Automated solid-phase extraction method for the determination of atovaquone in capillary blood applied onto sampling paper by rapid high-performance liquid chromatography

A bioanalytical method for the determination of atovaquone in 100 mul blood-spots by solid-phase extraction and high-performance liquid chromatography has been developed and validated, Atovaquone was extracted from the sampling paper in 0.2 M phosphoric acid and a structurally similar internal standard was added with acetonitrile before being loaded onto a CX end-capped solid-phase extraction column. Atovaquone and internal standard were analysed by high-performance liquid chromatography on a C,, J'Sphere ODS-M80 (150x4.0 mm) column with mobile phase acetonitrile-phosphate buffer, 0.01 M, pH 7.0 (65:35, v/v) and UV detection at 277 nm. The intra-assay precision was 2.7% at 12.00 muM and 13.5% at 1.00 muM. The inter-assay precision was 3.3% at 12.00 muM and 15.6% at 1.00 muM. The lower limit of quantification was 1.00 muM The limit of detection was 0.50 muM. (C) 2001 Elsevier Science B.V. All rights reserved.