Application of solvent microextraction to the analysis of nitroaromatic explosives in water samples

The application of solvent microextraction to the analysis of nitroaromatic explosives is presented. Extraction of 11 nitroaromatics was achieved by suspending 1 μl of organic solvent to the tip of a microsyringe in a stirred aqueous solution. Parameters such as extraction solvent, stirring rate, salt concentration and sampling time were studied and optimized. The limits of detection using bench-top quadrupole mass spectrometry and short extraction times (15 min) were found to be between 0.08 and 1.3 μg/l and the relative standard deviations ranged between 4.3 and 9.8%. Although precision and accuracy of quantification of the method are still needed, solvent microextraction proved to be a fast, simple and inexpensive tool for preconcentration and matrix isolation of nitroaromatics on a microscale.