Biodegradation of Fenitrothion in Soil

✍ Scribed by Shalini Roy; Reena Kumar; Sharmila Roy; C. B. Sharma

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 369 KB
• Volume: 10
• Category: Article
• ISSN: 0269-3879
• DOI: 10.1002/(sici)1099-0801(199603)10:2<60::aid-bmc559>3.0.co;2-t

✦ Synopsis

The biodegradation of fenitrothion (an organophosphorus pesticide) in garden soil of western Uttar Pradesh in northern India has been studied. Both natural and autoclaved soil were treated with 10 p.p.m. of fenitrothion at field capacity moisture and incubated for 90 days in glass containers at 25 and 40°C. The soil samples were collected at various intervals between 0 and 90 days and analysed by HPLC for the residual pesticide and metabolites formed. At 0 days the recovery of the pesticide was 98% and the pesticide then degraded linearly with incubation time. The concentration of pesticide in the natural soil decreased with incubation time with concomitant formation of two metabolites at 25°C and three metabolites at 40°C. These metabolites were purified to homogeneity by HPLC and characterized by IR spectroscopy. The results showed oxidative desulphuration of the pesticide at the first step followed by hydrolytic cleavage of P-0-aryl linkage and demetbylation at the second and third step, respectively. EXPERIMENTAL Material and methods. Fenitrothion was a generous gift from Bayer (India) Ltd (Bombay, India). All other reagents used were Analar or HPLC grade from E.Merck (Bombay, India) and Spectrochem (Bombay, India).

Bulk samples of garden alluvial soil (pH 6.2. organic matter 6.4% and total nitrogen 0.09%) was taken from three different places from the farm of the University of Roorkee, Roorkee, situated in the north-west region of India. The moist soil was left for about 5-6 days in open air so as to dry it. It was then sieved through a 2 mm sieve. Portions (20 g) of sieved soil were placed in a sterile glass test-tube (200 X 25 mm) and adequate distilled