High-performance liquid chromatographic-tandem mass spectrometric method for the determination of ethionamide in human plasma, bronchoalveolar lavagefluid and alveolar cells

We have developed and validated an accurate, sensitive, and rapid high-perf ormance liquid chromatographic-tandem mass spectrometric method (HPLC-MS-MS ) for the determination of ethionamide in plasma, bronchoalveolar fluid (BA L) and alveolar cells (AC). The retention times for ethionamide, clemastine fumarate (internal standard for plasma), promethazine (internal standard f or plasma) and propranolol (internal standard for BAL and AC) were approxim ately 2.62, 1.21, 2.14, and 2.22 min, respectively, with a total run time o f 3.2 min. Ethionamide detection for plasma was carried out on a PE Sciex A PI III (Perkin-Elmer, Foster City, CA, USA). BAL and cell pellets and some plasma specimens were analyzed on a Micromass Quattro LC (Micromass Co., Ma nchester, UK), The detection limits for ethionamide were 0.05 mug/ml for pl asma, and 0.005 mug/ml for BAL supernatants and alveolar cell suspensions. (C) 2001 Elsevier Science B.V. All rights reserved.