不同地区rPET样品中半挥发性有机物的筛查识别及差异分析

目的 探究回收聚对苯二甲酸乙二醇酯（Recycled Polyethylene Terephthalate, rPET）的半挥发性污染物分布和地域差异性。方法本文利用全二维气相色谱-四极杆飞行时间高分辨质谱（GC×GC-QTOF-MS）非靶向筛查不同区域rPET中的半挥发性有机物质（SVOC）,结合正交偏最小二乘法判别分析（OPLS-DA）探索区域间的差异、关键差异物质和影响因素。结果 北方地区和广东地区的rPET分别检出260和90种SVOCs;1,1’-[1,2-乙二酰双(氧基)]双苯和壬醛二甲基缩醛均是检出频率最高的物质;OPLS-DA结果证明广东地区和北方地区的rPET之间存在显著差异（RC2YU M为0.98,QC2YUM为0.932）。关键差异物质主要包括邻苯二甲酸二丁酯、十一烷和对苯二甲酸二乙二醇酯。结论 添加剂、其他废塑料的降解产物以及香精香料残留等因素是导致rPET区域差异的主要原因,不同区域间rPET中的半挥发性污染物存在显著差异,因此可以通过半挥发性有机物质结合化学计量学方法对rPET的来源进行溯源分析。

Quantitative Identification and Difference Analysis of Semi-volatile Organic Compounds in rPET Samples from Different Regions

The work aims to investigate the distribution and regional difference of the semi-volatile contaminants of recycled PET (rPET). Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-QTOF-MS) was used to tentatively identify the semi-volatile organic compounds (SVOCs) from different regions, after which OPLS-DA was performed to investigate the regional difference, key different compounds and their affecting factors. A total of 90 and 260 semi-volatile organic compounds were tentatively identified in rPET from Guangdong region and north region, respectively. In the meantime, 1,1''-[1,2-oxalylbis(oxy)]bisphenyl and nonanal dimethyl acetal were the most frequently detected semi-volatile organic compounds. Furthermore, OPLS-DA revealed that and accounted for 0.98 and 0.932, proving that significant differences were observed in the semi-volatile organic compounds of rPET from Guangdong region and north region. Herein, dibutyl phthalate, undecane, 2-hydroxyethyl methyl terephthalate were the key different compounds. The regional difference of rPET is attributed to the additives, degradation of other plastics, and residuals of fragrances. The semi-volatile organic compounds in rPET differ significantly between regions and regional traceability of rPET can be achieved by combining semi-volatile organic compounds with chemometrics.