This review article discusses the most recent significant advances in the s
ample preparation and mass spectrometry aspects of high-throughput bioanaly
sis by LC/MS/MS for the quantitation of drugs, metabolites and endogenous b
iomolecules in biological matrices. The introduction and implementation of
automated 96-well extraction has brought about high-throughput approaches t
o the biological sample preparation techniques of solid-phase extraction, l
iquid-liquid extraction and protein precipitation The fast-flow on-line ext
raction technique is a different high-throughput approach that has also sig
nificantly speeded up analysis by LC/MS/MS. The use of pierceable caps for
biological tubes further enhances the analysis speed and improves the safet
y in handling biological samples. The need for adequate chromatographic sep
aration in order to eliminate interferences due to metabolites and/or matri
x effects in LC/MS/MS is discussed. To highlight our limited understanding
of atmospheric pressure ionization mass spectrometry, results from recent i
nvestigations that appear to be counter-intuitive are presented. Looking ah
ead to the future, multiplexed LC/MS/MS systems and capillary LC are presen
ted as areas that can bring about further improvements in analysis speed an
d sensitivity to quantitative bioanalysis by LC/MS/MS. Copyright (C) 2000 J
ohn Wiley & Sons, Ltd.