Biomedical chromatography : BMC
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Biomed. Chromatogr. · Jan 2011
ReviewQuantitative liquid chromatography tandem mass spectrometry analysis of macromolecules using signature peptides in biological fluids.
Targeted protein quantification using peptide surrogates has increasingly become important to the validation of biomarker candidates and development of protein therapeutics. These approaches have been proposed and employed as alternatives to immunoassays in biological fluids. ⋯ This review article focuses on these processes or hyphenated techniques for quantification of proteins with peptide surrogates. The most recent advances and strategies involved with hyphenated techniques are discussed.
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Biomed. Chromatogr. · Jan 2009
ReviewMeasurement of xenobiotics in saliva: is saliva an attractive alternative matrix? Case studies and analytical perspectives.
The use of saliva for measuring xenobiotic concentrations has been practiced for a number of years. While the use of saliva has been generally reserved for the analysis of diagnostic and forensic/toxicology samples, attempts have been made to further enhance the value of saliva as an alternate matrix to those of plasma and serum. It is understood that saliva represents a handy tool for therapeutic drug monitoring (TDM) as it offers certain distinctive advantages. ⋯ While parent compound and phase I metabolite(s) for many xenobiotics have been generally quantifiable in saliva, phase II metabolites have not generally been detected in saliva. Therefore saliva samples could also be used to answer some specific PK/PD questions during the drug development process, if applicable. However, the development and validation of the assay in saliva needs to be carried out carefully with particular focus on proper sample collection, processing and storage to ensure the stability of the xenobiotics and with the same rigor as applied to plasma, serum and urine matrices.
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Biomed. Chromatogr. · May 2008
Simultaneous determination of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone in rat plasma by liquid chromatography-tandem mass spectrometry: application to a pharmacokinetic study of a standardized fraction of Salvia miltiorrhiza, PF2401-SF.
A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the simultaneous determination of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone, the active components of Salvia miltiorrhiza in rat plasma, was developed. After liquid-liquid extraction with tariquidar as an internal standard, tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone were eluted from an Atlantis dC18 column within 5 min with a mixture of methanol and ammonium formate (10 mm, pH 6.5; 85:15, v/v). The analytes were detected by an electrospray ionization tandem mass spectrometry in the selected reaction monitoring (SRM) mode. ⋯ The coefficients of variation and the relative errors of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone for intra- and inter-assay at four quality control (QC) concentrations were 1.1-5.1% and -4.0-6.0%, respectively. The lower limit of quantification for tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone was 0.25 ng/mL from 100 microL of plasma. This method was successfully applied to the pharmacokinetic study of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone after oral administration of PF2401-SF, the standardized fraction of Salvia miltiorrhiza enriched with tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone to male Sprague-Dawley rats.
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Biomed. Chromatogr. · Nov 2006
Liquid chromatographic-electrospray tandem mass spectrometric determination of clarithromycin in human plasma.
A rapid, sensitive and specific LC-MS-MS method has been developed for the determination of clarithromycin (CLA) in human plasma using roxithromycin (ROX) as the internal standard. Samples were prepared via liquid-liquid extraction with methyl tert-butyl ether (MTBE) and chromatographed on a Supelco RP(18) (4.6 x 50 mm, 3 microm particle size) column with a mobile phase consisting of acetonitrile:methanol:60 mM (pH 3.5) ammonium acetate buffer (32.5:32.5:35) at a constant flow rate of 0.8 mL/min. The run time was 3 min with retention times of approximately 1.65 and 1.70 min for CLA and ROX, respectively. ⋯ No matrix ionization suppression was observed when extracted blank matrix or reconstitution solvent was injected onto the system with post-column infusion of clarithromycin and roxithromycin. No carryover was observed when an extracted blank plasma sample was injected immediately after a 5000 ng/mL ULOQ (the upper limit of quantification) standard. The mean recovery was 81.5 and 78.3%, respectively, for clarithromycin and internal standard.
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Biomed. Chromatogr. · Jun 2006
Alterations of plasma and cerebrospinal fluid glutamate levels in rats treated with the N-methyl-D-aspartate receptor antagonist, ketamine.
It has been reported that the repeated administration of a sub-anesthetic dose of an N-methyl-D-aspartate receptor antagonist, ketamine, can produce an animal model of schizophrenia. Since no information is available on the alterations of the amino acid levels in ketamine-treated rats, we investigated the amino acid composition in the plasma and cerebrospinal fluid of rats that were repeatedly administered with ketamine for 5 consecutive days (30 mg/kg/day). ⋯ Among the amino acids investigated in the present study, the level of plasma glutamic acid increased significantly (p < 0.05), while that of the cerebrospinal fluid glutamic acid decreased significantly in the ketamine-treated rats as compared with these levels in control rats injected with saline (p < 0.05, n = 7). These alterations in the glutamic acid level in the plasma and cerebrospinal fluid resemble those in schizophrenic patients, suggesting that ketamine-treated rats may be a useful model for performing research on the pathophysiology of schizophrenia.