Determination of Five Hydroxy Acids in Cosmetics by High Performance Liquid Chromatography and Identification by Mass Spectrometry
An HPLC method and a LC-MS/MS method for the simultaneous determination of five hydroxy acid(lactobionic acid,gluconic acid,glyceric acid,pyruvic acid and hydroxymalonic acid)in cosmetics have been estabished.The sample was firstly dispersed with a small amount of isopropanol,and then extracted with primary water.A 30 mmol/L aqueous solution of ammonium acetate(adjusted to pH 2.9 with phosphoric acid)-methanol was used as the mobile phase,and the sample was subjected to ZORBAX SB-Aq(250 mm × 4.6 mm × 5 μm)chromatographic column separation and detection using diode array detector;if there is a suspected positive sample,it should be further confirmed by liquid chromatography-tandem mass spectrometry,and the ESI ion source should be used to establish the quantitative and qualitative ions and the relative abundance ratio of ion pairs of the five hydroxy acid components under the SRM negative ion monitoring mode.The results showed that the linear relationship of the five hydroxy acids was good within their respective concentration ranges,the correlation coefficients were all greater than 0.999,the detection concentration was 30-100 mg/kg,the quantitative concentration was 120-300 mg/kg,the average standard addition recovery was 91.8%-104.1%,and the RSD was 0.1%-1.9%.The method is efficient,accurate and reliable.It is suitable for qualitative screening and content determination of five hydroxy acids in cosmetics.