化学试剂

为建立土壤中脂肪烃与芳香烃的同步气相色谱分析方法，系统考察了土壤样品基质中的脂肪烃和芳香烃分离纯化过程中，压力、填料种类、洗脱溶剂类型等关键影响因素，并探究了样品基质对优化后分析方法检测结果的干扰效应，明确了该方法在土壤样品实际检测中的可行性。实验称取10 g冻干土壤样品，采用加压流体萃取法进行萃取，经净化除杂、浓缩处理后获得净化液;选取硅胶小柱作为分离柱，先以正己烷为洗脱溶剂收集脂肪烃组分，再加入二氯甲烷继续洗脱得到芳香烃组分，将两组分分别浓缩、定容、过滤后，采用GC-FID进行定性定量分析。结果表明，石油烃经硅酸镁柱净化后，在常压条件下选用SPE硅胶小柱作为分离柱，以正己烷、二氯甲烷依次梯度洗脱，可实现脂肪烃与芳香烃的高效分离纯化，且方法受样品基质干扰较小。基质加标试验结果回收率范围为80.9%～95.3%，相对标准偏差范围为1.11%～11.2%，该方法优化了土壤中两类烃类化合物的前处理流程与分离参数，操作简便、分离效果良好，为土壤环境中脂肪烃和芳香烃的精准检测提供了可靠的技术支撑，适用于土壤烃类污染监测与风险评估工作。

To establish a synchronous gas chromatographic analysis method for aliphatic and aromatic hydrocarbons in soil,the effects of key factors,such as pressure,packing material,and elution solvent,on the separation and purification of these hydrocarbons in the soil matrix were systematically investigated. In addition,the interference effect of the sample matrix on the detection results of the optimized analytical method was evaluated,thereby confirming the feasibility of the proposed method for the analysis of actual soil samples.In the experiment,10 g of a freeze-dried soil sample was subjected to pressurized fluid extraction.A purified solution was obtained after purification,impurity removal,and concentration steps. A silica gel column was used for separation.First,n-hexane was used as the elution solvent to collect the aliphatic hydrocarbon fraction,and dichloromethane was then added to continue elution and obtain the aromatic hydrocarbon fraction.The two fractions were separately concentrated,diluted to a fixed volume,filtered,and subjected to qualitative and quantitative analyses by GC-FID. The results indicated that after purification of petroleum hydrocarbons with magnesium silicate columns,efficient separation and purification of aliphatic and aromatic hydrocarbons can be achieved under atmospheric pressure using SPE silica gel cartridges as the separation column and sequential elution with n-hexane and dichloromethane in a gradient mode; this method was less affected by sample matrix interference.The recovery percentage derived from the results of the matrix spike test ranged from 80. 9% to 95. 3%,and the relative standard deviation ranged from 1. 11% to 11. 2%. The proposed GC-FID analytical method optimizes the pretreatment process and separation parameters for the two types of hydrocarbon compounds in soil.Overall,the method is simple to operate,has a good separation effect,and provides reliable technical support for the accurate detection of aliphatic and aromatic hydrocarbons in soil.This analytical method applies to soil hydrocarbon pollution monitoring and risk assessment.