高效液相色谱-气相色谱在线联用同时测定土壤中饱和烃和芳香烃  

Simultaneous determination of saturated and aromatic hydrocarbons in soil by on-line high performance liquid chromatography-gas chromatography

作　　者：刘玲玲[1] 李冰宁[1] 武彦文[1] LIU Lingling;LI Bingning;WU Yanwen(Beijing Center for Physical&Chemical Analysis,Beijing Food Safety Analysis and Testing Engineering Research Center,Beijing 100094,China)

机构地区：[1]北京市理化分析测试中心,北京市食品安全测试工程技术研究中心,北京100094

出　　处：《色谱》2021年第8期905-912,共8页Chinese Journal of Chromatography

基　　金：北京市改革与发展专项(2021ZL0111).

摘　　要：为加强对土壤中石油烃类污染物的风险管控,生态环境部已将石油烃类列为土壤中的重点监测项目。石油烃源于石油与合成油,是涵盖一定碳数范围的碳氢化合物,主要分为饱和烃和芳香烃两大类。芳香烃通常是高度烷基化的单环、双环与多环芳烃,其对人和动物的毒性较饱和烃大很多,因此,仅仅测定土壤中总石油烃含量难以准确评估其环境毒性。目前环境领域的标准方法尚未区分土壤中饱和烃和芳香烃。该研究针对土壤样品的基质干扰特点,对样品的提取和净化环节进行了优化,并且应用高效液相色谱-气相色谱在线联用(HPLC-GC)技术,建立了同时测定土壤中饱和烃和芳香烃的方法。其中,提取方法选择正己烷-乙醇(1∶1,v/v)以固液比1∶4常温振荡提取1 h,然后水洗去除乙醇,取正己烷层提取液净化;净化方法选择自制硅胶柱,以正己烷-二氯甲烷(8∶2,v/v)洗脱;洗脱液经浓缩注入HPLC-GC分析,以内标法同时测定试液中的饱和烃和芳香烃,方法的定量限为0.4 mg/kg。该方法经过土壤石油烃标准物(SQC-116)验证,测定值在证书提供的可信区间内,相对误差(RE)为10.6%,相对标准偏差(RSD)为1.4%,说明方法准确可靠且精密度达到分析要求。最后,该文采用建立的方法检测了北京地区的5个土壤样品,结果表明:5个样品均含有饱和烃(C_(10)~C_(40)),其含量范围为3.3~32.1 mg/kg;其中4个样品中检出芳香烃(C_(10)~C_(40)),其含量范围为0.8~4.3 mg/kg;此外,通过谱图分析还可以初步判别烃类物质的污染来源。To strengthen regulation for mitigating the risk posed by petroleum contaminants in soil,the Ministry of Ecology and Environment of the People’s Republic of China has classified petroleum hydrocarbons as a key monitoring item for regulatory contamination monitoring.Petroleum is principally derived from petroleum and synthetic fuels,which contain an extremely high content of hydrocarbon compounds that have varied boiling points.These compounds are chemically classified primarily as saturated and aromatic.Aromatic hydrocarbons are typically highly alkylated monocyclic,bicyclic,and polycyclic,which are more toxic to human and animal life than saturated hydrocarbons.Because of the significant toxicological differences among the various hydrocarbons,it is difficult to accurately assess their environmental toxicity by only determining the total content of petroleum in soil.However,there are no analytical methods for the simultaneous determination of saturated hydrocarbons and aromatic hydrocarbons in soil according to Chinese standards.In this study,extraction and purification procedures were completely optimized depending on the matrix of the soil samples.The advanced analytical technique of on-line high performance liquid chromatography-gas chromatography(HPLC-GC)was performed after sample preparation for the simultaneous determination of saturated hydrocarbons and aromatic hydrocarbons in soil.For the extraction,n-hexane/ethanol(1∶1,v/v)was chosen as the extraction solvent.The ratio of solid sample(soil)to the solvent was chosen as 1∶4,and extraction was performed once at room temperature,for 1 h.Water was then added and mixed to remove ethanol from the extracts,and the upper n-hexane layer was separated;thus,the petroleum hydrocarbons in the samples were completely extracted.However,the oils and fats in the matrix of the soil sample were also simultaneously extracted.Because of the limited retention capacity of the HPLC column,the presence of oils,fats,and other interferents would affect the subsequent determ

关 键 词：高效液相色谱-气相色谱在线联用 饱和烃 芳香烃 土壤 

分 类 号：O658[理学—分析化学]