Determination of toluene and chlorobenzene in food-contact recycled polyethylene terephthalate by headspace gas chromatography-mass spectrometry
- VernacularTitle:顶空气相色谱-质谱法测定食品接触用再生聚对苯二甲酸乙二醇酯中甲苯和氯苯
- Author:
Runhua WANG
1
;
Xuheng FU
1
;
Song YU
1
;
Yu’e JIN
1
;
Dasheng LU
1
;
Guoquan WANG
1
Author Information
- Publication Type:Experimentaltechnique
- Keywords: polyethylene terephthalate; challenging test; headspace gas chromatography-mass spectrometry; toluene; chlorobenzene
- From: Journal of Environmental and Occupational Medicine 2026;43(3):363-367
- CountryChina
- Language:Chinese
-
Abstract:
Background Toluene and chlorobenzene have been designated as surrogate contaminants in the challenge test for evaluating the safety of recycling processes for food-contact recycled polyethylene terephthalate (rPET). Establishing a reliable analytical method is essential for ensuring the compliant use of rPET and safeguarding food safety. Objective To develop a rapid quantitative method for determining toluene and chlorobenzene in rPET using headspace gas chromatography-mass spectrometry (HS-GC-MS), as part of the challenge test for process safety evaluation. Methods The effects of different chromatographic columns and headspace conditions on detection of target analytes were investigated. Three columns HP-5 ms UI (30 m×0.25 mm×0.25 μm), DB-624 (30 m×0.32 mm×1.8 μm), and VF-WAXms (30 m×0.25 mm×0.25 μm) were compared for separation efficiency and peak shape. Headspace equilibration temperatures (50-100 ℃) and equilibration times (10-30 min) were evaluated to determine the optimal instrumental parameters. The effect of sample grinding on recovery was assessed to select the best pretreatment conditions. The established method was validated for selectivity, linearity, sensitivity, accuracy, and precision, and was subsequently applied to the analysis of 12 rPET samples. Results The target analytes achieved good separation and response within 15 min, under the optimized conditions using an HP-5 ms UI column, a headspace equilibration temperature of 60 ℃ and a 10 min equilibration time. Direct analysis without grinding yielded satisfactory recovery rates. Toluene and chlorobenzene showed excellent linearity (
0.0030 -5.0 mg·kg−1, R2≥0.999). The limits of detection (LOD) and quantification (LOQ) were0.00003 mg·kg−1 and0.00011 mg·kg−1 for toluene respectively, and0.00011 mg·kg−1 and0.00037 mg·kg−1 for chlorobenzene respectively. The recoveries of the matrix spike at low and high spiking levels ranged from 88.6% to 110%, with relative standard deviations of 0.52%-4.9% (n=6). Among the 12 rPET samples from different recycling stages, three samples contained detectable levels of toluene (0.196-0.250 mg·kg−1) and chlorobenzene (0.704-0.867 mg·kg−1). Conclusion The proposed method is simple, rapid, highly sensitive, and accurate, making it suitable for determining toluene and chlorobenzene in food-contact rPET. It provides a robust technical approach for the safety evaluation of rPET recycling processes.
