反相离子对色谱-电感耦合等离子体质谱法测定化妆品中不同形态的铬

Simultaneous determination of chromium speciation in cosmetics using reversed-phase ion-pair chromatography-inductively coupled plasma mass spectrometry

建立了反相离子对色谱(RP-IPC)与电感耦合等离子体质谱(ICP-MS)联用技术快速分离测定化妆品中Cr(Ⅲ)和Cr(Ⅵ)的方法。样品经乙二胺四乙酸钠盐(EDTA)50℃水浴中提取后,采用XDB-C18色谱柱分离,以5%(v/v)甲醇-2.0 mmol/L四正丁基铵盐(TBA)水溶液(pH 6.0)作为流动相,流速为1.0 mL/min,进样量为100μL。采用碰撞池技术消除ICP-MS测定时40Ar12C+、35Cl16O1H+对52Cr+的光谱学干扰。Cr(Ⅲ)和Cr(Ⅵ)的分离过程在5min内完成。样品中加标量为0.01～0.50μg时,其回收率为82.7%～107.2%,相对标准偏差(RSD)小于5.62%。该方法操作简便、灵敏度高、重现性好,适合于化妆品中Cr(Ⅲ)和Cr(Ⅵ)的同时分析。

A method was developed to determine chromium speciation simultaneously in cosmetics using reversed-phase ion-pair chromatography（RP-IPC） with inductively coupled plasma mass spectrometry（ICP-MS）.After the extraction with disodium ethylenediaminetetraacetate（EDTA） in a water bath,the sample was separated on an XDB C18 column with the mobile phase of 5%（v/v） methanol-2.0 mmol/L tetrabutylammonium（TBA）（pH 6.0）,the flow rate of 1.0 mL/min and the injection volume of 100 μL.The collision cell technology was applied to eliminate the mass interferences of 40Ar12C＋and 35Cl16O1H＋in the analysis of 52Cr＋.The separation was achieved within 5 min.The recoveries of Cr（Ⅲ） and Cr（Ⅵ） ranged from 82.7% to 107.2% with the relative standard deviations（RSDs） less than 5.62%（n=6） with the spiked amounts of 0.01-0.50 μg in different kinds of cosmetic samples.The developed method has the advantages of simplicity,sensitivity and good reproducibility,and can be used for the simultaneous determination of Cr（Ⅲ） and Cr（Ⅵ） in cosmetics.