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Determination of trichothecenes A (T-2 toxin, HT-2 toxin, and diacetoxyscirpenol) in the tissues of broilers using liquid chromatography coupled to tandem mass spectrometry
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Lingchen Yang , Zhiyong Zhao , Aibo Wu , Yifeng Deng , Zhenlei Zhou , Jianpeng Zhang , Jiafa Hou
A stable and sensitive method has been developed for use in food and livestock product safety for the detection of mycotoxins. This newly developed method allows for the determination of T-2 toxin, HT-2 toxin and diacetoxyscirpenol (DAS) in heart, liver, spleen, lung, kidney, Glandular stomach, muscular stomach, small intestine, muscle, bone and brain samples from broilers using liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). The samples were initially extracted with ethyl acetate before being filtered through a 0.22μm nylon syringe filter and subjected to chromatographic separation on a reversed-phase C18 (50×2.1mm, 3μm) column. A mobile phase composed of 0.1% acetic acid and 10mM ammonium acetate in methanol and water was used in an assay of the levels of T-2 toxin, HT-2 toxin and DAS. For the analysis of the target compounds, the mass spectrometer was operated under positive electrospray ionization conditions in the selected reaction monitoring mode. The limit of detection was in the range of 0.02–0.05ng/g, whereas the limit of quantification was in the range of 0.08–0.15ng/g. The extraction recoveries of spiked samples from the high, intermediate and low levels ranged from 58.5% to 110.5%, and the relative standard deviation (RSD (%)) values were less than 17.0%. The results of inter- and intra-day precision (RSD (%)) were within 14.7%. The results revealed that the present method could be successfully applied to the analysis of T-2 toxin, HT-2 toxin and DAS in the real samples
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Lingchen Yang , Zhiyong Zhao , Aibo Wu , Yifeng Deng , Zhenlei Zhou , Jianpeng Zhang , Jiafa Hou
A stable and sensitive method has been developed for use in food and livestock product safety for the detection of mycotoxins. This newly developed method allows for the determination of T-2 toxin, HT-2 toxin and diacetoxyscirpenol (DAS) in heart, liver, spleen, lung, kidney, Glandular stomach, muscular stomach, small intestine, muscle, bone and brain samples from broilers using liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). The samples were initially extracted with ethyl acetate before being filtered through a 0.22μm nylon syringe filter and subjected to chromatographic separation on a reversed-phase C18 (50×2.1mm, 3μm) column. A mobile phase composed of 0.1% acetic acid and 10mM ammonium acetate in methanol and water was used in an assay of the levels of T-2 toxin, HT-2 toxin and DAS. For the analysis of the target compounds, the mass spectrometer was operated under positive electrospray ionization conditions in the selected reaction monitoring mode. The limit of detection was in the range of 0.02–0.05ng/g, whereas the limit of quantification was in the range of 0.08–0.15ng/g. The extraction recoveries of spiked samples from the high, intermediate and low levels ranged from 58.5% to 110.5%, and the relative standard deviation (RSD (%)) values were less than 17.0%. The results of inter- and intra-day precision (RSD (%)) were within 14.7%. The results revealed that the present method could be successfully applied to the analysis of T-2 toxin, HT-2 toxin and DAS in the real samples
Pharmacokinetics, tissue distribution and excretion study of dictamnine, a major bioactive component from the root bark of Dictamnus dasycarpus Turcz. (Rutaceae)
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Pei Wang , Jianbo Sun , Jingyao Xu , Qin Yan , Enze Gao , Wei Qu , Yunli Zhao , Zhiguo Yu
Dictamnine is an herbal ingredient isolated from the root bark of Dictamnus dasycarpus Turcz. (Rutaceae). The present study was aimed at the development of an ultra-high performance liquid chromatography–tandem mass spectrometry method to quantify the concentration of dictamnine in rat plasma and tissues for the in vivo pharmacokinetics, tissue distribution and excretion study. Biological samples were processed with protein precipitation. Skimmianine was chosen as internal standard. The chromatographic separation was carried out on a Thermo Syncronis C18 column (2.1mm×50mm, 1.7μm) with an isocratic mobile phase consisting of methanol and 0.1% formic acid water (75:25, v/v). The detection was accomplished by using positive ion electrospray ionization in multiple reaction monitoring (MRM) mode. The MS/MS ion transitions were monitored at m/z 200.0→129.0 for dictamnine and 260.3→227.1 for IS, respectively. An excellent linearity was observed over the concentration range from 0.5 to 250ng/mL. The lower limit of quantification (LLOQ) was 0.5ng/mL for dictamnine. The developed method was rapid, accurate, and highly sensitive and selective. It was successfully applied to the in vivo pharmacokinetics, tissue distribution and excretion study of dictamnine in rats after oral or intravenous administration of dictamnine.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Pei Wang , Jianbo Sun , Jingyao Xu , Qin Yan , Enze Gao , Wei Qu , Yunli Zhao , Zhiguo Yu
Dictamnine is an herbal ingredient isolated from the root bark of Dictamnus dasycarpus Turcz. (Rutaceae). The present study was aimed at the development of an ultra-high performance liquid chromatography–tandem mass spectrometry method to quantify the concentration of dictamnine in rat plasma and tissues for the in vivo pharmacokinetics, tissue distribution and excretion study. Biological samples were processed with protein precipitation. Skimmianine was chosen as internal standard. The chromatographic separation was carried out on a Thermo Syncronis C18 column (2.1mm×50mm, 1.7μm) with an isocratic mobile phase consisting of methanol and 0.1% formic acid water (75:25, v/v). The detection was accomplished by using positive ion electrospray ionization in multiple reaction monitoring (MRM) mode. The MS/MS ion transitions were monitored at m/z 200.0→129.0 for dictamnine and 260.3→227.1 for IS, respectively. An excellent linearity was observed over the concentration range from 0.5 to 250ng/mL. The lower limit of quantification (LLOQ) was 0.5ng/mL for dictamnine. The developed method was rapid, accurate, and highly sensitive and selective. It was successfully applied to the in vivo pharmacokinetics, tissue distribution and excretion study of dictamnine in rats after oral or intravenous administration of dictamnine.
Novel superparamagnetic sanoparticles for trypsin immobilization and the application for efficient proteolysis
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Jun Sun , Kunya Hu , Yuntao Liu , Yuting Pan , Yanjun Yang
Immobilization of trypsin onto the superparamagnetic carboxymethyl chitosan (Fe3O4 (PEG+CM-CTS)) nanoparticles was studied. FTIR and fluorescence spectroscopy data demonstrated that the Fe3O4 (PEG+CM-CTS) nanoparticles were capable of preventing the trypsin unfolding. Due to the large specific surface area and excellent dispersibility, the adsorption equilibrium of trypsin onto the nanoparticles was achieved quickly within 30min. The results of kinetic parameters (Michaelis constant, Km) with regards to the free trypsin (FT) and immobilized trypsin (IT) were 23.1 and 24.1mg/mL separately, implying that IT has less affinity to the BAEE used as the substrate. However, the MALDI-TOF MS analysis indicated that, IT could be used for fast and efficient Bovine Serum Albumin (BSA) digestion under very facile processes, thanks to the easy manipulation of the magnetic nanoparticles (MNs), as well as the greatly reduced digestion time (from 12h to 15min). IT exhibited a sound stability after re-uses for six times, with 76.3% of the initial activity thereof still retained, thus making it more attractive in the application fields. These results are expected to open up a great potential use of such Fe3O4 (PEG+CM-CTS) nanoparticles as a superior nanosupport for trypsin immobilization.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Jun Sun , Kunya Hu , Yuntao Liu , Yuting Pan , Yanjun Yang
Immobilization of trypsin onto the superparamagnetic carboxymethyl chitosan (Fe3O4 (PEG+CM-CTS)) nanoparticles was studied. FTIR and fluorescence spectroscopy data demonstrated that the Fe3O4 (PEG+CM-CTS) nanoparticles were capable of preventing the trypsin unfolding. Due to the large specific surface area and excellent dispersibility, the adsorption equilibrium of trypsin onto the nanoparticles was achieved quickly within 30min. The results of kinetic parameters (Michaelis constant, Km) with regards to the free trypsin (FT) and immobilized trypsin (IT) were 23.1 and 24.1mg/mL separately, implying that IT has less affinity to the BAEE used as the substrate. However, the MALDI-TOF MS analysis indicated that, IT could be used for fast and efficient Bovine Serum Albumin (BSA) digestion under very facile processes, thanks to the easy manipulation of the magnetic nanoparticles (MNs), as well as the greatly reduced digestion time (from 12h to 15min). IT exhibited a sound stability after re-uses for six times, with 76.3% of the initial activity thereof still retained, thus making it more attractive in the application fields. These results are expected to open up a great potential use of such Fe3O4 (PEG+CM-CTS) nanoparticles as a superior nanosupport for trypsin immobilization.
Simple segmental hair analysis for α-pyrrolidinophenone-type designer drugs by MonoSpin extraction for evaluation of abuse history
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Akira Namera , Kyohei Konuma , Takeshi Saito , Shigenori Ota , Hiroshi Oikawa , Shota Miyazaki , Shumari Urabe , Hiroaki Shiraishi , Masataka Nagao
For detection of a history of drug abused, we developed a simple method for extracting pyrrolidinophenone-type designer drugs in human hair by using a MonoSpin® C18 column. Target drugs were extracted from a single alkaline-digested hair segment (length, 10mm; weight, ca 0.1mg). The analytes extracted were then analyzed by high-performance liquid chromatography–mass spectrometry without evaporation of the eluent after MonoSpin extraction. Linearity from 0.5 to 500ng/mg was observed for all the tested drugs using an internal standard method (correlation coefficients >0.998) and the limit of detection was 0.2ng/mg. The recoveries were between 0.7 and 11.1%. The coefficients for intraday and interday variations at 4, 40, 200, and 400ng/mg in hair were between 0.7 and 11.1%. This method was successfully applied to the identification of these designer drugs in segmented human hair from drug abusers and indicated their history of drug abuse. The results were consistent with the patients’ statements, indicating that this rapid method can be used to detect a history of drug abuse.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Akira Namera , Kyohei Konuma , Takeshi Saito , Shigenori Ota , Hiroshi Oikawa , Shota Miyazaki , Shumari Urabe , Hiroaki Shiraishi , Masataka Nagao
For detection of a history of drug abused, we developed a simple method for extracting pyrrolidinophenone-type designer drugs in human hair by using a MonoSpin® C18 column. Target drugs were extracted from a single alkaline-digested hair segment (length, 10mm; weight, ca 0.1mg). The analytes extracted were then analyzed by high-performance liquid chromatography–mass spectrometry without evaporation of the eluent after MonoSpin extraction. Linearity from 0.5 to 500ng/mg was observed for all the tested drugs using an internal standard method (correlation coefficients >0.998) and the limit of detection was 0.2ng/mg. The recoveries were between 0.7 and 11.1%. The coefficients for intraday and interday variations at 4, 40, 200, and 400ng/mg in hair were between 0.7 and 11.1%. This method was successfully applied to the identification of these designer drugs in segmented human hair from drug abusers and indicated their history of drug abuse. The results were consistent with the patients’ statements, indicating that this rapid method can be used to detect a history of drug abuse.
Capillary electrophoresis–mass spectrometry for direct determination of urinary modified nucleosides. Evaluation of synthetic urine as a surrogate matrix for quantitative analysis
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Encarnación Rodríguez-Gonzalo , Raquel Hernández-Prieto , Diego García-Gómez , Rita Carabias-Martínez
This work describes the development of a fast and reliable method based on capillary zone electrophoresis coupled with electrospray ionization–mass spectrometry (CZE–ESI–MS) for the determination of modified nucleosides in untreated human urine. The target compounds were guanine, 1-methyl-guanine, 7-methyl-guanine, 9-methyl-guanine, adenosine, 1-methyl-adenosine, cytidine, guanosine, 7-methyl-guanosine. As internal standards, ribose-2-13C-adenosine and 8-13C-guanine were used. The CZE separation was carried out in acidic medium (pH 2.5). MS detection with a single quadrupole, with ESI operating in positive-ion mode, was optimized. For the analysis of urine samples, owing to the endogenous character of these analytes different quantification strategies were explored. The standard additions method, matrix-matched calibration in synthetic urine and calibration in pure aqueous medium were compared in order to evaluate the endogenous levels of these compounds in human urine. The results obtained showed that calibration in synthetic urine as a surrogate matrix was an appropriate alternative to the method of standard additions for the accurate quantitation of compounds such as guanine, 1-methyl-guanine, 7-methyl-guanine, adenosine, 1-methyl-adenosine and cytidine by CE–ESI–MS directly in the urine matrix; values in the range 0.1μg/mL for cytidine and 6.4μg/mL for 7mGua, as the lowest and the highest level, were found in untreated urine from healthy volunteers. These results were confirmed by LC–MS/MS detection. It can be concluded that the electrophoretic CZE–ESI–MS methodology offers a valid and reliable alternative for the determination of urinary nucleosides at naturally occurring levels in healthy individuals.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Encarnación Rodríguez-Gonzalo , Raquel Hernández-Prieto , Diego García-Gómez , Rita Carabias-Martínez
This work describes the development of a fast and reliable method based on capillary zone electrophoresis coupled with electrospray ionization–mass spectrometry (CZE–ESI–MS) for the determination of modified nucleosides in untreated human urine. The target compounds were guanine, 1-methyl-guanine, 7-methyl-guanine, 9-methyl-guanine, adenosine, 1-methyl-adenosine, cytidine, guanosine, 7-methyl-guanosine. As internal standards, ribose-2-13C-adenosine and 8-13C-guanine were used. The CZE separation was carried out in acidic medium (pH 2.5). MS detection with a single quadrupole, with ESI operating in positive-ion mode, was optimized. For the analysis of urine samples, owing to the endogenous character of these analytes different quantification strategies were explored. The standard additions method, matrix-matched calibration in synthetic urine and calibration in pure aqueous medium were compared in order to evaluate the endogenous levels of these compounds in human urine. The results obtained showed that calibration in synthetic urine as a surrogate matrix was an appropriate alternative to the method of standard additions for the accurate quantitation of compounds such as guanine, 1-methyl-guanine, 7-methyl-guanine, adenosine, 1-methyl-adenosine and cytidine by CE–ESI–MS directly in the urine matrix; values in the range 0.1μg/mL for cytidine and 6.4μg/mL for 7mGua, as the lowest and the highest level, were found in untreated urine from healthy volunteers. These results were confirmed by LC–MS/MS detection. It can be concluded that the electrophoretic CZE–ESI–MS methodology offers a valid and reliable alternative for the determination of urinary nucleosides at naturally occurring levels in healthy individuals.
A simple sample preparation approach based on hydrophilic solid-phase extraction coupled with liquid chromatography–tandem mass spectrometry for determination of endogenous cytokinins
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Bao-Dong Cai , Jiu-Xia Zhu , Zhi-Guo Shi , Bi-Feng Yuan , Yu-Qi Feng
Cytokinins (CKs), a vital family of phytohormones, play important roles in the regulation of shoot and root development. However, the quantification of CKs in plant samples is frequently affected by the complex plant matrix. In the current study, we developed a simple, rapid and efficient hydrophilic interaction chromatography-solid phase extraction (HILIC–SPE) method for CKs purification. CKs were extracted by acetonitrile (ACN) followed by HILIC–SPE (silica as sorbents) purification. The extraction solution of plant samples could be directly applied to HILIC–SPE without solvent evaporation step, which simplified the analysis process. Moreover, with HILIC chromatographic retention mechanism, the hydrophobic co-extracted impurities were efficiently removed. Subsequently, CKs were separated by RPLC, orthogonal to the HILIC pretreatment process, and detected by tandem mass spectrometry. The method exhibits high specificity and recovery yield (>77.0%). Good linearities were obtained for all eight CKs ranging from 0.002 to 100ngmL−1 with correlation coefficients (r) higher than 0.9927. The limits of detection (LODs, signal/noise=5) for the CKs were between 1.0 and 12.4pgmL−1. Reproducibility of the method was evaluated by intra-day and inter-day measurements and the results showed that relative standard deviations (RSDs) were less than 10.5%. Employing this method, we successfully quantified six CKs in 20mg Oryza sativa leaves and the method was also successfully applied to Brassica napus (flower and leaves).
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Bao-Dong Cai , Jiu-Xia Zhu , Zhi-Guo Shi , Bi-Feng Yuan , Yu-Qi Feng
Cytokinins (CKs), a vital family of phytohormones, play important roles in the regulation of shoot and root development. However, the quantification of CKs in plant samples is frequently affected by the complex plant matrix. In the current study, we developed a simple, rapid and efficient hydrophilic interaction chromatography-solid phase extraction (HILIC–SPE) method for CKs purification. CKs were extracted by acetonitrile (ACN) followed by HILIC–SPE (silica as sorbents) purification. The extraction solution of plant samples could be directly applied to HILIC–SPE without solvent evaporation step, which simplified the analysis process. Moreover, with HILIC chromatographic retention mechanism, the hydrophobic co-extracted impurities were efficiently removed. Subsequently, CKs were separated by RPLC, orthogonal to the HILIC pretreatment process, and detected by tandem mass spectrometry. The method exhibits high specificity and recovery yield (>77.0%). Good linearities were obtained for all eight CKs ranging from 0.002 to 100ngmL−1 with correlation coefficients (r) higher than 0.9927. The limits of detection (LODs, signal/noise=5) for the CKs were between 1.0 and 12.4pgmL−1. Reproducibility of the method was evaluated by intra-day and inter-day measurements and the results showed that relative standard deviations (RSDs) were less than 10.5%. Employing this method, we successfully quantified six CKs in 20mg Oryza sativa leaves and the method was also successfully applied to Brassica napus (flower and leaves).
Activity-guided identification of acetogenins as novel lipophilic antioxidants present in avocado pulp (Persea americana)
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Dariana Rodríguez-Sánchez , Christian Silva-Platas , Rocío P. Rojo , Noemí García , Luis Cisneros-Zevallos , Gerardo García-Rivas , Carmen Hernández-Brenes
Avocado fruit is a rich source of health-related lipophilic phytochemicals such as monounsaturated fatty acids, tocopherols, carotenes, acetogenins and sterols. However, limited information is available on the contribution of specific phytochemicals to the overall antioxidant capacity (AOC) of the fruit. Centrifugal partition chromatography was used as fractionation tool, guided by an in vitro chemical assay of oxygen radical absorbance capacity (ORAC). Subsequent experiments focused on isolation and characterization of the chemical nature of the main contributors to lipophilic AOC of avocado pulp. ORAC values obtained for acetogenins were contrasted with results from an isolated kidney mitochondria membrane lipid peroxidation bioassay. The present study established that lipophilic AOC of the pulp was significantly higher than its hydrophilic AOC. Our results confirmed the presence of acetogenins in the fractions with highest lipophilic AOC, and for the first time linked them as contributors to lipophilic-ORAC values. Further HPLC-PDA/MS-TOF analysis led to structural elucidation of two novel acetogenins, not previously reported as present in avocado pulp, along with five already known related-compounds. Antioxidant properties observed for avocado pulp acetogenins by the ORAC assay suggested that, in the presence of an emulsifying agent, acetogenins could serve as novel lipophilic antioxidants in a food matrix. Results from isolated mitochondria lipid peroxidation bioassay, indicated that L-ORAC values which may have relevance for food matrix applications, should not be interpreted to have a direct relevance in health-related claims, compounds need to be evaluated considering the complexity of biological systems.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Dariana Rodríguez-Sánchez , Christian Silva-Platas , Rocío P. Rojo , Noemí García , Luis Cisneros-Zevallos , Gerardo García-Rivas , Carmen Hernández-Brenes
Avocado fruit is a rich source of health-related lipophilic phytochemicals such as monounsaturated fatty acids, tocopherols, carotenes, acetogenins and sterols. However, limited information is available on the contribution of specific phytochemicals to the overall antioxidant capacity (AOC) of the fruit. Centrifugal partition chromatography was used as fractionation tool, guided by an in vitro chemical assay of oxygen radical absorbance capacity (ORAC). Subsequent experiments focused on isolation and characterization of the chemical nature of the main contributors to lipophilic AOC of avocado pulp. ORAC values obtained for acetogenins were contrasted with results from an isolated kidney mitochondria membrane lipid peroxidation bioassay. The present study established that lipophilic AOC of the pulp was significantly higher than its hydrophilic AOC. Our results confirmed the presence of acetogenins in the fractions with highest lipophilic AOC, and for the first time linked them as contributors to lipophilic-ORAC values. Further HPLC-PDA/MS-TOF analysis led to structural elucidation of two novel acetogenins, not previously reported as present in avocado pulp, along with five already known related-compounds. Antioxidant properties observed for avocado pulp acetogenins by the ORAC assay suggested that, in the presence of an emulsifying agent, acetogenins could serve as novel lipophilic antioxidants in a food matrix. Results from isolated mitochondria lipid peroxidation bioassay, indicated that L-ORAC values which may have relevance for food matrix applications, should not be interpreted to have a direct relevance in health-related claims, compounds need to be evaluated considering the complexity of biological systems.
Simultaneous determination of eight illegal dyes in chili products by liquid chromatography–tandem mass spectrometry
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Juan Li , Xiao-Ming Ding , Dan-Dan Liu , Fei Guo , Yu Chen , Yan-Bing Zhang , Hong-Min Liu
A sensitive and accurate method based on the use of liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed for the simultaneous determination of eight illegal synthetic dyes (Sudan (I–IV), Para Red, Rhodamine B, Chrysoidin and Auramine O) in chili products. A simple sample treatment procedure entailing the use of an extraction step with acetonitrile/H2O (9/1) without further cleanup was developed. HPLC was performed on a C18 column using a multistep gradient elution with 5mM ammonium acetate (pH 3.0 with formic acid) and methanol as the mobile phase. Mass spectral acquisition was done in multiple reaction monitoring (MRM) mode using positive electrospray ionization (ESI). Linear calibrations were obtained with correlation coefficients R 2 >0.99. Limit of detection (LOD) and limit of quantification (LOQ) for the studied dyes were in the ranges of 0.05–0.6μgkg−1 and 0.3–3.0μgkg−1 depending on matrices, respectively. The recoveries of the eight synthetic dyes in five matrices ranged from 70.5% to 119.2%. The intra- and inter-day precisions (RSDs) were between 2.3–15.8% and 5.7–15.6%, respectively. The applicability of the method to the determination of eight banned dyes in chili products was demonstrated.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Juan Li , Xiao-Ming Ding , Dan-Dan Liu , Fei Guo , Yu Chen , Yan-Bing Zhang , Hong-Min Liu
A sensitive and accurate method based on the use of liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed for the simultaneous determination of eight illegal synthetic dyes (Sudan (I–IV), Para Red, Rhodamine B, Chrysoidin and Auramine O) in chili products. A simple sample treatment procedure entailing the use of an extraction step with acetonitrile/H2O (9/1) without further cleanup was developed. HPLC was performed on a C18 column using a multistep gradient elution with 5mM ammonium acetate (pH 3.0 with formic acid) and methanol as the mobile phase. Mass spectral acquisition was done in multiple reaction monitoring (MRM) mode using positive electrospray ionization (ESI). Linear calibrations were obtained with correlation coefficients R 2 >0.99. Limit of detection (LOD) and limit of quantification (LOQ) for the studied dyes were in the ranges of 0.05–0.6μgkg−1 and 0.3–3.0μgkg−1 depending on matrices, respectively. The recoveries of the eight synthetic dyes in five matrices ranged from 70.5% to 119.2%. The intra- and inter-day precisions (RSDs) were between 2.3–15.8% and 5.7–15.6%, respectively. The applicability of the method to the determination of eight banned dyes in chili products was demonstrated.
The profile of bile acids and their sulfate metabolites in human urine and serum
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Sai Praneeth R. Bathena , Sandeep Mukherjee , Marco Olivera , Yazen Alnouti
The role of sulfation in ameliorating the hepatotoxicity of bile acids (BAs) in humans remains unknown due to the lack of proper analytical methods to quantify individual BAs and their sulfate metabolites in biological tissues and fluids. To this end, a simple and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated to characterize the detailed BA profile in human urine and serum. The limit of quantification was 1ng/mL and baseline separation of all analytes was achieved within in a run time of 32min. The method was validated over the dynamic range of 1–1000ng/mL. The LC–MS/MS method was more accurate, precise, and selective than the commercially available kits for the quantification of sulfated and unsulfated BAs, and the indirect quantification of individual sulfated BAs after solvolysis. The LC–MS/MS method was applied to characterize the BA profile in urine and serum of healthy subjects. Thirty three percent of serum BAs were sulfated, whereas 89% of urinary BAs existed in the sulfate form, indicating the role of sulfation in enhancing the urinary excretion of BAs. The percentage of sulfation of individual BAs increased with the decrease in the number of hydroxyl groups indicating the role of sulfation in the detoxification of the more hydrophobic and toxic BA species. Eighty percent of urinary BAs and 55% of serum BAs were present in the glycine-amidated form, whereas 8% of urinary BAs and 13% of serum BAs existed in the taurine-amidated form.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Sai Praneeth R. Bathena , Sandeep Mukherjee , Marco Olivera , Yazen Alnouti
The role of sulfation in ameliorating the hepatotoxicity of bile acids (BAs) in humans remains unknown due to the lack of proper analytical methods to quantify individual BAs and their sulfate metabolites in biological tissues and fluids. To this end, a simple and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated to characterize the detailed BA profile in human urine and serum. The limit of quantification was 1ng/mL and baseline separation of all analytes was achieved within in a run time of 32min. The method was validated over the dynamic range of 1–1000ng/mL. The LC–MS/MS method was more accurate, precise, and selective than the commercially available kits for the quantification of sulfated and unsulfated BAs, and the indirect quantification of individual sulfated BAs after solvolysis. The LC–MS/MS method was applied to characterize the BA profile in urine and serum of healthy subjects. Thirty three percent of serum BAs were sulfated, whereas 89% of urinary BAs existed in the sulfate form, indicating the role of sulfation in enhancing the urinary excretion of BAs. The percentage of sulfation of individual BAs increased with the decrease in the number of hydroxyl groups indicating the role of sulfation in the detoxification of the more hydrophobic and toxic BA species. Eighty percent of urinary BAs and 55% of serum BAs were present in the glycine-amidated form, whereas 8% of urinary BAs and 13% of serum BAs existed in the taurine-amidated form.
Simultaneous detection of 22 toxic plant alkaloids (aconitum alkaloids, solanaceous tropane alkaloids, sophora alkaloids, strychnos alkaloids and colchicine) in human urine and herbal samples using liquid chromatography–tandem mass spectrometry
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Sau Wah Ng , Chor Kwan Ching , Albert Yan Wo Chan , Tony Wing Lai Mak
A liquid chromatography–tandem mass spectrometry method for simultaneous detection of 22 toxic plant alkaloids, including aconitum alkaloids and their hydrolyzed products (aconitine, hypaconitine, mesaconitine, yunaconitine, crassicauline A, benzoylaconine, benzoylmesaconine, benzoylhypaconine, deacetylyunaconitine, deacetylcrassicauline A), solanaceous tropane alkaloids (atropine, anisodamine, scopolamine, anisodine), sophora alkaloids (matrine, sophoridine, oxymatrine, cytisine, N-methylcytisine), strychnos alkaloids (brucine, strychnine) and colchicine, in herbal and urine samples was developed and validated. Following sample preparation by liquid–liquid extraction, chromatographic separation was achieved on Eclipse XDB C8 column. Identification was based on two multiple reaction monitoring transitions and the relative ion intensity. Method selectivity was demonstrated. The limits of detection were 5ng/mL for all analytes, except 50ng/mL for cytisine. The herbal matrix effects ranged from 89% to 118%, whereas the urine matrix effects were between 91% and 109% for all analytes except cytisine (57%) and N-methylcytisine (67%). The urine extraction recovery ranged from 74% to 110% for all analytes, except cytisine (15%) and oxymatrine (30%). With the good extraction efficiency of the other major sophora alkaloids, the relatively low extraction recovery of the minor sophora alkaloids cytisine and oxymatrine did not affect identification of sophora alkaloids as a group. Carry-over was minimal at less than 0.1%. The method was successfully applied in analysis of 170 cases of suspected herbal poisoning, with aconitum alkaloids, sophora alkaloids, solanaceous tropane alkaloids, and strychnos alkaloids being detected in 53, 42, 18, and 6 cases, respectively.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Sau Wah Ng , Chor Kwan Ching , Albert Yan Wo Chan , Tony Wing Lai Mak
A liquid chromatography–tandem mass spectrometry method for simultaneous detection of 22 toxic plant alkaloids, including aconitum alkaloids and their hydrolyzed products (aconitine, hypaconitine, mesaconitine, yunaconitine, crassicauline A, benzoylaconine, benzoylmesaconine, benzoylhypaconine, deacetylyunaconitine, deacetylcrassicauline A), solanaceous tropane alkaloids (atropine, anisodamine, scopolamine, anisodine), sophora alkaloids (matrine, sophoridine, oxymatrine, cytisine, N-methylcytisine), strychnos alkaloids (brucine, strychnine) and colchicine, in herbal and urine samples was developed and validated. Following sample preparation by liquid–liquid extraction, chromatographic separation was achieved on Eclipse XDB C8 column. Identification was based on two multiple reaction monitoring transitions and the relative ion intensity. Method selectivity was demonstrated. The limits of detection were 5ng/mL for all analytes, except 50ng/mL for cytisine. The herbal matrix effects ranged from 89% to 118%, whereas the urine matrix effects were between 91% and 109% for all analytes except cytisine (57%) and N-methylcytisine (67%). The urine extraction recovery ranged from 74% to 110% for all analytes, except cytisine (15%) and oxymatrine (30%). With the good extraction efficiency of the other major sophora alkaloids, the relatively low extraction recovery of the minor sophora alkaloids cytisine and oxymatrine did not affect identification of sophora alkaloids as a group. Carry-over was minimal at less than 0.1%. The method was successfully applied in analysis of 170 cases of suspected herbal poisoning, with aconitum alkaloids, sophora alkaloids, solanaceous tropane alkaloids, and strychnos alkaloids being detected in 53, 42, 18, and 6 cases, respectively.
Preclinical pharmacokinetics, tissue distribution and excretion studies of a potential analgesics – corydaline using an ultra performance liquid chromatography–tandem mass spectrometry
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Jianfeng Wang , Lishuang Liang , Qiongyu Zhang , Xingang Li , Zhijian Fu
A rapid resolution ultra performance liquid chromatography (UPLC) coupled with electrospray ionization (ESI) mass spectrometry method was developed and validated for the quantitative analysis of corydaline in rats’ plasma and various tissues for pharmacokinetic, tissue distribution and excretion studies of corydaline. The analytes were separated on an Acquity UPLC BEH C18 column (2.1mm×100mm, 1.7μm) and detected with a triple quadrupole mass spectrometer using positive ion ESI in the multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 370.0→192.0 for corydaline and 354.1→188.0 for IS, respectively. Calibration curves (1/x 2 weighted) offered satisfactory linearity (r 2 >0.9984) within 1–1000ng/mL. The accuracy and precision ranged from −7.4% to 8.5% and 3.4% to 12.8%, respectively. The absolute matrix effect (94.2–119.2%), relative matrix effect (1.7–9.6%) and recoveries (81.4–93.7%) were satisfactory in all the biological matrices examined. The assay was successfully applied to the plasma pharmacokinetics, tissue distribution and excretion studies of corydaline in rats. The pharmacokinetic parameters such as half-life (t 1/2), mean residence time (MRT) and maximum concentration (C max) were determined. These preclinical data of corydaline would be useful for the clinical reference.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Jianfeng Wang , Lishuang Liang , Qiongyu Zhang , Xingang Li , Zhijian Fu
A rapid resolution ultra performance liquid chromatography (UPLC) coupled with electrospray ionization (ESI) mass spectrometry method was developed and validated for the quantitative analysis of corydaline in rats’ plasma and various tissues for pharmacokinetic, tissue distribution and excretion studies of corydaline. The analytes were separated on an Acquity UPLC BEH C18 column (2.1mm×100mm, 1.7μm) and detected with a triple quadrupole mass spectrometer using positive ion ESI in the multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 370.0→192.0 for corydaline and 354.1→188.0 for IS, respectively. Calibration curves (1/x 2 weighted) offered satisfactory linearity (r 2 >0.9984) within 1–1000ng/mL. The accuracy and precision ranged from −7.4% to 8.5% and 3.4% to 12.8%, respectively. The absolute matrix effect (94.2–119.2%), relative matrix effect (1.7–9.6%) and recoveries (81.4–93.7%) were satisfactory in all the biological matrices examined. The assay was successfully applied to the plasma pharmacokinetics, tissue distribution and excretion studies of corydaline in rats. The pharmacokinetic parameters such as half-life (t 1/2), mean residence time (MRT) and maximum concentration (C max) were determined. These preclinical data of corydaline would be useful for the clinical reference.
Pharmacokinetics and tissue distribution of a novel marine fibrinolytic compound in Wistar rat following intravenous administrations
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Tongwei Su , Wenhui Wu , Ting Yan , Chaoyan Zhang , Quangang Zhu , Bin Bao
We investigated a novel marine fibrinolytic compound for use in thrombolytic therapy. Pharmacokinetics and the tissue distribution of this novel marine fibrinolytic compound, FGFC1 2 FGFC1: Fungi fibrinolytic compound 1,2,5-bis-[8-(4,8-dimethyl-nona-3,7-dienyl)-5,7-dihydroxy-8-methyl-3-keto-1,2,7,8-tertahydro-6H-pyran[a]isoindol-2-yl]-pentanoic acid, a novel pyran-isoindolone derivative with bioactivity isolated from marine microorganism in our laboratory. (fungi fibrinolytic compound 1), were investigated in Wistar rats after intravenous (IV) bolus administration of two concentrations (10 and 20mg/kg). Plasma FGFC1 and tissue extracts were measured using HPLC with UV detection. FGFC1 was detected using a C18 column with a gradient eluted mobile phase of acetonitrile–water (0.1% trifluoroacetic acid), 1.0mL/min. Chromatograms were monitored at 265nm (column temperature: 40°C). Pharmacokinetic data indicate that FGFC1 fitted well to a two-compartment model. Elimination half-lives (t 1/2) of FGFC1 were 21.51±2.17 and 23.22±2.11min for 10 and 20mg/kg, respectively. AUC0 - t were 412.19±19.09, 899.09±35.86μg/mLmin, systemic clearance (CL) was 0.023±0.002, 0.022±0.002 ((mg/kg)/(μg/mL)/min) and the mean residence time (MRT) was 10.15±0.97, 9.65±1.40min at 10 and 20mg/kg, respectively. No significant differences were observed in the systemic clearance and mean residence time at the tested doses, suggesting linear pharmacokinetics in rats. Tissue distribution data reveal that FGFC1 distributed rapidly in most tissues except the brain and that the highest concentration of the drug was in the liver. In the small intestine, FGFC1 initially increased and then declined, but remained comparatively high 60min after administration, suggesting that enterohepatic circulation may exist
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Tongwei Su , Wenhui Wu , Ting Yan , Chaoyan Zhang , Quangang Zhu , Bin Bao
We investigated a novel marine fibrinolytic compound for use in thrombolytic therapy. Pharmacokinetics and the tissue distribution of this novel marine fibrinolytic compound, FGFC1 2 FGFC1: Fungi fibrinolytic compound 1,2,5-bis-[8-(4,8-dimethyl-nona-3,7-dienyl)-5,7-dihydroxy-8-methyl-3-keto-1,2,7,8-tertahydro-6H-pyran[a]isoindol-2-yl]-pentanoic acid, a novel pyran-isoindolone derivative with bioactivity isolated from marine microorganism in our laboratory. (fungi fibrinolytic compound 1), were investigated in Wistar rats after intravenous (IV) bolus administration of two concentrations (10 and 20mg/kg). Plasma FGFC1 and tissue extracts were measured using HPLC with UV detection. FGFC1 was detected using a C18 column with a gradient eluted mobile phase of acetonitrile–water (0.1% trifluoroacetic acid), 1.0mL/min. Chromatograms were monitored at 265nm (column temperature: 40°C). Pharmacokinetic data indicate that FGFC1 fitted well to a two-compartment model. Elimination half-lives (t 1/2) of FGFC1 were 21.51±2.17 and 23.22±2.11min for 10 and 20mg/kg, respectively. AUC0 - t were 412.19±19.09, 899.09±35.86μg/mLmin, systemic clearance (CL) was 0.023±0.002, 0.022±0.002 ((mg/kg)/(μg/mL)/min) and the mean residence time (MRT) was 10.15±0.97, 9.65±1.40min at 10 and 20mg/kg, respectively. No significant differences were observed in the systemic clearance and mean residence time at the tested doses, suggesting linear pharmacokinetics in rats. Tissue distribution data reveal that FGFC1 distributed rapidly in most tissues except the brain and that the highest concentration of the drug was in the liver. In the small intestine, FGFC1 initially increased and then declined, but remained comparatively high 60min after administration, suggesting that enterohepatic circulation may exist
Determination of naloxone-3-glucuronide in human plasma and urine by HILIC–MS/MS
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Ji Dong , Shuaibing Liu , Hua Zhang , Qianli Hua , Xuegang Zhao , Liyan Miao
A hydrophilic interaction chromatography–tandem mass spectrometric (HILIC–MS/MS) method was developed for the direct determination of naloxone-3-glucuronide (N3G) in human plasma and urine. After a straightforward sample preparation by protein precipitation, N3G was analyzed directly without the need for hydrolysis. Chromatographic separation was performed on a HILIC column. The mobile phase was composed of acetonitrile–10mmol/L ammonium formate (86:14, v/v), with a flow rate of 0.4mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via positive electrospray ionisation (ESI+) source. The linear calibration range was 0.5 to 200ng/mL in plasma and 10 to 5000ng/mL in urine (r 2 >0.99). The intra- and inter-day precision (relative standard deviation, RSD) values were below 15% and the accuracies (relative error, RE) were −7.1% to 2.8% in plasma and −1.3% to 10.3% in urine at three quality control levels. In human subjects receiving 100mg tilidine and 8mg naloxone, mean AUC0–24 of N3G was 160.93±52.77ng/mLh and mean C max was 75.33±25.27ng/mL. In 24-h urine samples, 8.0% of the dose was excreted in the form of N3G in urine. These results demonstrated a new method suitable for in vivo pharmacokinetic studies of N3G.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): Ji Dong , Shuaibing Liu , Hua Zhang , Qianli Hua , Xuegang Zhao , Liyan Miao
A hydrophilic interaction chromatography–tandem mass spectrometric (HILIC–MS/MS) method was developed for the direct determination of naloxone-3-glucuronide (N3G) in human plasma and urine. After a straightforward sample preparation by protein precipitation, N3G was analyzed directly without the need for hydrolysis. Chromatographic separation was performed on a HILIC column. The mobile phase was composed of acetonitrile–10mmol/L ammonium formate (86:14, v/v), with a flow rate of 0.4mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via positive electrospray ionisation (ESI+) source. The linear calibration range was 0.5 to 200ng/mL in plasma and 10 to 5000ng/mL in urine (r 2 >0.99). The intra- and inter-day precision (relative standard deviation, RSD) values were below 15% and the accuracies (relative error, RE) were −7.1% to 2.8% in plasma and −1.3% to 10.3% in urine at three quality control levels. In human subjects receiving 100mg tilidine and 8mg naloxone, mean AUC0–24 of N3G was 160.93±52.77ng/mLh and mean C max was 75.33±25.27ng/mL. In 24-h urine samples, 8.0% of the dose was excreted in the form of N3G in urine. These results demonstrated a new method suitable for in vivo pharmacokinetic studies of N3G.
Analysis of neutral lipids from microalgae by HPLC-ELSD and APCI-MS/MS
13 November 2013,
09:24:38
Publication date: 30 December
2013
Source:Journal of Chromatography B, Volumes 942–943
Author(s): F. Donot , G. Cazals , Z. Gunata , D. Egron , J. Malinge , C. Strub , A. Fontana , S. Schorr-Galindo
A method was developed to analyze neutral lipids through the use of three triglycerides, four free fatty acids, six di- and four mono-glycerides standards by high performance liquid chromatography (HPLC) normal phase coupled with either with evaporative light scattering detector (ELSD) or with mass spectrometry (MS) operating in atmospheric pressure chemical ionization (APCI) mode. The method was applied to the determination of the neutral lipid fraction from a Botryococcus braunii race A (B. braunii) culture. This method led us to identify neutral lipids synthesized by B. braunii in a single analysis within 45min through HPLC–APCI-MS/MS technique.
Source:Journal of Chromatography B, Volumes 942–943
Author(s): F. Donot , G. Cazals , Z. Gunata , D. Egron , J. Malinge , C. Strub , A. Fontana , S. Schorr-Galindo
A method was developed to analyze neutral lipids through the use of three triglycerides, four free fatty acids, six di- and four mono-glycerides standards by high performance liquid chromatography (HPLC) normal phase coupled with either with evaporative light scattering detector (ELSD) or with mass spectrometry (MS) operating in atmospheric pressure chemical ionization (APCI) mode. The method was applied to the determination of the neutral lipid fraction from a Botryococcus braunii race A (B. braunii) culture. This method led us to identify neutral lipids synthesized by B. braunii in a single analysis within 45min through HPLC–APCI-MS/MS technique.
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