【作者】 任鹏；

【导师】 马彤梅； 黄理纳；

【作者基本信息】 华南理工大学 ， 化学工程（专业学位）， 2020， 硕士

【摘要】 我国是玩具及婴童用品的生产大国,每年都有相当数量的玩具及婴童用品因有害物质含量不符合各出口国的相关法律法规要求而被召回,有机锡(OTC)就是其中之一。欧盟标准是目前检测玩具中OTCs运用最广泛的标准,在2019年发布的EN 71-3:2019中对11种OTCs的含量进行了限制。随着人们安全意识的提高,不仅玩具行业,其他行业对OTCs的种类也做了更多的限制。国际环保纺织品协会2016年发布的Oeko-Tex标准100,与2015年发布的旧版本相比,将其限定的4种OTCs增加到14种,其中有4种OTCs是欧盟玩具标准中未曾限定的。由此可知,欧盟最新标准EN 71-3:2019中限定的11种有机锡已逐渐不能满足人们的需要;同时,国内检测实验室对于各类玩具样品中OTCs的检测仍然以欧盟旧标准EN 71-3:2013/A2:2017为主,然而该标准已难以实现第二类玩具材料OTCs检测要求,必须寻求新的检测方法以解决第二类玩具材料的测试限量问题。此外,当日常测试按照欧盟玩具安全标准EN 71-3:2019中的胃液迁移程序测试锡或镀锡为基材的涂层材料(不含有机锡)时,却经常有单甲基锡检出,检测结果不符合原材料中不含有机锡这一事实,经验证为单甲基锡的假阳性现象。基于此,本文在调研各行各业所限定有机锡种类的基础上,首次建立了基于GC-MS/MS检测玩具材料中20种可迁移有机锡的方法,并可搭配不同的前处理方式服务各行各业;其次运用GC-MS对玩具涂层材料中单甲基锡假阳性的现象进行检测和确证。论文主要内容如下:(1)基于GC-MS/MS法检测玩具中的20种可迁移有机锡样品中的OTCs经模拟胃液(盐酸)迁移及衍生剂(四乙基硼酸钠)衍生化后,采用选择离子监控模式(MRM)进行分析,并对迁移条件、衍生步骤及GC-MS/MS工作参数等进行了优化。实验结果表明,20种OTCs在0.005～0.200 mg/L范围内线性关系良好,线性相关系数(R~2)为0.9963～0.9999;样品加标回收率为80.6%～117.2%,相对标准偏差(RSD)小于5%(n=6);20种OTCs的方法检出限为0.019～3.196μg/kg,定量限为0.065～10.652μg/kg。与日常检测玩具中OTCs最常用的GC-MS测试方法相比,该方法在20 min内同时对20种OTCs进行分离,选择性强,定量准确,灵敏度高,降低了检出限和定量限,解决了第二类玩具材料中有机锡定量限难以达到的问题,也弥补了目前玩具检测的OTCs种类少等局限性,是一种广泛、高效、灵敏、可靠的检测方法。该工作详见本论文第二章。(2)GC-MS法测定玩具材料中的单甲基锡及其假阳性现象的确证样品中的单甲基锡经模拟胃液迁移及衍生剂衍生化后,采用选择离子监控模式(MRM)进行分析,并对迁移条件、衍生步骤及GC-MS工作参数等进行了优化。实验结果表明,单甲基锡在0.02～1.0 mg/L浓度范围内呈现良好的线性关系,线性相关系数为0.9992,加标回收率为86.2%～104.2%,RSD为3.1%～8.2%(n=6),方法检出限和定量限分别为0.11、0.32 mg/kg。日常检测中发现,以锡或镀锡为基材的涂层材料按欧盟EN 71-3:2019标准所述胃液迁移模型进行有机锡检测时,常出现单甲基锡的假阳性现象,且经研究证实该现象是由模拟胃液和衍生试剂两个关键环节引起,故从此两方面对其进行确证:1、用甲醇和丙酮替代模拟胃液;2、用四丙基硼酸钠代替四乙基硼酸钠。结果表明,用甲醇和丙酮替代模拟胃液后,无相应的单甲基锡衍生产物检出;而用四丙基硼酸钠替代四乙基硼酸钠后,仍有相应单甲基锡衍生产物检出,故前者可用于确证胃液迁移模型中的有机锡假阳性现象。此外,当单甲基锡检出时,可以通过比较滤液中的锡含量与正己烷层检出的锡含量大小,作为甲基锡假阳性的辅助判据。该工作详见本论文第三章。上述研究结果为国内检测机构难以达到欧盟标准中玩具材料有机锡定量限的问题提供了有效的解决方法,为各玩具生产商及专业检测机构找到了一种广泛、高效、灵敏、可靠的检测方法。同时,也建立了一种简便、高效、可靠的实验方法来判断涂层样品中单甲基锡假阳性的现象,确保了实验结果的可靠性。本论文的研究成果将推动我国和世界玩具贸易的发展。更多还原

【Abstract】 China is a major producer of toys and baby products.However,a considerable number of toys and baby products were recalled every year because the content of harmful substances wasn’t in conformity with the relevant laws and regulations of each exporting country.Organotin compound(OTC)is one of the harmful substances.The EU standard is currently the most widely used standard for testing OTCs in toys.In EN 71-3:2019 released in 2019,the content of 11 kinds of OTCs were restricted.With the improvement of people’s safety awareness,not only the toy industry but also other industries have imposed more restrictions on the types of OTCs.Compared with the old version released in 2015 by the International Environmental Protection Textile Association,the Oeko-Tex standard 100 issued in 2016increased its limit to the types of OTCs from 4 to 14,of which 4 types of OTCs were not limited by the EU toy standard.It can be seen that the 11 types of OTCs defined in the latest EU standard EN 71-3:2019 have gradually failed to meet people’s needs.Meanwhile,domestic testing laboratories still use the dated European standard EN 71-3:2013/A2:2017which has been difficult to achieve the OTCs testing requirements for the second category of toy materials.Therefore new testing methods must be sought to solve the problem of testing limits for the second category of toy materials.In addition,when routine tests for tin or tin-plated coating materials(no organotin contained)in accordance with the gastric juice migration procedure in the EU Toy Safety Standard EN 71-3:2019,monomethyltin was often detected,which didn’t in accordance with the fact that the raw material didn’t contain organotin,leading to a false positive of monomethyltin.In this thesis,based on theof all types of organotin defined in various industries,a method for detecting 20kinds of migratory organotin in toy materials based on GC-MS/MS has been established for the first time,which can be combined with different pretreatment ways to serve in other fields.Moreover,by employing GC-MS,the false positive phenomenon of monomethyltin in toy coating materials has been detected and confirmed.The main content of the thesis is as follows:(1)Determination of 20 migratable organotins in toys based on GC-MS/MS methodAfter migration from simulated gastric juice(HCl)followed by derivatization using the derivatizing agent(sodium tetraethylborate),the OTCs were analyzed by selective ion monitoring mode(MRM),during which,migration conditions,derivatization steps as well as operating parameters of GC-MS/MS have been optimized.From the experimental result,all of the 20 kinds of OTCs displayed good linear relationship in the concentration range from0.005 to 0.200 mg/L with the linear correlation coefficients(R~2)of 0.9963～0.9999,their detection limits were as low as 0.019～3.196μg/kg with the limit of quantifications between0.065 and 10.652μg/kg,and the recoveries of OTCs in samples were in the range of 80.6%～117.2%with relative standard deviations(RSD)less than 5%(n=6).Compared with GC-MS,the most commonly employed method for OCTs detection in toys,the newly established method can separate 20 different kinds of OTCs within 20 min at one time,indicating the advantages of strong selectivity,accurate quantification,high sensitivity with a very low detection limits and quantitation limits,dissolving the problem that the quantitation limit of OTCs for the second type of toy materials was difficult to be achieved.Furthermore,this method also extends the detection limitation of OTCs types in toys to 20 types from the original 11 types given in the EU standard.The developed method is proved to be comprehensive,efficient,reliable and sensitive for fast determination of OTCs in toys.The work is detailed in Chapter 2 of this article.(2)Detection and confirmation of monomethyltin false positive from toys by GC-MSAfter migration from simulated gastric juice(HCl)followed by derivatization using the derivatizing agent(sodium tetraethylborate),the monomethyltin was analyzed by selective ion monitoring mode(MRM),during which,migration conditions,derivatization steps as well as operating parameters of GC-MS have been optimized.From the experimental result,the monomethyltin displayed good linear relationship in the concentration range from 0.02 to 1.0mg/L with the linear correlation coefficients(R~2)of 0.992,the detection limit was 0.11 mg/kg with the limit of quantification of 0.32 mg/kg,and the recoveries of monomethyltin in samples were in the range of 86.2%～104.2%with relative standard deviations(RSD)of 3.1%～8.2%(n=6).In daily testing,it was found that when tin or tin-plated coating materials were tested for organotin according to the gastric juice migration model described in the European Union EN 71-3:2019 standard,false positive phenomena of monomethyltin often occur,and studies have confirmed that this phenomenon was caused by the two key links of simulated gastric fluid and derivative reagents.Therefore,it was confirmed from these two aspects:1.replacement of simulated gastric fluid with methanol and acetone;2.replacement of sodium tetraethylborate with sodium tetrapropylborate.The results showed that after replacing the simulated gastric fluid with methanol and acetone,no corresponding monomethyltin derivative products were detected.However,after replacing sodium tetraethyl borate with sodium tetrapropylborate,the corresponding monomethyltin derivative products were still detected.Thus,the former can be used to confirm the false positive phenomenon of organotin in the gastric fluid migration model.In addition,when monomethyltin was detected,the tin content in the filtrate can be compared with the tin content detected in the n-hexane layer as an auxiliary criterion for false positive of methyl tin.The work is detailed in Chapter 3 of this article.The above research has provided an effective solution to the problem that available domestic testing methods can hardly reach the quantitative limit of organotin in toy materials in the EU standards,and figured out a broad,efficient,sensitive and reliable organotin detection method for toy manufacturers and professional testing labs.What’s more,a simple,efficient and reliable experimental method was established to judge the false positive phenomenon of monomethyltin in the coating samples,which ensured the reliability of the experimental results.The research results of this thesis will promote the development of toy trade between China and the world.更多还原