Ionic liquid based microwave-assisted extraction of triazine and phenylurea herbicides from soil samples

The analysis of triazine and phenylurea herbicides in soil by ionic liquid based microwave-assisted extraction (IL-MAE) coupled with high-performance liquid chromatography was studied. The operational IL-MAE parameters were optimized, including types and concentration of ionic liquid, microwave power, irradiation temperature, extraction time and extractant volume. The results obtained under the optimized conditions were compared with methanol-MAE and IL-heating extraction, and it was determined that the IL-MAE method was rapid (4 min compared with 2 h for the heating extraction), efficient (recoveries were 1.6-12.2% higher than the other methods) and environmentally friendly (no volatile organic solvents were used). The proposed analytical method was evaluated by considering the average spike recoveries (84.0-101%) and relative standard deviations (2.8-6.0%), all of which indicate that the IL-MAE method is accurate, reproducible, and could be applied to real sample analyses.