Simultaneous development of six LC-MS-MS methods for the determination of multiple analytes in human plasma

Traditional sequential single analyte method development is both time-consuming and labor-intensive. In this report, a concept of simultaneously developing multiple liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) methods were proposed. Mass spectrometric and chromatographic conditions as well as sample preparation methods for all analytes were optimized concurrently. Mass spectrometric conditions for six analytes, i.e. clonidine (CLO), albuterol (ALB), fentanyl (FEN), ritonavir (RIT), naltrexone (NAL), and loratadine (LOR), were established simultaneously using the Sciex Analyst software. LC-MS-MS sensitivities obtained using gradient elution methods on reversed-phase Inertsil ODS3 and normal phase Betasil silica columns were compared. Sample extraction methods using protein precipitation, liquid/liquid extraction, or solid-phase extraction (SPE) were evaluated. Recovery of analytes was determined. Matrix effects and interference due to endogenous compounds were investigated. Selection of a potential internal standard was discussed.