Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

Ying Gao; Zeming Shi; Qinxia Zong; Peng Wu; Jing Su; Rui Liu

doi:10.1016/j.aca.2014.01.002

Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

Anal Chim Acta. 2014 Feb 17:812:6-11. doi: 10.1016/j.aca.2014.01.002. Epub 2014 Jan 9.

Authors

Ying Gao¹, Zeming Shi¹, Qinxia Zong¹, Peng Wu¹, Jing Su¹, Rui Liu²

Affiliations

¹ Sichuan Provincial Key Laboratory of Nuclear Technology in Geology, College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China.
² Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China. Electronic address: liur.ray@gmail.com.

PMID: 24491757
DOI: 10.1016/j.aca.2014.01.002

Abstract

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 (201)Hg isotopic spike is added to cosmetics and the isotope ratios of (201)Hg/(202)Hg 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.

Keywords: Cosmetic; Formic acid; Inductively coupled plasma mass spectrometry; Isotope dilution; Mercury; Photochemical vapor generation.