Research On Online Ion Concentration Technology For Electrophoresis Microchip

At present,ion detection technology has been widely used in heavy metal pollution of soil,eutrophication of water body,auxiliary medical treatment and so on.However,most of the traditional ion detection technology depends on the laboratory environment,and has the disadvantages of time-consuming,expensive equipment,single detection function,etc.,which greatly limits the development of ion detection technology.In recent years,Microchip Electrophoresis-Capacitively Coupled Contactless Conductive Detection(ME-C~4D)has made ion detection technology portable and on-site due to its high integration and reagent requirements less,rapid detection and other advantages.However,compared with other detection methods such as chemiluminescence,ME-C~4D has the problem of low detection sensitivity,which severely limits its practical application range.Online enrichment of samples can effectively compensate for the lack of detection sensitivity.However,the current ion enrichment methods commonly used at home and abroad have defects such as poor enrichment effect,high manufacturing cost or very complicated operation.Therefore,an ion online enrichment technology with simple operation,short time consumption and good enrichment effect has become the key to the widespread application of electrophoretic microchip detection.A new electrophoresis microchip for ion on-line double concentration by microchip electrophoresis-capacitively coupled contactless conductive detection and voltage control-field amplified sample stacking is described.In this study,an additional reservoir was introduced after the sample reservoir of the traditional cross-electrophoresis microchip and achieved ion on-line double concentration by using voltage control.The K~+,Na~+,Li~+were used as analytes to investigate the function of the microchip.Under the optimal concentration and electrophoresis conditions,the sample solution(K~+,Na~+,Li~+)was successfully enriched and separated within 100 s.The experimental results show that the concentration factors of K~+,Na~+and Li~+are 41,37 and 34 times.The RSD of the three ion migration times is within 5.3-6.2%,and the RSD of peak height is maintained below5%.The chip has the characteristics of inexpensive,simple,fast and easy of operation.In this paper,based on the goal of practical application,the separation of microchips has been successfully improved through complexation,and a variety of nutrients and heavy metal ions have been successfully detected.The work in this paper provides a new idea for the current concentration technology,and also has an important role in promoting the real portability and on-site ion detection technology.