Determination of ochratoxin A in pig liver-derived pates by high-performance liquid chromatography

A solid phase extraction procedure followed by HPLC analysis with fluorescence detection has been developed for ochratoxin A (OTA) in pates derived from pig liver. After a previous extraction of OTA with 60% acetonitrile, all the samples were purified through C-8 columns. The percentage recovery was 85.7% and the lower limits calculated for accurate detection and quantitation were 0.56 ng/g and 0.84 ng/g respectively. The HPLC procedure showed a good linearity in the interval of equivalent OTA concentrations of 0.84 to 3 ng/g. Values <10% were obtained for precision in HPLC determinations performed (n=3) and (n=9). Stability of calibration standards and samples during the analytical procedure was also demonstrated. This method was successfully applied to 38 pig-derived pates and three samples were found to be positive with OTA levels above the detection limit. The highest concentration (1.77 ng/g) has been found in a home-made pate.