节点文献
快速测定HVP和酱油中3-MCPD方法的研究与应用
Research and Application on Rapid Determination of 3-MCPD in HVP and Soy Sauce
【作者】 王悦宏;
【导师】 闫吉昌;
【作者基本信息】 东北师范大学 , 环境科学, 2008, 博士
【摘要】 氯丙醇是在生产酸水解植物蛋白调味液(HVP)的过程中残留的甘油三酯氯化产生的一系列污染物,经毒理学验证对人体具有生殖系统损害和致癌作用。酱油、蚝油及各种调味品中因广泛加入HVP作为风味剂而受到氯丙醇的污染,而且污染十分严重。研究表明系列氯丙醇污染物中,3-氯-1,2-丙二醇(3-MCPD)无论从含量上还是从危害性上都很突出,是尤其需要重点监控的对象。世界各国对不同食品中3-MCPD的限量有不同的规定,覆盖产品分别为酱油、HVP、其它食品三者中的一种或几种,监控的氯丙醇也有种类和限量上的差异,如3-MCPD从0.01~1.0 mg/kg不等。中国大陆只在HVP的产品标准中有3-MCPD项目的限量要求(<1.0mg/kg),而酱油产品中没有。这便使得酱油等产品的氯丙醇污染得不到很好的控制。调查表明,我国有些地区的酱油产品中,氯丙醇检出率在40%以上,而且有些酱油中的含量还很高。检验和控制食品中3-MCPD的含量至少有两方面的意义:首先,避免含量高的3—MCPD的调味品危害人体健康;其次,酿造酱油已经被证实不含氯丙醇,含有氯丙醇的酱油多是以酸水解植物蛋白调配而成的,这就成为鉴别真假酿造酱油的重要的依据之一。我国氯丙醇检测的方法应用并不普遍,主要原因之一是食品中除了HVP以外,都没有强制的氯丙醇检测的要求;另外一个很重要的原因是,现有检测方法或简单或复杂,要么检出限和灵敏度不佳,要么步骤太复杂,检测成本太高,不便于应用和推广。文献报导的氯丙醇的分析方法很多,首先体现在提取、净化、衍生化步骤中各种不同的方法,其次定性定量分析的手段也有很大差异,可以进行包括气相色谱法、气-质联用法、毛细管电泳法、分子印迹法等等仪器的分析。复杂的检测方法消耗大量的人力物力和财力,同时也影响检测的并容易引入更多的误差和不确定度。按照国家标准GB/T 5009-2006的规定,检测一个样品层析净化步骤的洗脱溶剂需要量超过330 ml。溶剂的回收处理成为一个大的问题。本文在建立并验证了一种快速检测3-MCPD的方法:试样中加入3-MCPD的氘代同位素(3-MCPD-d5)作为内标,经超声混匀后加入到自行填装的弗罗里硅土柱中,以乙醚洗脱,洗脱液经氮气吹至近干后在正己烷溶剂中进行衍生化,衍生化试剂采用七氟丁酰咪唑。采用GC—MS选择离子监测(SIM)模式进行定性定量分析。方法的添加回收率为95%—101%,相对标准偏差为3.4%~4.8%,检出限0.010 mg/kg,符合欧盟标准的要求。本方法步骤简单,溶剂用量少(杏?0mL),定性定量准确可靠。可快速测定酱油等调味品中3-MCPD的含量。同时,对于节约成本、保护环境具有很大的意义。对于化学分析工作者来说,出具的检测数据要具有高的可信度和量值上的可溯源性,不确定度的评估在很大程度上弥补了误差理论的不足,对过程的精密度进行分析。其给出结果的形式和内涵上都具有很高的理论意义和实际意义。然而这种方法并未被广泛使用。本论文对新建立的快速检测3-MCPD的过程的不确定度进行了详尽的评估,给出了不确定度报告,在此基础上还对过程作了分析和改进。使检测方法和检测过程合理优化,检测结果更加科学可靠。采用快速检测HVP和酱油中3-MCPD的方法,对吉林地区市场上销售的HVP和酱油产品作了抽样调查,分析结果显示,HVP中3-MCPD含量在0.06~56.41mg/kg之间,仅20%的样品3-MCPD符合我国酸水解调味液行业标准SB10338-2000的限量要求(1.0mg/kg),40%的样品3-MCPD超过10mg/kg;这表明我国市售HVP产品3-MCPD污染状况严重,市场状况不容乐观。酱油中3-MCPD含量在未检出(<0.01.mg/kg)和2.34mg/kg之间,其中检出3-MCPD的酱油占调查总量的54.6%,且标识为酿造酱油且检出3-MCPD的为53%,说明有大量的配制酱油冒充酿造酱油在市场上公然销售,欺诈消费者。
【Abstract】 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.
【Key words】 3-Chloro-1,2-propanediol; gas chromatography-mass spectrometry; isotopic dilution;