Analysis of trifluralin and other dinitroaniline herbicide residues by zero-order and derivative ultraviolet spectrophotometry
Abstract
The utility of zero-order and first- and second-derivative ultraviolet (UV) spectrophotometry for the identification of benfluralin, trifluralin, isopropalin and oryzalin is discussed. These four herbicides were determined by zero-order and first-derivative UV spectrophotometry, with linear calibration graphs established between 50 and 100 concentration units and limits of detection ranging from 1 to 7 µg ml–1. The application of these techniques to the residue analysis of fortified soils and niebe and peanut leaves is described. Trifluralin residues were found to be 6.7, 8 and 1.7 µg ml–1 in samples of fortified soils, niebe leaves and peanut leaves, respectively. Isopropalin residues were found to range from 62 to 154 µg ml–1 in samples of fortified niebe leaves.