Examine by thin-layer chromatography (2.2.27), using silica gel G R as the coating substance. Test solution. Dissolve 10 mg of the substance to be examined in a mixture of 2 volumes of water R and 3 volumes of methanol R and dilute to 20 ml with the same mixture of solvents.Reference solution(a). Dissolve 10 mg of (a suitable reference) CRS in a mixture of 2 volumes of water R and 3 volumes of methanol R and dilute to 20 ml with the same mixture of solvents.
Reference solution(b). Dissolve 10 mg each of fructose CRS, glucose CRS, lactose CRS and sucrose CRS in a mixture of 2 volumes of water R and 3 volumes of methanol R and dilute to 20 ml with the same mixture of solvents.
Apply separately to the plate 2 �l of each solution and thoroughly dry the starting points. Develop over a path of 15 cm using a mixture of 10 volumes of water R, 15 volumes of methanol R, 25 volumes of anhydrous acetic acid R and 50 volumes of ethylene chloride R, measured accurately as a slight excess of water causes cloudiness of the solution.
Dry the plate in a current of warm air. Repeat the development immediately, after renewing the mobile phase. Dry the plate in a current of warm air and spray evenly with a solution of 0.5 g of thymol R in a mixture of 5 ml of sulphuric acid R and 95 ml of alcohol R. Heat at 130 �C for 10 min.
The principal spot in the chromatogram obtained with the test solution is similar in position, colour and size to the principal spot in the chromatogram obtained with reference solution (a). The test is not valid unless the chromatogram obtained with reference solution (b) shows four clearly separated spots. (Dit is natuurlijk de system suitabillity-test)
2 juli 1999