Derivative spectrophotometry in the analysis of pesticides

The method for the determination of propazine, simazine, bromacil, hexazinone and metoxuron by zero order and derivative spectrophotometry has been worked out. First order derivative spectra were applied for the determination of bromacil and the second order ones for the determination of hexazinone in their mixtures. Metoxuron was determined in the presence of hexazinone by normal or derivative spectrophotometry, whereas hexazinone only by the first or the second order derivative spectrophotometry. First order derivative spectrophotometry was also applied for the determination of propazine and simazine in the presence of bromacil, hexazinone and metoxuron. In the three-component mixtures it was possible to analyse metoxuron in the presence of bromacil and hexazinone using the first order derivative spectra and bromacil in the presence of metoxuron and hexazinone applying the second order derivative spectra.