Immunoaffinity column for ochratoxin aids in identifying and measuring the amount of ochratoxin in food and feed samples. Ochratoxin is a dangerous secondary metabolite that can infect a variety of food and feed products, including cereals, coffee, wine, and pork. It is produced by a number of fungi, including species of the aspergillus and penicillium genus. A chromatographic column called an immunoaffinity column for ochratoxin is filled with a solid support matrix coated with certain antibodies that bind only to the molecules of ochratoxin. The antibodies trap the ochratoxin molecules while a sample is run through the column, while other interfering elements are flushed away.