Rapid high-performance liquid chromatographic method for simultaneous determination of androstenone, skatole and indole in back fat from pigs.

A rapid high-performance reversed-phase liquid chromatographic method for the simultaneous quantitative determination of the main boar taint compounds androstenone, skatole (3-methylindole) and indole, in back fat from pigs has been developed. The compounds are extracted by a simple homogenisation of adipose tissue in methanol; interfering lipids are removed by precipitation after cooling and centrifugation. Androstenone is derivatized pre-column with dansylhydrazine (5 min at ambient temperature) using BF3 as catalyst. The compounds are separated on a 60 x 4.6 mm I.D., 3 microns Hypersil ODS column (Hewlett-Packard) using a step-gradient; total time for the separation is 15 min. Fluorescence is used for selective detection. The limit of quantitation for indole and skatole is 30 ng/g and for androstenone 200 ng/g back fat. The results for skatole obtained by the present method were compared with those of colorimetric method, while androstenone determinations were compared with two GC-MS methods and a RIA method. The correlations observed were in the range of 0.946-0.993. The average contents of androstenone and skatole were 640 +/- 700 and 78 +/- 113 ng/g (n = 1162 male pigs), respectively.