LAUSR

A certified reference material (CRM) for reserpine was investigated by raw material purification, qualitative analysis, quantitative analysis, homogeneity testing, stability testing, characterization, and uncertainty evaluation. The candidate reference material was prepared by recrystallization of purchased reserpine. After purification and drying, the candidate materials were enclosed in brown glass bottles. The chemical composition of the candidate reserpine reference material was confirmed by infrared spectroscopy, high-resolution mass spectrometry, and nuclear magnetic resonance. The homogeneity and stability of several sample bottles of the candidates were studied by stratified random sampling. With the cooperation of eight qualified laboratories, the purity of reserpine was analyzed by a mass balance method (including area normalization, water content, ash content and residual solvent analyses by liquid chromatography) with a certified purity mass fraction of 99.3 % and an expanded uncertainty of 0.5 % ( k  = 2). This reference material has been identified as a Chinese national-grade secondary CRM, which is numbered GBW(E) 090901, and is expected to be used in the calibration of instruments such as those used for liquid chromatography or method evaluations in food, medicine, environmental, and cosmetic analyses.