A new method was proposed for the accurate determination of mercury in cosmetic samples based
on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry
(ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and
subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection.
Therefore, the risks of analyte contamination and loss were avoided. Highly enriched 201Hg isotopic
spike is added to cosmetics and the isotope ratios of 201Hg/202Hg were measured for the quantitation
of mercury. With ID calibration, the influences originating from sample matrixes for the determination
of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental
parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample
were investigated. The method provided good reproducibility and the detection limits were found to be
0.6 pg mL−1. Finally, the developed method was successfully applied for the determination of mercury in
six cosmetic samples and a spike test was performed to verify the accuracy of the method.