Ultrasound Assisted Surfactant Enhanced Emulsification Microextraction and Spectrofluorimetry for Determination of Oxadiazon in Agricultural Water Samples

In this work, an environmentally friendly sample pre-treatment method, Ultrasound Assisted Surfactant Enhanced Emulsification Microextraction (UASEME) followed with spectrofluorimetry was performed for determination of oxadiazon residues in water samples. After the determination of the most suitable extraction solvent and its volume, other parameters such as type and concentration of surfactant, pH, extraction time and ionic strength were optimized. Under the best conditions for extraction recovery, 50µL of chlorobenzene was chosen as extraction solvent and Tween 20 in concentration of 0.06 mmol/L as emulsifier and 2 min was the required time for quantitative analysis, without ionic strength and pH adjustment. Limit of detection and relative standard deviation were calculated as 0.05µg/L and 3.2% respectively. The procedure was applied successfully for assessing matrix effect in real water samples with relative recovery 96-104% with the precision in the range of 2.9-3.4%. The results demonstrate that UASEME procedure as reported is reliable, rapid and easy to use for analysis of oxadiazon in water samples.