Photodegradation of Pesticides. Photolysis Rates and Half-Life of Pirimicarb and Its Metabolites in Reactions in Water and in Solid Phase

摘要: The photodegradation of Pirimicarb under three different artificial lights and sunlight was studied in water solutions (buffers pH 5, 6, 7) solid phase. Five photocompounds were formed solution two undergoes fast degradation all conditions. In buffer it first gave compounds with a kinetic parallel process. These assigned the structures 2-[(methylformyl)amino]-5,6-dimethylpyrimidin-4-yl dimethylcarbamate (II), 2-(methylamino)-5,6-dimethylpyrimidin-4-yl (III), 2-(dimethylamino)-5,6-dimethyl-4-hydroxypyrimidine (V). V II stable to further photolysis (the latter t1/2 = 849 h) whereas III 2-amino-5,6-dimethylpyrimidin-4-yl (IV), 2-(formylamino)-5,6-dimethylpyrimidin-4-yl (IX). Both photodegraded undetectable species, IX shows very high (48 h). A behavior found phase...