中文摘要：

以国家标准方法和美国环保局（EPA）方法为基础，确定了最佳分析条件，用纯组分的甲醇配制溶液作标样，建立汽油污染土壤中气相特征组分的顶空气相色谱测定方法。结果表明，各组分的方法检出限较低，为0．39-2．25μg·L^-1。相对标准偏差（RSD％，n=7）为1．10％-6．64％，加标回收率为101．3％-109．2％，保证了测试结果的精密度和准确度。在采用的色谱条件下，分析周期仅为30min，除间二甲苯和对二甲苯谱图重合外，其他组分得到较好分离。用此方法对土壤气相抽提（Soil Vapor Extraction，即SVE）修复场地土壤中的气体样品进行了测定，结果满足实验要求。气体样品特征组分与其在汽油中的含量和含碳原子数有关，以低碳烃为主，随着碳原子数的增加，烃类物质的沸点也逐渐增高，越不易挥发，在气体样品中含量越少。气体样品组分与土壤中微生物的降解作用也有一定关系，微生物降解能力越强，高碳烃越倾向于分解为低碳烃。

英文摘要：

Soil contamination by gasoline and other petroleum-derived hydrocarbons released from underground storage tanks（USTs）is a serious and widespread environmental problem. Soil vapor Extraction（SVE）is gaining acceptance as a remediation technology for cost effective, high efficiency and safety. Change of gas phase concentration in SVE process is the base of estimating the tail-time and evaluating the remediation effect. Based on China National Standard Methods and American EPA methods, a new method by GC with a headspace sampler is estabhshed that can determine the gaseous characteristic components concentration in gasoline contaminated soil. N-alkane （pentane to dodecane）, benzene series and 2-methylpentane are chosen as the characteristic components. This method uses a mixture of pure components in methanol solvent as standard samples and results in an optimal analyses condition. The detection limits for each characteristic component range from 0.39 μg·L^-1 to 2.25 μg·L^-1, the relative standard deviations （RSD%, n=7） and recoveries are in range of 1.10% to 6.64% and 101.3%-109.2% respectively. The analytical period of sample is 30 minutes and the components are separated very well except the coincidence of m-xylene and p-xylene. Measured concentration in this retention time is the concentration sum of two components. The method has been applied to the analysis of gaseous samples with satisfactory results in gasoline contaminated soil restored by SVE. The characteristic components detected in gaseous sample are primarily hydrocarbons with fewer carbons and related to their content in gasoline and carbon number. Compound with more carbons is difficult for volatilization because of higher boiling point. Past research shows alkanes and aromatic hydrocarbons with 10 to 22 carbons are more easily degraded by microorganism, so the detected components have some relations to biodegradation. The biodegradability is greater, more easily the heavy hydrocarbons decompose.