Application of ultrasound-assisted emulsification microextraction for the determination of triazine herbicides in soil samples by high performance liquid chromatography

Ultrasound-assisted emulsification microextraction was applied to extract the herbicides simazine, atrazine, prometon, ametryn and prometryn from soil samples. They then were determined by HPLC with diode-array detection. Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, emulsification time and addition of salt, were optimized. Under the optimum conditions, the following analytical figures of merits are found: enrichment factors between 145 and 222, limits of detection between 0.1 to 0.5 ng g(-1), analytical linearity in the range from 1.0 to 200 ng g(-1), correlation coefficients (r) between 0.9989 and 0.9998, relative standard deviations from 2.8% to 3.6% (at n = 5, intraday) and 3.7% to 4.3% (interday), and recoveries (at spiking levels of 5.0 and 50.0 ng g(-1)) from 82.6% to 92.0%. The technique is simple, practical, rapid, and environmentally friendly.