Application of liquid phase microextraction based on solidification of floating organic drop for the determination of triazine herbicides in soil samples by gas chromatography with flame photometric detection

Abstract

A simple and efficient liquid phase microextraction based on solidification of floating organic drop coupled with gas chromatography–flame photometric detection was developed for the extraction and determination of some triazine herbicides (metribuzin, simetryn, ametryn and prometryn) in soil samples. The type and volume of the extraction solvent, sample solution temperature, salt addition, stirring rate, and the extraction time were optimized. Under the optimal conditions, the linear response was observed over the range of 10–2000 µg kg−1 for metribuzin and 2–500 µg kg−1 for simetryn, ametryn, and prometryn, respectively, with the correlation coefficients (r) varying from 0.9990 to 0.9992. The limits of detection were in the range between 0.2 and 1.0 µg kg−1 (S/N = 3 : 1). The recoveries of the target analytes for the spiked soil samples ranged from 75.5% to 97.3%, with the relative standard deviation values less than 7.2% (n = 5). The enrichment factors were achieved ranging from 122 to 336. The developed method was applied for the preconcentration and determination of triazine herbicides in real soil samples and a satisfactory result was obtained.