可见分光光度法测定胡椒碱纯度的研究

目的]考察可见分光光度法测定胡椒碱含量的最佳溶剂和最适宜检测波长。方法]以二氯乙烷、乙酸乙酯和无水乙醇作为溶剂,考察胡椒碱在380~420 nm波长范围内的最佳溶剂和测定波长,并将其测定纯度与HPLC法进行比较。结果]最佳的溶剂为无水乙醇;在较低浓度范围内（0~0.01 g/L）,胡椒碱最适宜的测定波长为380 nm,而在较高浓度范围（0.20~1.00 g/L）,其最适宜的测定波长则为400 nm。可见分光光度法所测定的样品中胡椒碱纯度与HPLC法进行比较,平均误差为0.85%。结论]利用可见分光光度计测定胡椒碱纯度具有较高的准确度,是可行的。

Study on Purity of Piperine by UV-VIS Spectrophotometry

Objective] To investigate the optimal solvent and detection wavelength for piperine by UV-VIS spectrophotometry.Method] Using dichloroethane,ethyl acetate and absolute ethanol as solvent,the optimal solvent and detection wavelength of piperine were surveyed at wavelength of 380-420 nm,and the determined result was compared with that detected by HPLC.Result]The optimum solvent was absolute ethanol,and the optimum detection wavelength for piperine was 380 nm at lower concentration(0-0.01 g/L),while that was 400 nm at higher concentration(0.20-1.00 g/L).The mean error between the purity determined by UV-VIS spectrophotometry and HPLC method was just 0.85%.Conclusion] Good in precision,UV-VIS spectrophotometry is favorable for the determination of piperine.