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

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100 μL。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5 min内完成。样品中加标量为0.01～0.50 μg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。

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

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 microL. The collision cell technology was applied to eliminate the mass interferences of 40Ar12 C+ and 35 C16O1 H+ in the analysis of 52 Cr+. 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 microg 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.