Column switching in high-performance liquid chromatography with tandem mass spectrometric detection for...

A high-throughput liquid chromatography-tandem mass spectrometry method is described for the determination of multiple compounds in dog and rat plasma. After acetonitrile precipitation of plasma proteins, the analytes are pre-concentrated and back-flushed on a reversed-phase column for separation using a switching valve. The analytes are ionized using TurboIon Spray in a positive mode, and detected by multiple reaction monitoring. Automatic tuning software is used for fast method development. The data processing is greatly speeded up by using a powerful quantitation software package. Chromatography of multiple compounds takes only 4 min. The linear calibration curve ranges from 0.5 to 1000 ng/ml. This method was successfully used in the analysis of multi-compounds for preclinical pharmacokinetic studies.