高效液相色谱法同时测定化妆品中壬二酸及其衍生物壬二酰二甘氨酸钾的含量

目的建立高效液相色谱法测定化妆品中壬二酸及其衍生物壬二酰二甘氨酸钾的分析方法。方法样品经60 mmol·L-1氢氧化钠?甲醇（1∶1）溶液超声提取，离心，经微孔滤膜过滤后，用SVEA C8柱（250 mm ×4.6 mm，5 μm）分离，以15 mmol·L-1（pH=3.0）磷酸二氢钾缓冲溶液?乙腈为流动相，梯度洗脱，流速1.0 mL·min-1，检测波长210 nm，外标法定量。结果回收率均在87.66%~108.96%，相对标准偏差（RSD）均在0.6%~3.3%，两种化合物检出限（LOD）分别为0.020%和0.015%。测定10批标签标识有壬二酸或壬二酰二甘氨酸钾化妆品，其中7批检出壬二酸，1批检出壬二酰二甘氨酸钾。结论该方法快速简便、灵敏度高，适用于市售化妆品中壬二酸及其衍生物壬二酰二甘氨酸钾的测定。

Determination of azelaic acid and potassium azeloycinate diglycinate in cosmetics by HPLC

ObjectiveAn HPLC method was established for the determination of azelaic acid and potassium azeloycinate diglycinate in cosmetics.MethodsThe samples were extracted with 60 mmol·L-1 sodium hydroxide water solution-methyl alcohol. After centrifugation and filtration， the analysis of azelaic acid and potassium azeloycinate diglycinate was performed with a SVEA C8（250 mm×4.6 mm， 5 μm） column， using 15 mmol?L-1 potassium dihydrogen phosphate solution （pH=3.0） and acetonitrile for gradient elution at a flow rate of 1.0 mL·min-1. The analytes were detected with UV detector， and quantified by external standard curve.ResultsThe results showed a good linearity in the range of 5?1 000 μg?mL-1 with correlation coefficients （r） larger than 0.999. The detection limit of azelaic acid and potassium azeloycinate diglycinate （LOD） was 0.020% and 0.015%， respectively. The spiked recoveries were 87.66% to 108.96% with the relative standard deviation （RSD） of 0.6% to 3.3%.ConclusionThe method is simple， rapid and highly sensitive. It is suitable for the determination of azelaic acid and potassium azeloycinate diglycinate in cosmetics.