Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Impact Factor & Information

Publisher: Elsevier

Journal description

The Journal of Chromatography B. addresses advancements in and applications of analytical methodologies related to drugs, other pharmacologically active compounds, metabolites, as well as to bio-polymers such as proteins and nucleic acids. The areas considered include: clinical analysis, therapeutic drug monitoring, pharmaceutical analysis and novel approaches to sample preparation in bioanalysis; the qualitative and quantitative analysis of proteins, peptides and their post-translational modifications as well as nucleic acids; the screening and profiling of body fluids and tissues related to monitoring the level of active substances, including metabolites, biomarkers and toxicants; the comparative analysis of biological systems and proteomics and genomics including novel ways of data handling and interpretation; analytical techniques covered include the various facets of chromatography, electrophoresis and related methods, including mass spectrometry and affinity-based methodologies.

Current impact factor: 2.69

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013 / 2014 Impact Factor 2.694
2012 Impact Factor 2.487
2011 Impact Factor 2.888
2010 Impact Factor 2.971
2009 Impact Factor 2.777
2008 Impact Factor 2.5
2007 Impact Factor 2.935
2006 Impact Factor 2.647
2005 Impact Factor 2.391
2004 Impact Factor 2.176
2003 Impact Factor 2.085
2002 Impact Factor 1.913
1996 Impact Factor 1.341
1995 Impact Factor 1.255
1994 Impact Factor 1.209

Impact factor over time

Impact factor
Year

Additional details

5-year impact 0.00
Cited half-life 6.60
Immediacy index 0.36
Eigenfactor 0.04
Article influence 0.73
Website Journal of Chromatography B website
ISSN 1873-376X

Publisher details

Elsevier

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    • NIH Authors articles will be submitted to PubMed Central after 12 months
    • Publisher last contacted on 18/10/2013
  • Classification
    ​ green

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: UTL-5g is a novel small-molecule TNF-α inhibitor under investigation as both a chemoprotective and radioprotective agent. Animal studies showed that pretreatment of UTL-5g protected kidney, liver, and platelets from cisplatin-induced toxicity. In addition, UTL-5g reduced liver and lung injuries induced by radiation in vivo. Although a number of preclinical studies have been conducted, a validated bioanalytical method for UTL-5g in human plasma has not been published. In this work, a sensitive and reproducible reverse-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) assay was developed and validated for the determination of UTL-5g and its metabolites, 5-methylisoxazole-3-carboxylic acid (ISOX) and 2,4-dichloroaniline (DCA), in human plasma. The method involves a simple methanol precipitation step followed by injection of the supernatant onto a Waters 2695 HPLC system coupled with a Waters Quattro Micro™ triple quadrupole mass spectrometer. Chromatographic separation was accomplished using a Waters Nova-Pak C18 column maintained at 30°C, running at gradient mode with mobile phase consisting of 0.1% formic acid in water and 0.1% formic acid in methanol at a flow rate of 0.2mL/min. The analytes were monitored under positive electrospray ionization (ESI). Quantitation of these compounds in plasma was linear from 0.05 to 10μM. The lower limit of quantitation (LLOQ) was 0.05, 0.1, and 0.2μM for UTL-5g, ISOX and DCA, respectively. The accuracy and intra-and inter-day precisions were within the generally accepted criteria for bioanalytical method (<15%). This method provides a practical tool to measure and characterize the plasma concentration-time profiles for UTL-5g and its metabolites, ISOX and DCA. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 06/2015; 991. DOI:10.1016/j.jchromb.2015.04.015
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    ABSTRACT: In this study, a method for the quantitation of SK5474 in rat plasma was developed and validated using high performance liquid chromatography (HPLC). The plasma samples were prepared by deproteinization, and sildenafil was used as an internal standard. Chromatographic separation was achieved using a reversed-phase (C18) column. The mobile phase, 0.02M ammonium acetate buffer:acetonitrile (48:52, v/v), was run at a flow rate of 1.0mL/min, and the column eluent was monitored using an ultraviolet detector at 254nm at room temperature. The retention times of sildenafil and SK5474 were approximately 5.8 and 7.2min, respectively. The quantitation limit of SK5474 in rat plasma was 0.03μg/mL. Pharmacokinetic parameters of SK5474 was evaluated after intravenous (i.v.; at doses of 15mg/kg) and oral (p.o.; at doses of 30mg/kg) administration of SK5474 in rats. After p.o. administration (30mg/kg) of SK5474, F (fraction absorbed) value was approximately 46.0%. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 06/2015; 991. DOI:10.1016/j.jchromb.2015.04.010
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    ABSTRACT: The continuous enzymatic assay based on ESI-MS was developed to real-time monitoring of enzymatic reactions of acetylcholinesterase (AChE). The changes of product concentrations were continuously measured. Calibration curves were established for quantitative calculation. By this method, the Michaelis constant (Km) of acetylcholinesterase was determined to be 70.60±0.93μM and Huperzine A as an effective inhibitor of acetylcholinesterase displayed a mixed inhibition with competitive and noncompetitive inhibition behaviors. The half maximal inhibitory concentration (IC50) and inhibition constant (Ki) value of Huperzine A were also calculated as 48.51±1.16nM and 26.73±0.27nM, respectively. This method provides the rapid and accurate ways to monitor enzyme reactions. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.022
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    ABSTRACT: Urolithins were separated from the intestinal metabolites of pomegranate ellagitannins by high-speed counter current chromatography in two steps using two solvent systems composed of n-hexane-ethyl acetate-methanol-acetic acid-water (2.5:2:0.25:5, v/v/v/v/v) and n-hexane-ethyl acetate-methanol-acetic acid-water (2.5:0. 8:0.25:5, v/v/v/v/v) for the first time. Each injection of 100mg extract yielded 21mg of pure urolithin A and 10mg of pure urolithin B. High-performance liquid chromatography analyses revealed that the purity of urolithin A and urolihtin B was over 98.5%. The structures of urolithin A and urolitihn B were identified by high resolution-MS, NMR and single crystal x-ray analysis. Urolithins reduced the oxidative stress status in colon cancer by decreasing the intracellular ROS and malondialdehyde levels, and increasing SOD activity in H2O2 treated Caco-2 cells. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.024
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    ABSTRACT: Biochemical response stressors results in an increase of adrenocortical activity. Before knowing the corticosteroid levels in saliva in a stressful situation, baselines salivary levels should be established. A method for simultaneous determination of five corticosteroids was developed, validated and applied to pig saliva at farms. The method employs solid-phase extraction (SPE) coupled with clean-up extraction step using silica cartridge in the same step followed by liquid chromatography/tandem mass spectrometry (LC-MS/MS), using electrospray ionization (ESI) in positive mode. The overall method quantification limits range from 0.050 to 0.30μg/L for the enrichment of 1.0mL saliva samples and analyte recoveries are between 60 and 90% (RSD<11%). Some factors studied were: pig sex, breeds, and time at farm. The analytical method clearly shows that CRL and CRS levels of, respectively, 3.0 and 4.0μg/L in saliva can be indicative of maxima non-stress levels in different pig breeds at farm. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.021
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    ABSTRACT: Polybrominated diphenyl ethers (PBDEs) have become ubiquitous environmental contaminants due to their incorporation into many consumer products. Their ability to bioaccumulate to alarming levels in fat-rich matrices such as fish demands fast and efficient methods to monitor these contaminants. We present an analytical method for selective-pressurised liquid extraction (S-PLE) of PBDEs from fish tissue. Fat removal performance of different mixtures of Florisil, silica gel and sulphuric acid-impregnated silica gel were evaluated using a response surface experimental design approach for determining the optimal fat-retaining mixture for S-PLE. Acid-silica gel had the greatest individual effect on fat retention; with a two-thirds acid-silica one-third Florisil mixture found to be the most efficient (>97%). Method validation was performed using recovery experiments at three spiked concentration levels (0.05, 0.5 and 5ngg(-1) ww). Mean recoveries of target analytes in spiked samples ranged from 70 to 124%, with relative standard deviations <27%. The S-PLE lipid removal efficiency combined with the sensitivity of triple quadrupole mass spectrometers provides a fast and comparatively inexpensive analytical method for analysis of PBDEs in fish samples. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.02.045
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    ABSTRACT: A novel method was developed for the determination of cyproheptadine in feeds using molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography. The polymers were prepared using cyproheptadine as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linking agent, and dichloromethane as a solvent by bulk polymerization. Under the optimum solid-phase extraction conditions, the molecular imprinting cartridge can selectively extract and enrich cyproheptadine from a variety of feeds. Mean recoveries of cyproheptadine from four kinds of feeds spiked at 0.1, 1.0 and 10mgkg(-1) ranged from 85.5% to 96.2%, with intra-day and inter-day relative standard deviation less than 10%. The calibration curve of cyproheptadine was good linear relationship (r>0.9993) within the range of 0.1-50μgmL(-1). The limit of detection (LOD) and the limit of quantification (LOQ) were 0.04 and 0.1mgkg(-1), respectively. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.009
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    ABSTRACT: Chromatographic properties of two columns was compared: commercial IAM.PC.DD2 that imitates the cell membrane and home-made Amino-P-C18 (N,O-dialkylphosphoramidate C18). The comparison has been done by correlation of retention (logkw parameters) of a series of solutes: hydrophobic (alkyl benzene derivatives and PAHs) and polar, with both acidic (flavonoids) and basic (nucleosides and nucleic bases) character. The slope of correlation plots for hydrophobic compounds and polar basic was very close to 1.0 that confirms the chromatographic similarity. Only for flavonoids the slope of correlation plot was 1.5. For hydrophobic compound retention parameters logkw were also correlated with hydrophobic parameter logP with very good determination coefficients. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.033
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    ABSTRACT: A suspension comprising of the three antibiotic substances amphotericin B, colistin sulfate and tobramycin sulfate is often used in clinical practice for the selective decontamination of the digestive tract of patients in intensive care. Since no detailed procedures, specifications or stability data are available for manufacturing this suspension, there may be discrepancies regarding formulation and stability of suspensions prepared in different pharmacies. The aim of this work is to develop a standardized formulation and to determine its stability under defined storage conditions. This would help guarantee that all patients receive the same preparation, therefore ensuring similar efficacy and improved safety. The first step in this process is to develop the required analytical tools to measure the content and purity of the drug substances in this complex mixture. In this paper, the development and validation of these tools as well as the development of the drug suspension formulation is described. The formulation comprises of Ampho-Moronal(®)-Suspension (Dermapharm) and a buffered, preservated aqueous solution of colistin sulfate and tobramycin sulfate. Two simple, well established high-performance liquid chromatography (HPLC) methods in the European Pharmacopoeia (EP) for impurity profiling of the two active ingredients amphotericin B and colistin sulfate were combined with a newly developed sample extraction procedure for the suspension. Sufficient selectivity and stability-indicating power have been demonstrated. Additionally, a new robust routine method was developed to determine possible degradation products of tobramycin sulfate in the investigated suspension. The specificity, precision, accuracy and linearity of the analytical procedures were demonstrated. The recovery rate was in the range of 90-110%. The precision results for the calculated impurities showed variation coefficients of <10%. The calibration curves were found to be linear with correlation of greater than 0.9994 for all components. The results show the suitability of the methods for the quality control analysis of the suspension. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.02.043
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    ABSTRACT: Triacylglycerols (TAGs) are a large class of neutral lipids that naturally occur in both plant and animal oils and fats. Their analyses in Non-Aqueous Reversed Phase Liquid Chromatography (NARP) require a mixture of weak solvent (mostly acetonitrile) and strong solvent. In the present work, we have established eluotropic solvent strength scale of several binary mobile phases on C18 bonded silica at different temperatures (acetonitrile/methylene chloride, acetonitrile/acetone, acetonitrile/ethyl acetate, acetonitrile/propan-2-ol, and acetonitrile/butan-1-ol at 25°C, 43°C, 63°C and 85°C); it is based on the methylene selectivity and the use of homologous series. We show that this scale is well suited to the TAGs analysis. The analysis of nine seed oils (Aleurites fordii, Calophyllum inophyllum, Glycina max, Olea europea, Orbignya olifeira, Pinus koraiensis, Pistacia lentiscus, Punica granatum and Ribes nigrum) in iso-eluotropic conditions leads to propose unambiguously the couple MeCN/BuOH at 25°C as the best system to separate TAGs. The use of butanol, as strong solvent, provides very good TAGs congeners separations and avoids the use of chlorinated solvents which gave to this day the best separations. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.007
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    ABSTRACT: Epimedii herba is a traditional Chinese medicine for the treatment of osteoporosis. Epimedin A, B and C and icariin are the primary effective ingredients of this medicine. In this study, a simple and low-cost method based on pipette tip solid-phase extraction, high-performance liquid chromatography separation, and diode array detection has been developed for the simultaneous analysis of four flavonoids (epimedin A, B and C and icariin) from Epimedii herba in rat serum samples. In this novel extraction configuration, the sorbents were placed between a filter (hollow fiber) and the pipette tip. Pipette tip solid-phase extraction has several advantages compared to conventional extraction methods: faster extraction time (6.0min); lower sample volume (100μL); lower solvent volume (100μL); and less solvent waste. Under the optimum extraction conditions, the method showed good linearity (0.05-10.0μgmL(-1)), acceptable intra- and inter precision (RSD<6%), low limits of quantification (0.027-0.045μgmL(-1)) and satisfactory relative recoveries (98.63-103.18%). This method was successfully applied to investigate the pharmacokinetics of the major flavonoids in Epimedii herba extract after oral administration to rats (10gkg(-1) body weight). The primary pharmacokinetic parameters for rats were determined as follows: Cmax, 0.45-4.11μgmL(-1); Tmax, 0.21-0.26h; t1/2α, 0.06-0.12h; t1/2β, 2.02-3.48h; AUC0-∞: 0.50-2.58μghmL(-1); CL, 19.53-44.72Lkg(-1)h(-1); and MRT0-∞, 2.25-3.77h. The developed method has the potential to promulgate the pharmacokinetics and provide more information for clinical applications. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.012
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    ABSTRACT: Differences among lipidomic profiles of healthy volunteers, obese people and three groups of cardiovascular disease (CVD) patients are investigated with the goal to differentiate individual groups based on the multivariate data analysis (MDA) of lipidomic data from plasma, erythrocytes and lipoprotein fractions of more than 50 subjects. Hydrophilic interaction liquid chromatography on ultrahigh-performance liquid chromatography (HILIC-UHPLC) column coupled with electrospray ionization mass spectrometry (ESI-MS) is used for the quantitation of four classes of polar lipids (phosphatidylethanolamines, phosphatidylcholines, sphingomyelins and lysophosphatidylcholines), normal-phase UHPLC-atmospheric pressure chemical ionization MS (NP-UHPLC/APCI-MS) is applied for the quantitation of five classes of nonpolar lipids (cholesteryl esters, triacylglycerols, sterols, 1,3-diacylglycerols and 1,2-diacylglycerols) and the potential of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is tested for the fast screening of all lipids without a chromatographic separation. Obtained results are processed by unsupervised (principal component analysis) and supervised (orthogonal partial least squares) MDA approaches to highlight the largest differences among individual groups and to identify lipid molecules with the highest impact on the group differentiation. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 990. DOI:10.1016/j.jchromb.2015.03.010
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    ABSTRACT: The unripe Fructus Forsythiae (Qingqiao) and ripe Fructus Forsythiae (Laoqiao) are two types of the clinical forms of commercial fructus of Forsythia suspensa(Thunb.) Vahl. There is limited information available for differences in pharmacokinetic properties of active components between unripe and ripe Fructus Forsythiae in vivo. A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the simultaneous determination of 9 typical components in rat plasma. The separation of nine analytes was performed on an Eclipse plus C18 (4.6mm×100mm, 1.8μm) column with the mobile phases consisted of a mixture of 0.1% formic acid in water and acetonitrile. Method validation indicated that the developed method was rapid, specific and sensitive. It was found that the AUC(0-24h) of 5 ingredients (forsythoside A, rutin, phillyrin, isorhamnetin and quercetin) in rats after single orally administrated unripe Fructus Forsythiae also had significant differences compared with those after single dose oral administration of ripe Fructus Forsythiae extract. The systemic exposure of 5 ingredients after multiple oral administration of Fructus Forsythiae extract had significantly increased than those after single oral administration. The results indicated that harvest time is not only effects the contents but the bioavailability of active components of Fructus Forsythiae, which suggests that the rate and extent of drug metabolism were altered when the clinical forms of commercial Fructus Forsythiae with different harvest time. The administration times could influence the bioavailability of active components of Fructus Forsythiae. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 993-994. DOI:10.1016/j.jchromb.2015.04.041
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    ABSTRACT: A selective and sensitive high-performance liquid chromatography-electro-spray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the simultaneous quantitative determination of Picroside-I, II, and III in rat plasma and tissue homogenate to aid the pre-clinical studies. The chromatographic separation was performed on a Hypersil GOLD AQ C18 column using a gradient elution program with a mobile phase consisting of 2mM ammonium acetate and acetonitrile. The detection was achieved using a triple quadrupole tandem MS in negative ionization multiple reaction monitoring (MRM) mode. One-step protein precipitation was selected for plasma and tissue sample preparation while liquid-liquid extraction failed to achieve satisfactory recoveries. The calibration curves of all three analytes in either plasma or tissue homogenate showed good linearity over the concentration range of 0.5-500ng/mL with a limit of quantitation at 0.5ng/mL. Both the intra- and inter-day accuracy and precision were within ±10%. The extraction recoveries were >70%, and the relative matrix effect ranged from 80.4% to 107.4% in all the biological samples. All the analytes were stable in matrices for at least 24h at room temperature, or 21 days in frozen. Three freeze/thaw cycles did not cause degradation. The method was successfully applied for quantification of the three iridoid glycosides in the collected plasma and various tissues following intravenous administration in rats. Picroside-I, II, and III were all eliminated rapidly with large volume of distribution. Among the three glycosides, Picroside-II showed the highest liver uptake, and only Picroside-I and II were found to get across the blood brain barrier (BBB). These results were consistent with their hepatoprotective or neuroprotective effects reported clinically. With the aid of the efficient and reliable simultaneous LC-ESI-MS/MS assay this pharmacokinetic study provided insights into their therapeutic targets of these three iridoid glycosides as well as valuable experimental basis for an expansion of their clinical indications. Copyright © 2015. Published by Elsevier B.V.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 993-994. DOI:10.1016/j.jchromb.2015.04.036
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    ABSTRACT: This study reports on the development of a rapid, selective, and sensitive column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyze sixteen drugs (antidepressants, anticonvulsants, anxiolytics, and antipsychotics) in plasma samples from schizophrenic patients. The developed organic-inorganic hybrid monolithic column with cyanopropyl groups was used for the first dimension of the column-switching arrangement. This arrangement enabled online pre-concentration of the drugs (monolithic column) and their subsequent analytical separation on an XSelect SCH C18 column. The drugs were detected on a triple quadrupole tandem mass spectrometer (multiple reactions monitoring mode) with an electrospray ionization source in the positive ion mode. The developed method afforded adequate linearity for the sixteen target drugs; the coefficients of determination (R(2)) lay above 0.9932, the interassay precision had coefficients of variation lower than 6.5%, and the relative standard error values of the accuracy ranged from -14.0 to 11.8%. The lower limits of quantification in plasma samples ranged from 63 to 1250pgmL(-1). The developed method successfully analyzed the target drugs in plasma samples from schizophrenic patients for therapeutic drug monitoring (TDM). Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 993–994:26-35. DOI:10.1016/j.jchromb.2015.04.040
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    ABSTRACT: Nifedipine is a dihydropyridine calcium channel blocker used for the treatment of hypertension in pregnant women. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for analysis of nifedipine in human plasma and amniotic fluid. Separation of nifedipine and nitrendipine (IS) was performed using a LiChroCART(®) RP-Select B column and a mixture of water:acetonitrile:glacial acetic acid (30:70:0.5 v/v) as the mobile phase. Aliquots of 500μL of biological samples were extracted at pH 13 using dichloromethane:n-pentane (3:7 v/v). The validated method was applied to a study of the pharmacokinetics of nifedipine in human plasma and amniotic fluid samples collected up to 12h after administration of the last slow-release nifedipine (20mg/12h) dose to 12 hypertensive pregnant women. The estimated pharmacokinetic parameters of nifedipine showed a mean AUC(0-12) of 250.2ngh/mL, ClT/F of 89.2L/h, Vd/F of 600.0L and t1/2 5.1h. The mean amniotic fluid/plasma concentration ratio was 0.05. The methods proved to be highly sensitive by showing a lower quantification limit of 0.1ng/mL for both matrices. And this study reports for the first time the complete development and validation of the method to quantify nifedipine in amniotic fluid using LC-MS-MS. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 993-994. DOI:10.1016/j.jchromb.2015.04.030
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    ABSTRACT: A rapid selective and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed for the quantitative determination of derivatised cytochrome P450-2C19 oxidation product (dansyl-4-OH mephenytoin) and its underivatised form (4-OH mephenytoin). Samples were anaysed on C18 column (Waters Xbridge, 50mm×4.6mm, 3.5μm particle size) with the mobile phase consisting of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. A gradient method with a short run time of 2.5min and 3.5min was developed for the analysis of dansyl-4-OH mephenytoin and 4-OH mephenytoin, respectively. The standard curve was linear (r(2)=0.9972 for 4-OH mephenytoin; r(2)=0.9946 for dansyl-4-OH mephenytoin) over the concentration range of 0.16 to 40ng/mL for both derivatised and underivatised forms. The CV (%) and relative error (RE) for inter and intraassay at three QC levels for dansyl-4-OH mephenytoin was 0.97-5.85% and -9.80 to 2.51%, respectively. Whereas, for 4-OH mephenytoin the CV (%) and RE (%) at three QC levels was 0.82-3.47% and -6.69 to -0.01%, respectively. The developed method was validated for various parameters such as linearity, precision & accuracy, extraction recovery, matrix effect, autosampler stability and was proved to be consistent across three QC levels with overall CV (%) less than 15. Dansylation helped in increasing the sensitivity of hydroxy mephenytoin by 100-200 fold. Given the simplicity involved in derivatisation process, we believe that this novel methodology will change the current approaches used for the enhancing the detection sensitivity of 4-OH mephenytoin. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 989. DOI:10.1016/j.jchromb.2015.02.031
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    ABSTRACT: LC-MS based drug metabolism studies are effective in the optimization stage of drug discovery for rapid partial structure identification of metabolites. However, these studies usually do not provide unambiguous structural characterization of all metabolites, due to the limitations of MS-based structure identification. LC-MS-SPE-NMR is a technique that allows complete structure identification, but is difficult to apply to complex in vivo samples (such as bile collected during in vivo drug metabolism studies) due to the presence, at high concentrations, of interfering endogenous components, and potentially also dosage excipient components (e.g. polyethylene glycols). Here, we describe the isolation and structure characterization of seven metabolites of the drug development candidate 1-isopropyl-4-(4-isopropylphenyl)-6-(prop-2-yn-1-yloxy) quinazolin-2(1H)-one from a routine metabolism study in a bile-duct cannulated rat by LC-MS-SPE. The metabolites were isolated from bile and urine by repeated automatic trapping of the chromatographic peak of each metabolite on separate Oasis HLB SPE columns. The micropreparative HPLC/MS was performed on an XBridge BEH130 C18 HPLC column using aqueous formic acid/acetonitrile/methanol as mobile phase for the gradient elution. Mass spectrometric detection was performed on a LTQ XL linear ion trap mass spectrometer using electrospray ionization. Desorption of each metabolite was performed after the separation sequence. NMR spectra ((1)H, (13)C, 2D ROESY, HSQC and HMBC were measured on a Bruker AVANCE III spectrometer (600MHz proton frequency) equipped with a 1.7mm (1)H{(13)C,(15)N} Bruker Biospin's TCI MicroCryoProbe™. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2015; 989. DOI:10.1016/j.jchromb.2015.02.044