| Abstract: | Abstract A method is described for the hydrolysis of urea herbicides on silica gel surfaces, making use of the acidic silanol groups. Only a heating step is needed without reagents being added and complete hydrolysis to the corresponding anilines can be achived in about 15 min at 165°C. Gas and liquid chromatographic techniques coupled with derivatization of the anilines before and after the column are then introduced as the actual analysis step. The potential of these analytical systems is demonstrated with a residue analysis in soil. The selectivity and sensitivity (detection limits, low nanogram to low picogram level) permit quantitation of urea herbicide traces with a minimum of sample clean-up. |
