同位素稀释高分辨气相色谱-高分辨质谱法检测烟道气中的低氯代二恶英

建立了同位素稀释高分辨气相色谱-高分辨质谱检测烟道气中痕量低氯代二恶英的分析方法。采用索氏提取富集烟道气样品中的目标物，提取液经过复合硅胶柱和碱性氧化铝柱净化后，进行高分辨气相色谱-高分辨质谱检测。采用DB-5MS毛细管色谱柱（30 m×0.25 mm×0.25 μm）分离，以保留时间和同位素特征离子丰度比定性，以与同位素的峰面积比值定量。实验结果表明，方法的回收率为66.6%~112.5%，相对标准偏差（RSD）的范围为19.9%~40.5%（n=5），方法的检出限（LOD）为0.027~0.485 μg/L。应用该方法检测了3个焚烧炉烟道气样品，回收率在85.7%~137.0%范围内，样品中目标物含量分布在11.4~9183 pg/Nm³之间。结果表明该方法适合用于烟道气中痕量低氯代二恶英的检测。

Determination of mono-to tri-chlorinated dibenzo-p-dioxins and dibenzofurans in stack gas using isotope dilution high resolution gas chromatography-high resolution mass spectrometry

A method for the determination of mono- to tri- chlorinated dibenzo-p-dioxins and dibenzofurans (mono- to tri-CDD/Fs) in stack gas using isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) was developed. The samples were extracted by Soxhlet extraction, and then the extracts were concentrated and purified using a multilayer silica gel column and a basic alumina column. The analytes were separated by HRGC on a DB-5MS column (30 m×0.25 mm×0.25 μm) and determined by HRMS. The identification of mono- to tri-CDD/Fs was based on the retention times of ¹³C-labelled standard and the abundance ratios of the two exacted mass-to-charge ratios. The quantitative analysis was performed using the ratios of the integrated areas of the ¹³C-labelled standards. This method had the recoveries ranging from 66.6% to 112.5% and the relative standard deviations (RSD) ranging from 19.9% to 40.5% (n=5). The limits of detection (LODs) of this method for the mono- to tri-CDD/Fs were ranging from 0.027 to 0.485 μg/L. Three stack gas samples from waste incinerators were measured using this method, with the recoveries ranging from 85.7% to 137.0% and the concentrations ranging from 11.4 to 9183 pg/Nm³. The results indicated that the method can be applied to the precise determination of mono- to tri-CDD/Fs at trace level in stack gas.