NOPR Collection:

One–step simple method for the determination of palladium using 3-acetyl- 2-thiohydantoin as a releasing agent

2009-10-20T16:30:18Z

Title: One–step simple method for the determination of palladium using 3-acetyl- 2-thiohydantoin as a releasing agent Authors: Karthikeyan, J; Naik, P Parameshwara; Shetty, A Nityananda Abstract: A simple, rapid and accurate complexometric method for the determination of palladium(II) is proposed, based on the selective masking property of 3-acetyl-2-thiohydantoin (ATH) towards palladium(II). In the presence of diverse metal ions, palladium(II) is complexed with excess of EDTA and the surplus EDTA is back titrated with standard lead nitrate solution at pH 5-6 (acetic acid – sodium acetate buffer) using xylenol orange as indicator. An excess of a 0.5% solution of ATH is then added to displace EDTA from Pd(II) – EDTA complex. The released EDTA is titrated with the same standard lead nitrate solution as before. Reproducible and accurate results are obtained in the concentration range 0.35–11.00 mg of palladium with relative error of ±0.46% and coefficient of variation not exceeding 0.36%. The effects of diverse ions are studied. The method is used for the determination of palladium in alloys, hydrogenation catalyst and complexes with a fair degree of accuracy. Page(s): 442-446

Spectrophotometric determination of uranium (VI) via complexation with piroxicam

2009-10-17T16:30:20Z

Title: Spectrophotometric determination of uranium (VI) via complexation with piroxicam Authors: Lutfullah; Khan, Farheen; Rahman, Nafisur; Azmi, Syed Najmul Hejaz Abstract: An optimized and validated spectrophotometric method has been described for the quantitative analysis of uranyl ion in soil samples. The method is based on the chelation of uranyl ion with piroxicam to produce a yellow complex in 1,4-dioxan–water medium at room temperature which absorbs maximally at 390 nm. Beer’s law is obeyed in the concentration range of 6.75 × 10^-2 – 9.45 × 10^-1 g mL^-1 with apparent molar absorptivity and Sandell’s sensitivity of 4.114 × 10⁵L/mol/cmand 0.00066 g/cm²/ 0.001 absorbance unit, respectively. Interference due to various non-target ions was also investigated. The proposed method was successfully applied to the analysis of uranyl ion in synthetic soil samples. The validity of the proposed method was checked by applying the standard addition technique in addition to a comparison with the results obtained from other earlier reported methods. Page(s): 437-441

New spectrophotometric methods for the estimation of Lercanidipine hydrochloride

2009-10-15T16:30:23Z

Title: New spectrophotometric methods for the estimation of Lercanidipine hydrochloride Authors: Sastry, T Manikya; Ramakrishna, K Abstract: Three simple and sensitive visible spectrophotometic methods (A-C) have been developed for the assay of Lercanidipine hydrochloride (LER) in bulk and formulations. Method A is based on the formation of colour species by condensation reaction of drug with vanillin (_max=600). Method B is based on the formation of colour species between the drug and citric acid/acetic anhydride (_max=555) by means of forming inner salt formation. Method C is based on the formation of colour species by charge transfer complex formation with chloranil-acetaldehyde (_max=585). The results of analysis have been validated statistically. Recoveries range from 99.4 to 100.5% for the routine assay of LER formulations. Page(s): 431-436

Estimation of Ibuprofen solubilization in cationic and anionic surfactant media: Application of micelle binding model

2009-10-16T16:30:20Z

Title: Estimation of Ibuprofen solubilization in cationic and anionic surfactant media: Application of micelle binding model Authors: Bhattamishra, S D; Padhy, R K Abstract: Drug solubility is an important parameter for efficient drug delivery and absorption. Ibuprofen, -methyl-4-[2-methylpropyl] benzene acetic acid is a NSAID group of drug with antipyretic and analgesic properties. It has poor solubility in water. Its solubilisation properties in presence of cetyltrimethylammonium bromide (CTAB) and sodiumdodecyl sulphate (SDS) have been studied. Saturation solubilities in aqueous and aqueous-micellar media have been studied spectrophotometrically by measuring absorbance at 264 nm. Plot of solubility versus [SDS] shows a maximum in the pre-micellar region followed by the linear relationship between the variables in the region past critical micellar concentration (cmc). With CTAB, the solubility- [surfactant] profile shows double maxima, one each in pre- and post- micellar region. Appropriate explanation has been forwarded and the nature of solubilizate-surfactant interaction suggested. The pK_a values of ibuprofen determined pH-metrically in aqueous and aqueous-SDS media have been used to supplement the inference. The association constant values and free energy change of solubilisation are reported. Page(s): 426-430