Developments of a fully automated parallel HPLC mass spectrometry system for the analytical characterization and preparative purification of combinatorial libraries

An automated parallel analytical/preparative HPLC/MS workstation has been developed to increase the analysis speed for characterizing and purifying combinatorial libraries. The system incorporates two columns operated in parallel for both LC/MS analysis and preparative LC/MS purifications (a technique we have named "parallel Analyt/PrepLCMS"). Keys to the successful development of this system have been the design of a multiple sprayer IonSpray interface to support flows from multiple columns and the design of a valving configuration which is under complete software control for delivering the crude samples to the two HPLC columns from a single autosampler. In comparison with the conventional LC/MS systems, where compounds are analyzed sequentially (i.e., one at a time), our parallel Analyt/PrepLCMS system provides an important increase in sample throughput, especially critical in the held of combinatorial chemistry, where compound libraries are generated frequently in parallel arrays and require high-throughout analysis techniques. Minor hardware modifications to the HPLC system were made to facilitate parallel chromatography analyses. By incorporating fast chromatography and mass-based fraction collection on our new parallel Analyt/PrepLCMS system, we demonstrate that more than 200 compounds can be characterized per instrument per day, and more than 200 compounds can be purified per instrument per night. The concept, design, and applications of parallel HPLC/MS to combinatorial libraries are presented and discussed.