PROCEDURE FOR THE DETERMINATION OF RETINOL AND ALPHA-TOCOPHEROL IN POULTRY TISSUES USING CAPILLARY GAS-CHROMATOGRAPHY WITH SOLVENT VENTING INJECTION

A procedure designed for the determination of retinol (vitamin A) and alpha-tocopherol (vitamin E) in poultry tissues has been developed. Th e procedure involves lipid extraction, saponification, solid-phase cle an-up and capillary gas chromatography (cGC). Retinol and alpha-tocoph erol were determined separately by cGC-flame ionisation detection usin g a fused-silica open tubular capillary column, 30 m X 0.25 mm I.D. co ated with 5% phenylmethylsilicone and with a film thickness of 0.25 mu m. Solvent extraction followed by saponification were sufficient to p rovide a purified extract which was directly analyzed for retinol by c GC in the solvent venting mode. However, in order to accurately determ ine alpha-tocopherol by cGC, further purification of the extract by so lid-phase extraction was necessary. A silica SPE column was used to re move interfering cholesterol from the extract. alpha-Tocopherol was an alyzed in its derivatized form. Absolute and relative recoveries for b oth vitamins from spiked samples were evaluated. Absolute and relative recoveries ranging from 80 to 95% were obtained for both compounds. 5 alpha-Cholestane and alpha-tocopheryl acetate were used as internal s tandards. Poultry muscle meat and liver tissue were analyzed for their retinol and alpha-tocopherol content and the peaks detected by cGC we re confirmed by cGC-mass spectrometry. (C) 1998 Elsevier Science B.V. All rights reserved.