2 research outputs found
Transformation of linezolid during water treatment with chlorine ─ A kinetic study
38-43The experimental studies on transformation
of emerging contaminant linezolid during water chlorination process have been
carried out using UV-Visible spectrometer. The pseudo-first order rate
constants of linezolid reaction with free available chlorine (FAC) at 5.0 - 8.8
pH have been determined.
The second order rate constants are found to decrease with increase in pH (e.g. apparent second rate constant;
k”app=2.88 dm3 mol-1s-1 at pH 5.0 and k”app = 0.076 dm3
mol-1 s-1 at pH
8.8 at 298K). Monochlorinated reaction product has been identified by LC/ESI/MS
spectra under the experimental conditions. A mechanism involving electrophilic
halogenation is proposed based on the kinetic data and LC/ESI/MS spectra. The
effect of temperature on the rate of the reaction has been studied at four
different temperatures. It is observed that rate constants increase with the
increase in temperature and the thermodynamic activation parameters Ea, ΔH#, ΔS#
and ΔG# are
evaluated for the reaction and discussed. The product of the reaction between
linezolid and FAC retains the antibacterial activity. The geometry optimization
of the reactants and the products has been done using dispersion corrected
density functional
(DFT-D) method. All the DFT calculations are accomplished using the
TurboMole-5.10 package