Application of potassium dichromate and iron–thiocyanate in the spectrophotometric investigations of phenothiazines

Basavaiah, K.; Swamy, Javarappa Manjunatha

doi:10.1016/s0014-827x(01)01096-5

Cited by 32 publications

(20 citation statements)

References 19 publications

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“…Basavaiah et al 48,49 proposed two indirect spectrophotometric methods for the determination of phenothiazines with K2Cr2O7. The methods are based on the following: • The oxidation of the 2,10-disubstituted drugs by a known excess of chromium(VI), and a subsequent determination of the unreacted oxidant by interacting with methanol and sulfanilic acid;…”

mentioning

confidence: 99%

Efficient Oxidizing Agents for Determination of 2,10-Disubstituted Phenothiazines

Puzanowska-Tarasiewicz

Kuźmicka

Karpińska

et al. 2005

ANAL. SCI.

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confidence: 99%

Efficient Oxidizing Agents for Determination of 2,10-Disubstituted Phenothiazines

Puzanowska-Tarasiewicz

Kuźmicka

Karpińska

et al. 2005

ANAL. SCI.

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“…Potassium dichromate has been a useful oxidizing agent in the determination of a number of substances of pharmaceutical importance [26][27][28][29][30]. All the four methods described here are indirect and are based on the determination of residual dichromate after allowing the reaction between a measured excess of dichromate and RNH to go to completion under acidic conditions.…”

Section: Resultsmentioning

confidence: 99%

Quantitation of ranitidine in pharmaceuticals by titrimetry and spectrophotometry using potassium dichromate as the oxidimetric reagent

Basavaiah

Somashekar

2007

JICS

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Four new methods are described for the determination of ranitidine hydrochloride (RNH) in bulk drug and in formulations employing titrimetric and spectrophotometric techniques and using potassium dichromate as the oxidimetric reagent. In titrimetry (method A), RNH is treated with a measured excess of dichromate in acid medium, and the unreacted oxidant is back titrated with iron(II) ammonium sulfate. The three spectrophotometric methods are also based on the oxidation of RNH by a known excess of dichromate under acidic conditions followed by the determination of surplus oxidant by three different reaction schemes. In one procedure (method B), the residual dichromate is treated with diphenylcarbazide and the absorbance measured at 540 nm. Calculated amount of iron(II) is added to residual dichromate and the resulting iron(III) is complexed with thiocyanate and measured at 470 nm (method C). Method D involves reduction of unreacted dichromate by a calculated amount of iron(II) and estimation of residual iron(II) as its orthophenanthroline complex after raising the pH, and measuring the absorbance at 510 nm. In all the methods, the amount of dichromate reacted corresponds to the drug content. The experimental conditions are optimized. The titrimetric procedure is applicable over 5-10 mg range. In spectrophotometric methods, Beer's law is obeyed in the ranges 5-50, 5-80, and 10-100 μg ml -1 for method B, method C, and method D, respectively. The methods were validated for accuracy, precision and recovery. The proposed methods were applied to the analysis of RNH in the tablet and the injection forms, and the results were in agreement with those obtained by the reference method.

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“…So they could be applied to determine CPZ. The sensitivities of the three methods were not only higher than that of SP by 1 to 2 orders of magnitude [5,6], but also higher than that of FL [7], PV [9], CL [11][12][13] and spectroelectrochemical with flowinjection analysis (SPE-FIA) [26]. Therefore, the proposed method was more suitable for the determination of trace CPZ in the pharmaceutical form, moreover it could be used to determine residue of CPZ in pork.…”

Section: Introductionmentioning

confidence: 96%

“…So it is important to develop a new method for the determination of CPZ. Presently, the common methods to detect CPZ are spectrophotometry (SP) [1,2,[4][5][6], spectrofluorimetry [7], high performance liquid chromatography (HPLC) [8], pulse voltammetry (PV) [9] and chemiluminescence (CL) [10][11][12][13]. The official methods for CPZ, listed in the British Pharmacopoeia (BP) [1], US Pharmacopoeia (USP) [2] and some pharmaceutical analysis books [4], were consisted of the non-aqueous potentiometry or spectrophotometry in the ultraviolet region, which need derivative agent.…”

Section: Introductionmentioning

confidence: 99%

Study on the interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate by the resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectra and its analytical application

Chen

Liu

et al. 2010

Sci. China Chem.

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The interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate was investigated by ultravioletvisible absorption, resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) spectroscopy. In pH 5.3 Britton-Robinson (BR) buffer medium, chlorpromazine hydrochloride (CPZ) reacted with Pd(II) to form 2:1 cationic chelate, which further reacted with Na 2 WO 4 to form a 1:1 ternary ion-association complex ([Pd(CPZ) 2 ]·WO 4 ). As a result, the signal intensities of RRS, SOS and FDS were enhanced greatly, and the enhancements of scattering were proportional to the CPZ concentration in a certain range. Their maximum wavelengths were located at 310 nm, 570 nm and 391 nm, respectively and the detection limits (3) were 1.6 ng/mL (RRS method), 3.2 ng/mL (SOS method) and 5.6 ng/mL (FDS method). The optimum reaction conditions, the influences of coexisting substances and analytical application were mainly investigated by RRS method due to its highest sensitivity. A highly sensitive, simple, rapid and new method had been proposed to determine CPZ in the pharmaceutical form and residue of CPZ in pork. In addition, the Gibbs free energy change (G f ) of ion-association reaction was computed by using B3LYP/3-21g*/LanL2dz method. The formation of ion-association and the reasons for the enhancement of RRS were also discussed.resonance Rayleigh scattering, second-order scattering, frequency doubling scattering, chlorpromazine hydrochloride, palladium(II), Na 2 WO 4

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Application of potassium dichromate and iron–thiocyanate in the spectrophotometric investigations of phenothiazines

Cited by 32 publications

References 19 publications

Efficient Oxidizing Agents for Determination of 2,10-Disubstituted Phenothiazines

Efficient Oxidizing Agents for Determination of 2,10-Disubstituted Phenothiazines

Quantitation of ranitidine in pharmaceuticals by titrimetry and spectrophotometry using potassium dichromate as the oxidimetric reagent

Study on the interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate by the resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectra and its analytical application

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