Simplified QuEChERS approach for the extraction of chlorinated compounds from soil samples

A simplified version of the QuEChERS method for the extraction of chlorinated pollutant compounds from soil samples is proposed. The procedure involves simple liquid extraction of the soil sample with ethyl acetate, followed by the addition of anhydrous MgSO4. Gas chromatography/electron capture detection (ECD) is then used to analyse the extracts without any other sample pretreatment. This new QuEChERS version includes, therefore, fewer treatment stages of the sample, which makes the final procedure simpler, faster, and cheaper and minimizes the creation of errors associated with this step. Three chlorinated compounds (chloroform, 1,2-dichlorobenzene, and hexachlorobenzene) of different volatility and polarity have been selected as target compounds and two different solvents (acetonitrile and ethyl acetate) have been evaluated in order to prove the suitability of the proposed approach for the extraction of these compounds from different soil samples. The suitability of the acetonitrile and ethyl acetate for PTV-GC analysis has also been evaluated. Recoveries between 62 and 93% and reproducibilities between 3.5 and 7.6% have been achieved.