Photodiode Array HPLC Detectors in Metabolic Profiling and other Analytical Screening Techniques

Abstract

A new generation of UV-visible spectrophotometers has appeared in which a compound’s absorption spectrum is depicted in a fraction of a second by a multichannel photodiode array system. These detectors can record a series of spectra of very low intensity and store the data in their own memory and/or in external devices such as magnetic tapes or discs. These properties give diode array detectors (DAD’s) great potential as on-line detectors in HPLC.

We have evaluated two commercially available DAD’s for use in drug metabolite profiling and systematic toxicological analysis. The combined HPLC-DAD system proved to be very useful, comparable in potential to a GC-MS or LC-MS combination yet much cheaper. However, limitations became apparent, particularly in the area of data generation, storage and retrieval. Some of these may be inherent in the technique; others may be obviated when the technique is further developed.