显微拉曼光谱法检测紫菜中5种微塑料

Detection of 5 Microplastics in Seaweed Nori Based on Micro-Raman Spectra

目的:微塑料因生物传递和生物富集效应,成为食品链中的新型持久性污染物。通过对前处理方法和检测条件进行优化,建立紫菜中聚对苯二甲酸乙二酯、聚碳酸酯、聚丙烯、高密度聚乙烯、聚氯乙烯5种微塑料的显微拉曼光谱测定方法。方法:1 g紫菜先用纤维素酶于65℃酶解12 h,再于10%氢氧化钾溶液中65℃消解48 h,用钨酸钠饱和溶液进行悬浮,溢流法收集后过银滤膜,使用显微拉曼光谱面扫描模式进行扫描,多组分分布成像分析法处理数据。结果:紫菜消解率为94.2%,除聚氯乙烯加标回收率为65.1%,其余4种微塑料的加标回收率均高于91.2%,紫菜中5种微塑料均能实现准确定性及可视化计数,最低检测粒径为10μm。结论:建立的方法具有回收率高、定性准确、检测粒径小的优点,适用于紫菜中5种微塑料的定性检测和可视化计数。

Objective:Microplastics(MPs)has been the new persistent pollutant in food web due to their biotransfer and bioaccumulation effects.The micro-Raman spectra based measuring method for 5 MPs,including polyethylene terephthalate(PET),polycarbonate(PC),polypropylene(PP),high density polyethylene(HDPE)and polyvinyl chloride(PVC),in Seaweed Nori was established through optimizing the sample preparation and analysis processes.Methods:1 g Seaweed Nori was digested by cellulase at 65℃for 12 h followed by 10%potassium hydroxide solution at 65℃for 48 h,then was suspended by sodium tungstate saturated solution,solutions were collected by overflow method and filtered by silver membrane.The region scan mode of micro-Raman spectra involved MCR analysis was used to detect the pretreated sample.Results:The sample digesting rate was 94.2%,the spiked recovery of 4 MPs was above 91.2%except that of PVC,which was 65.1%,5 MPs could be identified accurately and be counted visibly.Conclusion:With the advantages of high recovery rate,accurate identification and smaller detecting particle size,the developed method in this study is applicable for determination of 5 MPs in Seaweed Nori.