Research And Application On Rapid Determination Of 3-MCPD In HVP And Soy Sauce

Chloropropanols are some chemicals which may be formed in foods by the reaction of chloride with lipids in the process of Hydrolized Vegetable Protein(HVP) manufacturing,Some have been shown to be a carcinogen in laboratory animal studies and harm to procreation system.These HVP are widely used in soy sauce, oyster sauce and other flavour foods which result in the containminent of them.the containminent in the world has involed a lot of investigation and research during the end of last century.Some kinds of foods being monitoring,some kind of Chloropropanols being tested and the Limited concentration of different countries are various from 0.02mg/kg to 1.00mg/kg.In China,it is more severious since we eat a lot of soy sauce and oyster sauce.,we only give a limit value to HVP in SB 10338 on 1.0mg/kg,none for the soy sauce by now.Some surveys show a big volume of 3-MCPD in both HVP and soy sauce.The portion of samples contain 3-MCPD is more than 40%,some of them are very high concentration.It has at least 2 significant meanings of monitoring and controlling the concentration of 3-MCPD:one is to avoid toxic effect to human health by examination and information to consumer;the second is to expose the unreal fermented soy sauce which mixed chemical HVP with soy sauce without a right label on product.There are a lot of methods could be used for testing the concentration of 3-MCPD,including gass chromatography(GC),gass chromatography mass spectrum (GC-MS),capillary electrophoresis(CE),molecular imprinting(MI)et al.The preparation methods for sample before instrument test have big difference including external standard quantity,internal standard quantity,different material selected as standard,direct injection,reacted with some chemicals before injection etc.The same problem of these test method is complicated preparation steps with result in large cost both on time and solvent.According to GB/T 5009-2006,each sample for 3-MCPD test will have to use more than 300 ml solvent.the treatment of these used solvent become a big issue which also cost much for environment protection.This thesis set a fast method for 3-MCPD determination using GC-MS and isotope dilution based on former experiment and research.The test capability is confirmed by it:The method using isotopic dilution and solid phase extraction(SPE)technique was established to determine the concentration of 3-chloro-1,2-propanediol in soy sauce by gas chromatography-mass spectrography(GC-MS).Internal standard,3-chloro-1, 2-propanediol-d₅ was added into soy sauce,after sonication,the mixture was transferred to a Florisil SPE column and eluted with ethyl ether.Evaporate the solution just to dry at room temperature under a stream of N2.1.0 mL hexane and 0.05 mL heptafluorobutyry-limidazole were added immediately.GC-MS with SIM mode was applied to identify and quantitate.The recoveries ranged from 95.0%—101.0%.The relative standard deviation was 3.2%—4.8%with a detection limit of 0.010mg/kg.Method can act fast with lower solvent consumption(less than 20ml)in addition to meet the requirement of Europe,it is very friendly to environmental protection and energy saving.Uncertainty assessment for a test process shows the process variation in addition to the theory of error be widely used to measure and demonstrate the accuracy.It provide a result with more information not only in form but also in meaning.It was not adopted that much by now.the thesis give an assessment by analysis the sources,quantity each of the sauce,caculate the whole uncertainty and give a report,more important,it also give an analysis for improvement.The thesis also give a survey to market HVP and soy sauce.the test result shows: 3-MCPD in HVP is from 0.06mg/kg to 56.41mg/kg,only 20%pass the standard SB10338-2000,40%HVP with a 3-MCPD concentration higher than 10 mg/kg. Which worthy of big concern.The soy sauce has a result from ND(＜0.01.mg/kg)to 2.3,4,the report shows the contaimination of 3-MCPD,also a trade ethic case.