Carbofuran-7-phenol

Degradation to carbofuran phenol was most rapid under anaerobic conditions (Venkatswarlu and Sethunathan 1978). 

Hydrolyzes in soil and water to carbofuran phenol, carbon dioxide, and methylamine (Rajagopal et al, 1986 Seiber et al, 1978 Somasundaram et al., 1989, 1991). Hydrolysis of carbofuran occurs in both flooded and nonflooded soils, but the rate is slightly higher under flooded conditions (Venkateswarlu et al., 1977), especially when the soil is pretreated with the hydrolysis product, carbofuran phenol (Rajagopal et al., 1986). In addition, the hydrolysis of carbofuran was found to be pH dependent in both deionized water and rice paddy water. At pH values of 7.0, 8.7, and 10.0, the hydrolysis half-lives in deionized water were 864, 19.4, and 1.2 h, respectively. In paddy water, the hydrolysis half-lives at pH values of 7.0, 8.7, and 10.0 were 40, 13.9, and 1.3, respectively (Seiber et al, 1978). 

Rajagopal, B.S., Panda, S., and Sethunathan, N. Accelerated degradation of carbatyl and carbofuran in a flooded soil pretreated with hydrolysis products, 1-naphthol and carbofuran phenol. Bull. Environ. Contam. Toxicol, 36(6) 827-832, 1986. Rajagopal, B.S., Rao, V.R., Nagendrappa, G., and Sethunathan, N. Metabolismof carbatyl and carbofuran by soil-enrichment and bacterial cultures. Can. J. Microbiol, 30(12) 1458-1466, 1984a. 

Carbofuran has hydrolytic half-lives of about one year at pH 6, of about 4 weeks at pH 7, and less than one day at pH 9. Carbofuran phenol Is the principal product formed at pH 5-9 (19). 

The lab half-life of carbofuran In six soils (each under 4 different levels of moisture and 2-3 different temperatures) was In the range of 5-261 days. After 28 days of aerobic Incubation In two of the six soils, parent carbofuran was the major extractable compound degradation products comprised <5% of the extractable material (65). However, under anaerobic (flooded soil) conditions, the degradation product carbofuran phenol was found to be the principal product and to persist (66). 

Carbofuran, phenolic metabolite Hydrolysis, distillation, column (alumina) Corn GC 44... 

Chromatographic conditions are the same as in Figure 6 working electrode potential +0.9 V—fA) 0.1 mL of acidified (pH 2) river water spiked with 1.0 ppm carhofuran and 0.1 carbofuran phenol (B) same sample after adjustment to pH 12. 

Mobility in Soils. Chlorpyrifos was not mobile in any of the soils studied, but its hydrolysis product trichloropyridinol was mobile, especially in loamy sand and silt loam soils (Table VI). Parathion, diazinon, and isofenphos were slightly mobile (Rf < 0.25), and their hydrolysis products were significantly more mobile than the respective parent compounds (p < 0.01). Carbofuran phenol was more mobile in all soils studied (Rf 0.33 to 0.68). 2,4-D was mobile in... 

Implications of Mobility on the Availability and Degradation of Pesticides in Soil. Repeated application of 2,4-dichlorophenol, p-nitrophenol, and salicylic acid (as observed in current studies) and carbofuran phenol (20) has induced enhanced microbial degradation of their parent compounds. Rf values of these hydrolysis products indicate intermediate to high mobility in soils. The p-nitrophenol, 2,4-dichlorophenol, and salicylic acid were utilized as energy sources by microbes, and their availability in soil may contribute to the induction of rapid microbial metabolism. Carbofuran phenol did not serve as a microbial substrate but also enhanced the degradation of its parent compound, carbofuran (20). Carbofuran phenol is freely available in anaerobic soils, but the significance of its availability is yet to be understood. 

The size of Che microbial populations able to rapidly degrade carbofuran in soils enhanced for its degradation were enumerated by means of substrate addition and fumigation. Use of these techniques followed unsuccessful attempts to enumerate the population using plate or direct counts in the enhanced soils. Overall biomass size declined following application of carbofuran. No biomass suppression was observed in the non-enhanced soils and implies this suppression may be related to the formation of metabolites such as carbofuran-phenol or methylamine. In the enhanced soils, 6% of applied pesticide was initially incorporated into biomass carbon. This contrasts with 0.87% incorporation in the non-enhanced soils. After 15 days there was complete loss of Che pesticide at this time the biomass contained 2% of the applied material. 

Table IV. Carbofuran Degradation and Carbofuran Phenol Production in Liquid Suspensions Inoculated with Enhanced and Non-enhanced Soil...

The principal hydrolytic products are carbofuran phenol and 3-hydroxy- and 3-ketophenol. (water) 3 h (soil) 4 to 28 h Decomposed by strong acids and strong alkalis. Decomposes slowly in the presence of moisture. Decomposes on storage in contact with water and under moist conditions in soil. Benomyl is rapidly converted into carbendazim in the environment, with a of 2 and 19 h in water and in soil, respectively Unstable in highly alkaline media... 

Rajagopal BS, Panda S, Sethunathan N (1986) Accelerated degradation of carbaryl and carbofuran in a flooded soil pretreated with hydrolysis products, 1-naphthol and carbofuran phenol. Bull Environ Contam Toxicol 36(6) 827-32... 

Carbofuran phenol is formed from the hydrolysis of caibofuian at pH 7.0. Caibofuran phenol was also found to be the major biodegradation product by lipoferum... 

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