RESUMO
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.
