A flow injection vapor generation method is described for the analysis of lipstick for Pb by isotope dilution inductively
coupled plasma mass spectrometry (ICP-MS). A sample homogenatewas prepared as emulsion containing
1% m/v lipstick, 0.5% m/v K3Fe(CN)6, 0.5% v/vHNO3 and 0.5% m/v Triton X-100 andwas injected into a VG-ICP-MS
systemfollowed by sodiumborohydride for the vapor generation of Pb. Since the efficiency of hydride generation
of Pb in emulsion and that of aqueous solution was quite different, isotope dilution and standard addition
methods were used for the determination of Pb in selected lipstick samples. The influences of vapor generation
conditions on the Pb ion signal were reported. This method has been validated by the determination of Pb
in GBW09305 Cosmetic (cream) reference material. The method was also applied for the determination of Pb
in lipsticks of different colors obtained locally. The analytical results obtained by isotope dilution and standard
addition methods were in good agreement and also with those of digested samples analyzed by pneumatic
nebulization ICP-MS. Under the optimum operating conditions, the detection limit obtained was 0.001 ng mL−1
in prepared emulsified solutions, corresponding to 0.11 ng g−1 of Pb in the original lipstick samples