采用高效液相色谱法测定化妆品中的甲硝唑、替硝唑、奥硝唑和塞克硝唑。样品经甲醇和0.1 mol·L-1盐酸溶液以体积比1比1组成的混合溶液超声提取15 min后,以C18色谱柱为分离柱,以甲醇-乙腈-水(7+1+2)混合液为流动相,在检测波长315 nm处进行测定。4种硝基咪唑类药物在一定的质量浓度范围内与峰面积呈线性关系,方法检出限(3S/N)和测定下限(10S/N)分别低于10 mg·kg-1和30 mg·kg-1。以空白样品为基体进行加标回收试验,测得回收率在93.8%~104%之间,相对标准偏差(n=6)在0.2%~4.1%之间。

HPLC was applied to the determination of metronidazole, tindazole, ornidazole and secnidazole in cosmetics. The sample was extracted ultrasonically with a mixture of methanol and 0.1 mol·L-1 HCl solution (1+1) for 15min. C18 chromatographic column was used as stationary phase, and a mixture of methanol, acetonitrile and water (7+1+2) was used as mobile phase. UV-detection at 315 nm was adopted in the determination. Linear relationships between values of peak area and mass concentration of the 4 nitroimidazoles were kept in definite ranges, with detection limits (3S/N) and lower limits of determination (10S/N) less than 10 mg·kg-1 and 30 mg·kg-1 respectively. On the base of a blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 93.8%-104% with RSD′s (n=6) in the range of 0.2%-4.1%.