Application Research Of Analyzing Toxic And Harmful Substances In Food By High Performance Liquid Chromatography-tandem Mass Spectrometry (HPLC-MS/MS)

Food safety issues, in particular the toxic pollution substances in food, hasbecome the focus of attention of society and government, and consumers are alsomost worried about it. In view of the uncertainty of toxic substances，it is particularlyimportant to use trace analysis and ultra-trace analysis technology for detection.Nowadays, there have been some detection methods which can be used to analyzetoxic substances in food by liquid chromatography-mass spectrometry. But there arestill no related testing standards and references for some other toxic substances.In this paper，in order to solve the problem of food security, the methods whichare used to detecting the typical toxic substances (such as ractopamine, clenbuterol,methenamine, basic dyes) by using liquid chromatography-mass spectrometry havebeen established.(1) Determination of Ractopamine and Clenbuterol in Processed Meats byHigh Performance Liquid Chromatography-Tandem Mass Spectrometry and theInfluence of Contents Using Different Processing MethodsA high performance liquid chromatography-tandem mass spectrometric(HPLC-MS/MS) method was developed for simultaneous determination of clenbuteroland ractopamine in processed meats. A new cation exchange column chromatographywas utilized to separate target compounds and a improved pre-treatment method wasuesed in this study. The eluent solution types and chromatographic parameters wereoptimized. The optimal conditions were using flow rate of0.4mL/min,injectionvolume of10μL and column temperature of40°C. The homogenized samples wereextracted with0.02mol/L ammonium acetate (pH=5.2), hydrolyzed by30μLβ-glucuronidase/arylsulfatase, centrifuged, and cleaned through solid phase extractioncolumn. The calibration curves showed good linearity for two target compounds inthe range of0.1-100μg/L. The limits of detection and quantitation of two targetcompounds were not more than0.04μg/kg and0.15μg/kg, respectively. The spikedrecoveries in processed meats ranged from71%to98%with RSDs less than8.5%.This proposed method was simple, sensitive which was suitable for the quantificationof ractopamine and clenbuterol in processed meats.(2) Rapid determination of methenamine in foods by liquidchromatography-tandem mass spectrometryA method of liquid chromatography–tandem mass spectrometry(LC-MS/MS) was developed to monitor methenamine which illegally added in foods. Anhydrous sodiumsulfate was used for drying and dehydration, and the solution of acetonitrile was usedfor extracting methenamine. Then, a strong cation exchange(SCX) was applied toseparate target compound with gradient elute. The target compound was detected byMultiple Reaction Monitoring(MRM) at electro spray positive ionization(ESI+) mode.external standard method was adopted to quantify. The calibration curves showedgood linearity for target compound with the detection range of1-1000μg/L.Correlative coefficient was0.9988, the method of limits of detection(LOD) and themethod of limits of quantitation(LOQ) were respectively0.2μg/kg and1.0μg/kg. Thespiked recoveries in foods ranged52.6%from118%with RSDs less than10.2%. Thisproposed method was rapid, accuracy, strong specificity, high sensitivity.Pretreatment was easy to operate and satisfied with fast speed. The conclusion in thisstudy might showed it is suitable for the quantitative determination methenamine infoods.(3) Rapid determination of five common basic dyes in fish products by highperformance liquid chromatography-tandem mass spectrometryA method was developed for simultaneous rapid qualitative and quantitativeanalysis of five common basic dyes, including rhodamine B, malachite green, crystalviolet, basic orange2, auramine O in by liquid chromatography–tandem massspectrometry(LC-MS/MS). After derosination, the sample was extracted usingmethanol, then frozen centrifugation. The supernatant was filtered through0.22μmnylon filter, followed testing. The mobile phase A was0.01mol/L ammoniumacetate(pH=3.0) and the mobile phase B was acetonitrile. Under gradient elution, thetarget compounds were separated by SCX column which were detected by MultipleReaction Monitoring(MRM) at electro spray positive ionization(ESI+) mode. Theresult showed that the method of limits of detection(LOD) of malachite green, crystalviolet, rhodamine B, basic orange2, auramine O were respectively0.5μg/kg,0.5μg/kg,0.6μg/kg,0.6μg/kg and0.3μg/kg. The recovery of these five targetcompounds were between71.5%to95.5%. The relative standard deviation was notexceeding9.07%. This method was high sensitivity and simple pretreatment whichwas fit for testing simultaneously five common basic dyes in fish fry foods.