Application Of Capillary Electrophoresis-Inductively Coupled Plasma Mass Spectrometry In Speciation Analysis

The benefit and harm of selenium on human body depend on its form and content,in order to make it beneficial and harmless we should control the content of selenium in body.Selenium is contained in many health-care products which is influential to consumers,so the speciation analysis method for selenium is of great significance.Arsenic is widely present in seafood such as fish,shrimp,kelp,shellfish,etc,it has various speciations which has respective toxicity,in order to test the safety of seafood,it is necessary to detect all forms of arsenic.This article chooses CE-ICP-MS as the analysis method to analyze the speciation and designs the control circuit of the automatic sample introduction device,the design ideas and principles are explained,including the communication circuit,stepper motor drive circuit,solenoid valve circuit and power circuit,the measures to improve reliability is emphasized,including optocoupler isolation circuit,power isolation circuit and filter circuit.A CE-ICP-MS method applied to determination of Selenic acid(Se(VI)),selenomethionine(SeMet)and selenocystine(SeCys2)was developed,three selenium compounds was separated within 15 min,the detection limit was 2.0-3.9 ug/L,the relative standard deviation(n=5)of peak area was below 5%,the linear correlation coefficients are all above 0.998,this method was successfully applied to determine the shrimps sample,and the recovery rate is 90%-110%.A CE-ICP-MS method applied to determination of AsB,AsC,As(?),DMA,MMA was developed based on self-made autosampler system,five arsenic compounds was separated with in 15 min,the detection limit was 1.6-3.1ug/L,the relative standard deviation(n=5)of peak area was within 7%.This method was successfully applied to determine the shrimps sample,and the results show that this method is reliable and can be used for quantitative analysis of arsenic species in shrimps.