The integration of mass spectrometry and combinatorial chemistry is becoming commonplace in many laboratory settings. Combinatorial chemistry provides a means for synthesis of mixtures of large numbers of compounds, thereby greatly increasing the diversity of molecular architectures available for screening. Mass spectrometry is being utilized as a rapid and sensitive tool not only to characterize combinatorial libraries, but also to aid in the identification of active compounds.

Keywords: electrospray ionization (ESI), matrix-assisted laser desorption/ionization (MALDI), secondary ion mass spectrometry (SIMS),noncovalent complexes, beads, affinity selection, combinatorial library, mixture analysis, capillary electrophoresis, tandem mass spectrometry (MS/MS).