Application Of Ultra Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry In Speciation Of Mercury In Biological Samples

Mercury is an important environmental pollutant,which has the characteristics of persistence and bioaccumulation.It has different chemical forms and oxidation states in the atmosphere,soil and aquatic ecosystem,presents in complex biogeochemical cycles.The toxicity of mercury is closely related to its speciation.In the analysis of mercury content in biological samples,it is necessary to analyze both the content of total mercury and the content of different mercury species,so as to provide more sample information.A method used a reversed-phase column,Waters BEH C18 with a flow rate of 0.35 mL min-1 and a sample injection volume of 3?L,the method separate of methyl mercury(MeHg),p-Chloromercuribenzoate(PCMB),Hg2+ and ethylmercury(EtHg)completely within 13.3 min,the corresponding limit of detection were 0.28?g L-1,0.46?g L-1,0.30 ?g L-1,and 0.93?g L-1 respectively.The method is suitable for routine analysis.We proved the accuracy of the method by applied this method to analysis of the certified reference materials IAEA-436 and GBW10020,the results consistent with the reference values.Then,we used this method to analyze the actual samples of Escherichia coli with different anti-mercury genes,compared the degradation ability of different Escherichia colis.The other method used a reversed-phase Waters BEH C18 with a flow rate of 7?L min-1 and a sample injection volume of 1?L,this method reach the target of mercury speciation analysis in trace biological samples.The limit of detection of methylmercury and Hg2+ was 0.28 ?g L-1,0.32 ?g L-1 respectively,the absolute limit of detection of methylmercury and Hg2+ was 0.28 pg,0.32 pg respectively,increased about 300 times when compare with the previous method.Then,this method was used to analyze the actual samples of rice plants,which was exposed to methylmercury.When we compared the content of total of mercury and mercury species in roots and leaves,we found that demethylation of methylmercury in the process of rice growth.It provides a method for further research of mercury accumulation and transformation in plants and biological toxicity.