Determination of ochratoxin A in pig tissues by liquid-liquid extraction and clean-up and high-performance liquid chromatography

A fast, simple, and sensitive HPLC-FD method is described for determination of ochratoxin A (OTA) in pig kidney and muscle; a small mass (<2.5 g) of sample and a relatively small volume (<15 mL) of a non-halogenated extraction solvent are required. Ochratoxin B, systematically absent from all the samples investigated, was used as internal standard. Liquid-liquid partition was used for sample clean-up. Recoveries at the 1 ng g(-1) level were 86+/-15% and 74+/-8% for kidney and muscle, respectively, and detection limits were 0.14 and 0.15 ng g(-1). Clean-up by solid-phase extraction (SPE) is required for pig liver. A survey of the OTA content of tissues of pigs slaughtered in southern Italy revealed that 52 out of 54 analysed samples were contaminated; the OTA concentration in kidney ranged between 0.26 and 3.05 ng g(-1). The effect of measurement precision on compliance with legal limits is also discussed.