Determination of ochratoxin A using solid-phase extraction and narrow-bore HPLC with fluorescence and ESI-MS detector

A new, fast and simple high-performance liquid chromatographic (HPLC) method has been developed for the determination of ochratoxin A (OTA) production by fungi in culture media. The sample preparation consists of one step solid-phase extraction using a polymeric sorbent. The HPLC analysis uses a narrow-bore reversed-phase C18 column and an isocratic mobile phase composed of acetonitrile + water (0.1% HCOOH) (40+60) and fluorescence detector. The identity of this toxin was confirmed using electrospray ionization mass spectrometric detection (ESI/MS) in the positive ionization mode. The method had a recovery of 89.7% and a precision of 4.7% (n=6) for a sample which contains 17.3 ng/ml of OTA in culture media. The performance of the polymeric sorbent tested is as good as other studies published in the analysis of OTA. The detection limit of the new method is 0.05 ng/ml in culture media.