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  • 1
    Electronic Resource
    Electronic Resource
    Determination of Bisphenol A diglycidyl ether (BADGE) and its hydrolysis products in canned oily foods from the Austrian market (1999)
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 208 (1999), S. 208-211 
    Details
    ISSN: 1431-4630
    Keywords: Key words BADGE ; Bisphenol A diglycidyl ether ; Bisphenol A bis(2 ; 3-dihydroxypropyl) ether ; HPLC ; Epoxy resins ; Canned food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Bisphenol A diglycidyl ether (BADGE) is determined in canned oily foods from Austria using a new simplified HPLC method. Samples are extracted with pentane, back extracted with methanol, and finally dissolved in the mobile phase (cyclohexane/tert–butyl methyl ether). Separation is performed on a normal-phase HPLC column using fluorescence detection. Verification of the BADGE-containing peak is carried out by using off-line GC-MS. Additionally, the synthesis and determination of BADGE hydrolysis products, Bisphenol A bis(2,3-dihydroxypropyl) ether (BADGE.2H2O) and Bisphenol A glycidyl (2,3-dihydroxypropyl) ether (BADGE.H2O) are presented. From 67 analyzed cans, containing various fatty meat or fish products, 16% were above the maximum quantity of 1 mg/kg tolerated by the European Community, 45% were in the range between 0.1–1 mg/kg, 24% between 0.02 and 0.1 mg/kg, and in 15% the BADGE concentrations were below the detection limit of 0.02 mg/kg. The hydrolysis product BADGE.H2O was not detected in any sample, whereas BADGE.2H2O was found in some samples up to a concentration of 0.5 mg/kg.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002170050404
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  • 2
    Electronic Resource
    Electronic Resource
    The analysis of antimony species by using ESI-MS and HPLC-ICP-MS (1998)
    Springer
    Fresenius' journal of analytical chemistry 361 (1998), S. 96-102 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new method for the separation of organic antimony as trimethylantimony dichloride (TMSbCl2) and inorganic Sb(V) and Sb(III) by using anion exchange high-performance liquid chromatography coupled with inductively-coupled plasma mass spectrometry (ICP-MS) is presented. In comparison with previous work the detection limits for both species were significantly decreased, down to 5 ngL–1, mainly by avoiding any contamination from the chromatographic device. Using an ultrasonic nebulizer (USN) improved the detection limits for inorganic Sb species, but was useless for the HPLC method due to problems in the recovery of the TMSbCl2. Matrix interferences of the chromatographic determination were studied in detail and the method was applied to environmental samples assumed to contain organic antimony species. Additionally, the molecular structure of the TMSbCl2 in solution was studied by using electrospray-ionization mass spectrometry (ESI-MS) showing that this species occurs most probably as [TMSbOH]+ in aqueous solutions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050841
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  • 3
    Electronic Resource
    Electronic Resource
    A new method for the analysis of arsenic species in urine by using HPLC-ICP-MS (1998)
    Springer
    Fresenius' journal of analytical chemistry 362 (1998), S. 313-318 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Urinary arsenic speciation is considered to be an effective procedure to differentiate between toxic inorganic and less toxic organic arsenic exposure. The aim of the present work was to develop a new method for the simultaneous determination of the main arsenic species so far detected in urine: arsenite (As(III)), arsenate (As(V)), methylarsonic acid (MA), dimethylarsinic acid (DMA), and arsenobetaine (AsB). The method is based on anion exchange HPLC coupled on-line to an inductively coupled plasma mass spectrometer (ICP-MS) for element specific detection. Experimental parameters, such as column type and composition of the mobile phases were optimized in order to get best separation, little matrix interferences, lowest detection limits, and short total times of analyses. Best chromatographic conditions were obtained by using a Dionex AS14 anion exchange column and a gradient elution with tetramethylammonium hydroxide and ammonium carbonate as eluting compounds. The detection limits (3 σ) were found to be in the sub μg L–1 range. The method was applied to analyze different urine samples from persons with and without consumption of seafood. To avoid significant matrix influences, samples (24 h urine) had to be diluted 1 : 5 with water and were filtered through a 0.45 μm filter prior to analyses. Special attention was focused on the validation of the method according to the regulations of the “Deutsche Forschungsgemeinschaft” (DFG) for the analyses of hazardous substances in biological materials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160051080
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  • 4
    Electronic Resource
    Electronic Resource
    Determination of antimony species with high-performance liquid chromatography using element specific detection (1997)
    Springer
    Fresenius' journal of analytical chemistry 359 (1997), S. 484-491 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new method for the fast and simultaneous determination of Sb(III) and Sb(V) is presented involving the use of anion exchange high-performance liquid chromatography (HPLC), a complexing reagent in the mobile phase, and element specific detection with flame atomic absorption spectrometry (FAAS) or inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic parameters such as nature and concentration of the complexing and eluting compounds and pH of the mobile phase were investigated in detail. Additionally, the separation of inorganic Sb(III) and Sb(V) from organically bounded antimony (as (CH3)3SbCl2 and (CH3)3Sb(OH)2) was investigated by using anion, and cation exchange, and reversed phase HPLC. Best separation was obtained with anion exchange HPLC under alkaline conditions. Cation exchange and reversed-phase HPLC were not useful for the separation of the above compounds. With FAAS concentrations in the upper mg L–1 range are detectable, which is not sensitive enough for the analyses of environmental samples. When the chromatographic system was coupled to ICP-MS, the detection limits are in the lower μg L–1 range. The method was applied to various environmental samples with anthropogenic and naturally elevated Sb concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050618
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  • 5
    Electronic Resource
    Electronic Resource
    Uptake of various trace elements during germination of wheat, buckwheat and quinoa (1997)
    Springer
    Plant foods for human nutrition 50 (1997), S. 223-237 
    Details
    ISSN: 1573-9104
    Keywords: Ascorbic acid ; Bioavailability ; Germination ; Grains ; Trace elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The practice of sprouting is widely used to improve the nutritional value of grain seeds. Several nutritive factors such as vitamin concentrations and bioavailability of trace elements and minerals increase during germination. The objective of this work was to study the enrichment of various essential trace elements during germination of wheat (Triticum aestivum), buckwheat (Fagopyrum esculentum), and quinoa (Chenopodium quinoa) seeds in order to improve their nutritional role as a source of bioavailable trace elements. Seeds were sprouted either in distilled- or tap-water and in five different electrolyte solutions to investigate the concentration-dependent uptake. The time-dependence was investigated by analyzing aliquots of the sprouts after certain germination periods. Samples were analyzed after freeze drying for their Li, V, Cr, Fe, Mn, Co, Cu, Zn, Sr, Mo, As and Se concentrations with inductively-coupled plasma mass-spectrometry (ICP-MS). As a control for possible changes in the biochemical metabolism of the sprouts, the biosynthesis of vitamin C was also determined by using reversed-phase ion-pair HPLC. It was shown that quinoa was the most resistant to the applied electrolyte solutions and had the highest uptake rates for almost all elements, followed by buckwheat and wheat. Greatest increases were observed for Co, Sr, and Li. No significant changes in vitamin C biosynthesis were observed between sprouts grown in different electrolyte solutions. The time-dependent uptake for most elements was characterized by a significant absorption during soaking of the seeds, followed by a lag phase during the first day of germination and an increased uptake during the second and third day. Se and As showed distinctly different uptake behaviors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02436059
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  • 6
    Electronic Resource
    Electronic Resource
    Simultaneous determination of bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether and their hydrolysis and chlorohydroxy derivatives in canned foods (2000)
    Springer
    European food research and technology 211 (2000), S. 211-217 
    Details
    ISSN: 1438-2385
    Keywords: Key words Bisphenol A-diglycidyl ether ; Bisphenol F-diglycidyl ether ; Reverse-phase high performance liquid chromatography ; Organosol varnishes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A new method for the simultaneous determination of bisphenol A-diglycidyl ether (BADGE), bisphenol F-diglycidyl ether (BFDGE) and their hydrolysis and chlorohydroxy derivatives in canned foods is presented. Oily and aqueous food samples were extracted with tert-butyl methyl ether and acetonitrile, respectively. The compounds in both extracts were determined by using reverse-phase gradient high-performance liquid chromatography with fluorescence detection. Optimization of extraction and chromatographic determination is outlined in detail. After validation the method was used to analyze various canned food samples, such as tuna and sardine in oil, vegetables, fruit cocktails, etc. In none of the samples were significant amounts ( 〉100 μg/kg) of BADGE or BFDGE found, whereas in most samples BADGE/BFDGE chlorohydroxy compounds were detected. These originate most probably from the use of organosol varnishes instead of epoxy resins. Risk assessment and regulations of these compounds by the European Union are urgently needed. Additionally, the syntheses and characterization of the not available standard compounds bisphenol A-p-glycidyl-p′-(3-chloro-2-hydroxypropyl) ether (BADGE.HCl) and bisphenol A-p-(2,3-dihydroxypropyl)-p′-(3-chloro-2-hydroxypropyl) ether (BADGE.HCl.H2O) are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002170050026
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  • 7
    Electronic Resource
    Electronic Resource
    Simultaneous determination of chromium (III) and chromium (VI) by reversed-phase ion-pair HPLC with chromium-specific detection (1995)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 351 (1995), S. 604-609 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A method for the simultaneous determination of Cr(III) and Cr(VI) with reversed-phase ion-pair HPLC employing chromium-specific detection by flame atomic absorption spectrometry (FAAS) and inductively-coupled plasma mass spectrometry (ICP-MS) is presented. Experimental parameters of the chromatographic separation, such as concentration of the ion-pairing reagent, pH and polarity of the mobile phase have been optimized for two different ion-pairing reagents, tetrabutylammonium phosphate (TBA) and tetraethylammonium nitrate (TEA). Best chromatographic conditions have been obtained with a polymer-based reversed-phase column (Hamilton PRP1) and mobile phases containing either TBA (1 mmol/l) in methanol-water (60:40, v/v) or TEA (2 mmol/l) in water at a pH between 3 and 4. With FAAS the detection limits (3σ) have been found to be 24 μg/l for Cr(III) and 40 μg/l for Cr(VI). A detection limit of 0.3 μg/l Cr(3σ) for both chromium species has been obtained when ICP-MS has been used for detection. The method has been applied to analyze tap- and groundwater and to investigate the behaviour of Cr(III) and Cr(VI) in spiked tap-water, as well as to analyze aqueous extracts of coal fly ash (NIST SRM 1633a) and of an ash from a wood treatment company.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323333
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  • 8
    Electronic Resource
    Electronic Resource
    Demethylation of trimethylantimony species in aqueous solution during analysis by hydride generation/gas chromatography with AAS and ICP MS detection (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 12 (1998), S. 129-136 
    Details
    ISSN: 0268-2605
    Keywords: trimethylantimony ; molecular rearrangement ; demethylation ; speciation ; hydride generation ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The method of hydride generation for the speciation of antimony compounds was examined with respect to the problem of molecular "rearrangement'. Specifically, demethylation of trimethylstilbine during the analysis of trimethylantimony dichloride (Me3SbCl2) was studied. Previously published observations that enhanced demethylation takes place as a result of inadequate preconditioning of the analytical apparatus were found to be not reproducible. However, demethylation was enhanced as the pH decreased when using two different analytical methods: semi-continuous flow hydride generation-gas chromatography-atomic absorption spectrometry (HG- GC-AAS), and batch-type hydride generation- gas chromatography-inductively coupled plasma mass spectrometry (HG-GC-ICP MS). Applications of the hydride generation method to environmental samples revealed differences in analytical results at high and low pH, and enhanced demethylation taking place because of the matrix in a fungal extract sample. The authors recommend that researchers using the method of hydride generation for antimony compounds carefully test the reaction conditions with standard compounds and use the method of standard addition only. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Chlorella sp. and Arsenic Compounds: An Attempt to Prepare an Algal Reference Material for Arsenic Compounds (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 11 (1997), S. 57-66 
    Details
    ISSN: 0268-2605
    Keywords: Chlorella sp. ; biomethylation ; arsenic ; HPLC-ICP-MS ; cadmium ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The growth of Chlorella Böhm, Chlorella kessleri and Chlorella 108 in media containing sodium arsenate at 200 or 2000 mg As dm-3 was investigated. The cell densities in the stationary phases were 40% higher for Chlorella Böhm (5.6×105 cells cm-3) and Chlorella kessleri (4.5×105 cells cm-3) grown in the 2000 mg As dm-3 arsenate media compared with the arsenic-free media. The growth of Chlorella 108 was depressed by arsenate. Dimethylarsinic acid (at concentrations never exceeding 1.2 mg As dm-3) and arsenite (≲0.2 mg As dm-3) were detected in the growth medium. The cells harvested during the stationary phase had 2400 mg arsenic associated with 1 kg dry mass. A water/methanol (80:20) mixture extracted all the arsenic from the cells. Most of the arsenic (99%) was arsenate. Arsenite, methylarsonic acid and dimethylarsinic acid accounted for the remaining arsenic. Cadmium in the arsenic-containing growth media (50 μg to 100 mg dm-3) reduced the yield of algal cells and induced the formation of an unidentified arsenic compound in Chlorella Böhm. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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