanisms are suggested for the majority of fragmentation processes occurring in the spectra of these compounds. The proposed mechanisms have been confirmed by low electron voltage spectra, measurements on metastable ion decompositions, high resolution mass measurements and deuterium labelling.
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  • 140
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A mass fragmentographic method is described for the simultaneous assay of both the acidic and alcoholic metabolites of tyramine, octopamine, dopamine and norepinephrine. The method was successfully applied for the measurement of nanogram quantities of these metabolites in human ventricular and lumbar cerebrospinal fluids and in the rat brain. Mass fragmentography was carried out on the methyl ester/pentafluoroproprionyl derivatives of the acidic and the pentafluoropropionyl derivatives of the alcoholic metabolites, employing an 8 ft 3% SE-54 column. Chemical methods for the synthesis of a number of deuterated isomers (isotopomers) of the above metabolites are also described. These isotopomers were utilized as internal reference standards for the assay of the metabolites in biological materials. They were also used to study the fragmentation reactions of these metabolite derivatives.
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  • 141
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    Biological Mass Spectrometry 2 (1975), S. 204-205 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A N-dealkylated metabolite, 1-phenylcyclohexylamine, was detected in a urine sample of a patient who had ingested phencyclidine. The identification was facilitated by a feeding experiment using a mouse administered a 1:1 mixture of unlabeled and phenyl-d5-labeled drug. A control experiment was also performed in which a mouse was fed only the unlabeled drug. Two hydroxylated metabolities were also identified in human urine samples. One of the hydroxylated metabolites has a hydroxy group located at the piperidine moiety of phencyclidine while the other has the hydroxy group located at the cyclohexane ring of the drug. It was also shown that 1-phenyl-cyclohexene detected in the human samples, was an artifact which arose from pyrolysis of phencyclidine during gas chromatography.
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  • 142
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    Biological Mass Spectrometry 2 (1975), S. 225-225 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 143
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Interfering nonpolar lipid material was removed from the acetone extracts of several samples of benign hyperplastic prostate tissue. Endogenous steroids were separated by preparative thin-layer chromatography into fractions containing testosterone, 5α-dihydrotestosterone and the 5α-androstane-3, 17-diols, and concentrations of these steroids were measured by molecular ion monitoring of suitable derivatives at a resolution of 8500 to 10 000 during combined gas chromatography mass spectrometry. The sensitivity and specificity of this procedure allowed unequivocal detection of the steroids of interest at the femtomole level and the incorporation of epimers as internal standards enabled accurate quantitative measurements. The results indicated that 5α-dihydrotestosterone is usually the most predominant of the steroids measured, and that of the 5α-androstanediols, only the 3α, 17β and 3β, 17β isomers occur in measurable concentration, with the former usually predominant.
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  • 144
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 145
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 146
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    Biological Mass Spectrometry 2 (1975), S. 254-260 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The extent of C-methylation, an artifact of the permethylation procedure used to derivatize peptides for mass spectrometric sequencing, was investigated by mass spectrometry. Ten glycine-containing peptides were N-acetylated and then permethylated by the Hakomori method and analyzed by chemical ionization and, in some cases, by electron ionization mass spectrometry. A comparative study was made of the tripeptides Gly Pro Ala and Ala Pro Gly, derivatized by three permethylation procedures. The results show that while C-methylation occurs primarily at glycine, other amino acids (Gln, Glu, Met, Tyr) are also C-methylated, but to a lesser degree. The extent to which C-methylation occurs varies widely and depends on residue position and on the identity of neighboring residues. Such artifacts could lead to serious errors in peptide sequences determined by mass spectrometry, especially when mixtures of peptides are analyzed.
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  • 147
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    Biological Mass Spectrometry 2 (1975), S. 261-265 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrolysis gas chromatography mass spectrometry studies of the whole lyophilized microorganism Streptomyces longisporoflavus, an actinomycete, are reported. Identification of the pyrolysis products indicate that the vast majority arise from protein and carbohydrate origin. There is a paucity of lipid fragments evident. Some of the details of its biochemical composition evident in these results are compared with our previous similar studies on the bacteria Micrococcus luteus and Bacillus subtilis var. niger and suggest this actinomycete lies in biochemical complexity somewhere between the latter two organisms. Although the pyrolysis patterns of these three organisms possess considerable similarities, they are drastically different to that from the fungus Aspergillus niger.
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  • 148
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    Biological Mass Spectrometry 2 (1975), S. 279-280 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A pressure measuring probe has been built for the chemical ionization source of a Du Pont 21 490-B mass spectrometer. The probe fits exactly in the place of the solid sample probe and, when connected to a Baratron manometer, enables pressure measurement directly in the source. This can be used to calibrate an ionization gauge connected to the source housing or a manometer in the reagent gas inlet line. The probe has been used to determine the maximum source pressure attainable for various reagent gases in the Du Pont 21 490-B mass spectrometer.
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  • 149
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    Biological Mass Spectrometry 2 (1975), S. 284-284 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 150
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    Biological Mass Spectrometry 2 (1975), S. viii 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 151
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    Biological Mass Spectrometry 2 (1975), S. x 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 152
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method employing gas-liquid chromatography and combined gas-liquid chromatography mass spectrometry was developed for the quantitative determination of α-D-mannopyranoside-(1 → 3)-β-D-mannopyranoside-(1 → 4)-2-acetamido-2-deoxy-D-glucose in urines. The concentration of this trisaccharide varied between 123 and 469 mg per litre of urine in the patients with mannosidosis but was not detected in twenty normals and two heterozygotes.
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  • 153
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    Biological Mass Spectrometry 2 (1975), S. 304-306 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The identification of 6-methoxy 8-aminoquinoline as a metabolite of Primaquine, an important antimalarial drug, is described. The metabolite is present in urine, plasma and erythrocytes following drug ingestion. It was identified by mass fragmentography of its 1H and 2H acetate and the acetate produced from authentic material. No evidence of further metabolites was obtained.
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  • 154
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    Biological Mass Spectrometry 2 (1975) 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 155
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A sensitive analytical method involving isotope dilution analysis with multilabeled standards and using field ionization mass spectrometry has been developed for the determination of methaqualone and its metabolie, 6-hydroxymethaqualone, in urine. The limit of sensitivity measured with urine samples is 200 pg/ml for the two compounds. Analysis of urines collected over 11 days following ingestion of a single 250 mg tablet of Mandrax™ by a human subject indicates that the slow phase of excretion of the two compounds has a half-life approximately 50 h long.
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  • 156
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    Biological Mass Spectrometry 2 (1975), S. 288-298 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Techniques are described for the computer reduction and identification of complex high resolution mass spectrometric data to yield qualitative and quantitative data for one hundred or more components in a complex mixture. The procedures described have been applied to direct insertion probe separations coupled with high resolution mass spectrometry. Two mass spectrometer computer systems are described in this paper. The basic techniques were developed at the University of Washington utilizing an A.E.I. MS-9 high resolution mass spectrometer, which was interfaced with a PDP-12 digital computer. The most recent system utilizes a Nova II computer interfaced to a Varian MAT 311 mass spectrometer. Programs were developed which were capable of determining the accurate mass (± 3 millimass) of up to 1000 ions per scan. High accuracy limited mass searches were first used to reduce the data. A correlation program was developed to resolve pure mass spectra from the composite mass spectral data using data obtained from the limited mass searches. A library search program was developed which used up to four major identifying masses and their relative abundances in addition to relative volatilization temperatures (probe) or relative retention times (gas chromatographic) for obtaining qualitative data. Quantitative data for each compound were obtained by comparing the total integrated ion current of one ion fragment to that of an internal standard. Instrumental and computer parameters are discussed with respect to the accuracy of the quantitative work. Final computer results gave compound identification and concentrations in μg/m3 or ppm. The use of this analytical technique for the analysis of complex mixtures of pollutants present in atmospheric aerosols is described.
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  • 157
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    Biological Mass Spectrometry 2 (1975), S. vii 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 158
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A generally applicable strategy for polypeptide sequencing has been developed which involves cleavage of a large peptide (for example, primary degradation peptides obtained by tryptic or cyanogen bromide cleavage of a protein) to a mixture of small peptides whose individual amino acid sequences are then determined without their prior isolation. This is accomplished by conversion of the peptide mixture into the corresponding mixture of O-trimethylsilylated polyamino alcohols through reduction of the N-acetylated peptide esters with lithium aluminum deuteride, followed by treatment with trimethylsilyldiethylamine. The conditions for the enzymatic or chemical cleavage were optimized to yield mixtures of peptides best suited for this technique and which represented complete overlap. Limited acid hydrolysis combined with a second experimen utilizing either an enzyme with broad specificity, a set of enzymes, or dipeptidyl aminopeptidase I on the original and/or Edman-degraded molecule was found to be the best choice. This sequencing strategy was evaluated using 0.4 to 1.4 μmol of peptides with known structures (ribonuclease S-peptide, glucagon) and then applied to primary degradation peptides of rabbit skeletal muscle actin up to twenty amino acids long (0.4 to 1 μmol per experiment).
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  • 159
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    X-Ray Spectrometry 4 (1975) 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 160
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    X-Ray Spectrometry 4 (1975), S. 1-1 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 161
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    X-Ray Spectrometry 4 (1975), S. 85-89 
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The zinc concentration in an epitaxial layer of InSb was measured by proton excited X-rays. For the determination of zinc concentration, the X-ray yield was compared to that from known zinc concentrations. As layer thickness, stopping power and X-ray absorption must be taken into account, a general mathematical evaluation was developed. In an appendix, the derived equations are shown to allow a layer thickness determination. The calculated values agree quite well with the experimental results.
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  • 162
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The use of Nickel-59 as an excitation source for the X-ray fluorescence analysis of carbon and low alloy steels has been investigated. Nickel-59 has a half life of 80 000 y and is essentially a pure source of cobalt K X-rays. It is ideal as an X-ray source for field systems because the encapsulated source is small, rugged and requires no external power or maintenance. The prototype system require ∼2½ minutes to obtain a manganese analysis, and 15 minutes to determine vanadium, chromium and manganese concentrations. These times could be shortened about a factor of 40 with a more intense excitation source and a larger area detector. The feasibility of portable field systems is discussed.
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    X-Ray Spectrometry 4 (1975), S. 74-76 
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A single crystal of indium antimonide (zinc blende type InSb) was evaluated as an X-ray monochromator. The long 2d spacing of 7.481 Å makes it possible to diffract Si K α in an ordinary X-ray emission spectrometer. The indium antimonide data were compared with crystals of EDDT, Ge and LiF. Indium antimonide shows seven times higher Si Kα intensity than EDDT. It also has very low second order reflection. A low coefficient of thermal expansion (4.9 × 10-6 °C-1), together with its very stable chemical nature will facilitate high precision measurement ranging from 14Si to 46Pd(Kα), 38Sr to 92U(Lα) and 74W to 92U(Mα).
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  • 164
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    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: For the case where the power method fails to give a non-negative eigenvector for system (1) a program has been set up to calculate all the eigenvalues and eigenvectors of system (1).
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  • 165
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    X-Ray Spectrometry 4 (1975), S. 93-93 
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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    X-Ray Spectrometry 4 (1975), S. A16 
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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    X-Ray Spectrometry 4 (1975), S. 138-148 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A Monte Carlo model is derived for the simulation X-ray fluorescence from homogeneous samples including primary, secondary and tertiary fluorescence events. The model is designed specifically for an annular radioisotope source mounted coaxially with a circular detector. It is verified with analytical relationships for the limited case of fixed sample entrance and exit angles. The results indicate accuracies (2% or better) that are well within our knowledge of X-ray fluorescence parameters (such as fluorescence yields), yet can be calculated with very modest (15 seconds) digital computer calculation time.
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    X-Ray Spectrometry 4 (1975), S. 157-157 
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 169
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    X-Ray Spectrometry 4 (1975), S. 159-160 
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A method is presented discussing the determination of gadolinium in Gd2O3 + UO2 pellets. The relative accuracy ranges between 1 and 2%.
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    X-Ray Spectrometry 4 (1975), S. 166-170 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The theoretical relationship between relative intensity and concentration is used for the estimation of influence coefficients for the Rasberry-Heinrich, Claisse-Quintin and Lachance-Traill method. Those coefficients are used to evaluate Rasberry-Heinrich, Beattie-Brissey and Shiraiva-Fujino measurements in the system of iron + nickel + chromium. An improved program, printing the average error of calculation per element had containing safeguards to avoid the divergence of iteration, is used for computation. The Rasberry-Heinrich method gives the best results. Theoretical reasons are given in explanation.
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    X-Ray Spectrometry 4 (1975), S. 178-185 
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    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The application of a simple, empirical inter-element correction procedure to the analysis of nickel-base alloys is described. The correction factors are considered in relation to the effects predicted from a study of the mass absorption coefficients.
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    X-Ray Spectrometry 4 (1975), S. 186-189 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Using a commercially available flat crystal spectrometer in a slightly modified form, an investigation was made of the peak intensity ratios (Kβ5/Kβ1) and the relative intensities of Kβ″ to Kβ5 in different oxidation states of 3d-transition metal atoms existing in forms of oxidic compounds. The peak intensity ratios (Kβ5/Kβ1) for V, Cr, Mn, Fe, Co, Ni and Cu, as well as the peak profiles of Kβ″ and Kβ5 for V, Cr and Mn, were investigated. Results suggest that changes in the intensities of the Kβ5 and Kβ″ bands can be applied to determining the oxidation number of a metal atom in its oxide.
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    X-Ray Spectrometry 4 (1975), S. 190-195 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Techniques have been developed for analysing the heavy element content of atmospheric particulate fractions by means of X-ray fluorescence spectrometry. Special attention is devoted to the nondestructive analysis of particulates collected on the cellulose and fibreglass filters used in high volume air samplers. It is shown that the X-ray fluorescence data must be corrected for absorption of radiation by the filter medium in the case of cellulose due to penetration of the particulates into the body of the filter. Fibreglass is shown to be superior to cellulose in that most of the particulates are trapped near the surface of the paper. A novel feature of the analytical method described is that a comparison of X-ray fluorescence intensities from the front and back of the filter leads to a determination of filter collection efficiency. A second method for determining collection efficiency, using a tandem arrangement of filter papers, is also described.
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  • 174
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    X-Ray Spectrometry 4 (1975), S. 196-201 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A Comprehensive study of the interfacing of an X-ray energy dispersive spectrometer to a transmission electron microscope is presented. Optimum detector location, sample tilt, collimation and accelerating voltage are discussed. Quantitative elemental analysis is obtained for thin film specimens using corrections for spectrometer response, absorption and background. Peak spectra are sorted using a method of profile fitting based on nonlinear simplex minimization. Using a simple analysis scheme, the peak data is reduced to elemental composition with an accuracy and precision on the order of 1%. Examples from Fe-Ni and Ho-Co alloys are given.
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    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. A17 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 176
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    X-Ray Spectrometry 4 (1975), S. 62-64 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: One way carrying out quantitative X-ray fluorescence analysis with fundamental parameters is the method of variable take-off angle. At angles nearly parallel to the sample surface, the equations can be solved more easily and no knowledge of the white spectrum and μ(λ) is needed. For practical application, in order to get a well defined geometry, we used a diffraction goniometer, an X-ray tube with Mo target and an energy dispersive detector, followed by a multichannel analyser. After calibrating the system, all information essential for a quantitative analysis was obtained from a single measurement. The validity of the final equations was verified by experiments with different alloys, consisting of two, three and four components.
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  • 177
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    X-Ray Spectrometry 4 (1975), S. 52-61 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A fast, efficient calibration procedure is proposed based on the accurate analysis of multicomponent systems by means of the influence coefficient method. It relies on a series of well designed additions made to a suitable standard composition, the latter also being used as a reference sample. We show that, for an n element composition, using the hypothesis of constant coefficients, (n + 1) preparations - allowing n(n + 1) intensity measurements - are in principle sufficient to calculate the n2 calibration parameters [i.e. n(n - 1) influence coefficients and n referenc relative intensities] which are necessary for a complete analysis. Actual analyses are carried out by measuring the fluorescent intensities using the ratio (i.e. unknown/standard) method, and then calculating the concentrations from the usual relationships through an iterative calculation, preferably executed by a computer program. A detailed description of a typical application is given, which involved the study of fused specimens (borax fusion) of bauxite and resulted in the very accurate analysis of calcined samples, as well as the direct analysis of raw bauxites following an adequate treatment of the ignition loss problem. While the method is immediately applicable to every system studied in either solid or liquid solution, it clearly extends to compact systems over a suitable compositional range, provided that carefully controlled additions can be achieved and that all prepared samples are homogeneous.
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  • 178
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    X-Ray Spectrometry 4 (1975), S. 71-73 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Direct X-ray fluorescence analysis of pieces of cloth cut from clothing on which there is a suspected paint smear has been found to be a useful forensic technique for comparing a reference paint sample with the smeared substance. Even though the X-ray method does not compare all the constituents of the paint, it may often be sufficient to distinguish rapidly between two suspect paint sources, and can therefore be a valuable method in paint transfer cases such as hit and run accidents. A feature of the method is that elements present in the cloth, such as sulphur in wool and titanium in some synthetic fibres, can be used as internal standards.
    Additional Material: 4 Ill.
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  • 179
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    X-Ray Spectrometry 4 (1975), S. 90-91 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A table is presented summarizing recently available data of experimentally determined K shell X-ray fluorescence yields.
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  • 180
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    X-Ray Spectrometry 4 (1975), S. 92-92 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 181
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    X-Ray Spectrometry 4 (1975) 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 182
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    X-Ray Spectrometry 4 (1975), S. 95-98 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: An X-ray method for the analysis of thin oxide films on steels has been developed. The oxide layer is first stripped off by the action of bromine in methanol in an inert atmosphere. It is then dissolved and a small amount of the solution is allowd to evaporate on a filter paper impregnated with disodium carbonate. The matrix effects are thus negligible, which can be seen from the standard curves obtained from synthetic oxides in this way. From the standard curves the precision has been estimated to be about ± 5%. The method has been used to analyse oxide layers formed on four different steels oxidized at high temperatures.
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  • 183
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    X-Ray Spectrometry 4 (1975), S. 114-116 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Measurements on several Ge(111) crystals have shown a variation of a factor of two in their reflectivity for p Kα radiation. High background readings for phosphorous using the Ge(111) crystal are shown to be due to germanium L spectra fluorescence from the crystal. The background can be reduced by almost a factor of four without appreciably diminishing the net P Kα count rate by selecting the optimum setting of the pulse height analyser.
    Additional Material: 3 Ill.
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  • 184
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    X-Ray Spectrometry 4 (1975), S. A18 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 185
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    X-Ray Spectrometry 4 (1975), S. A19 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 186
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    X-Ray Spectrometry 4 (1975), S. A18 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 187
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    X-Ray Spectrometry 4 (1975), S. 11-13 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Two simple approximate formulae have been derived for binary calibration curves. These formulae contain one or two constants, which can be determined experimentally with one or two standard specimens, respectively. These formulae can be applied within a wide range around the composition of the standard specimen. These approximations can be used both in X-ray and in isotope excited fluorescence analysis.
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  • 188
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    X-Ray Spectrometry 4 (1975), S. 108-113 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The question as to whether the multiple least squares regression of X-ray fluorescence analytical data used in an earlier paper and based on an equation derived for excitation by monochromatic radiation can be considered as valid with sufficient accuracy in an experimental system using polychromatic radiation as source of excitation was examined. The results of computer simulation of the process of X-ray fluorescence show that although definite differences in the intensities of fluorescent radiation arise as a result of the substitution of polychromatic primary radiation for a monochromatic source, the flexibility of the particular equation used for regression eliminates such deviations by incorporating them in the experimental regression coefficients. The overall accuracy of the regression was found to be satisfactory by any practical criteria.
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  • 189
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    X-Ray Spectrometry 4 (1975), S. 117-118 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The chemical shift of V Kβ1, 3 and width of V Kα1 were measured with a two crystal X-Ray spectrometer. It was found that V Kβ1, 3 shift and V Kα1width can be utilized for identification of the vanadium oxidation state. Applications to vanadium containing catalysts and several perovskite structure compounds are discussed.
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  • 190
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    X-Ray Spectrometry 4 (1975), S. 119-122 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: X-ray mass absorption coefficients for aluminium have been measured for nine wavelengths in the range 1.9 to 9.9 Å. The values obtained disagree with many published compendia of mass absorption coefficients, but agree well with some published experimental values.
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  • 191
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: In this work quantitative measurements performed by EDX on SEM, abd by WDX on EPMA are compared. The commerical SEM has been improved by the addition of a beam regulation and an anticontamination device. The spectra are detected by a Si(Li) detector (FWHM = 180 eV) and digitalized by an analog-to -digital converter. The spectra obtained are treated by an on-line minicomputer PDF 11/05 included in a NS 880 system. A teminal byilt-in magnetic tape cassette functions as a storage device for the computer. The dialogue between the system and the operator and programmation are possible through a keyboard and a visualization screen. The programs used include: spectrun smoothing, background subtaction selected area totalizing and spectrum stripping. The count rate is maintained at the order of 3000 counts per second to avoid pulse pile up and dead time losses. The experimental intensities are then corrected through a ZAF method by the profgram C ø R on an IBM 360. Binary alloys TiA1, FeA1, ZrNi, NbA1 and TiZr have been studied by K and L lines at different values of the excitation voltage. Alloys MgA1, FeMn and TiVCr Presenting overlapping peaks, and a glass, have also been analysed. The errors, advantages and limits of the method are discussed: in a homgeneous bulk material the minimum detectable limit calculated by C(DL)A = 3IB½ CA/IA is of the order of 0.03 wt % with WDX and 0.2 Wt % with EDX for 100 seconds counting time. It could be improved by increasing the counting time and by using better electronics. The precision of the result is comparable to that obtained by WDX. With EDX on SEM the rapid and simultaneous quentitative micro analysis of all the elements of 11 〈 Z ≤ 92 can be performed with good precision. This method is very interesting for thin targets and dispersion of precipitates.
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  • 192
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    X-Ray Spectrometry 4 (1975), S. 202-204 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A design is described which conforms to OSHA recommendations for good radiation protection procedures. This design can be used on most units where X-ray optics are exposed to the atmosphere. It proves sufficient and should make most nonvacuum X-ray units comply with today's recommended dosage levels. A survey of our instrument gave results well below the maximum permissible level of 2.5 milliröntgen per hour for scattered radiation at a distance five centimeters from the housing surface. The detected scattered radiation was in the range of 0.03 milliröntgen per hour, which is within the limits of normal background radiation.
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  • 193
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    X-Ray Spectrometry 4 (1975), S. A18 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
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  • 194
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    Organic Magnetic Resonance 7 (1975), S. 240-243 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical shift differences of diastereotopic protons in aliphatic acyclic alcohols, mostly of the type R—CH2—CR′R″—(CH2)nOH, have been investigated. Fairly small amounts of Eu(dpm)3 cause the spectra of these materials to simplify dramatically; indeed, even diastereotopic protons rather far removed form the hydroxyl group give discrete signals in the presence of the shift reagent. Large shift differences were realized in the γ-protons (n = 1) and the δ-protons (n = 2), particularly if R is bulky and R' and R″ have different steric requirements. Semi-quantitative conformational preferences can be determined from the data obtained.
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  • 195
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    Organic Magnetic Resonance 7 (1975), S. 237-239 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR spectra of a series of β-diketones in the enol form with various β-substituents have been studied. An additive influence of the β-substituents on the chemical shifts of the carbon atoms in the hydrogen bonded chelate ring has been found. It is shown that the α- and β-carbon chemical shifts can be calculated by means of a set of increments for arbitrary combinations of the X and Y substituents. Analysis of the experimental data enables the conclusions to be drawn that enol-enolic tautomerism with different populations of the forms (A) and (B) is absent in β-diketones and that the carbon chemical shift changes are caused by electron density redistribution in the hydrogen bonded chelate ring (C).
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  • 196
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The NMR parameters are determined for a series of disubstituted (R = CH3, (CH3)3C; X = COOCH3, CN) and specifically deuterated cyclohexenes. The 3 J(HH), 3J(HD), 4J(HH) and 5 J(HH) coupling constants are used to evaluate the conformational equilibria. Three of the five compounds with an allylic t-butyl substituent, are conformationally heterogeneous; these equilibria, and those between stereoisomers are used for an analysis of this phenomenon, carried out within the framework of the hypothesis of additivity of conformational free energies and gauche interactions.
    Notes: Les paramètres RMN d'une série de cyclohexènes disubstitués (R = CH3, (CH3)3C; X = COOCH3, CN) et spécifiquement deutériés sont déterminés. A partir des valeurs des constantes de couplage 3J(HH), 3J(HD), 4J(HH) et 5J(HH), les équilibres conformationnels sont évalués. Trois des cinq composés ayant un groupement t-butyle en position allylique sont conformationnellement hétérogènes; les équilibres correspondants et les équilibres entre stéréoisomères permettent une analyse de ce phénomène dans le cadre de l'hypothèse de l'additivité des enthalpies libres conformationnelles et des interactions gauches.
    Additional Material: 13 Ill.
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  • 197
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    Organic Magnetic Resonance 7 (1975), S. 244-246 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: One bond and long range 13C—1H coupling constants for some methoxy-, amino- and hydroxypyridines are described. An unambiguous assignment of carbon-13 resonances is carried out based on the analysis of the fine splitting caused by long range couplings. J values for compounds other than 2- and 4-hydroxy-pyridines are explainable in terms of the values previouly obtained for cyano- and methylpyridines. The hydroxypyridine-pyridone tautomerism affects 2J(Hα), i.e. 2J associated with the α proton. This effect can be used to differentiate pyridones from hydroxypyridines.
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  • 198
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    Organic Magnetic Resonance 7 (1975) 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 199
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    Organic Magnetic Resonance 7 (1975), S. 247-248 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton NMR spectra of certain arylhydroxylamines in DMSO-d6 show a vicinal coupling through nitrogen and oxygen. The assignment of OH and NH signals was made using a 15N labelled derivative.
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  • 200
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    Organic Magnetic Resonance 7 (1975), S. 313-314 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dihedral and bond direction angles between all pairs of vicinal protons of the arabinofuranose residue were calculated from the coordinatees of the hydrogen atoms found by an X-ray study of 3-O-acetyl-β-L-arabinofuranose 1,2,5-orthobenzoate. The values found were compared with those calculated with the help of correlation equations previously proposed by Karplus and recently by the authors, linking the values of those angles with the spin-spin coupling constants of vicinal protons [3J(H,H′)]. It has been found that the best agreement between the angles found crystallographically and calculated from the 1H NMR data can be achieved using the equation which includes bond direction angles and the sum of the chemical shifts of the protons involved.
    Additional Material: 1 Tab.
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