气相色谱-质谱法分段测定土壤中的可提取总石油烃

本文建立了用气相色谱-质谱法分段分析土壤中可提取总石油烃的检测方法,并对该方法进行了质量控制研究。土壤中的总石油烃的检测范围是C8(C7.6)~C34(C34.01)。用索氏提取,柱层析分离方法进行前处理,用C8(C7.6),C10(C10.1),C12(C11.7),C16(C15.5),C21(C20.8),C34(C34.01)标准品分别作为C8~C10(C7.6~C10.1),C10~C12(C10.1~C11.7),C12~C16(C11.7~C15.5),C16~C21(C15.5~C20.8),C21~C34(C20.8~C34.01)每段馏分的"替代物"定量,将C8~C34之间所有波峰面积分段积分,以"替代物"的线性关系计算每段馏分的浓度。该方法的质控结果:脂肪烃:相关系数为0.990 3~0.999 8;最低检出限为0.011~0.373 ng/μl;回收率为50.3%~109.3%;相对标准偏差为1.5%~11.3%;芳香烃:相关系数为0.991 3~0.997 6;最低检出限为0.004~0.047 ng/μl;回收率为53.6%~107.7%;相对标准偏差为3.2%~12.2%。本方法检测结果能准确反映土壤的污染程度并有助于生物毒性计算。

The Sectional Determination of Extractable Total Petroleum Hydrocarbons in Soil by Gas Chromatography-Mass Spectrometry

A testing method by using gas chromatograph-mass spectrometry has been established, which might be employed to carry out simultaneous analyses of total petroleum hydrocarbons. In addition, quality assurance and quality control (QA/QC) of the analysis method have also been performed. The range of petroleum hydrocarbons determined in the soil by this method covers the range from C8 (C7.6) to C34 (C34.01) for aliphatics (aromatics). Soxhlet extraction and column chromat-ography separation had been taken as the pretreatment. C8 (C7.6), C10 (C10.1), C12 (C11.7), C16 (C15.5), C21 (C20.8) and C34 (C34.01) substitute C8–C10 (C7.6–C10.1), ＞C10–C12 (＞C10.1–C11.7), ＞C12–C16 (＞C11.7–C15.5), ＞C16–C21 (＞C15.5– C20.8) and ＞C21–C34 (＞C20.8–C34.01) , respectively for quantitative determination. Using the“substitute”linear relationship calculate each segment fractions’ concentration，then integrate all the peak areas from C8 to C34. The results of linear relationship and precision test of aliphatic petroleum hydrocarbon in this method demonstrate the correlation coefficient (0.990 3 to 0.999 8), the method detection limits (MDLs) (0.011 to 0.373 ng/μl), recovery rates (50.3% to 109.3%) and relative standard deviation (1.5% to 11.3%); and those of aromatic petroleum hydrocarbon in this method are the correlation coefficient (0.991 3 to 0.997 6), the method detection limits (MDLs) (0.004 to 0.048 ng/μl), recovery rates (53.6% to 107.7%) and relative standard deviation (3.2% to 12.2%). The test results of the method could accurately reflect the degree of soil contamination and toxicity.