Rapid method for the determination of ochratoxin A in urine by immunoaffinity column clean-up and high-performance liquid chromatography.

A rapid and accurate method to quantify ochratoxin A (OTA) at ppt (pg/ml) levels in urine has been developed. The method uses commercial immunoaffinity columns for clean-up and reversed phase high-performance liquid chromatography (HPLC) with fluorescence detector for quantification of the toxin. Average recoveries of OTA from human urine spiked at levels from 0.05 ng/ml to 1.0 ng/ml ranged from 88% to 93%, with relative standard deviations (RSDs) between 1% and 8%. Detection limit was 0.005 ng/ml. Out of 41 human urine samples, 25 were found positive to OTA with only one sample exceeding 0.05 ng/ml; the latter originated from a patient affected by karyomegalic interstitial nephritis. The method can be used as a rapid and non-invasive tool to assess human and animal exposure to OTA in epidemiological studies and to establish the possible role of OTA in acute animal intoxications or human end-stage renal diseases.