Study On Determination Element Speciation Of As And Hg In Cosmetics By HPLC-ICP-MS

Some heavy metals, such as mercury, lead and arsenic, are prohibited by using in cosmetics for a long time because of their significant toxicity. However, in all the standard methods and criterions, it was paid more attention to the determination total amount of the elements, while neglecting the element speciation analysis.In this experiment, elemental seciation analysis about the arsenic and mercury in cosmetics has been studied. By using high-performance liquid chromatography as a signal of high sensitivity detection, and inductively coupled mass spectrometer electricity as a final quantitative method, the content of arsenic and mercury are determined in different type of cosmetics.For the separation of arsenic speciation, the selection of different mobile phase and pH are optimized. And then2mmol/L of NaH2PO4and0.2mmol/L of EDTA are used as the mobile phase. When pH is set as6.0, it gets the best separation efficiency in various speciation of arsenic. A method is set up to separate different speciation of arsenic in cosmetics, and the detection limits of different speciation of arsenic were, As(III):0.9μg/mL, DMA (Dimethyl-arsenic):1.0μg/mL, MMA(Methyo-arsenic):1.2μg/mL, and As(V):1.7μg/mL. Through determinating different cosmetics samples, the recovery rate of As (Ⅲ) is:77.31%～92.57%, and its relative standard deviation is (CV%):2.46～13.84; DMA’s recovery as follows:70.35%～90.58%, and its relative standard deviation is (CV%):5.62～13.19; MMA’s recovery as follows:70.00%～97.18%, its relative standard deviation is (CV%):2.06～14.15; recovery of As (V) is:80.39%～91.29%, and its relative standard deviation is (CV%):2.90-12.15.For the separation of mercury speciation, in this experiment, the selection of different mobile phase and pH are optimized. And then,0.06mol/L ammonium acetate,0.1%of2-mercaptoethanol and methanol (5%V/V) are used as mobile phase. When pH is set as7.0, it gets the best separation efficiency of in various speciation of mercury. The detection limits of different speciation of mercury are established, respectively, methylmercury:0.5μg/mL, ethyl mercury:0.2μg/mL, inorganic mercury:0.6μg/mL. The recovery of Methylmercury is:70.67%～91.8%, relative standard deviation is (CV%):5.21～15.68. The recovery of ethyl mercury is:73.75%～92.67%, relative standard deviation is (CV%):5.37～15.30. The recovery of inorganic mercury is:74.17%～94.17%, relative standard deviation is (CV%):3.54-12.41.