快速溶剂萃取-气相色谱-质谱法测定土壤中苯胺类化合物

Determination of aniline compounds in soil by rapid solvent extraction-gas chromatography-mass spectrometry

建立快速溶剂萃取(ASE)-气相色谱-质谱(GC-MS)法测定土壤中苯胺、邻硝基苯胺、间硝基苯胺、对硝基苯胺、二硝基苯胺5种苯胺类化合物的方法。样品经丙酮-二氯甲烷混合溶剂(体积比为1∶1)提取,用硅酸镁小柱净化,经无水硫酸钠脱水,氮吹浓缩至1.0 mL,用GC-MS法测定,外标法定量。5种苯胺类化合物的质量浓度在0.2~2.0μg/mL范围内与特征离子色谱峰面积具有良好的线性关系,相关系数均不小于0.995,方法检出限为0.7~5.7μg/kg。当空白土壤样品加标质量分数分别为60、140μg/kg时,苯胺回收率为51.0%~64.2%,其余4种硝基苯胺的回收率为68.0%~121.5%,测定结果的相对标准偏差为1.2%~7.4%(n=6)。该方法适用于低含量苯胺类化合物的土壤测定。

A method for the determination of aniline, o-nitroaniline, m-nitroaniline, p-nitroaniline and dinitroaniline in soil by rapid solvent extraction(ASE)-gas chromatography-mass spectrometry(GC-MS) was established. The sample was extracted with acetone-dichloromethane mixed solvent(volume ratio was 1∶1), purified with magnesium silicate column, dehydrated with anhydrous sodium sulfate, concentrated to 1.0 mL by nitrogen blowing, determined by gas chromatography-mass spectrometry and quantified by external standard method. The mass concentration of five aniline compounds had a good linear relationships with the characteristic ion chromatographic peak area in the range of 0.2-2.0μg/mL, the correlation coefficients were all not less than 0.995, the method detection limits of five aniline compounds were 0.7-5.7 μg/kg. The recovery of aniline was 51.0%-64.2%, and the recoveries of the other four nitroaniline were 68.0%-121.5% when the spiked mass fractions of blank soil samples were 60 and 140 μg/kg respectively, and the relative standard deviations of the determination results were 1.2%-7.4%(n=6). The method is suitable for the determination of low content aniline compounds in soil.