DETERMINATION OF INDOLIC COMPOUNDS IN PIG BACK FAT BY SOLID-PHASE EXTRACTION AND GRADIENT HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH SPECIAL EMPHASIS ON THE BOAR TAINT COMPOUND SKATOLE

A gradient high-performance liquid chromatographic method for the separation of thirteen indolic compounds and the determination of seven of them was developed. The indolic compounds include indole and skatole, both of which are involved in the boar taint. A solid-phase extraction method for sample preparation for the determination of the indolic compounds in pig back fat is described. The indolic compounds are extracted with acetone-Tris buffer, and lipids and fatty acids are trapped on a Bond-Elut C18 column. Fluorescence (excitation and emission at 280 and 340 nm, respectively) is used for selective detection. The detection limit for indole and skatole is 15 mug kg-1 back fat. The sample preparation procedure is simple and the method is sensitive and reproducible. The method was compared with a spectrophotometric method for the determination of skatole in back fat.