Determination Of Drug Residues In Aquatic Products By Pressurized Capillary Electrochromatography

Drug is an indispensable means in prevention aquatic animals diseases. Drug residueof aquatic products will injury human health directly and indirectly. Detection method ofdrugs in aquatic animals is an important research topic of food safety science. In thisdissertation, detection of drug residue of aquatic animals using pressurized capillaryelectrochromatography(pCEC) is investigated. The main contents of this work are asfollowing:(1) A method using pCEC has been developed and validated for the determination ofmelamine residue in Pacific Saury. Extraction of melamine from Pacific Saury wasperformed with acid acetonitrile solution at10.0MPa and a temperature of110℃for10min. Extraction liquid was degreased with hexane and then cleaned by solid-phaseextraction with MCX cartridges. A satisfactory separation was achieved on a C18shortcolumn using the mobile phase of acetonitrile-sodium heptane sulfonate-citric acid buffersolution25:75(V/V). Detection was performed by pCEC and the UV detector was set at240nm. The linear range was0.5~20μg/mL, and the correlation coefficient was0.9993, therecoveries were in the range of84.92%~91.27%, the relative standard deviations was lessthan4.2%, and the determination limit was0.05mg/kg.(2) A pCEC method for the simultaneous determination of chloramphenicol,thiamphenicol and metronidazole in aquatic products had been developed.Afterchloramphenicol, thiamphenicol and metronidazole in aquatic animals were extracted withethyl acetate and degreased with hexane, the samples were cleaned by solid-phaseextraction with C18cartridges. Then the samples were separated by C18column with amobile phase of acetonitrile and buffer solution35:65(V/V) and detection using differentwavelength. The linear ranges of chloramphenicol, thiamphenicol and metronidazole were0.45~10μg/mL,0.2~10μg/mL,0.25~10μg/mL, respectively. And the limits of quantificationin aquatic products was0.04mg/kg,0.02mg/kg and0.05μg/mL for the tree compounds.The average recovery were in the range of83.1%~88.9%, and the relative standarddeviations was2.3~3.16.(3) A pCEC method had been developed for the simultaneous determination of flumequine and oxolinic acid in aquatic products. The samples were separated by C18column with a mobile phase of acetonitrile and buffer solution45:55(V/V), the UV detectorwas set at324nm, flow rate was0.07mL/min, the peak flowing out time could controlwithin10minutes. The linear ranges of flumequine and oxolinic acid were0.2~5μg/mL.The limits of quantification in aquatic products was0.1mg/kg and0.08mg/kg, respectively.The sample was extracted by acidification acetonitrile and concentrated by HLB cartridges,an aliquot of2μL of the the resulting solution was injected into the pCEC system. Theaverage recovery were in the range of82~92%, and the relative standard deviations was3.63~5.96%.(4) A pressurized capillary electrochromatography (pCEC) method was developed forthe determination of sulfadiazine, sulfamonomethoxine sodium, sulfachinoxalin,sulfamethoxazole and sulfisoxazole in aquatic products. The sample was extracted by ethylacetate, then the extracts were dehydrated with sodium sulphate anhydrous. After the ethylacetate extraction was purified and concentrated by HLB cartridges, an aliquot of1μL ofthe the resulting solution was injected into the pCEC system. The effects of organic phase,mobile phase salt concentration and separation voltage on separation efficiency wereinvestigated, respectively; the operating time was within6.5minutes. The calibrationcurves were lined under the content of0.5~5μg/mL, with correlation higher than0.9990.The limit of detection (LOD) of sulfadiazine, sulfamonomethoxine sodium was0.02mg/kg,and the LOD of sulfachinoxalin was0.03mg/kg, the LODs of sulfamethoxazole,sulfisoxazole was0.04mg/kg. The mean recoveries varied from71%to82%at two spikedlevels of2and5mg/kg.