Green Sample Preparation Based on Directly Suspended Droplet Microextraction using Deep Eutectic Solvent for Ultra-Trace Quantification of Nitroaromatic Explosives by High Performance Liquid Chromatography

Abstract

In the present study, a simple and efficient directly suspended-solidified floating organic droplet microextraction using deep eutectic solvent in combination with high performance liquid chromatography has been proposed for the extraction and ultra-trace quantification of nitroaromatic explosives. The predominant experimental factors such as type and amount of deep eutectic solvent, extraction time, salt concentration and temperature that affect the extraction efficiency of nitroaromatic explosives were considered and optimized. By performing the process in optimal conditions, the calibration curves were linear in the range of 0.6-200 μg/L for 2,4,6-trinitrotolouene (TNT), 0.5-200 μg/L for 2,4-dinitrotolouene (2,4-DNT) and 0.5-200 μg/L for 2,6-dinitrotolouene (2,6-DNT). The limits of detection were 0.19, 0.16 and 0.14 μg/L for TNT, 2,4-DNT and 2.6-DNT, respectively. The relative standard deviations were between 4.8-6.4% (n = 6). The proposed method was successfully applied to the analysis of soil and water samples. At the different spiking levels recovery values ranged between 89 to 102% for soil and water samples, which indicates the negligible effect of the matrix on the extraction process.