High-throughput quantitative bioanalysis by LC/MS/MS

This review article discusses the most recent significant advances in the sample preparation and mass spectrometry aspects of high-throughput bioanalysis by LC/MS/MS for the quantitation of drugs, metabolites and endogenous biomolecules in biological matrices. The introduction and implementation of automated 96-well extraction has brought about high-throughput approaches to the biological sample preparation techniques of solid-phase extraction, liquid-liquid extraction and protein precipitation. The fast-flow on-line extraction technique is a different high-throughput approach that has also significantly speeded up analysis by LC/MS/MS. The use of pierceable caps for biological tubes further enhances the analysis speed and improves the safety in handling biological samples. The need for adequate chromatographic separation in order to eliminate interferences due to metabolites and/or matrix effects in LC/MS/MS is discussed. To highlight our limited understanding of atmospheric pressure ionization mass spectrometry, results from recent investigations that appear to be counter-intuitive are presented. Looking ahead to the future, multiplexed LC/MS/MS systems and capillary LC are presented as areas that can bring about further improvements in analysis speed and sensitivity to quantitative bioanalysis by LC/MS/MS.