提出了高效液相色谱法同时测定化妆品中7种防腐剂(6种尼泊金酯和苯甲酸)含量的方法。样品经甲醇超声提取,ZORBAX Extend XDB-C18色谱柱(250 mm×4.6 mm,10 μm)分离,以乙腈-甲醇-磷酸二氢钠(15+35+50)溶液为流动相洗脱,在波长254 nm处用二极管阵列检测器检测。7种防腐剂的质量浓度分别在一定的范围内与其峰面积呈线性关系,方法的检出限(3S/N)为0.4~2.5 mg·L-1。在已知含量的化妆品样品中分别加入3个浓度水平的7种防腐剂标准溶液,按方法测定后计算其回收率在87.5%~98.5%之间,测定值的相对标准偏差(n=6)在0.41%~2.6%之间。

HPLC was applied to the determination of 7 preservatives, including 6 nipagin esters and benzoic acid, in cosmetics. The sample was ultrasonically extracted with methanol and separated with a mixture of acetonitrile-methanol-NaH2PO4 (15+35+50) as mobile phase on ZORBAX Extend XDB-C18 column (250 mm×4.6 mm, 10 μm). The contents of 7 preservatives were determined at the wavelength 254 nm with DAD. Linear relationships between values of peak area and mass concentration of 7 preservatives were kept in the definite ranges, with their detection limits (3S/N) in the range of 0.4-2.5 mg·L-1. Recovery and precision were tested by adding 7 preservatives standard solution to cosmetic samples of known preservative concentrations at 3 concentration levels, values of recovery found were in the range of 87.5%-98.5%, and values of RSD′s (n=6) found were in the range of 0.41%-2.6%.