分散式固相萃取净化-气相色谱-质谱联用测定土壤中的邻苯二甲酸酯

Dispersive Solid Phase Extraction Clean-up and Gas Chromatography-Mass Spectrometry for Determination of Phthalate Esters in Soil Samples

建立了土壤中18种邻苯二甲酸酯类内分泌干扰物的微波提取-分散式固相萃取净化-GC/MS分析方法。10g土壤样品经20mL二氯甲烷和丙酮混合溶剂微波提取后,以丙酮为置换溶剂并浓缩至1.5mL。浓缩液中加入0.2gC18吸附剂,振摇3min后离心10min(8000r/min),取1.0mL上层清液经正己烷置换后用气相色谱-质谱联用分析,并通过基质标准加入校准曲线补偿邻苯二甲酸酯的基体效应。净化所需时间少于20min。净化后土壤萃取液的基质去除率达到72.7%。方法线性范围7.5～750μg/kg,相关系数大于0.998;6次土壤样品测定值的RSD在5.5%～12.1%之间;加标土壤样品测定值RSD在7.3%～19.4%之间;平均回收率在94.4%～114.6%之间;检出限为1.2～4.3μg/kg。

A method was developed to determine phthalate esters in soil samples.The entire pre-treatment process involved microwave-assisted extraction,solvent conversion and clean-up of dispersive solid-phase extraction（DSPE）.A total of 10 g soil sample was extracted by microwave mixed with 20 mL mixed-phase solvent of dichloromethane and acetone.And then the extract of mixed-phase was converted into the acetone-phase and then concentrated to 1.5 mL extract.The concentrated extract was shaken for 3 min that mixed with 0.2 g C18 absorbent,and centrifuged for 10 min（8000 r/min）.The supernatant（1.0 mL） was quantitatively transferred and converted into n-hexane phase.The entire clean-up process was lower than 20 min.1.0 mL of the supernatant liquid was transferred into vial and then exchanged to hexane.Gas chromatography/mass spectrometry（GC/MS） was used for quantitative and confirmatory analysis of phthalate esters.The matrix effect of phthalate esters was compensated by matrix spiked calibration.The best removal efficiency of soil matrix was 72.65%.The method linearity range was 7.5-750 μg/kg（r〉0.998）.The RSDs of the actual soil samples and the spiked samples were 5.5%-12.1% and 7.3%-19.4%,respectively.The average recovery of the spiked samples was 94.4%-114.6%,and the detection limit of the phthalate esters in soil samples was 1.2-4.3 μg/kg.