色谱2023，Vol.41Issue(12)：1127-1134,8.DOI:10.3724/SP.J.1123.2023.01002
气相色谱-质谱法测定土壤中14种苯胺类和联苯胺类化合物
Determination of 14 aniline and benzidine compounds in soil by gas chromatography-mass spectrometry
摘要
Abstract
The complex matrix of soil samples and low extraction efficiency of aniline com-pounds limit many methods developed for detecting aniline and benzidine compounds in soil.In this study,a rapid and sensitive method based on gas chromatography-mass spectrometry was developed for the simultaneous determination of 14 aniline and benzidine compounds in soil.The collected soil samples were sealed with 5％sodium sulfite solution and refrigerated to in-hibit the oxidation of the target compounds for up to 7 d.The extraction efficiencies of acceler-ated solvent extraction and oscillating dispersion extraction were compared,and the recovery of accelerated solvent extraction was found to be unsuitable.Hence,three-phase oscillating dis-persion extraction was adopted.A certain amount of alkaline aqueous solution was added to the test system during extraction to improve the extraction efficiency because aniline and benzidine compounds are weakly alkaline substances.When the pH of the extracted water phase was greater than 12,relatively good recoveries were obtained.Next,a mixed solvent of ethyl ace-tate-methylene chloride(1:4,v/v)was added to extract the target compounds via oscillation for 20 min.The solid phase was discarded via centrifugation,and the aqueous and organic phases were transferred to a liquid separation funnel for further separation.Finally,the organic phase was retained.This pretreatment process prevents the co-extraction of acidic compounds or other impurities,thereby enhancing the purification ability of the method.Solid phase ex-traction(SPE)is generally recommended for soil extraction and purification.A preliminary test showed that compared with other columns,the Florisil SPE column could better retain the tar-get substances and exhibited higher elution efficiency.After purification,the organic phase was concentrated to 1 mL using a nitrogen blower.The analytes were analyzed by gas chromatogra-phy-mass spectrometry using a capillary column(DB-35MS,30 m×0.25 mm×0.25 μm).The temperature program was optimized to separate the target compounds at the baseline.Specific-ally,the initial oven temperature was set to 60℃,held for 2 min,increased to 130℃ at a rate of 5℃/min,increased to 300℃ at a rate of 30℃/min,and held for 4 min.The injector and ion source temperatures were 250 and 300℃,respectively.Aniline-d5 and acenaphthene-d10 were used as the internal standards for quantification.The effects of antioxidant addition,ex-traction solvent type,salting out,and other factors on extraction efficiency were investigated.The results showed that the method performed well under the optimized experimental condi-tions when actual soils were used as real sample matrices.The accuracy and precision of the proposed method were verified.A total of 14 aniline and benzidine compounds demonstrated good linearities in the range of 0.5-100 mg/L.The method detection limits(MDLs)ranged from 0.02 to 0.07 mg/kg,and the limits of quantification(LOQs)ranged from 0.08 to 0.28 mg/kg.The target compounds were spiked at contents of 1 and 10 mg/kg.The spiked recover-ies of the 14 targets in actual soils were 62.9％-101％,and the relative standard deviations(RSDs)of six precision tests were 3.8％-10.3％.The proposed method effectively inhibited the oxidation of aniline and benzidine compounds during extraction,and the target compounds ex-hibited high recoveries and good stabilities in the presence of three phases.Moreover,the oper-ating procedure was simple and easy to implement.The proposed method was applied to the soil collected from an industrial enterprise in Jiangsu province that was suspected to be contam-inated with aniline,and two aniline compounds were detected.The developed method requires a small sample size,and the preservation step is simple and effective.In addition,it can be ap-plied to various types of actual soils.The method meets the requirements of current soil pollu-tion risk control standards for aniline and benzidine compounds in soils.关键词
气相色谱-质谱/苯胺类化合物/联苯胺类化合物/土壤Key words
gas chromatography-mass spectrometry/aniline compounds/benzidine com-pounds/soil分类
化学化工引用本文复制引用
吴丽娟,杨丽莉,胡恩宇,王美飞,杨超,尹明明..气相色谱-质谱法测定土壤中14种苯胺类和联苯胺类化合物[J].色谱,2023,41(12):1127-1134,8.基金项目
国家生态环境标准制修订计划(2021-17). Establishment and Revision Plan of National Eco-Environmental Standards(No.2021-17) （2021-17）
