Correction: EPR detection and characterisation of a paramagnetic Mo(iii) dihydride intermediate involved in electrocatalytic hydrogen evolution.

Correction for 'EPR detection and characterisation of a paramagnetic Mo(iii) dihydride intermediate involved in electrocatalytic hydrogen evolution' by Christopher Prior, et al., Dalton Trans., 2016, 45, 2399-2403.

EPR detection and characterisation of a paramagnetic Mo(iii) dihydride intermediate involved in electrocatalytic hydrogen evolution.

EPR spectroscopy and theoretical data show that the slow heterogeneous electron-transfer kinetics associated with the reduction of an 18-electron Mo(IV) acetato dihydride are a consequence of an η(2)-η(1) rearrangement of the carboxylate ligand which gives a unique paramagnetic 17-electron Mo(III) dihydride.

Electrochemical oxidation behavior of hydrochlorothiazide on a glassy carbon electrode and its voltammetric determination in pharmaceutical formulations and biological fluids.

The electrochemical oxidation behavior of hydrochlorothiazide (HCT) on a glassy carbon as a working electrode was investigated in Britton-Robinson (B-R) buffer pH 3, by using anodic stripping voltammetry (ASV) and cyclic voltammetry (CV). This drug gave a well-defined voltammetric oxidation peak at + 1200 mV versus an Ag/AgCl reference electrode. The electrochemical oxidation process was shown to be irreversible and diffusion controlled, with adsorption characterized over the entire pH range. The optimized conditions, such as accumulation time and potential, scan rate, frequency, pulse amplitude, varying of working electrodes, and instrumental parameters were studied. The calibration graph for HCT was obtained from 4 × 10-6 to 4 × 10-5 M (correlation coefficient = 0.997) using the developed electroanalytical method (ASV). The detection limit of this drug was 4.3 × 10-9 M. ASV and CV techniques with adequate precision and accuracy have been developed and applied for direct determination of HCT in commercial tablets without separation or extraction procedures and biological fluids such as urine and plasma.

Determination of carmine food dye (E120) in foodstuffs by stripping voltammetry.

The behavior of the food colorant agent carmine (E120) was studied by square-wave adsorptive stripping voltammetry (SW-AdSV) at the hanging mercury drop electrode. It was observed that carmine gave a sensitive stripping voltammetric peak at -350 mV in pH 3 acetate buffer. The cyclic voltammetric technique was also used to characterize the electrochemical reduction process of carmine. The adsorptive voltammetric signal was evaluated with respect to various experimental conditions, and the optimized values were supporting electrolyte, acetate buffer; buffer acidity, pH 3; dye concentration, 3 x 10(-7) M; accumulation time, 150 s; accumulation potential, -0.2 V; scan rate, 300 mV/s; pulse amplitude, 185 mV; SW frequency, 20 Hz; working electrode area, 0.6 mm2; and convection rate, 2600 rpm. The SW-AdSV peak currents depended linearly on the concentration of carmine from 5 x 10(-8) to 1.25 x 10(-7) mol/L (r = 0.99). A detection limit of 1.43 x 10(-9) mol/L with an RSD of 2.2% and a mean recovery of 97.9% were obtained. Possible interferences by several substances usually present in food products such as food additive dyes (E102, E100, E123, E127, and E129), artificial sweeteners, preservatives, and antioxidants were also evaluated. The proposed electrochemical procedure was successfully applied to the determination of carmine food dye in spiked commercially available ice cream and soft drinks.