Abstract
The fate of C 18 898, i.e. dimethametryn or N-(1', 2'-dimethylpropyl)-N'-ethyl-6-methylthio-1, 3, 5-triazine-2, 4-diamine (I), was followed in greenhouse-grown rice after application of 0.4 kg/ha of ring-14C-labelled herbicide into the paddy water. At maturity the leaves contained 1.37 ppm and the hulled grains 0.088 ppm of 14C-C 18 898 equivalents. The following degradation products were isolated from the plant: N-(1', 2'-dimethylpropyl)-6-methylthio-1, 3, 5-triazine-2, 4-diamine (II), N-(1', 2'-dimethyl-2'-hydroxypropyl)-N'-ethyl-6-methylthio-1, 3, 5-triazine-2, 4-diamine (III), N-(1', 2'-dimethyl-3'-hydroxypropyl)-VN'-ethyl-6-methylthio-1, 3, 5-triazine-2, 4-diamine (IV), N-(1', 2'-dimethylpropyl)-N'-ethyl-1, 3, 5-triazine-2, 4, 6-triamine (V), N-(1', 2'-dimethylpropyl)-1, 3, 5-triazine-2, 4, 6-triamine (VI), N-(1', 2'-dimethylpropyl)-N'-ethyl-6-hydroxy-1, 3, 5-triazine-2, 4-diamine (VII), and N-(1', 2'-dimethylpropyl)-6-hydroxy-1, 3, 5-triazine-2, 4-diamine (VIII). Some polar transformation products were characterized as amino acid conjugates. Products isolated from the soil were : (I), (II), (III), (IV), 6-hydroxy-analogues of (III) and (IV), (VII), (VIII), and N-(1', 2'-dimethylpropyl)-N'-ethyl-6-methylsulfinyl-1, 3, 5-triazme-2, 4-diamine (IX).
