The Experts below are selected from a list of 9963 Experts worldwide ranked by ideXlab platform
G Spyres - One of the best experts on this subject based on the ideXlab platform.
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determination of 3 chloropropane 1 2 diol in hydrolysed vegetable proteins by Capillary Gas Chromatography with electrolytic conductivity detection
Journal of Chromatography A, 1993Co-Authors: G SpyresAbstract:Abstract The determination of 3-chloropropane-1,2-diol in hydrolyzed vegetable protein using Capillary Gas Chromatography is improved through the specificity of an electrolytic conductivity detector operated in the halogen mode. The hydrolysate is absorbed onto a Extrelut QE column of kieselguhr, 3-chloropropane-1,2-diol is partitioned into ethyl acetate and is quantitatively measured by Gas Chromatography using 1-chlorotetradecane as the internal standard. A concentration of 1 mg/kg dry substance is easily determined.
C Taeschler - One of the best experts on this subject based on the ideXlab platform.
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sensitive method for the determination of 3 chloropropane 1 2 diol and 2 chloropropane 1 3 diol by Capillary Gas Chromatography with mass spectrometric detection
Journal of Chromatography A, 1998Co-Authors: D C Meierhans, S Bruehlmann, J Meili, C TaeschlerAbstract:Abstract An improved routine method for the determination of 3-chloropropane-1,2-diol (3-MCPD) and 2-chloropropane-1,3-diol (2-MCPD) in different savoury foods using Capillary Gas Chromatography with mass spectrometric detection is presented. Monochloropropanediols were extracted from Extrelut columns with diethyl ether and derivatised with acetone to the corresponding dioxolanes. Detection was performed on two different mass spectrometers using single ion monitoring, to reach ultimate sensitivity in the low μg/kg range. A limit of detection of 1 μg kg−1 was achieved using Extrelut 20 for extraction. The method proved to be fast and reliable and showed good recoveries and good accuracy, confirmed by successful participation in two ring test studies. Results of analyses of finished goods, such as seasonings and soy sauces, often containing MCPDs only in the sub-ppb level, are presented.
D C Meierhans - One of the best experts on this subject based on the ideXlab platform.
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sensitive method for the determination of 3 chloropropane 1 2 diol and 2 chloropropane 1 3 diol by Capillary Gas Chromatography with mass spectrometric detection
Journal of Chromatography A, 1998Co-Authors: D C Meierhans, S Bruehlmann, J Meili, C TaeschlerAbstract:Abstract An improved routine method for the determination of 3-chloropropane-1,2-diol (3-MCPD) and 2-chloropropane-1,3-diol (2-MCPD) in different savoury foods using Capillary Gas Chromatography with mass spectrometric detection is presented. Monochloropropanediols were extracted from Extrelut columns with diethyl ether and derivatised with acetone to the corresponding dioxolanes. Detection was performed on two different mass spectrometers using single ion monitoring, to reach ultimate sensitivity in the low μg/kg range. A limit of detection of 1 μg kg−1 was achieved using Extrelut 20 for extraction. The method proved to be fast and reliable and showed good recoveries and good accuracy, confirmed by successful participation in two ring test studies. Results of analyses of finished goods, such as seasonings and soy sauces, often containing MCPDs only in the sub-ppb level, are presented.
Patrizia Sticca - One of the best experts on this subject based on the ideXlab platform.
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residue analysis of organophosphorus pesticides in animal matrices by dual column Capillary Gas Chromatography with nitrogen phosphorus detection
Journal of Chromatography A, 2005Co-Authors: Giampiero Pagliuca, Teresa Gazzotti, Elisa Zironi, Patrizia SticcaAbstract:Organophosphorus pesticides (OPPs) were determined in matrices of animal origin by dual column Capillary Gas Chromatography using nitrogen-phosphorus detection (NPD). This method was tested on cow milk and on liver and muscle of wild boar. The isolation of these pesticides was performed by liquid partition followed by cleanup with solid phase cartridge (SPE C18), after extraction from the matrix. The analytes identification was obtained by comparing the retention times in two columns with different polarity. The quantification of each OPP was obtained using parathion-ethyl as internal standard. The method was developed in a UNI EN ISO 9001:2000 certified laboratory. The recovery, investigated by analyzing samples spiked at 5, 10 and 50 ppb, ranged from 59 to 117% in milk, from 60 to 81% in liver and from 68 to 76% in muscle. The limit of quantification (LOQ) and limit of detection (LOD) were, respectively, 5 and 1 ppb for each compound and allowed quantifying the residues below the legal limits.
Pat Sandra - One of the best experts on this subject based on the ideXlab platform.
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high throughput Capillary Gas Chromatography for the determination of polychlorinated biphenyls and fatty acid methyl esters in food samples
Journal of Chromatographic Science, 2002Co-Authors: Pat Sandra, Frank DavidAbstract:High-throughput Capillary Gas Chromatography (CGC) methods, developed during the Belgian 1999 “dioxin” food crisis, for the determination of the contaminating polychlorinated biphenyls (PCBs) and the fatty acid composition of the lipids are described. For PCB analysis, the fat obtained by ultrasonic extraction is fractionated by matrix solid-phase dispersion, and the PCBs are analyzed by CGC‐electron capture detection on a 10-mL × 100-µmi.d. HP-5MS column. Analytical conditions for the high-speed column are deduced from analyses on conventional CGC columns using the method translation software. The concept of retention time locking is implemented to facilitate the elucidation of the PCB markers. The fatty acid methyl esters (FAMEs) are prepared by the sodium methylate procedure on part of the ultrasonic extract followed by analysis on 10-mL × 100-µm-i.d. HP-WAX or BPX-70 Capillary columns. By optimizing both the sample preparation and CGC analysis, the throughput is more than fifty PCB and FAME samples per day with the same robustness as conventional methods.
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stir bar sorptive extraction thermal desorption Capillary Gas Chromatography mass spectrometry applied to the analysis of polychlorinated biphenyls in human sperm
Journal of Chromatography B: Biomedical Sciences and Applications, 2001Co-Authors: Tom Benijts, Joeri Vercammen, Riet Dams, Hai Pham Tuan, Willy E Lambert, Pat SandraAbstract:Stir bar sorptive extraction (SBSE) on polydimethylsiloxane (PDMS) was applied to the enrichment of polychlorinated biphenyls (PCBs) from human sperm. The seven Ballschmiter PCBs were used as model compounds. The extracted PCBs were then thermally desorbed from the stir bar and analysed on-line by Capillary Gas Chromatography (CGC) with mass spectrometric detection (MS). Method development started with the analysis of PCBs spiked in water. Methanol had to be added to the samples in order to reduce the influence of glass adsorption on recovery and reproducibility. Recoveries in water for all PCBs varied around 50-60% and were limited for low molecular mass (MM) PCBs by polarity changes in the sample due to methanol addition and for high MM PCBs by non-equilibrium conditions. Matrix suppression by the lipophilic medium lowered the recoveries in the sperm samples proportional with PCB polarity. The method was validated and although limits of detection (LOD) for the individual congeners were in the sub-ppt level (
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stir bar sorptive extraction for the determination of ppq level traces of organotin compounds in environmental samples with thermal desorption Capillary Gas Chromatography icp mass spectrometry
Analytical Chemistry, 2001Co-Authors: Jordy Vercauteren, Pat Sandra, Christophe Peres, Christophe Devos, Frank Vanhaecke, Luc MoensAbstract:The extraction and preconcentration capabilities of a new extraction technique, stir bar sorptive extraction, were combined with the separation power of Capillary Gas Chromatography (CGC) and the low limits of detection (LODs) of inductively coupled plasma mass spectrometry (ICPMS) for the determination of the organotin compounds tributyltin (TBuT) and triphenyltin (TPhT) in aqueous standard solutions, harbor water, and mussels (after digestion with tetramethylammonium hydroxide). Throughout, tripropyltin for TBuT and tricyclohexyltin for TPhT were used as internal standards to correct for variations in the derivatization and extraction efficiency. Calibration was accomplished by means of single standard addition. Derivatization to transform the trisubstituted compounds into sufficiently volatile compounds was carried out with sodium tetraethylborate. The compounds were extracted from their aqueous matrix using a stir bar of 1-cm length, coated with 55 μL of poly(dimethylsiloxane) (PDMS). After 15 min of ...
