High‐performance liquid chromatography with fluorescence detection of ochratoxin A in cereal, coffee, and wine: Effective pretreatment with bovine serum albumin‐immobilized adsorbent

Ochratoxin A is a fluorescent mycotoxin that is present in many foods. It is difficult to detect by high‐performance liquid chromatography because of interfering substances. We immobilized bovine serum albumin on resin and used it to extract ochratoxin A from various food samples. Sample extracts were applied to a cartridge packed with bovine serum albumin‐immobilized resin. The adsorbed ochratoxin A was eluted by octanoate, which is a serum albumin ligand. The chromatograms of the eluate showed no endogenous peaks that interfered with ochratoxin A detection. The recovery rates of ochratoxin A from coffee and wine samples were more than 82% with relative standard deviations of less than 5%. The positive detection result in the certified reference material of wheat agreed with its certification value. This clean‐up method with bovine serum albumin‐immobilized resin has great potential for assessing compliance of foods with ochratoxin A regulations.