Analysis of lac color in diets and feces of rats for toxicity studies

An analytical method was developed for lac color in diets fed to rats and in the feces, and the contents of lac color were determined. After lac color was extracted with 0.05% sodium carbonate and 50% ethanol containing 0.02% sodium lauryl sulfate from the diets and feces, the extracted color solutions were analyzed by HPLC. The recoveries of lac color from diets spiked at 1.25, 5.00% and that from feces spiked at 5.00% were 85.6, 93.4% and 69.5%, respectively. Contents of lac color in diets prepared to contain 1.25 and 5.00% were 1.1 and 5.2%, and dose levels were confirmed by these results. Contents of lac color in feces of male and female rats given lac color were 127.8 mg/g and 138.6 mg/g, respectively. By comparing the HPLC chromatograms of laccaic acids in the diet with those in feces of rats, laccaic acid A, B, C and E were detected in both, and their content ratios were approximately determined.