Cieri U R
U.S. Food and Drug Administration, Philadelphia, PA 19106, USA.
J AOAC Int. 1998 Mar-Apr;81(2):373-80.
A liquid chromatographic (LC) method for determining reserpine and rescinnamine in Rauwolfia serpentine powders and tablets, which uses fluorescence detection, was subjected to a collaborative study. The procedure for extraction and purification is a simplified version of that used in the current official method for analysis of these products. LC separations are performed on a normal-phase column. The mobile phase is methanol to which a small volume of an aqueous solution of 1-pentanesulfonic acid sodium salt can be added to achieve desired elution characteristics. Reserpine and rescinnamine elute at approximately the same time but can be individually quantitated by appropriate settings of the fluorescence detector. Reserpine is determined at an excitation wavelength of 280 nm and an emission wavelength of 360 nm, because rescinnamine is completely non-fluorescent at these wavelengths. Rescinnamine is determined at an excitation wavelength of 330 nm and an emission wavelength of 435 nm, because reserpine is completely nonfluorescent at these wavelengths. The following materials were used for the study: one sample of United States Pharmacopeia (USP) standard R. serpentine powder, one tablet type labeled as containing 100 mg R. serpentine and 2 tablet types labeled as containing 50 mg R. serpentine. For each of the 4 materials, 2 pairs of blind duplicates were prepared. Three materials were analyzed in duplicate by 8 laboratories. One of the 2 tablets labeled to contain 50 mg R. serpentine was analyzed only by 7 of 8 participating laboratories. Average combined content of reserpine and rescinnamine was 0.144% for the USP raw material and 0.132, 0.135, and 0.137% for the 3 commercial tablets. Reproducibility relative standard deviation values were 5.72, 5.93, 8.61, and 3.48% and repeatability relative standard deviation values were 2.57, 4.87, 3.19, and 1.99% for the 4 samples. The Associate Referee conducted a study to determine recoveries of reserpine plus rescinnamine by this method from mixtures simulating sample extracts. Average recovery of 15 determinations was 100.1%, with a relative standard deviation of 1.3%. The LC method for determination of reserpine and rescinnamine in R. serpentine powders and tablets has been adopted first action by AOAC INTERNATIONAL.
采用荧光检测的液相色谱（LC）法测定蛇根木粉末和片剂中的利血平和萝芙木碱，并进行了协同研究。提取和纯化程序是当前这些产品官方分析方法所用程序的简化版本。LC分离在正相柱上进行。流动相为甲醇，可加入少量1-戊烷磺酸钠盐水溶液以实现所需的洗脱特性。利血平和萝芙木碱几乎同时洗脱，但可通过荧光检测器的适当设置分别进行定量。利血平在激发波长280 nm和发射波长360 nm处测定，因为萝芙木碱在这些波长下完全无荧光。萝芙木碱在激发波长330 nm和发射波长435 nm处测定，因为利血平在这些波长下完全无荧光。研究使用了以下材料：一份美国药典（USP）标准蛇根木粉末样品、一种标示含100 mg蛇根木的片剂和两种标示含50 mg蛇根木的片剂。对于这4种材料中的每一种，制备了2对盲法重复样品。8个实验室对其中3种材料进行了重复分析。标示含50 mg蛇根木的2种片剂中的1种仅由8个参与实验室中的7个进行了分析。USP原料中利血平和萝芙木碱的平均总含量为0.144%，3种市售片剂的含量分别为0.132%、0.135%和0.137%。4个样品的再现性相对标准偏差值分别为5.72%、5.93%、8.61%和3.48%，重复性相对标准偏差值分别为2.57%、4.87%、3.19%和1.99%。副裁判进行了一项研究，以确定该方法从模拟样品提取物的混合物中回收利血平和萝芙木碱的情况。15次测定的平均回收率为100.1%，相对标准偏差为1.3%。测定蛇根木粉末和片剂中利血平和萝芙木碱的LC方法已被AOAC INTERNATIONAL首次采用。
