title: Determination of a beta(3)-agonist in human plasma by LC/MS/MS with semi-automated 48-well diatomaceous earth plate.
abstract: Methods for the determination of a beta(3)-agonist (A) in human plasma were developed and compared based on high-performance liquid chromatography (HPLC) with tandem mass spectrometric (MS/MS) detection using a turbo ion spray (TIS) interface. Drug and internal standard were isolated from plasma by three sample preparation methods, liquid-liquid extraction, Chem Elut cartridges and 48-well diatomaceous earth plates, that successively improved sample throughput for LC/MS/MS. MS/MS detection was performed on a PE Sciex API 365 tandem mass spectrometer operated in positive ion mode and using multiple reaction monitoring (MRM). The precursor/product ion combinations of m/z 625/607 and 653/515 were used to quantify A and internal standard, respectively, after chromatographic separation of the analytes. Using liquid-liquid extraction and Chem Elut cartridges, the assay concentration range was 0.5-100 ng/ml. Using diatomaceous earth plates, the concentration range of the assay was extended to 0.5-200 ng/ml. For all three assays, the statistics for precision and accuracy is comparable. The assay accuracy ranged from 91-107% and intraday precision as measured by the coefficient of variation (CV) ranged 2-10%. The sample throughput was tripled when the diatomaceous earth plate method was compared with the original liquid-liquid extraction method.
authors.affiliation: Merck Research Laboratories, Merck & Co., Inc., WP 75A-303, West Point, PA 19486, USA. amy_wang@merck.com
authors.forename: A Q
authors.initials: AQ
authors.lastname: Wang
authors.forename: A L
authors.initials: AL
authors.lastname: Fisher
authors.forename: J
authors.initials: J
authors.lastname: Hsieh
authors.forename: A M
authors.initials: AM
authors.lastname: Cairns
authors.forename: J D
authors.initials: JD
authors.lastname: Rogers
authors.forename: D G
authors.initials: DG
authors.lastname: Musson
mesh_terms: D058667:Adrenergic beta-3 Receptor Agonists; D000318:Adrenergic beta-Agonists / Q000097:blood*; D002853:Chromatography, Liquid; D006801:Humans; D013058:Mass Spectrometry
chemical_list: D058667:Adrenergic beta-3 Receptor Agonists; D000318:Adrenergic beta-Agonists