高效液相色谱法测定防晒化妆品中22种化学防晒剂的含量

Determination of 22 Chemical Sunscreens in Sunscreen Cosmetics by High Performance Liquid Chromatography

建立了高效液相色谱法(HPLC)测定防晒化妆品中22种化学防晒剂的含量的方法。防晒化妆品样品0.25 g在25 mL混合溶剂Ⅰ或混合溶剂Ⅱ中涡旋,超声提取30 min。混合溶剂Ⅰ为体积比为5∶9的含0.1%(体积分数,下同)磷酸的甲醇-异丙醇的混合液,用于提取1~20号化学防晒剂;混合溶剂Ⅱ为体积比为5∶9∶2的甲醇-异丙醇-0.02 mol·L^(-1)乙酸铵溶液(磷酸调至pH 5.0)的混合液,用于提取21号对苯二亚甲基二樟脑磺酸和22号苯基二苯并咪唑四磺酸酯二钠。取所得提取液1 mL,用甲醇稀释至10 mL,经0.45μm滤膜过滤,供HPLC分析。以Agilent ZORBAX SB-C_(18)色谱柱为固定相,分别用不同体积比的甲醇-异丙醇-0.1%磷酸溶液的混合液(分离1~20号化学防晒剂)、甲醇-0.02 mol·L^(-1)乙酸铵溶液的混合液(分离21号和22号化学防晒剂)为流动相进行梯度洗脱,21号化学防晒剂的检测波长为340 nm,其余防晒剂的检测波长为311 nm。结果表明:22种化学防晒剂的质量浓度在一定范围内与其对应的峰面积呈线性关系,检出限(3S/N)为0.0005%~0.06%;以空白样品为基质进行加标回收试验,回收率为86.9%~113%,测定值的相对标准偏差(RSD,n=9)为0.10%~5.6%。方法用于测定20批防晒化妆品,检出14种化学防晒剂,所得结果与《化妆品安全技术规范》(2015年版)中方法结果一致。

A method for determination of 22 chemical sunscreens in sunscreen cosmetics by high performance liquid chromatography(HPLC)was established.The sunscreen cosmetic sample of 0.25 g was swirled in 25 mL of mixed solvent I or mixed solventⅡ,and was extracted for 30 min by ultrasound.The mixed solvent I was a mixture of methanol containing 0.1%(φ,the same below)phosphoric acid solution and isopropanol at volume ratio of 5∶9,which was used to extract No.1-20 chemical sunscreens.The mixed solventⅡwas a mixture of methanol-isopropanol-0.02 mol·L^(-1) ammonium acetate solution(adjusted to pH 5.0 with phosphoric acid)at volume ratio of 5∶9∶2,which was used to extract p-phenylenemethylbiscamphor sulfonicacid(No.21 chemical sunscreen)and phenyldibenzimidazole tetrasulfonate disodium ester(No.22 chemical sunscreen).The obtained extract of 1 mL was taken,diluted to 10 mL with methanol,and passed through a 0.45μm filter membrane for HPLC analysis.Agilent ZORBAX SB-C_(18) column was used as the stationary phase,and the mixture of methanol-isopropanol-0.1%phosphoric acid solution at various volume ratios(for separating No.1-20 chemical sunscreens)and the mixture of methanol-0.02 mol·L^(-1) ammonium acetate solution(for separating No.21 and No.22 chemical sunscreens)were used as mobile phases for gradient elution.The detection wavelength of No.21 chemical sunscreen was 340 nm,and that of other chemical sunscreens was 311 nm.As shown by the results,linear relationships between values of peak area and mass concentration of 22 chemical sunscreens were found in definite ranges,with detection limits(3 S/N)in the range of 0.0005%-0.06%.The recovery test was carried out with blank sample as substrate,giving results in the range of 86.9%-113%,with RSDs(n=9)of determined values ranged from 0.10%to 5.6%.The method was applied for determination of 20 batches of sunscreen cosmetics,and 14 chemical sunscreens were detected.The results obtained were consistent with those of the method in Safety and Technical Standards for Cosmetics(2015 Edition).