同位素稀釋-氣相色譜-串聯質譜法測定土壤中的指示性毒殺芬

張 兵, 吳嘉嘉, 劉國瑞, 高麗榮, 鄭明輝

(中國科學院生態環境研究中心,北京100085)

同位素稀釋-氣相色譜-串聯質譜法測定土壤中的指示性毒殺芬

張 兵, 吳嘉嘉, 劉國瑞, 高麗榮, 鄭明輝＊

(中國科學院生態環境研究中心,北京100085)

建立了土壤樣品中指示性毒殺芬Parlar N o.26(P26)、Parlar No.50(P50)和Parlar N o.62(P62)的同位素稀釋-氣相色譜-串聯質譜(ID-GC-MS/MS)的分析方法。土壤樣品使用壓力溶劑萃取裝置(PLE)提取,以丙酮-正己烷(1∶1,v/v)混合溶液為提取溶劑;提取液依次經由多層酸性硅膠柱和活化硅膠柱凈化;洗脫液經氮吹濃縮至20μL后,利用GC-MS/MS的多反應監測(MRM)模式進行定性和定量。結果表明本方法可對樣品中的P26、P50和P62進行分析,相對標準偏差(RSD)小于11%,回收率可以達到55%～110%;P26、P50和P62的儀器檢出限分別為3.0、3.0和6.0pg。將該方法用于某地區農田表層土壤中3種指示性毒殺芬的檢測,其中P26的含量為0.17

ng/g、P50為0.08ng/g、P62為0.09ng/g。此方法適用于土壤樣品中指示性毒殺芬的分析。

同位素稀釋法;氣相色譜;串聯質譜;指示性毒殺芬;土壤

Abstract:Although toxaphene is now banned in use,the analysis of toxaphene has attracted increasing interest due to its persistence and widespread atmospheric transport in the environment.A new method based on isotope dilution-gas Chromatography-tandem mass spectrometry(ID-GC-MS/MS)has been developed for the determination of three toxaphene specific congeners comprised of Parlar No.26(P26),Parlar N o.50(P50)and Parlar N o.62(P62)in soil.13C10-labeled indicator toxaphene solution was added to the sample prior to pretreatment.Then the sample was extracted using p ressurized liquid extraction(PLE)follow ed by purification on multilayer acidic silica column and neutral silica column.The eluent was concentrated under gentle nitrogen gas flow and spiked with the injection of internal standard of13C10-chlordane.I-dentification and quantification of the analytes were carried out in the multip le reaction m onitoring(MRM)m ode after the GC separation.The linear range was20-800μg/L for three congeners,limits of detection(LOD)ranged from3.0to6.0pg.The five point calibration curves show ed a good linearity for all the congeners(R2>0.99).The relative standard deviations(RSD s)were below11%for and the spiked recoveries were in the range of55%-110%.The developed analytical method is suitable for the determination of toxaphene specific congeners in soil.

Key words:isotope dilution;gas Chromatography(GC);tandem mass spectrometry(MS/MS);indicator toxaphene;soil

毒殺芬是一種廣譜性殺蟲劑,由5～10個氯取代的莰烯或莰烷組成,根據其結構式理論推斷,它的同類物的數量多達32 768種[1]。在20世紀70年代,毒殺芬被用作滴滴涕(DD T)的替代品,為了保護農作物、家禽和家畜免受害蟲和病毒侵害,曾經在世界范圍內被廣泛使用[2]。由于它具有較高的毒性、持久性和生物富集性,所以可在大氣中進行遠距離傳輸[3],在遠離使用地點的海洋哺乳動物體內、魚類甚至是人乳中都檢測到了不同濃度的毒殺芬[4-6];毒殺芬已被列為《斯德哥爾摩公約》中首批控制的12種持久性有機污染物(persistent organic pollutants,PO Ps)之一。雖……