title: Automated determination of rifampicin in plasma samples by in-tube solid-phase microextraction coupled with liquid chromatography.
abstract: A sensitive and automated method is described for determination of rifampicin in plasma samples for therapeutic drug monitoring by in-tube solid-phase microextraction coupled with liquid chromatography (in-tube SPME/LC). Important factors in the optimization of in-tube SPME are discussed, such as coating type, sample pH, sample draw/eject volume, number of draw/eject cycles, and draw/eject flow rate. Analyte pre-concentrated in the polyethylene glycol phase was directly transferred to the liquid chromatographic column by percolation of the mobile phase, without carryover. The method was linear over the 0.1-100 μg/mL range, with a linear coefficient value (r(2)) of 0.998. The inter-assay precision presented coefficient of variation ≤ 1.7%. The effectiveness and practicability of the proposed method are proven by analysis of plasma samples from ageing patients undergoing therapy with rifampicin.
authors.affiliation: Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, SP, Brazil.
authors.forename: L P
authors.initials: LP
authors.lastname: Melo
authors.forename: R H C
authors.initials: RH
authors.lastname: Queiroz
authors.forename: M E C
authors.initials: ME
authors.lastname: Queiroz
mesh_terms: D001331:Automation; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D012293:Rifampin / Q000097:blood* / Q000302:isolation & purification*; D052617:Solid Phase Microextraction / Q000379:methods*
chemical_list: D012293:Rifampin