Application of ultrasound-assisted emulsification-microextraction combined with high performance liquid chromatography to the determination of propoxur in environmental and beverage samples

Ultrasound-assisted emulsification-microextraction coupled to HPLC was applied to the determination of propoxur in environmental and beverage samples. Carbon tetrachloride (the extraction solvent) is added to the aqueous sample, and the liquids are sonificated at 60 A degrees C, upon which an emulsion is formed. This is followed by centrifugation the lower phase being analyzed by HPLC. The extraction solvent, its volume, extraction time, temperature and salt concentration were optimized. Linear range (0.01-10 A mu g mL(-1)), correlation coefficient (0.9965), detection limit (1 ng mL(-1) at a SNR of 3), and precision (4.5% RSD, n = 5) were determined. The technique was applied to the determination of propoxur in environmental and beverage samples and no target analyte was found in these samples. Therefore, samples were spiked and recoveries of 93-106% and RSDs of 1.5-6.2% were obtained.