加速溶剂萃取-流体控制系统净化-高分辨气相色谱/高分辨质谱定量测定底泥中的二噁英

采用高分辨气相色谱/高分辨质谱(HRGC/HRMS)定量测定了底泥中的17种2,3,7,8位多氯代二噁英和呋喃(PCDD/Fs) ,并测定了四至八氯取代的二噁英和呋喃总量。样品经加速溶剂萃取,然后通过流体控制系统（FMS）自动过硅胶柱、氧化 铝柱和碳柱净化，最后浓缩。以HRGC/HRMS电压选择离子检测模式对样品中的PCDD/Fs进行了定性分析,采用同位素稀释 技术定量,该方法可精确定量到pg/g水平。结果表明该方法分析的17种二噁英和呋喃异构体的检出限可达0.1 pg/g。同 位素标准的回收率为49.8%～85.3%,样品中各异构体的回收率为93.2%～115.6%。该方法不但满足国际标准的要求,还大 大提高了分析速度,使分析周期从原来的2周缩短到2 d以内。

Determination of Polychlorinated Dibenzo-p-Dioxins and Dibenzo-Furans in Sediment by Accelerated Solvent Extraction,Fluid Management Systems and High Resolution Gas Chromatography/High Resolution Mass Spectrometry

A rapid,sensitive and accurate method has been developed for the determination of seventeen 2,3,7,8-substituted congeners of polychlorinated dibenzo-p-dioxins and dibenzo-furans(PCDD/Fs) in sediment using isotope dilution high resolution gas chromatography/high resolution mass spectrometry(HRGC/HRMS).Dibenzo-p-dioxins and dibenzo-furans were extracted from samples by accelerated solvent extraction(ASE) and then purified by fluid management systems(FMS) with silica column,alumina column and carbon column.Confirmation and quantitative analysis at pg/g level of PCDD/Fs were performed by HRGC/HRMS using voltage selective ion record(VSIR) mode.Recoveries of fifteen isotopically labeled compound solutions(LCS) and the precision and recovery standards(PAR) were found to be in the range of 49.8%-85.3% and 93.2%-113.8%,respectively.The detection limits of the method for both 2,3,7,8-tetrachlorodibenzo-furan(TCDF) and 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD) were determined to be 0.1 pg/g.This method not only meets the requirements of international standards,but also shortens analysis time from 2 weeks to 2 days.