Dispersive liquid-liquid microextraction based on solidification of floating organic drop and fluorescence detection for the determination of nitrated polycyclic aromatic hydrocarbons in aqueous samples

In this study, a dispersive liquid-liquid microextraction method based on the solidification of a floating organic drop (DLLME-SFO) combined with molecular fluorescence detection was developed for the analysis of nitrated polycyclic aromatic hydrocarbons in environmental samples. Parameters affecting the efficiency of the extraction procedure were evaluated and optimized, including the nature of the dispersant agent, extractant and dispersant volumes, salt addition effect, and extraction time. Additionally, various strategies in the emulsion formation process were assayed. After optimization, the values obtained for limits of detection and quantification for 3-nitrofluoranthene were 2.3 ng mL(-1) and 5 ng mL(-1) respectively, and for 9-nitroanthracene 1.7 ng mL-1 and 2.5 ng mL(-1). The recovery values ranged from 95% to 100% and the enrichment factor attained varied from 380 to 400-fold. The developed method was successfully applied to the analysis of lake water and drinking water samples. The results indicated that the proposed approach is a novel, sensitive, fast and reproducible methodology suitable for the analysis of traces of environmentally important nitrated polycyclic aromatic hydrocarbons in water samples. (C) 2016 Published by Elsevier B.V.