Determination Of Nitroimidazoles In Water And Chicken Tissues By Single Drop Microextraction Combined With GC/MS

Liquid phase microextraction (LPME) is a novel sample pretreatment technique that integrates sampling, extraction and concentration into a single step. With little organic solvent, SDME was proved to be an excellent enrichment character and environment friendly sample pretreatment method. Single drop microextraction (SDME) was evoled from this technique. Due to its extreme simplicity, many successful appliciations on envrionment and food polluants have been reported. This technique combined with gas chromatography-mass spectrum(GC/MS) was applied for analysis of nitroimidazoles in water and chicken tissues, which provided the technical foundation for determination of nitroimidazoles residues.The studies in this thesis are included as follows:1. SDME-GC/MS was developed for the simultaneous determination of dimetridazole, secnidazole, metronidazole, orinidazole in water. Then the new technique was applied to the extraction of nitroimidazoles in South lake water and tap water in our laboratory. The limits of detection (LOD) for the four studied analytes in water were between 0.16 and 0.57ng/mL, the linearity of the method was demonstrated in the range of 0.5～400ng/ml with a correlation coefficient r>0.998, and the recoveries for the spiked in tap water in our laboratory and South lake water were from 81.9% to 96.4%. Both the intra-day and inter-day relative standard deviation in water samples were less than 10%.2. Single drop microextraction coupled with gas chomatography-mass specturm was presented for the simultaneous analysis of dimetridazole, secnidazole, metronidazole, orinidazole in chicken tissues. The linearity of the method was demonstrated in the range of 1～1000ng/mL with a correlation coefficient r>0.998, the limits of detection (LOD) for the four nitronidazole in chicken tissues were between 0.5 and 1.86ng/mL, and the recoveries for the spiked chicken tissues were from 74.5% to 89.5%. The intra-day and inter-day relative standard deviation in tissuse samples were less than 10% and 15%, respectively.