Application of dispersive liquid-liquid microextraction based on solidification of floating organic drop for simultaneous determination of alachlor and atrazine in aqueous samples

Dispersive liquid-liquid microextraction based on solidification of floating organic drop coupled with HPLC-UV detection as a fast and inexpensive technique was applied to the simultaneous extraction and determination of traces of two common herbicides, alachlor and atrazine, in aqueous samples. The critical experimental parameters, including type of the extraction and disperser solvents as well as their volumes, sample pH, salt addition, and extraction time were investigated and optimized. Under the optimum conditions, the calibration graphs found to be linear in the range of 0.1-200 mu g/L with LOD in the range of 0.02-0.05 mu g/L. The RSDs were in the range of 4.2-5.3% (n = 5). The relative recoveries of well, tap, and river water samples which have been spiked with different levels of herbicides were 94.0-106.0, 99.0-105.0, and 88.5-97.0%, respectively.