The Experts below are selected from a list of 1107 Experts worldwide ranked by ideXlab platform
Pascal Vachon - One of the best experts on this subject based on the ideXlab platform.
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development of a lc esi ms ms assay for the quantification of vanillin using a simple off line Dansyl Chloride derivatization reaction to enhance signal intensity
Biomedical Chromatography, 2007Co-Authors: Francis Beaudry, Andreanne Ross, Pascal VachonAbstract:Vanillin is responsible for producing the familiar smell of vanilla. Vanillin has many similarities with other flavor phenolic compounds and could potentially show similar pharmacological activity. A previously published analytical method was adapted, developed and tested. Vanillin was extracted from rat plasma using protein precipitation with acetone. Prior to LC-ESI/MS/MS analysis, an aliquot of the supernatant was used to proceed to the derivatization of vanillin and the internal standard with Dansyl Chloride to enhance signal intensity in positive electrospray mode. The chromatography was performed on a 100 x 2.1 mm C8 column and an isocratic mobile phase composed of 75:25 acetonitrile:0.5% formic acid in water with a flow rate fixed at 500 microL/min. A linear (weighted 1/concentration) relationship was used to perform the calibration over an analytical range of 10-10,000 ng/mL. The intra-batch precision and accuracy at the limit of quantitation (10 ng/mL), medium (500 ng/mL) and high (10,000 ng/mL) concentrations were 10.7, 7.0 and 7.2% and 103.5, 108.0 and 100.1%, respectively. The observed recovery was greater than 87% and no significant ionization suppression or matrix effect was observed. This LC-ESI/MS/MS method for the determination of vanillin in rat plasma provided results within generally accepted criteria used for bioanalytical assay.
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determination of eugenol in rat plasma by liquid chromatography quadrupole ion trap mass spectrometry using a simple off line Dansyl Chloride derivatization reaction to enhance signal intensity
Biomedical Chromatography, 2006Co-Authors: Francis Beaudry, Sarah Annie Guenette, Pascal VachonAbstract:A rapid, selective and sensitive method was developed for the determination of eugenol concentration using an off-line Dansyl Chloride derivatization step to enhance signal intensity. The method consisted of a protein precipitation extraction followed by derivatization with Dansyl Chloride and analysis by full scan liquid chromatography electrospray quadrupole ion trap mass spectrometry (LC-ESI-QIT). The separation was achieved using a 100 x 2 mm C(8) analytical column combined with an isocratic mobile phase composed of 75:25 acetonitrile: 0.1% formic acid in water set at a flow rate of 0.25 mL/min. Signal intensity of the eugenol-Dansyl Chloride derivative was increased up to 100-fold as compared with the underivatized eugenol in positive electrospray mode. An analytical range of 100-20,000 ng/mL was used in the calibration curve of plasma and blood samples. The LOD observed was 0.5 pg injected on column. The novel method met all requirements of specificity, sensitivity, linearity, precision, accuracy and stability. In conclusion, a rapid and sensitive LC-ESI/MS/MS method using a derivatization agent was developed to enhance signal intensity of eugenol.
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development of a rapid and sensitive lc esi ms ms assay for the quantification of propofol using a simple off line Dansyl Chloride derivatization reaction to enhance signal intensity
Journal of Pharmaceutical and Biomedical Analysis, 2005Co-Authors: Francis Beaudry, Sarah Annie Guenette, Andrew Winterborn, Jeanfrancois Marier, Pascal VachonAbstract:Abstract A rapid, selective and sensitive method was developed for the determination of propofol concentration using an off-line Dansyl Chloride derivatization step to enhance signal intensity. The method consisted of a protein precipitation extraction followed by derivatization with Dansyl Chloride and analysis by liquid chromatography ionspray tandem mass spectrometry (LC–ESI/MS/MS). The separation was achieved using a 100 mm × 2 mm C 8 analytical column combined with an isocratic mobile phase composed of 80:20 acetonitrile: 0.5%formic acid in water. Signal intensity of the propofol-Dansyl Chloride derivative was increased up to 200-fold as compared to the underivatized propofol in positive electrospray mode. An analytical range of 20–20,000 ng/mL was used in the calibration curve of plasma and blood samples. The novel method met all requirements of specificity, sensitivity, linearity, precision, accuracy and stability. A pharmacokinetic study was performed in rats and the novel analytical method was used as a routine analysis to provide enhanced measurements of plasma and blood concentrations of propofol. Blood and plasma pharmacokinetic results show that a very important fraction of propofol distributes into red blood cells. In conclusion, a rapid and sensitive LC–ESI/MS/MS method using a derivatization agent was developed to enhance signal intensity of propofol. Routine analysis with the novel method provided accurate results and enhanced the detection levels of plasma and blood concentrations of propofol to better characterize the in vivo biodiposition of propofol.
G J De Jong - One of the best experts on this subject based on the ideXlab platform.
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sensitive liquid chromatographic determination of alkyl nitro and chlorophenols by precolumn derivatization with Dansyl Chloride postcolumn photolysis and peroxyoxalate chemiluminescence detection
Journal of Chromatography A, 1991Co-Authors: P J M Kwakman, D A Kamminga, U Th A Brinkman, G J De JongAbstract:Abstract A liquid chromatographic method is described for the determination of alkyl-, nitro- and chlorophenols at sub-ppb levels using a very sensitive and selective detection system. The phenols are labelled by two-phase Dansylation. The deprotonated phenolic anions are extracted as tetrabutylammonium ion pairs into an organic phase in which Dansyl Chloride is dissolved. After derivatization, the excess of reagent is removed on an amino-bonded column; Dansyl Chloride reacts with the amino groups whereas the phenol derivatives are not retained. Chromatography is carried out with a methanol-water gradient followed by photolysis of the derivatives. The strongly quenching electronegative nitro- and chlorophenol groups are photochemically removed from the derivative and the products, Dansyl hydroxide and Dansyl methoxide, are sensitively detected by peroxyoxalate chemiluminescence. Chemical excitation is carried out by adding 2-nitrophenyl oxalate and hydrogen peroxide dissolved in acetonitrile to the column eluate. Detection limits of about 0.01–0.1 ng/ml have been achieved and the method has been applied to the determination of several phenolic compounds in surface water.
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liquid chromatographic determination of oestradiol in serum by pre column derivatization with Dansyl Chloride or laryl Chloride and peroxyoxalate chemiluminescence detection
Journal of Pharmaceutical and Biomedical Analysis, 1991Co-Authors: P J M Kwakman, D A Kamminga, U Th A Brinkman, G J De JongAbstract:Abstract Column liquid chromatography with chemiluminescence detection is used to determine oestradiol in serum. Oestradiol is labelled by means of a two-phase derivatization procedure with either Dansyl Chloride or laryl Chloride. After derivatization the excess reagent is removed on a short amino-bonded column: the sulphonyl Chloride functional group reacts with the amino groups causing removal of the label; the oestradiol derivatives are not retained. Chromatography of oestradiol derivatives is performed with methanol—water mixtures as eluent. Chemical excitation is carried out by adding bis(2-nitrophenyl)oxalate and hydrogen peroxide dissolved in acetonitrile to the column eluate. Linearity is observed ( r = 0.9998; n = 7) over at least three decades (10 −6 -10 −9 M) for both Dansyl Chloride and laryl Chloride. A detection limit of 5 × 10 −10 M (50 fmol injected) has been achieved and the Dansyl derivatization method has been applied to the determination of oestradiol in spiked serum.
Cuicui Guo - One of the best experts on this subject based on the ideXlab platform.
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the dose effect of Dansyl Chloride on the derivative products of bisphenols and its application for the determination of bisphenols in human serum by high performance liquid chromatography tandem mass spectrometry
Journal of Separation Science, 2021Co-Authors: Cuicui Guo, Xueqin Zhao, Jing Jin, Longxing Wang, Dongqin Tan, Jiping ChenAbstract:Human exposure to bisphenols has rarely been reported. The most important challenges in this regard are the sensitivity and accuracy of the analytical methods employed. Dansyl Chloride derivatization prior to high-performance liquid chromatography-tandem mass spectrometry has been prevalently employed to improve sensitivity. However, the dose effect of the derivatization reagent on the reaction products is not well understood, especially for reactants with two or more active groups. This study investigated the mass ratio of Dansyl Chloride to bisphenols and found the mass ratio played a vital role in changing the composition of derivatives; further, the optimal ratio for obtaining di-substituted derivatives was confirmed. Under optimal conditions, solid-phase extraction followed by Dansyl Chloride derivatization coupled with high-performance liquid chromatography-tandem mass spectrometry was used to detect eight bisphenols in human serum samples. The method detection limits of the eight bisphenols were 0.025-0.28 ng/mL, and the recoveries were 72.9-121.7% by spiking bisphenols (2, 5, and 20 ng/mL) into bovine serum. The detection frequencies of bisphenol A and bisphenol F in 73 serum samples obtained from children from Guangzhou were 41.1% and 71.2%, respectively, while the detection frequencies of other bisphenols were below 20%. The concentrations of bisphenol A and bisphenol F were < 0.28-8.0 ng/mL and < 0.028-7.6 ng/mL, respectively.
Francis Beaudry - One of the best experts on this subject based on the ideXlab platform.
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development of a lc esi ms ms assay for the quantification of vanillin using a simple off line Dansyl Chloride derivatization reaction to enhance signal intensity
Biomedical Chromatography, 2007Co-Authors: Francis Beaudry, Andreanne Ross, Pascal VachonAbstract:Vanillin is responsible for producing the familiar smell of vanilla. Vanillin has many similarities with other flavor phenolic compounds and could potentially show similar pharmacological activity. A previously published analytical method was adapted, developed and tested. Vanillin was extracted from rat plasma using protein precipitation with acetone. Prior to LC-ESI/MS/MS analysis, an aliquot of the supernatant was used to proceed to the derivatization of vanillin and the internal standard with Dansyl Chloride to enhance signal intensity in positive electrospray mode. The chromatography was performed on a 100 x 2.1 mm C8 column and an isocratic mobile phase composed of 75:25 acetonitrile:0.5% formic acid in water with a flow rate fixed at 500 microL/min. A linear (weighted 1/concentration) relationship was used to perform the calibration over an analytical range of 10-10,000 ng/mL. The intra-batch precision and accuracy at the limit of quantitation (10 ng/mL), medium (500 ng/mL) and high (10,000 ng/mL) concentrations were 10.7, 7.0 and 7.2% and 103.5, 108.0 and 100.1%, respectively. The observed recovery was greater than 87% and no significant ionization suppression or matrix effect was observed. This LC-ESI/MS/MS method for the determination of vanillin in rat plasma provided results within generally accepted criteria used for bioanalytical assay.
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determination of eugenol in rat plasma by liquid chromatography quadrupole ion trap mass spectrometry using a simple off line Dansyl Chloride derivatization reaction to enhance signal intensity
Biomedical Chromatography, 2006Co-Authors: Francis Beaudry, Sarah Annie Guenette, Pascal VachonAbstract:A rapid, selective and sensitive method was developed for the determination of eugenol concentration using an off-line Dansyl Chloride derivatization step to enhance signal intensity. The method consisted of a protein precipitation extraction followed by derivatization with Dansyl Chloride and analysis by full scan liquid chromatography electrospray quadrupole ion trap mass spectrometry (LC-ESI-QIT). The separation was achieved using a 100 x 2 mm C(8) analytical column combined with an isocratic mobile phase composed of 75:25 acetonitrile: 0.1% formic acid in water set at a flow rate of 0.25 mL/min. Signal intensity of the eugenol-Dansyl Chloride derivative was increased up to 100-fold as compared with the underivatized eugenol in positive electrospray mode. An analytical range of 100-20,000 ng/mL was used in the calibration curve of plasma and blood samples. The LOD observed was 0.5 pg injected on column. The novel method met all requirements of specificity, sensitivity, linearity, precision, accuracy and stability. In conclusion, a rapid and sensitive LC-ESI/MS/MS method using a derivatization agent was developed to enhance signal intensity of eugenol.
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development of a rapid and sensitive lc esi ms ms assay for the quantification of propofol using a simple off line Dansyl Chloride derivatization reaction to enhance signal intensity
Journal of Pharmaceutical and Biomedical Analysis, 2005Co-Authors: Francis Beaudry, Sarah Annie Guenette, Andrew Winterborn, Jeanfrancois Marier, Pascal VachonAbstract:Abstract A rapid, selective and sensitive method was developed for the determination of propofol concentration using an off-line Dansyl Chloride derivatization step to enhance signal intensity. The method consisted of a protein precipitation extraction followed by derivatization with Dansyl Chloride and analysis by liquid chromatography ionspray tandem mass spectrometry (LC–ESI/MS/MS). The separation was achieved using a 100 mm × 2 mm C 8 analytical column combined with an isocratic mobile phase composed of 80:20 acetonitrile: 0.5%formic acid in water. Signal intensity of the propofol-Dansyl Chloride derivative was increased up to 200-fold as compared to the underivatized propofol in positive electrospray mode. An analytical range of 20–20,000 ng/mL was used in the calibration curve of plasma and blood samples. The novel method met all requirements of specificity, sensitivity, linearity, precision, accuracy and stability. A pharmacokinetic study was performed in rats and the novel analytical method was used as a routine analysis to provide enhanced measurements of plasma and blood concentrations of propofol. Blood and plasma pharmacokinetic results show that a very important fraction of propofol distributes into red blood cells. In conclusion, a rapid and sensitive LC–ESI/MS/MS method using a derivatization agent was developed to enhance signal intensity of propofol. Routine analysis with the novel method provided accurate results and enhanced the detection levels of plasma and blood concentrations of propofol to better characterize the in vivo biodiposition of propofol.
Jiping Chen - One of the best experts on this subject based on the ideXlab platform.
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the dose effect of Dansyl Chloride on the derivative products of bisphenols and its application for the determination of bisphenols in human serum by high performance liquid chromatography tandem mass spectrometry
Journal of Separation Science, 2021Co-Authors: Cuicui Guo, Xueqin Zhao, Jing Jin, Longxing Wang, Dongqin Tan, Jiping ChenAbstract:Human exposure to bisphenols has rarely been reported. The most important challenges in this regard are the sensitivity and accuracy of the analytical methods employed. Dansyl Chloride derivatization prior to high-performance liquid chromatography-tandem mass spectrometry has been prevalently employed to improve sensitivity. However, the dose effect of the derivatization reagent on the reaction products is not well understood, especially for reactants with two or more active groups. This study investigated the mass ratio of Dansyl Chloride to bisphenols and found the mass ratio played a vital role in changing the composition of derivatives; further, the optimal ratio for obtaining di-substituted derivatives was confirmed. Under optimal conditions, solid-phase extraction followed by Dansyl Chloride derivatization coupled with high-performance liquid chromatography-tandem mass spectrometry was used to detect eight bisphenols in human serum samples. The method detection limits of the eight bisphenols were 0.025-0.28 ng/mL, and the recoveries were 72.9-121.7% by spiking bisphenols (2, 5, and 20 ng/mL) into bovine serum. The detection frequencies of bisphenol A and bisphenol F in 73 serum samples obtained from children from Guangzhou were 41.1% and 71.2%, respectively, while the detection frequencies of other bisphenols were below 20%. The concentrations of bisphenol A and bisphenol F were < 0.28-8.0 ng/mL and < 0.028-7.6 ng/mL, respectively.
