生物样品二恶英分析中两个常见干扰峰的鉴定

利用高分辨气相色谱/高分辨质谱联用仪(HRGC/HRMS)和高分辨气相色谱/低分辨质谱仪(HRGC/LRMS)对实际生物样品中二恶英(polychlorinated dibenzo-p-dioxins and dibenzofurans,PCDD/Fs)的分析过程中13 C标记的2,3,7,8-四氯代二苯并呋喃(13 C12-2,3,7,8-TCDF)监测碎片离子通道的两个常见干扰峰进行了分析鉴定。通过实际样品分析结果首先推测这两个干扰峰可能为有机氯农药类化合物滴滴涕(DDT)降解产物滴滴伊(DDE)的两个异构体,其次采用DDE的标准溶液(包括o,p′-DDE和p,p′-DDE)进行分析确认。通过HRGC/HRMS的色谱峰分离效果分析、色谱保留时间匹配以及与DDE碎片离子的理论丰度比进行比较,最终确认实际样品分析中的两个干扰峰依次为o,p′-DDE和p,p′-DDE。本文可为生物样品中二恶英的准确识别提供重要参考。

Identification of two interference peaks during dioxin analysis for biological samples

Two interference peaks which generally appeared in company with ¹³C labeled 2,3,7,8-tetrachlorodibenzofuran (¹³C₁₂-2,3,7,8-TCDF) in the same ion channel during dioxin analysis for biological samples were identified using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) and high resolution gas chromatography/low resolution mass spectrometry (HRGC/LRMS). It was firstly inferred that the interference peaks should be the two isomers of dichlorodiphenyldichloroethylene (DDE), which was a breakdown product of dichlorodiphenyltrichloroethane (DDT), one of the typical organic chlorine pesticides (OCPs). Thereafter, the standard solution of DDE including o,p''-DDE and p,p''-DDE was analyzed for confirmation. By evaluation of the peak separation in HRGC/HRMS, comparison of the GC retention times and ion abundance ratios of the two interference peaks in real samples with the two DDE isomers in standard solution, the interference peaks were finally confirmed as o,p''-DDE and p,p''-DDE in sequence on a DB-5MS column. This study provided valuable information for accurate identification of dioxin compounds during the biological sample analysis.