A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
Journal of Chromatography Bhttp://rss.sciencedirect.com/publication/science/7220
Selected papers from the latest issue:
Determination of Cediranib in Mouse Plasma and Brain Tissue Using High-Performance Liquid Chromatography-Mass Spectrometry
29 October 2011, 20:44:15
Publication year: 2011
Source: Journal of Chromatography B, Available online 29 October 2011
Tianli Wang, Rajneet K. Oberoi, William F. Elmquist
A new high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) assay for cediranib, a tyrosine kinase inhibitor for VEGFRs, was developed and validated, for the determination of plasma and brain levels of cediranib in small specimen volumes. Tyrphostin (AG1478) was used as internal standard. Mouse plasma and brain homogenate samples were prepared using liquid-liquid extraction. The assay was validated for a 2.5-2500 ng/mL concentration range for plasma, and for 1-2000 ng/mL range for brain homogenate. For these calibration ranges, within-assay variabilities were 1.1-14.3% for plasma and 1.5-9.4% for brain homogenate; between-assay variabilities were 2.4-9.2% for plasma, and 4.9-10.2% for brain homogenate. Overall accuracy ranged from 101.5 to 107.0% for plasma and 96.5 to 100.2% for brain homogenate, for all target concentrations. The developed assay has been successfully applied for a mouse brain distribution study in mice at an oral dose of 5 mg/kg.
Source: Journal of Chromatography B, Available online 29 October 2011
Tianli Wang, Rajneet K. Oberoi, William F. Elmquist
A new high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) assay for cediranib, a tyrosine kinase inhibitor for VEGFRs, was developed and validated, for the determination of plasma and brain levels of cediranib in small specimen volumes. Tyrphostin (AG1478) was used as internal standard. Mouse plasma and brain homogenate samples were prepared using liquid-liquid extraction. The assay was validated for a 2.5-2500 ng/mL concentration range for plasma, and for 1-2000 ng/mL range for brain homogenate. For these calibration ranges, within-assay variabilities were 1.1-14.3% for plasma and 1.5-9.4% for brain homogenate; between-assay variabilities were 2.4-9.2% for plasma, and 4.9-10.2% for brain homogenate. Overall accuracy ranged from 101.5 to 107.0% for plasma and 96.5 to 100.2% for brain homogenate, for all target concentrations. The developed assay has been successfully applied for a mouse brain distribution study in mice at an oral dose of 5 mg/kg.
Highlights
► This is the first study to describe a sensitive and precise LC-MS assay for cediranib. ► This assay allows small specimen volumes and adequate detectability to use in tissue distribution studies. ► We have employed the assay in a brain distribution study in the mouse, to examine different mechanisms that limit the CNS distribution of cediranib. ► The assay is generally applicable to a variety of pharmacokinetic and in vitro cell culture experimentsCapillary electrophoretic determination of DNA damage markers: content of 8-hydroxy-2’-deoxyguanosine and 8-nitroguanine in urine
29 October 2011, 20:44:15
Publication year: 2011
Source: Journal of Chromatography B, Available online 29 October 2011
Meng-Jie Li, Jun-Bo Zhang, Wen-Li Li, Qing-Cui Chu, Jian-Nong Ye
A sensitive and low-cost analytical method has been developed to determine 8-hydroxy-2’-deoxyguanosine (8-OHdG) and 8-nitroguanine (8-NO2Gua) based on capillary electrophoresis with amperometric detection (CE-AD) after solid phase extraction (SPE). Under optimized condition, these two markers were well separated from other components coexisting in urine, exhibiting a linear calibration over the concentration range of 0.1–50.0 μg/mL with the detection limits ranging from 0.02 to 0.06 μg/mL. The relative standard deviations (RSDs) were in the range of 0.1% - 2.1% for peak area, 0.1% - 1.5% for migration time, respectively. The average recovery and relative standard deviation (RSD) were within the range of 100.0-108.0% and 0.1-1.7%, respectively. It was found that the urinary contents of 8-OHdG and 8-NO2Gua in cancer patients were significantly higher than those in healthy ones.
Source: Journal of Chromatography B, Available online 29 October 2011
Meng-Jie Li, Jun-Bo Zhang, Wen-Li Li, Qing-Cui Chu, Jian-Nong Ye
A sensitive and low-cost analytical method has been developed to determine 8-hydroxy-2’-deoxyguanosine (8-OHdG) and 8-nitroguanine (8-NO2Gua) based on capillary electrophoresis with amperometric detection (CE-AD) after solid phase extraction (SPE). Under optimized condition, these two markers were well separated from other components coexisting in urine, exhibiting a linear calibration over the concentration range of 0.1–50.0 μg/mL with the detection limits ranging from 0.02 to 0.06 μg/mL. The relative standard deviations (RSDs) were in the range of 0.1% - 2.1% for peak area, 0.1% - 1.5% for migration time, respectively. The average recovery and relative standard deviation (RSD) were within the range of 100.0-108.0% and 0.1-1.7%, respectively. It was found that the urinary contents of 8-OHdG and 8-NO2Gua in cancer patients were significantly higher than those in healthy ones.
Highlights
► 8-OHdG and 8-NO2Gua were simultaneously determined by capillary electrophoresis with amperometric detection (CE-AD). ► CE-AD apparatus employed is inexpensive and easy to operate. ► The proposed method was rather simple and has been applied to analyze clinical samples. ► The excretion levels of urinary 8-OHdG and 8-NO2Gua of cancer patients were significantly higher than those of healthy persons. With the growth of age, 8-OHdG urinary levels also increase slightly.High-Performance Liquid Chromatography analysis of a novel small-molecule, anti-cancer drug, Palomid 529, in human and mouse plasma and in mouse tissue homogenates
29 October 2011, 20:44:15
Publication year: 2011
Source: Journal of Chromatography B, Available online 29 October 2011
Fan Lin, David Sherris, Jos H. Beijnen, Olaf Van Tellingen
Palomid 529 (8-(1-Hydroxy-ethyl)-2-methoxy-3-(4-methoxy-benzyloxy)-benzo[c]chromen-6-one), is a novel non-steroidal small-molecule drug, which inhibits both mTORC1 and mTORC2 assembly, and elicits both anti-angiogenic and direct anti-tumor effects in vivo. We have developed and validated a sensitive and selective method for the quantification of Palomid 529 in human and mouse plasma and in a range of mouse tissue samples. Sample pretreatment involved liquid-liquid extraction withtert-butyl methyl ether yielding a recovery of >75%. Palomid 529 and the internal standard Palomid 545 were separated using a GraceSmart RP18 column (2.1 × 150 mm) packed with 5 μm C-18 material and a mobile phase comprised of 50% (v/v) acetonitrile and 50% (v/v) water delivered at a flow rate of 0.2 ml/min, and were detected by UV absorbance at a wavelength of 315 nm. Within the linear range of the calibration curve (10 to 10,000 ng/ml), acceptable accuracy and precision was achieved for all tested matrices. The validation results show that the method was selective and reproducible. Palomid 529 was stable in plasma upon 3 repeated freeze-thaw cycles and during storage for up to 24 h at ambient temperature. However, pre-treated samples waiting for HPLC analyses need to be kept under dimmed light conditions at ambient temperature since a significant degradation of both Palomid 529 and Palomid 545 was observed when exposed to light. A pilot pharmacokinetic study in mice demonstrated the applicability of this method for pharmacokinetic purposes. Even at a low dose of 5.4 mg/kg this assay was still sensitive enough to determine the drug concentration in plasma samples obtained up to 24 h after administration.
Source: Journal of Chromatography B, Available online 29 October 2011
Fan Lin, David Sherris, Jos H. Beijnen, Olaf Van Tellingen
Palomid 529 (8-(1-Hydroxy-ethyl)-2-methoxy-3-(4-methoxy-benzyloxy)-benzo[c]chromen-6-one), is a novel non-steroidal small-molecule drug, which inhibits both mTORC1 and mTORC2 assembly, and elicits both anti-angiogenic and direct anti-tumor effects in vivo. We have developed and validated a sensitive and selective method for the quantification of Palomid 529 in human and mouse plasma and in a range of mouse tissue samples. Sample pretreatment involved liquid-liquid extraction withtert-butyl methyl ether yielding a recovery of >75%. Palomid 529 and the internal standard Palomid 545 were separated using a GraceSmart RP18 column (2.1 × 150 mm) packed with 5 μm C-18 material and a mobile phase comprised of 50% (v/v) acetonitrile and 50% (v/v) water delivered at a flow rate of 0.2 ml/min, and were detected by UV absorbance at a wavelength of 315 nm. Within the linear range of the calibration curve (10 to 10,000 ng/ml), acceptable accuracy and precision was achieved for all tested matrices. The validation results show that the method was selective and reproducible. Palomid 529 was stable in plasma upon 3 repeated freeze-thaw cycles and during storage for up to 24 h at ambient temperature. However, pre-treated samples waiting for HPLC analyses need to be kept under dimmed light conditions at ambient temperature since a significant degradation of both Palomid 529 and Palomid 545 was observed when exposed to light. A pilot pharmacokinetic study in mice demonstrated the applicability of this method for pharmacokinetic purposes. Even at a low dose of 5.4 mg/kg this assay was still sensitive enough to determine the drug concentration in plasma samples obtained up to 24 h after administration.
Highlights
► We describe an HPLC assay for Palomid 529 in human and mouse plasma and tissues. ► Sample pre-treatment involved liquid-liquid extraction withtert-butyl methyl ether. ► Separation involved reversed phase HPLC and detection by UV at 315 nm. ► The dynamic range was 10-10,000 ng/ml. ► The applicability for in vivo pharmacokinetics studies is demonstrated.Development of a quantification method for digoxin, a typical P-glycoprotein probe in clinical and non-clinical studies, using high performance liquid chromatography-tandem mass spectrometry: The usefulness of negative ionization mode to avoid competitive adduct-ion formation
29 October 2011, 20:44:15
Publication year: 2011
Source: Journal of Chromatography B, Available online 29 October 2011
Hideki Hirabayashi, Hiroshi Sugimoto, Shinichi Matsumoto, Nobuyuki Amano, Toshiya Moriwaki
Highly sensitive and accurate liquid chromatography-tandem mass spectrometry (LC/MS/MS) methods have been developed and validated for measuring digoxin (DGX), a typical P-glycoprotein probe, in human plasma, rat plasma, and rat brain. We extracted DGX and deuterium-labeled DGX (as internal standard) from sample fluids under basic conditions using acetonitrile and sodium chloride-saturated 0.1 mol/L sodium hydroxide. The upper organic layer was diluted with distilled water, and the resulting solution was injected into an LC/MS/MS system in negative ionization mode. Chromatographic separation was achieved on a C18-ODS column in the gradient mobile phase, which comprised of 0.05% (w/v) ammonium carbonate (pH 9.0) and methanol at a flow rate of 0.7 mL/min. Regardless of the type of biological matrix, intra-day and inter-day validation tests demonstrated good linearity of calibration curves within ranges of 0.1 to 10 ng/mL for plasma and 0.5 to 50 ng/g for rat brain and gave excellent accuracy and precision of quality control samples at 4 concentration levels. Unlike existing methods, our approach uses negative ionization to avoid competitive adduct formation of DGX. Our method showed higher sensitivity and wider applicability to various types of biological matrices than existing methods. Our method will support clinical and preclinical investigation ofin vivoP-glycoprotein functionality using DGX.
Source: Journal of Chromatography B, Available online 29 October 2011
Hideki Hirabayashi, Hiroshi Sugimoto, Shinichi Matsumoto, Nobuyuki Amano, Toshiya Moriwaki
Highly sensitive and accurate liquid chromatography-tandem mass spectrometry (LC/MS/MS) methods have been developed and validated for measuring digoxin (DGX), a typical P-glycoprotein probe, in human plasma, rat plasma, and rat brain. We extracted DGX and deuterium-labeled DGX (as internal standard) from sample fluids under basic conditions using acetonitrile and sodium chloride-saturated 0.1 mol/L sodium hydroxide. The upper organic layer was diluted with distilled water, and the resulting solution was injected into an LC/MS/MS system in negative ionization mode. Chromatographic separation was achieved on a C18-ODS column in the gradient mobile phase, which comprised of 0.05% (w/v) ammonium carbonate (pH 9.0) and methanol at a flow rate of 0.7 mL/min. Regardless of the type of biological matrix, intra-day and inter-day validation tests demonstrated good linearity of calibration curves within ranges of 0.1 to 10 ng/mL for plasma and 0.5 to 50 ng/g for rat brain and gave excellent accuracy and precision of quality control samples at 4 concentration levels. Unlike existing methods, our approach uses negative ionization to avoid competitive adduct formation of DGX. Our method showed higher sensitivity and wider applicability to various types of biological matrices than existing methods. Our method will support clinical and preclinical investigation ofin vivoP-glycoprotein functionality using DGX.
Highlights
► Highly sensitive and accurate LC/MS/MS method was developed for measuring digoxin. ► The developed method achieved higher sensitivity than previously reported methods requiring only 25 μL of the sample fluid. ► The key successful factor was to employ negative ionization to completely avoid competitive adduct formation. ► The unique, one-step sample pretreatment method may provide advantages over existing methods, such as the small required sample volume, no need for extensive sample cleanup, safety, and low cost of the procedure, among others.Extractive ethoxycarbonylation in high-temperature gas chromatography-mass spectrometry based analysis of serum estrogens
29 October 2011, 20:44:15
Publication year: 2011
Source: Journal of Chromatography B, Available online 29 October 2011
Ju-Yeon Moon, Se Mi Kang, Myeong Hee Moon, Jongki Hong, Ki Tae Kim, ...
A comprehensive gas chromatography-mass spectrometry (GC-MS)-based profiling was developed as a practical assay for quantification of 18 endogenous estrogens in serum samples. The present GC-MS method was conducted with the two-phase extractive ethoxycarbonlyation (EOC) of the phenolic hydroxy groups of estrogen with ethyl chlorformate combined with the non-polar n-hexane extraction. The subsequent perfluoroacylation of aliphatic hydroxy groups with pentafluoropropionyl anhydride (PFPA) was conducted. The serum samples were separated through a high temperature GC column (MXT-1) within an 8-min run and analyzed in selected-ion monitoring mode with good chromatographic properties for 18 estrogens as their EOC-PFP derivatives. The limit of quantification (LOQ) were 0.025 ∼ 0.10 ng/mL for most estrogens analyzed except for E3 and 2-OH-E3 (0.5 ng/mL each). The devised method was found to be linear over a 10-fold concentration range with a correlation coefficient (r > 0.992), whereas the precision (% CV) and accuracy (% bias) ranged from 3.1 to 16.3% and from 93.5 to 111.1%, respectively. Decreased 2-methoxy-17β-estradiol levels were confirmed in patients with preeclampsia than healthy pregnant women. This technique can be used for a clinical diagnosis as well as understanding the pathogenesis in estrogen-related disorders.
Source: Journal of Chromatography B, Available online 29 October 2011
Ju-Yeon Moon, Se Mi Kang, Myeong Hee Moon, Jongki Hong, Ki Tae Kim, ...
A comprehensive gas chromatography-mass spectrometry (GC-MS)-based profiling was developed as a practical assay for quantification of 18 endogenous estrogens in serum samples. The present GC-MS method was conducted with the two-phase extractive ethoxycarbonlyation (EOC) of the phenolic hydroxy groups of estrogen with ethyl chlorformate combined with the non-polar n-hexane extraction. The subsequent perfluoroacylation of aliphatic hydroxy groups with pentafluoropropionyl anhydride (PFPA) was conducted. The serum samples were separated through a high temperature GC column (MXT-1) within an 8-min run and analyzed in selected-ion monitoring mode with good chromatographic properties for 18 estrogens as their EOC-PFP derivatives. The limit of quantification (LOQ) were 0.025 ∼ 0.10 ng/mL for most estrogens analyzed except for E3 and 2-OH-E3 (0.5 ng/mL each). The devised method was found to be linear over a 10-fold concentration range with a correlation coefficient (r > 0.992), whereas the precision (% CV) and accuracy (% bias) ranged from 3.1 to 16.3% and from 93.5 to 111.1%, respectively. Decreased 2-methoxy-17β-estradiol levels were confirmed in patients with preeclampsia than healthy pregnant women. This technique can be used for a clinical diagnosis as well as understanding the pathogenesis in estrogen-related disorders.
Hey nice blog and the journals are really interesting, i wish to see more from this...
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