Photodegradation of Napropamide in Aqueous Methanol under UV Light and Sunlight Biswas Pabitra Kumar1, Pramanik Sukhendu Kumar2,3,4,, Bhattacharyya Jayati2,3, Bhattacharyya Anjan2,*, Mitra Santi Ranjan1 1Department of Soil Science and Agricultural Chemistry, Palli Siksha Bhabana, Institute of Agriculture, Visva-Bharati, Sriniketan, 731236, Birbhum, West Bengal, India 2Pesticide Residue Laboratory Department of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, 741 252, Nadia, West Bengal, India 3Department of Chemistry, University of Kalyani, Kalyani, 741235, Nadia, West Bengal, India 4Present address: Chemical Laboratory, Mejia Thermal Power Station, Damodar Valley Corporation, MTPS, 722183, Bankura, West Bengal, India (e-mail: skpramanik@gmail.com) *Corresponding author E-mail: anjan_84@rediffmail.com
Online published on 8 January, 2020. Abstract Photolysis of napropamide is reported under UV light (λ≥ 290 nm) and sunlight (λ≥ 250 max max nm). The rate of photodegradation of napropamide in aqueous methanol (10 μg mL−1) followed the first-order kinetics under UV (T½=1.09h.) and sunlight (7.72h.). On photolysis in aqueous methanol, it furnished four photoproducts (F1, F2, F3 and F4) of which F1 was a common photolysis product isolated from both sunlight and UV light. Photoproducts F2 and F3 were generated from UV irradiated solution and only F4 from sunlight irradiated solution. The plausible mechanism of photo transformation involved oxidation, dimerization, hydrolysis as well as nucleophilic displacement reactions. Top Keywords Napropamide, photo degradation, photoproduct, methanol, UV light, sunlight. Top |