DETERMINATION OF TRIAZINE HERBICIDES IN SOIL SAMPLES BY ULTRASOUND-ASSISTED EXTRACTION FOLLOWED BY DISPERSIVE LIQUID-LIQUID MICROEXTRACTION BASED ON SOLIDIFICATION OF FLOATING ORGANIC DROPLET AND HPLC-UV ANALYSIS

摘要

Nowadays, the miniaturized extraction techniques are increasingly used due to their environmentally friendly features, efficiency and short extraction time. In this study, a procedure for the extraction of seven triazines (simazine, prometon, atrazine, ametryn, propazine, prometryn, terbutryn) from soil samples which combines the Ultrasound-Assisted-Extraction (USAE) as an effective extraction method and the Dispersive Liquid-Liquid MicroExtraction based on Solidification of Floating Organic droplet (DLLME-SFO) as a method for the extract clean-up and the concentration of target triazines has been developed. The influence of several parameters (pH, ionic strenght and extraction solvent) over the triazine extraction from the soil matrix has been investigated. The determination of triazines was carried out by HPLC with UV detection at 220 nm. The developed USAE-DLLME-SFO-HPLC-UV procedure provided high enrichment factors (176-247), good linearity (R~2, 0.992-0.999), low limits of detection/quantification (0.19-0.68/0.62-2.06 μg/kg), and it was applied to analyse some real soil samples.