Micellar oxidative transformation of ciprofloxacin: a kinetic investigation

Shrivastava, A. and Singh, A.K. and Sachdev, N. and Shrivastava, D.R. and Prasad, Surendra (2017) Micellar oxidative transformation of ciprofloxacin: a kinetic investigation. Environmental Chemistry, 14 (4). pp. 231-242. ISSN 1448-2517

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Abstract

The kinetics of the oxidative transformation, i.e. oxidative degradation, of ciprofloxacin (CIP) by chloramine-T (CAT) in cationic and anionic micelle media during the water chlorination process was studied spectrophotometrically at 275 nm and 298 K. The influence of added salts (1–10 × 10–4 mol dm–3) and solvent polarity of the medium on the reaction was studied. The orders with respect to substrate CIP and oxidant CAT were found to be first order in each. The variation of acid concentrations showed opposite effects in cationic and anionic micellar aggregates. Liquid chromatography–electrospray ionisation mass spectrometry was used to identify degradation products of CIP, which confirmed the full dealkylation of the piperazine ring in CIP as the major product. The piperazine moiety of CIP is the principal active site for the CAT during oxidation. Activation parameters for the CIP degradation in cationic and anionic micelles were evaluated by studying the reaction at different temperatures, which lent further support to the proposed degradation mechanism for CIP. The rate constants were evaluated to confirm the micellar effect from incorporating sodium dodecyl sulfate and cetyltrimethylammonium bromide in the reaction mixture and the intrinsic reactivity constants were determined in the aqueous as well as in the micellar pseudo-phases as 4.85 and 0.0083.

Item Type:	Journal Article
Subjects:	Q Science > QD Chemistry
Divisions:	Faculty of Science, Technology and Environment (FSTE) > School of Biological and Chemical Sciences
Depositing User:	Ms Shalni Sanjana
Date Deposited:	03 May 2018 00:44
Last Modified:	03 May 2018 00:44
URI:	https://repository.usp.ac.fj/id/eprint/10691

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