DETERMINATION OF TRIAZINES AND ATRAZINE METABOLITES IN SOIL BY MICROWAVE-ASSISTED SOLVENT EXTRACTION AND HIGH-PRESSURE LIQUID CHROMATOGRAPHY WITH PHOTO-DIODE-ARRAY DETECTION
Helena Prosen,b and Lucija Zupančič-Kraljb
a ERICo Velenje, Institute for Ecological Research, Koroška 58, 3320 Velenje Slovenia
b Faculty of Chemistry and Chemical Technology, University of Ljubljana , Aškerčeva 5, 1000 Ljubljana , Slovenia
With our study microwave-assisted solvent extraction followed by chromatographic separation and quantification of selected triazines and atrazine metabolites were used. Soil matrix interferences negatively influenced the quantitation step, narrowing the linear range of the method. With the optimized microwave-assisted solvent extraction using 50:50 methanol/water mixture as the extraction solvent recoveries in the range 67-130% were reached, depending on the soil and the compound. The energy of microwaves was high enough to break down almost all sorption bonds between triazines/metabolites and soil. Due to matrix interferences desethyldesisopropylatrazine, desisopropylhydroxyatrazine and desethyldesisopropylhydroxyatrazine could not be determined. While higher organic matter content in soil seemed to slightly decrease the desorption, no correlation was proven between the clay content or soil pH and extraction efficiency.
Key words: microwave extraction, HPLC-DAD, triazines, metabolites, soil