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Abstract -- A spectrophotometric method employing 2-hydroxybenzaldiminoglycine is proposed for the determination of chromium(III). The results of the determinations are compared with those obtained by the standard diphenyl carbazide method. [...]

The article details the development of a poly(para amino benzene sulfonic acid) modified glassy carbon electrode as a sensor for simultaneous determination of purine bases; guanine, adenine and uric acid. When 0.1 M NaOH was used as the supporting electrolyte the electro-oxidation of these analytes took place at well resolved electrode potentials which facilitated their simultaneous determination without any electrode fowling. The sensor response has been calibrated for both simultaneous and individual determination. Wide linear working concentration ranges and good detection limits were obtained for both. The selectivity of the sensor for simultaneous determination has been checked among these purine bases as well as in the presence of other possibly co-existing species. The sensor has been demonstrated to be efficient for determination of uric acid, guanine and adenine in acid denatured herring sperm DNA. The mechanistic and kinetic parameters such as charge transfer coefficient, number of electrons involved in the rate determining step, diffusion coefficient and heterogeneous rate constant for the electro-oxidation of these bases on the poly(para amino benzene sulfonic acid) modified glassy carbon electrode has also been determined. [ABSTRACT FROM AUTHOR]

A gold electrode (GE) modified with L-cysteine and gold nanoparticles (AuNPs) has been generated for computing the individual and simultaneous determination of nimesulide (NM) and acetaminophen (APAP). The electrochemical behavior of the pair of molecules has been inspected utilizing squarewave voltammetry (SWV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Studies indicated that the oxidation of APAP and NM is expedited at AuNPs/L-cysteine GE giving well defined peaks for APAP and NM at 0.596 V and 1.072 V respectively in Britton-Robinson (B-R) buffer (pH 2). The assay enabled simultaneous determination of these drugs in the linear working range of 3.0 × 10-4 M-1.0 × 10-5 M with detection limits of 4.06 × 10-7 M and 6.49 × 10-6 M for APAP and NM respectively. The high selectivity and sensitivity of the proposed assay were illustrated by its active application in the ascertainment of both APAP and NM in pharmaceutical preparations. [ABSTRACT FROM AUTHOR]

The fabrication and electrochemical response characteristics of two novel potentiometric sensors for the selective determination of domperidone (DOM) are described. The two fabricated sensors incorporate DOM–PTA (phosphotungstic acid) ion pair as the electroactive material. The sensors include a PVC membrane sensor and a carbon paste sensor. The sensors showed a linear, stable, and near Nernstian slope of 56.5 and 57.8 mV/decade for PVC membrane and carbon paste sensors, respectively over a relatively wide range of DOM concentration (1.0 × 10−1–1.0 × 10−5 and 1.0 × 10−1–3.55 × 10−6 M). The response time of DOM–PTA membrane sensor was less than 25 s and that in the case of carbon paste sensor was less than 20 s. A useful pH range of 4–6 was obtained for both types of sensors. A detection limit of 7.36 × 10−5 M was obtained for PVC membrane sensor and 1.0 × 10−6 M was obtained for carbon paste sensor. The proposed sensors showed very good selectivity to DOM in the presence of a large number of other interfering ions. The analytical application of the developed sensors in the determination of the drug in pharmaceutical formulations such as tablets was investigated. The results obtained are in good agreement with the values obtained by the standard method. The sensors were also applied for the determination of DOM in real samples such as urine by the standard addition method. [ABSTRACT FROM AUTHOR]

A metalloporphyrin incorporated carbon paste sensor has been developed for the determination of metronidazole benzoate (MTZB). Zn(II) complex of 5,10,15,20-tetrakis (3-methoxy-4-hydroxy phenyl) porphyrin (TMHPP) was used as the active material. The MTZB gave a well-defined reduction peak at-0.713 V in 0.1 mol l-1 phosphate buffer solution of pH around 7. Compared with bare carbon paste electrode (CPE), the TMHPP Zn(II) modified electrode significantly enhanced the reduction peak current of MTZB as well as lowered its reduction potential. Under optimum conditions the reduction peak current was proportional to MTZB concentration over the range 1 × 10-3 mol l-1 to 1 × 10-5 mol l-1. The detection limit was found to be 4.36 × 10-6 mol l-1. This sensor has been successfully applied for the determination of MTZB in pharmaceutical formulations and urine samples. [ABSTRACT FROM AUTHOR]

An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 +/- 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 +/- 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5-15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, beta-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt.

An in vitro regeneration protocol has been standardized via direct and indirect methods from excised root explants of C. bonduc, a threatened woody legume used for the treatment of contagious diseases, inflammation, leprosy, antiperiodic, febrifuge, anthelmenthic, urinary disorders, leucorrhoea, piles and to heal wounds. MS medium supplemented with 17.75 micromol BAP and 2.46 micromol IBA, induced a mean of 3.40 +/- 1.07 shoots directly from the surface of excised root explant. Subsequently, the shoots rooted readily on MS half strength medium with out growth regulators. In indirect organogenesis, callogenic frequency was optimized (96.66%) at the concentration of 9.04 micromol 2, 4-D and 0.88 micromol BAP. An average, 15.30 +/- 5.25 shoots were differentiated from the root callus at the concentration of 17.57 micromol BAP and 2.85 micromol IAA. Shoots regenerated through callus were rooted well on MS half strength medium with growth regulators at 2.95 micromol IBA. Rooted plantlets were transferred to the pots containing sterilized soil and were successfully hardened at greenhouse condition for three weeks then exposed to the natural environment. Survival rate was more (95%) in plantlets derived through direct organogenesis than (60%) the plantlets regenerated through root calli.