土壤微塑料鉴别中的密度分离-消解法前处理方法优化  

Optimization of pre-treatment methods for density separation-digestion in the identification of microplastics in soil

作　　者：李舒洋 陈政 曹月婵 LI Shuyang;CHEN Zheng;CAO Yuechan(Guangzhou Inspection Testing and Certification Group Co.,LTD,Guangzhou,Guangdong 511447,China;Administration for Market Regulation of Sichuan Province,Sichuan,Chengdu 610056,China)

机构地区：[1]广州检验检测认证集团有限公司,广东广州511447 [2]四川省市场监督管理局,四川成都610056

出　　处：《中国纤检》2024年第12期63-67,共5页China Fiber Inspection

摘　　要：针对土壤微塑料检测前处理方法存在难以分离,导致样品提取效率低、提取不准确的问题,建立了基于密度分离-消解法的前处理方法,并对步骤参数进行了比较测试。通过不同浮选液、超声搅拌时间、浮选静置时间、干燥温度的试验分析,结果表明:30 min~40 min左右的超声洗脱时间最佳;NaCl和NaI的双密度浮选法,相比单独使用NaCl浮选液,双密度法对PE、PVC和PET的回收率分别提高了2.43个百分点、69.10个百分点和59.82个百分点。此外,为避免微塑料的热损伤,本研究确定干燥温度应在50℃~60℃之间;选用30%的H_(2)O_(2)进行24 h的氧化消解以去除有机杂质;不少于24 h的静置时间以确保土壤杂质与微塑料有效分离。本研究建立的密度分离-消解法前处理方法,操作简便、回收率高,可为研究各类微塑料在土壤中的分解和检测提供一定技术支持。To address the challenges of difficult separation in the pre-treatment methods for detecting microplastics in soil,which lead to low extraction efficiency and inaccuracy,a pre-treatment method based on density separation-oxidative digestion has been established and parameters of the steps were compared and tested.Experiments were conducted on various flotation liquids,ultrasonic mixing times,static settling times,and drying temperatures.The results indicate that an ultrasonic elution time of around 30 min~40 min is optimal.The dual-density flotation method using both NaCl and NaI shows an increased recovery rate for PE,PVC,and PET by 2.43%,69.10%,and 59.82%respectively,compared to the use of NaCl alone.Furthermore,to avoid thermal damage to microplastics,the drying temperature was determined to be between 50℃~60℃.The use of 30%H_(2)O_(2) for 24 hours of oxidative digestion was selected to remove organic impurities,and a settling time of at least 24 hours was ensured to effectively separate soil impurities from microplastics.The pre-treatment method based on density separation and oxidative digestion established in this study is simple to operate with high recovery rates,and can provide certain technical support for the study of the decomposition and detection of various microplastics in soil.

关 键 词：土壤 微塑料 密度分离 氧化消解 前处理 优化 

分 类 号：TS107[轻工技术与工程—纺织工程] O657.3[轻工技术与工程—纺织科学与工程] X82[理学—分析化学]