| Popis: |
A gas-liquid chromatographic (GLC) method, using the butyryl esters of sterols, has been developed for the measurement of cholesterol, stigmasterol, sitosterol, and campesterol in foods. An immobile phase of 1 % SE-30 coated on 100–120 mesh Gas-Chrom Q packed in a 6′ × 4 mm id glass column operated at 255°C was the most satisfactory of 7 column packings evaluated. Extraction with chloroform-methanol gave 98.7 % recovery with a coefficient of variation of 1.8% for cholesterol added to a variety of foods. When cholesteryl palmitate was added to vegetable oil and the butyryl derivative was prepared, followed by GLC analysis, the recovery was 99.3% with a coefficient of variation of 0.9%. Amounts as low as 1 mg/100 g food can be detected with a precision of 2.5%. The results of the analysis of a variety of foods for cholesterol, campesterol, sitosterol, and stigmasterol are given. |
