Determination of ochratoxin A in beer by high-performance liquid chromatography

Ochratoxin A (OTA) is a nephrotoxic and nephrocarcinogenic mycotoxin common ly produced by several ubiquitous Aspergillus and Penicillium species. OTA is found predominantly in cereals and derived products, and therefore OTA m ay be transferred into beer from contaminated grain. Thirty-five samples of German beers were analyzed: OTA was extracted with toluene and purified by solid phase extraction using silica cartridges. OTA was determined by high -performance liquid chromatography with fluorescence detection. Since of fl uorescence detection is not specific in this instance, the beer samples wer e also analyzed by high-performance liquid chromatography electrospray ioni zation-tandem mass spectrometry (HPLC-ESI-MS/MS). OTA levels in the range o f 0.1-0.2 mu g L-1 were found in 9 beef samples, 21 samples contained trace amounts of OTA (< 0.1 mu g L-1) and in 5 samples no OTA was detectable.