A supersensitive spectrophotometric method for the determination of uranium(VI) with eriochromazurol B in the presence of tensides

1984 ◽  
Vol 49 (9) ◽  
pp. 1974-1989 ◽  
Author(s):  
Milan Pištělka ◽  
Bohumil Stojek ◽  
Josef Havel

The influence of various tensides on the sensitivity of the reaction of uranyl with chromatographically pure Eriochromazurol B (2'',6''-dichloro-3,3'-dimethyl-4-hydroxyfuchsone-5,5'-dicarboxylic acid) was studied and considerable bathochromic and hyperchromic effects were observed. The reaction is most sensitive in the presence of cetyltrimethylammonium or certylpyridinium bromide. Based on the study of the equlibria and optimization of the conditions, a method is suggested for the determination of uranium traces in waters consisting in the measurement of absorbance at 624 nm at pH 5. With the molar absorptivity value of 136 000, the method ranks among the most sensitive spectrophotometric methods of determination of uranium in general. The uranium traces in waters can conveniently be extracted with tri-n-octylamine and reextracted into an aqueous phase. For 10 ml samples, the detection limit is 0.025 ppm uranium. The results obtained are evaluated statistically.

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Oleksandr S. Tymoshuk ◽  
Orest S. Fedyshyn ◽  
Lesia V. Oleksiv ◽  
Petro V. Rydchuk ◽  
Vasyl S. Matiychuk

The simple, rapid spectrophotometric method for palladium(II) ions determination using a new analytical reagent is described. The interaction of Pd(II) ions with a reagent, of the class of azolidones, 4-(N′-(4-imino-2-oxo-thiazolidine-5-ylidene)-hydrazino)-benzoic acid, in water medium results in the formation of a complex. The Pd(II)-p-ITYBA complex shows maximum absorbance at a wavelength of 450 nm. The molar absorptivity is 4.30 × 103 L·mol−1·cm−1. The optimal pH for complex formation is 7.0. The developed method has a wide linearity range of 0.64–10.64 µg·mL−1 for Pd(II). The detection limit is 0.23 µg·mL−1. It was found that Co(II), Ni(II), Zn(II), Fe(III), Cu(II), Al(III), and many anions do not interfere with the Pd(II) determination. The proposed method was tested in the analysis of model solutions and successfully applied for the determination of palladium in catalyst. The obtained results show that this method can be used for serial determinations of palladium in various objects.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
V. S. Anasuya Devi ◽  
V. Krishna Reddy

Simple, sensitive, selective, direct, derivative, and simultaneous spectrophotometric methods are developed for the determination of uranium and thorium individually and simultaneously. The methods are based on the reaction of 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) with thorium(IV) and uranium(VI). HNAHBH reacts with thorium and uranium at pH 6.0 forming stable yellow and reddish brown coloured complexes, respectively. [Th(IV)-HNAHBH] complex shows maximum absorbance at 415 nm. Beer’s law is obeyed over the concentration range 0.464–6.961 μg mL−1with a detection limit of 0.01 μg mL−1and molar absorptivity,ε, 3.5 × 104 L mol−1 cm−1. Maximum absorbance shown by [U(VI)-HNAHBH] complex is at 410 nm with Beer’s law range 0.476–7.140 μg mL−1, detection limit 0.139 μg mL−1and molar absorptivity,ε, 1.78 × 104 L mol−1 cm−1. Highly sensitive and selective second-order derivative methods are reported for the direct and simultaneous determination of Th(IV) and U(VI) using HNAHBH. The applicability of the developed methods is tested by analyzing water, ore, fertilizer, and gas mantle samples for thorium and uranium content.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Kumble Divya ◽  
Badiadka Narayana

A simple and highly selective spectrophotometric method has been developed for the determination of selegiline hydrochloride in bulk and formulations. Method A is based on the oxidation of 3-methyl-2-benzothiazolinone hydrazone in the presence of ceric ammonium sulphate, followed by its coupling reaction with drug to form a colored product having λmax of 629 nm. Method B is based on the coupling reaction of drug with 4-aminoantipyrine to give a new ligand that reacts with copper(II) to give intense bluish red colored chelate which is measured at 539 nm. Beer’s law is obeyed in the range of 10.00–85.00 μg mL−1 with molar absorptivity of 0.98×104 for method A and 20.00–120.00 μg mL−1 with molar absorptivity of 0.94×104 for method B. The optimum reaction condition and the analytical parameters are evaluated. The results obtained indicate that the methods are free from interference of the ingredients; thus they are successfully applied to pharmaceutical formulations.


2018 ◽  
Vol 35 (3) ◽  
pp. 93
Author(s):  
T. V. Badiadka ◽  
Badiadka Narayana

A simple and rapid spectrophotometric method for the determination of nevirapine is described. The method is based on the reaction of nevirapine with tetrathiocyanatocobalt(II) ion in buffer of pH 4 to form the corresponding complex. Beer’s law is obeyed in the range of 0.2 – 2.0 μg mL-1 for nevirapine. The optical parameters such as molar absorptivity, Sandell’s sensitivity, detection limit and quantitation limit were found to be 1.16× 104 Lmol-1cm-1, 2.09 X 10-3 μg cm-2, 0.073 μg mL-1 and 0.222 μg mL-1 respectively. The optimum reaction conditionsand other analytical parameters were evaluated. The statistical evaluation of the method was examined by determining intra-day and inter-day precision. The proposed method has been successfully applied for the determination of nevirapine in pharmaceutical formulations.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
V. S. Anusuya Devi ◽  
V. Krishna Reddy

Optimized and validated spectrophotometric methods have been proposed for the determination of iron and cobalt individually and simultaneously. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) reacts with iron(II) and cobalt(II) to form reddish-brown and yellow-coloured [Fe(II)-HNAHBH] and [Co(II)-HNAHBH] complexes, respectively. The maximum absorbance of these complexes was found at 405 nm and 425 nm, respectively. For [Fe(II)-HNAHBH], Beer’s law is obeyed over the concentration range of 0.055–1.373 μg mL−1with a detection limit of 0.095 μg mL−1and molar absorptivityɛ, 5.6 × 104 L mol−1cm−1. [Co(II)-HNAHBH] complex obeys Beer’s law in 0.118–3.534 μg mL−1range with a detection limit of 0.04 μg mL−1and molar absorptivity,ɛof 2.3 × 104 L mol−1cm−1. Highly sensitive and selective first-, second- and third-order derivative methods are described for the determination of iron and cobalt. A simultaneous second-order derivative spectrophotometric method is proposed for the determination of these metals. All the proposed methods are successfully employed in the analysis of various biological, water, and alloy samples for the determination of iron and cobalt content.


2011 ◽  
Vol 2011 ◽  
pp. 1-8
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah ◽  
Kanakapura B. Vinay

Titrimetric and spectrophotometric methods are described for the determination of oxcarbazepine (OXC) in bulk drug and in tablets. The methods use N-bromosuccinimide (NBS) and bromopyrogallol red (BPR) as reagents. In titrimetry (method A), an acidified solution of OXC is titrated directly with NBS using methyl orange as indicator. Spectrophotometry (method B) involves the addition of known excess of NBS to an acidified solution of OXC followed by the determination of the unreacted NBS by reacting with BPR and measuring the absorbance of the unreacted dye at 460 nm. Titrimetry allows the determination of 6–18 mg of OXC and follows a reaction stoichiometry of 1 : 1 (OXC : NBS), whereas spectrophotometry is applicable over the concentration range of 0.8–8.0 μg mL-1. Method B with a calculated molar absorptivity of2.52×104 L mol-1 cm-1is the most sensitive spectrophotometric method ever developed for OXC. The optical characteristics such as limits of detection (LOD), quantification (LOQ), and Sandell's sensitivity values are also reported for the spectrophotometric method. The accuracy and precision of the methods were studied on intraday and interday basis. The methods described could usefully be applied to routine quality control of tablets containing OXC. No interference was observed from common pharmaceutical adjuvants. Statistical comparison of the results with a reference method shows an excellent agreement and indicates no significant difference in accuracy and precision. The reliability of the methods was further ascertained by recovery studies in standard addition procedure.


2021 ◽  
Vol 3 (1) ◽  
pp. 72-78
Author(s):  
Enas Samer Thanoon ◽  
Lana Abdhameed Raheed ◽  
Imad Younus Hasan

A simple, rapid, and specific spectrophotometric method was developed for the determination of paracetamol  in pure form and drug formulations. The method depended on the hydrolysis of paracetamol to p-aminophenol, which, oxidized under the effect of dissolved oxygen to benzoquinoneimine. In the alkaline medium, benzoquinoneimine reacts with Methyldopa to produce a high stabile indophenol dye. The absorbance was measured at 580 nm, and the molar absorptivity was found to be 7.75 x 10-5 L/(mol cm). Paracetamol was determined in pharmaceutical products in the 10–100 μg.mL-1 concentration range with a detection limit of 1.5 μg.mL-1 PAP. The developed method can be applied to the determination of both paracetamol and p-aminophenol in the presence of each other without prior separation. The proposed method is successfully employed for the determination of paracetamol in various synthetic mixtures and pharmaceutical preparations. Our obtained results were statistically compared with those given by the similar methods and the procedures evaluated as regards to both figures of merit and ease of applicability.


2013 ◽  
Vol 12 (7) ◽  
pp. 460-465
Author(s):  
Sameer Amereih ◽  
Zaher Barghouthi ◽  
Lamees Majjiad

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.


Author(s):  
RUAA MUAYAD MAHMOOD ◽  
HAMSA MUNAM YASSEN ◽  
SAMAR , NAJWA ISSAC ABDULLA AHMED DARWEESH ◽  
NAJWA ISSAC ABDULLA

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.


2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Heba H. Abdine ◽  
Sawsan M. Amer ◽  
Lama I. Al-Rayes

Simple and rapid spectrophotometric method has been developed and validated for the determination of paroxetine (PRX) in tablets. The proposed method was based on nucleophilic substitution reaction of PRX with 1,2-naphthoquinone-4-sulphonate (NQS) in an alkaline medium to form an orange-colored product of maximum absorption peak () at 488 nm. The stoichiometry and kinetics of the reaction were studied, and the reaction mechanism was postulated. Under the optimized reaction conditions, Beer's law correlating the absorbance (A) with PRX concentration (C) was obeyed in the range of 1–8 g . The regression equation for the calibration data was: A = 0.0031 + 0.1609 C, with good correlation coefficients (0.9992). The molar absorptivity () was L  1 . The limits of detection and quantitation were 0.3 and 0.8 g , respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the determination of PRX in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was %. The results obtained by the proposed method were comparable with those obtained by the official method.


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