GC-C-IRMS测定污染场地土壤中苯系物单体碳同位素比值

Determination of Carbon Isotope Ratio of Benzenes in Soils from Contaminated Site by GC-C-IRMS

选取苯系物中的代表性组分苯、甲苯和二甲苯等化合物,通过热脱附、气相色谱质谱条件的优化及方法学考察,建立了热脱附进样-气相色谱-同位素比值质谱(GC-C-IRMS)测定苯系物单体碳同位素比值的方法。结果表明,单体化合物进样量在0.3μg以上均能满足测定要求;与直接进样方式相比,热脱附进样对单体碳同位素比值测定无分馏影响;标准溶液和苯系物土壤样品测定结果的RSD分别为1.0%~1.7%和0.3%~2.6%。

Taking benzene,toluene and xylene as representative components of benzenes,the carbon isotope ratio of each component was detected by thermal desorption injection-gas chromatography-isotopes ratio mass spectrometry.The results showed that above 0.3μg injection volume of each component could meet the determination requirements.Compared with direct injection,thermal desorption injection had no fractionation effect on the determination of carbon isotope ratio.The RSDs of standard solutions and spiked soil samples were 1.0%~1.7%and 0.3%~2.6%,respectively.