| Abstrakt: |
Abstract A modified QuEChERS (quick, easy, cheap, effective, rugged and safe) method was validated and applied for the estimation of half-lives of two imidazolinone group herbicides, imazethapyr and imazapic, in the Dystric Plinthosol (FX) and Ferralsol (LVA) agricultural soils using liquid chromatography tandem mass spectrometry. The solutions were prepared in a matrix extract to avoid matrix effects. The analytical method showed satisfactory specificity, selectivity, linearity (R2 > 0.99), recoveries (range 85.0–117.0%), with RSD between 6.7% and 16.6%, and precision (range 94.7–108.5%), with RSD between 6.0% and 11.9%. The limit of detections for imazethapyr and imazapic in the soils were 2.2 µg kg−1 and 2.0 µg kg−1, and the limit of quantifications were 6.6 µg kg−1 and 6.1 µg kg−1. The half-lives of imazethapyr (35.7 and 97.9 days) and imazapic (40.4 and 64.4 days), in the FX and LVA soils, respectively, indicate that they are medium-persistence herbicides with possibility of leaching into groundwater. In addition, high concentrations of imazethapyr and imazapic were found in the soil samples after the time of application, meaning that there is a potential for prolonged soil residual activity due to carryover. Graphical abstract fx1 Highlights • The QuEChERS-LC-MS/MS method contributed for the estimation of half-lives of imidazolinone herbicides in soils. • Imazethapyr and imazapic are medium-persistence herbicides in the soils and show prolonged soil residual activity. • The contamination of groundwater by imazethapyr and imazapic offers serious risks for the quality of drinking water. • Imazethapyr and imazapic persistence increases with clay and organic matter content (higher half-lives). [ABSTRACT FROM AUTHOR] |
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