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Two simple, rapid and sensitive extraction spectrophotometric methods have been developed for the assay of trazodone hydrochloride (TRH) in pure and pharmaceutical formulations. These methods are based on the formation of chloroform soluble ion-association complexes of TRH with bromocresol green (BCG) and with methyl orange (MO) in a KCl-HCl buffer of pH 1.5 (for BCG) and in a NaOAc-HCl buffer of pH 3.29 (for MO) with absorption maximum at 415 nm and at 422 nm for BCG and MO, respectively. The reaction conditions were optimized to obtain the maximum color intensity. The absorbance was found to increase linearly with increasing concentration of TRH, which was corroborated by the calculated correlation coefficient values (0.9992 and 0.9994). The systems obeyed the Beer law in the range of 0.9-17 and 1-20 μg/ml for BCG and MO, respectively. Various analytical parameters were evaluated and the results were validated by statistical data. No interference was observed from common excipients present in pharmaceutical formulations. The proposed methods are simple, accurate and suitable for quality control applications.

The present study reports a facile, simple, and eco‐friendly hydrothermal method of preparation of nanocomposite material, NdCoO3@Nd2O3‐rGO, and its utility as an electrochemical sensor and energy storage device. The synthesized NdCoO3@Nd2O3‐rGO nanocomposite was investigated in terms of structural and morphological characteristics. The electrochemical sensing performance of the reported material was tested by analyzing an antioxidant, α‐lipoic acid (ALA), in pharmaceutical formulations and biological samples. The sensing capability of demonstrated material was noticed to be improved by 28‐fold when compared to that at bare glassy carbon electrode. Good linearity was observed between the peak current and concentration of ALA in the range of (0.05–20.92) × 10−6 mol/L and (0.02–28.06) × 10−6 mol/L for DPV and SWV methods, respectively. Further, the electrochemical energy storage ability of NdCoO3@Nd2O3‐rGO was also investigated. For this, NdCoO3@Nd2O3‐rGO was fabricated over NF for supercapacitor application. The NdCoO3@Nd2O3‐rGO/NF electrode showed good super capacitive properties with a specific capacitance of 1502.22 F/g at a current density of 1 A/g in 1 M KOH electrolyte. The electrode showed good cycling stability with a retention of 78.0% after 5000 cycles. [ABSTRACT FROM AUTHOR]

A unique and irregular form distorted Cu2(V2O7) sphere with crumbled sheets of rGO nanocomposite was developed as a sensor over a glassy carbon electrode (GCE). It showed a higher sensitivity for an antipsychotic drug, pimozide (PMZ). Voltammetric techniques were used to investigate the electrochemical behavior of PMZ. The formation of Cu2(V2O7)-rGO nanocomposite was confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to examine the surface morphology and its properties. Cyclic voltammetric studies revealed that PMZ displayed intense electrocatalytic activity and exhibited an electro-oxidation peak at the modified electrode. The modified electrode possessed unique qualities such as fast electron transfer ability, repeatability, and reproducibility. The proposed differential pulse voltammetric (DPV) and square wave voltammetric (SWV) methods showed linearity in the concentration range of 5.12 × 10−9 M to 3.06 × 10−4 M and 1.02 × 10−9 M to 5.30 × 10−4 M, respectively. The limit of detection (LOD) was calculated to be 1.70 × 10−10 M and 8.52 × 10−11 M, while the limit of quantification (LOQ) was found to be 5.66 × 10−10 M and 2.84 × 10−10 M, respectively, for DPV and SWV methods. The developed methods were successfully applied for the determination of PMZ in pharmaceutical formulations and human urine samples. [ABSTRACT FROM AUTHOR]

An eco-friendly and sensitive electrode, SnO2-β-cyclodextrin-graphene oxide modified glassy carbon electrode, was developed for the determination of an antioxidant drug, α-lipoic acid (ALA). SnO2 nanoparticles were prepared by the sonication method by the treatment of SnCl2 with extracts of kiwi peel. SnO2-β-CD-GO was characterized by XRD, FTIR, SEM, UV–Vis and EIS. ALA exhibited enhanced anodic peak current at 0.88V (Epa) in BR buffer of pH 3 with the enhancement of ~ 26-fold at the SnO2-β-CD-GO/GCE compared to bare electrode. Scan rate studies revealed the electrode process was diffusion controlled. A linearity was observed between the peak current and concentration of ALA in the range of 6.5 × 10−8–7.22 × 10−5 mol L−1 for DPV and 3.12 × 10−8–4.99 × 10−5 mol L−1 for the SWV method. The lower concentration of LOD value of 1.42 × 10−9 mol L−1 was attained with the SWV method. The proposed sensor demonstrated its applicability for the determination of ALA in pharmaceutical formulations and biological samples. [ABSTRACT FROM AUTHOR]