Studies on the kinetics of carbamazepine degradation in aqueous matrix in the course of modified Fenton's reactions.

The present article describes a study into the kinetics of carbamazepine degradation under influence of the standard Fenton's reagent, light-enhanced Fenton's reagent, as well as modified Fenton's systems in which iron(II) ion is replaced by Cu(I), Cu(II), Ni(II), Mn(II), Cr(III) and V(V) ions. In the course of the study it was established that V(V) ion modified Fenton's reagent was equally effective in relation to carbamazepine as the standard reagent. Parameters of both standard and modified Fenton's reagents were optimized.

Studies on photodegradation of levomepromazine and olanzapine under simulated environmental conditions.

The present study discusses the influence of sunlight on the photostability of levomepromazine (LV) and olanzapine (OLA) hydrochlorides in river water. Four samples of water from different rivers were used in the research. In their course, it turned out that levomepromazine easily underwent photooxidation under simulated environmental conditions, resulting in the generation of its sulphoxide.

Quantification of ranitidine hydrochloride in the presence of its decomposition product by spectrophotometric methods. Application for kinetic study.

Three spectrophotometric methods, based on a spectral analysis, are proposed for quantification of ranitidine hydrochloride (RHCl) in the presence of its decomposition product (R-ox) without isolation from the matrix. One of them is a zero-crossing derivative-spectrophotometry. A value of the first derivative at 332 nm generated by the Savitzky-Golay algorithm (delta lambda = 22 nm and the first polynomial degree) allows for quantification of RHCI in the concentration range 0.

An application of UV-derivative spectrophotometry and bivariate calibration algorithm for study of photostability of levomepromazine hydrochloride.

Derivative spectrophotometry and bivariate calibration algorithm were used for study of run of photooxidation of levomepromazine hydrochloride (LV). The actual concentrations of LV and its main degradation product levomepromazine sulphoxide (LV-SO) were calculated using data provided by applied methods. The direct reading of absorbance values at 302 nm and 334 nm were employed for quantification of LV and LV-SO, respectively, in the case of bivariate method.