Coupling Solid-Phase Microextraction With Ambient Mass Spectrometry Using Molecularly Imprinted Polyers Coated Wooden Tips For Analysis Of Trace Of Malachite Green

Analysis of trace veterinary drug residues in complex samples is of significant importance in food chemistry and environmental science.However,it is a challenge task and techniques for rapid,direct,in situ,and high-throughput analysis of complex food and environmental samples are highly desirable.In this paper,a solid-phase microextraction(SPME)coupled with ambient mass spectrometry(AMS)method for rapid and sensitive analysis of trace malachite green,crystal violet and their metabolites in complex food and environmental samples was developed.Firstly,a molecularly imprinted polymers coated wooden-tip SPME probe(MIPCWT-SPME)was prepared,the detail was as follow:an emulsion was synthesized using methacrylic acidstyrene,acrylate and ethylene glycol dimethacrylate.After addition of malachite green,the wooden-tip was immersed in the emulsion and then dried at 120?to get an imprinting film on the surface.By SEM images,a large amount of uniform and dense holes were founded on the microprobe surface,which supplied a large specific surface area for good specific adsorption of molecular imprints.Then,amolecularlyimprintedpolymerscoatedwooden-tipESI-MS(MIPCWT-ESI-MS)method was developed.The method was preformed by applying the MIPCWT-SPME probe for selective enrichment of trace anlaytes under optimized detection conditions such as after 40 min of extraction and with at 100 mL of mixed solvent,and then,with the application of a high voltage and some spray solvent on the MIPCWT-SPME probe,ESI was induced directly for mass spectrometric analysis under ambient and open-air conditions.The MIPCWT-SPME probe had a satisfactory extraction capacity as high as 1000-1800 folds.It had very good linearity,with correlation coefficient values(r~2)greater than 0.9948 for four target antibiotic compounds.The limit of detection(LOD)of the four antibiotic compounds were form 0.01 to 0.04?g/L.In addition,the recovery of the method was satisfactory,we got 93.7-99.6%at pure water,87.7%-94.2%at river water and 53.1-66.4%at milk respectively.The MIPCWT-ESI-MS has great potential for complex matrix samples and small organisms.In this study,we will continue to explore the MIPCWT-SPME probe prepared with different SPME vectors for the analysis of trace compounds in complex matrix samples,such as milk and whole blood,as well as in small organisms.