Determination of ochratoxin A in pig's kidney using enzymic digestion, dialysis and high-performance liquid chromatography with post-column derivatisation

Abstract

A method for the determination of ochratoxin A in pig's kidneys is described. The detection limit is less than 1 µg kg^–1. By using enzymic digestion concurrently with dialysis and by controlling the pH conditions, the sample is extracted and interfering co-extracts removed without the use of column chromatography. The final determination employs reversed-phase high-performance liquid chromatography with either a phthalimidopropylsilane or a C₂₂(docosyl) bonded column, and the sensitivity of the fluorescence detector is increased ten-fold by the formation of a post-column derivative with ammonia solution.