ICP-MS Determination of 15 Harmful Elements in Cosmetics

Samples of cosmetics were dissolved by digestion with HNO3 and a small amount of H2SO4 in the CEM Mars XP Microwave digester,and the solutions obtained after dilution to a definite volume were used for ICP-MS determination of Be,V,Cr,Ni,As,Se,Sr,Mo,Pd,Cd,Nd,Au,Hg,Tl and Pb.Analytical conditions of ICP-MS were optimized,and the internal standard method was used in quantification to afford elimination of matrix effect and interferences.Detection limits (3S) of the 15 elements determined were determined and calculated as defined by IUPAC,and the values obtained were in the range of 0.004 μg·L-1 to 0.139 μg·L-1.Precision of the instrument operated under the prescribed parameters,and of the method of sample analysis were tested,giving values of RSD′s (n=6) in the ranges of 1.59%-9.88% and 1.88%-4.86% respectively.Tests for recovery were made at 3 different concentration levels,giving values in the range of 84.32%-123.70%.Sample solutions were kept in refrigerator at 0-5 ℃ and were stable within 2 days.