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Gerhardus J De Jong - One of the best experts on this subject based on the ideXlab platform.
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on fiber derivatization for direct immersion solid phase microextraction part ii acylation of amphetamine with Pentafluorobenzoyl Chloride for urine analysis
Analyst, 2002Co-Authors: Emile H M Koster, Chris H P Bruins, Gerhardus J De JongAbstract:On-fiber derivatization was used for solid-phase microextraction (SPME) in order to increase the detectability and extractability of drugs in biological samples. Amphetamine, which was used as a model compound, was derivatized with Pentafluorobenzoyl Chloride (PFBCl) and subjected to gas chromatography with electron capture or mass spectrometric detection. Extraction was performed by direct immersion of a 100 μm polydimethylsiloxane-coated fiber into buffered human urine. On-fiber derivatization was performed either after or simultaneously with extraction. The former procedure gave cleaner chromatograms but the latter turned out to be superior with respect to linearity and repeatability. For the on-fiber derivatization of amphetamine an excess of reagent is required. Because a considerable part of the PFBCl loaded on to the fiber is used up by reaction with matrix compounds and water, a reagent loading time of 5 min was needed to obtain a linear range (r = 0.9756) from 250 pg mL−1 to 15 ng mL−1. Due to an interfering matrix compound, the limit of detection was also found to be dependent on the reagent loading time, i.e., the limit of detection for a PFBCl loading time of 5 min is 250 pg mL−1 whereas that for a 1 min loading time it is 100 pg mL−1. The relative standard deviation (n = 7) of the method was about 11% at an amphetamine concentration of 1 ng mL−1. The applicability of the method for the determination of drugs in biological samples is shown.
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on fiber derivatization for direct immersion solid phase microextraction part i acylation of amphetamine with Pentafluorobenzoyl Chloride
Journal of Separation Science, 2001Co-Authors: Emile H M Koster, Chris H P Bruins, Corlien Wemes, Gerhardus J De JongAbstract:On-fiber derivatization has been used for solid-phase microextraction (SPME) with gas chromatography in order to increase the extractability and detectability. Amphetamine, which has been used as a model compound, was derivatized with Pentafluorobenzoyl Chloride that was loaded on the fiber prior to the direct immersion of the fiber into the sample. The extraction performance of amphetamine with and without on-fiber derivatization has been compared. As the derivative possesses properties other than its parent compound, its partitioning between the polydimethylsiloxane coated fiber and sample matrix is different, i.e., with on-fiber derivatization a yield of 55% could be obtained in 55 min while without derivatization a yield of 40% has been obtained after a 105 min extraction. As the derivatization reagent is very suitable for electron capture detection, this detection system gave a factor of about 1000 better response for the derivative compared to flame ionization detection. Optimization of the method is presented for buffer solutions to show its benefits. Good linearity (r = 0.9991) for a 50 pg/mL to 5 ng/mL range has been obtained. The applicability for urine analysis has shortly been demonstrated.
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A continuous two‐phase reaction system coupled on‐line with capillary chromatography for the determination of polar solutes in water
Hrc-journal of High Resolution Chromatography, 1992Co-Authors: Elise C. Goosens, Gerhardus J De Jong, Marcel H. Broekman, Margarete H. Wolters, Richard E. Strijker, Dirk De Jong, Udo A. Th. BrinkmanAbstract:Gas chromatographic procedures are described for the determination of carboxylic acids and chlorinated anilines in water samples. Propionic acid and 2,6-difluorobenzoic acid in aqueous solution have been simultaneously alkylated and extracted by means of a continuous two-phase reaction system, and then quantitated by on-line coupled capillary gas chromatography; tetrahexyl-ammonium hydrogen sulfate was used as phase transfer catalyst and pentafluorobenzyl bromide as reagent. A factorial design approach was used to optimize on-line derivatization of aqueous propionic acid with regard to pH and concentration of phase transfer catalyst. Alkylation and extraction, under optimized conditions, followed by quantitation of the pentafluorobenzyl ester by flame ionization detection furnished a linear calibration for concentrations between 0.1 and 10 μg/ml. The relative standard deviation was 9–15 %. The continuous two-phase reaction system was also used to determine (chlorinated) anilines present in water at concentrations of 0.1–1 μg/ml; Pentafluorobenzoyl Chloride was used as reagent and analysis was performed by capillary gas chromatography with flame ionization or electron capture detection. The on-line acylation of p-chloroaniline was optimized with regard to pH, reagent concentration, and reaction time. The on-line reaction system worked satisfactorily for both applications, although excess reagent caused some problems with the chromatography.
Emile H M Koster - One of the best experts on this subject based on the ideXlab platform.
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on fiber derivatization for direct immersion solid phase microextraction part ii acylation of amphetamine with Pentafluorobenzoyl Chloride for urine analysis
Analyst, 2002Co-Authors: Emile H M Koster, Chris H P Bruins, Gerhardus J De JongAbstract:On-fiber derivatization was used for solid-phase microextraction (SPME) in order to increase the detectability and extractability of drugs in biological samples. Amphetamine, which was used as a model compound, was derivatized with Pentafluorobenzoyl Chloride (PFBCl) and subjected to gas chromatography with electron capture or mass spectrometric detection. Extraction was performed by direct immersion of a 100 μm polydimethylsiloxane-coated fiber into buffered human urine. On-fiber derivatization was performed either after or simultaneously with extraction. The former procedure gave cleaner chromatograms but the latter turned out to be superior with respect to linearity and repeatability. For the on-fiber derivatization of amphetamine an excess of reagent is required. Because a considerable part of the PFBCl loaded on to the fiber is used up by reaction with matrix compounds and water, a reagent loading time of 5 min was needed to obtain a linear range (r = 0.9756) from 250 pg mL−1 to 15 ng mL−1. Due to an interfering matrix compound, the limit of detection was also found to be dependent on the reagent loading time, i.e., the limit of detection for a PFBCl loading time of 5 min is 250 pg mL−1 whereas that for a 1 min loading time it is 100 pg mL−1. The relative standard deviation (n = 7) of the method was about 11% at an amphetamine concentration of 1 ng mL−1. The applicability of the method for the determination of drugs in biological samples is shown.
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on fiber derivatization for direct immersion solid phase microextraction part i acylation of amphetamine with Pentafluorobenzoyl Chloride
Journal of Separation Science, 2001Co-Authors: Emile H M Koster, Chris H P Bruins, Corlien Wemes, Gerhardus J De JongAbstract:On-fiber derivatization has been used for solid-phase microextraction (SPME) with gas chromatography in order to increase the extractability and detectability. Amphetamine, which has been used as a model compound, was derivatized with Pentafluorobenzoyl Chloride that was loaded on the fiber prior to the direct immersion of the fiber into the sample. The extraction performance of amphetamine with and without on-fiber derivatization has been compared. As the derivative possesses properties other than its parent compound, its partitioning between the polydimethylsiloxane coated fiber and sample matrix is different, i.e., with on-fiber derivatization a yield of 55% could be obtained in 55 min while without derivatization a yield of 40% has been obtained after a 105 min extraction. As the derivatization reagent is very suitable for electron capture detection, this detection system gave a factor of about 1000 better response for the derivative compared to flame ionization detection. Optimization of the method is presented for buffer solutions to show its benefits. Good linearity (r = 0.9991) for a 50 pg/mL to 5 ng/mL range has been obtained. The applicability for urine analysis has shortly been demonstrated.
Chris H P Bruins - One of the best experts on this subject based on the ideXlab platform.
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on fiber derivatization for direct immersion solid phase microextraction part ii acylation of amphetamine with Pentafluorobenzoyl Chloride for urine analysis
Analyst, 2002Co-Authors: Emile H M Koster, Chris H P Bruins, Gerhardus J De JongAbstract:On-fiber derivatization was used for solid-phase microextraction (SPME) in order to increase the detectability and extractability of drugs in biological samples. Amphetamine, which was used as a model compound, was derivatized with Pentafluorobenzoyl Chloride (PFBCl) and subjected to gas chromatography with electron capture or mass spectrometric detection. Extraction was performed by direct immersion of a 100 μm polydimethylsiloxane-coated fiber into buffered human urine. On-fiber derivatization was performed either after or simultaneously with extraction. The former procedure gave cleaner chromatograms but the latter turned out to be superior with respect to linearity and repeatability. For the on-fiber derivatization of amphetamine an excess of reagent is required. Because a considerable part of the PFBCl loaded on to the fiber is used up by reaction with matrix compounds and water, a reagent loading time of 5 min was needed to obtain a linear range (r = 0.9756) from 250 pg mL−1 to 15 ng mL−1. Due to an interfering matrix compound, the limit of detection was also found to be dependent on the reagent loading time, i.e., the limit of detection for a PFBCl loading time of 5 min is 250 pg mL−1 whereas that for a 1 min loading time it is 100 pg mL−1. The relative standard deviation (n = 7) of the method was about 11% at an amphetamine concentration of 1 ng mL−1. The applicability of the method for the determination of drugs in biological samples is shown.
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on fiber derivatization for direct immersion solid phase microextraction part i acylation of amphetamine with Pentafluorobenzoyl Chloride
Journal of Separation Science, 2001Co-Authors: Emile H M Koster, Chris H P Bruins, Corlien Wemes, Gerhardus J De JongAbstract:On-fiber derivatization has been used for solid-phase microextraction (SPME) with gas chromatography in order to increase the extractability and detectability. Amphetamine, which has been used as a model compound, was derivatized with Pentafluorobenzoyl Chloride that was loaded on the fiber prior to the direct immersion of the fiber into the sample. The extraction performance of amphetamine with and without on-fiber derivatization has been compared. As the derivative possesses properties other than its parent compound, its partitioning between the polydimethylsiloxane coated fiber and sample matrix is different, i.e., with on-fiber derivatization a yield of 55% could be obtained in 55 min while without derivatization a yield of 40% has been obtained after a 105 min extraction. As the derivatization reagent is very suitable for electron capture detection, this detection system gave a factor of about 1000 better response for the derivative compared to flame ionization detection. Optimization of the method is presented for buffer solutions to show its benefits. Good linearity (r = 0.9991) for a 50 pg/mL to 5 ng/mL range has been obtained. The applicability for urine analysis has shortly been demonstrated.
Sunil Kumar Sanghi - One of the best experts on this subject based on the ideXlab platform.
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determination of aliphatic amines by gas chromatography mass spectrometry after in syringe derivatization with Pentafluorobenzoyl Chloride
Journal of Chromatography A, 2011Co-Authors: Deepesh Kumar Singh, Sunil Kumar Sanghi, Sorna Gowri, Navin ChandraAbstract:Abstract A simple and highly sensitive gas chromatographic method has been developed for the determination of low molecular weight short-chain aliphatic amines (SCAAs) after their simultaneous extraction and in-syringe derivatization with Pentafluorobenzoyl Chloride (PFBOC). Derivatization of the low molecular weight aliphatic amines in bicarbonate buffer of pH 10.5 with PFBOC was followed by immersed solvent microextraction. Derivatization conditions, including reagent concentration, reaction pH, ionic concentration of buffer, reaction time, stirring rate, reaction temperature and extraction solvent, have been investigated for method optimization. Linearity was studied within range of 0.15 pg ml −1 –50 ng ml −1 . The correlation coefficients were between 0.9934 and 0.9999. Detection limit of derivatized amines proved to be in the range of 0.117–1.527 pg ml −1 , and the intraday and interday relative standard deviation (RSD) values were less than 8% with respect to peak area. The method was applied for analysis of lake, river and industrial waste water. The recoveries of extraction from lake, river and industrial waste water samples, which have been spiked with different levels of aliphatic amines, were in the range of 68–99%, 63–102% and 62–105%, respectively.
Corlien Wemes - One of the best experts on this subject based on the ideXlab platform.
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on fiber derivatization for direct immersion solid phase microextraction part i acylation of amphetamine with Pentafluorobenzoyl Chloride
Journal of Separation Science, 2001Co-Authors: Emile H M Koster, Chris H P Bruins, Corlien Wemes, Gerhardus J De JongAbstract:On-fiber derivatization has been used for solid-phase microextraction (SPME) with gas chromatography in order to increase the extractability and detectability. Amphetamine, which has been used as a model compound, was derivatized with Pentafluorobenzoyl Chloride that was loaded on the fiber prior to the direct immersion of the fiber into the sample. The extraction performance of amphetamine with and without on-fiber derivatization has been compared. As the derivative possesses properties other than its parent compound, its partitioning between the polydimethylsiloxane coated fiber and sample matrix is different, i.e., with on-fiber derivatization a yield of 55% could be obtained in 55 min while without derivatization a yield of 40% has been obtained after a 105 min extraction. As the derivatization reagent is very suitable for electron capture detection, this detection system gave a factor of about 1000 better response for the derivative compared to flame ionization detection. Optimization of the method is presented for buffer solutions to show its benefits. Good linearity (r = 0.9991) for a 50 pg/mL to 5 ng/mL range has been obtained. The applicability for urine analysis has shortly been demonstrated.