Abstract
A convenient method to determine the antioxidative activities of chemicals by using α-methylindole (MI) reagent in conjunction with high-performance thin-layer chromatography (HPTLC) is described. One μl of a mixture of 2% linolenic acid and test sample in ethanol solution was applied to a thin-layer chromatographic (TLC) plate and peroxidized at 80°C for 20 min. The lipid peroxides which were produced from the linolenic acid on TLC were detected as pink spots by spraying MI reagent and were measured at 557 nm with a TLC densitometer.When the test samples showed intrinsic colors interfering with this measurement, they were separated by developing the TLC plate after spraying MI reagent. The antioxidative activity of the test sample is expressed as the amount required to inhibit the peroxidation of linolenic acid by 50%.This method is very simple and rapid. It may be useful when the test samples are available only in small amounts.
