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

Ochratoxin A (OTA) is a nephrotoxic and nephrocarcinogenic mycotoxin commonly produced by several ubiquitous Aspergillus and Penicillium species. OTA is found predominantly in cereals and derived products, and therefore OTA may 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 fluorescence detection is not specific in this instance, the beer samples were also analyzed by high-performance liquid chromatography electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). OTA levels in the range of 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.