气相色谱法同时测定土壤中脂肪烃与芳香烃含量OA

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.