Microchip IT-SPME Couple With High Resolution MS For Fast Determination Of Sulfonamides

Due to the complexity of the real sample,the component in the sample can`t be analyzed directly,so the sample pretreatment is required in analytical chemistry.Modern analytical chemistry is more and more tend to be fast and sensitive detection,which needs more excellent sample pretreatment.Sample pretreatment is the key factor to the accuracy of the analysis experiments.Therefore,reasonable sample pretreatment is needed to ensure the reliability of the analysis.In tube-solid phase microextraction(IT-SPME)has many characteristics such as strong mechanical and high extraction capacity,and IT-SPME easily couple to other analytical instrument,which are powerful competitive advantages of IT-SPME comparing with other sample pretreatment methods.Sulfonamides(SAs)are common antibiotics,and are commonly used to inhibit the growth of harmful bacteria in the animal husbandry.So,it`s inevitable to cause the residual of SAs in the animal-origin food.These residual SAs will be harmful to the human body if they are absorbed.Therefore,detecting SAs quickly and accurately in the complex environmental sample or food samples is still significant in analytical chemistry.Separation technology is an important segment during analyzing SAs.The separation effect will affect the accuracy of analysis results.Electrophoresis is common separation technology.In this study,capillary electrophoresis coupling with ultraviolet detector(UV)and mass spectrometer(MS)were designed and established.And these coupling systems were used to detecting SAs.The fused silica capillary(O.D.360,I.D.75)was selected as the electrophoresis channel,and the length of the capillary had been optimized was 25 cm.In this study,a method using hydrofluoric acid to etch capillary tip was mentioned,and the tip was used to be the ESI electrospray ionization tip when MS was selected as the detector.In order to ensure to reduce the interference of mass spectrometry detection,electrophoresis buffer solution was 50mmol/L ammonium acetate solution rather than traditional sodium phosphate solution.The separation electric field strength was 300 V/cm.The sample was injected with a liquid-level difference of 5.0 cm between the sample reservoir and ESI tip for 10 s.Under these experimental conditions,the baseline separation of three SAs was achieved with the resolution of 2.387,4.992 and 3.177 in 5.5 min.High column efficiency was received with the numbers of theoretical plates of three sulfonamides ranging from 5232 /m to 37560 /m.In recent years,attention of microfluidic chips has grown in analytical chemistry due to the integration and portability advantages and wide applications field.In this study,the whole separate channels and IT-SPME channels were transferred to the glass microchips,obtaining MCE-chip and IT-SPME chip.This IT-SPME chip was designed to be equipped array channels,and the methacrylic porous polymer monolithic columns with embedded grapheme was prepared in these channels by using UV.Then the CE-chip and IT-SPME-chip were combined with MS to enrich and analyze the SAs in the solution.Experimental results showed that extraction column has good extraction effect to enrich the low concentration SAs in solution.And SAs could be completely separate with the resolution of 2.129,4.876 and 2.406 in 7 min.High column efficiency was received with the numbers of theoretical plates of three sulfonamides ranging from 2250 /m to 6567 /m.In this study,the IT-SPME chip and the CE chip were prepared to enrich and separate SAs.The chips were small,had the characteristics of high integration,portable and automation,and easily couple with MS to detect the SAs.The method is sample,fast and sensitive.The method can be used in analyzing SAs in complex real sample after optimizing some experimental conditions in the future.