scholarly journals 2-Hydroxy-5-methylbenzophenone oxime(HMBO) as an Analytical Reagent for Gravimetric Determination of Cu(II)

2007 ◽  
Vol 4 (1) ◽  
pp. 97-102 ◽  
Author(s):  
S. K. Shingadia ◽  
K. K. Desai

2-Hydroxy-5-methylbenzophenone oxime (HMBO) was developed as a new analytical reagent for the gravimetric determination of divalent copper ion. In pH rang of 3.0 to 6.0, the reagent gives a buff colored precipitate with Cu(II). Job’s method and mole ratio method revealed that the stoichiometry of the complex is 1:2 (metal: ligand). Beer’s law is obeyed up to 61.25 ppm of Cu(II). Molar absorptivity and Sandell’s sensitivity at 400 nm were found to be 6.32 × 102L mol-1cm-1and 0.359 μg/cm2respectively. The stability constant of Cu(II)-HMBO complex is found to be 2.43 × 109. Gibb’s free energy change for complex formation reaction was found to be -12.88 Kcal/mol. The reagent can be used for the analysis of brass and alloy.

2009 ◽  
Vol 6 (2) ◽  
pp. 303-307 ◽  
Author(s):  
Ambily P. Nair ◽  
J. Christine

2-Hydroxy-4-n-propoxy-5-bromoacetophenone oxime (HnPBAO) was developed as a new analytical reagent for the gravimetric determination of pentavalent vanadium ion. In the pH range 4.0-6.0, the reagent gave a brown coloured precipitate with V(V). Job’s method and Mole ratio method revealed that the stoichiometry of the complex is 1:1 (metal: ligand). Beer’s law is obeyed up to 20.38 ppm of V(V). Molar absorptivity and Sandells sensitivity at 450 nm were found to be 10.22 × 102L/mol/cm and 0.049 µg/cm2respectively. The stability constant of V(V)-HnPBAO complex is found to be 1.195 × 106. Gibb’s free energy change for complex formation reaction was found to be –8.34 kcal/mol. The reagent can be used for the analysis of vanadium in ferro-vanadium alloys.


2005 ◽  
Vol 2 (2) ◽  
pp. 161-164 ◽  
Author(s):  
Miss Krishna Purohit ◽  
K. K. Desai

2-Hydroxy-4-methoxybenzophenoneoxime (HMBO) was developed as a new analytical reagent for the gravimetric determination of Cu(II). In pH 2.5-9.0 the reagent gives brown coloured precipitate with Cu(II). Spectrophotometric methods revealed that the stoichiometry of the complex is 1:2 (metal: ligand). Beer's law is obeyed up to 31.75 ppm of Cu(II). Molar absorptivity and Sandell's sensitivity at 400 nm were found to be 7.0×102L mol-1cm-1and 0.090 μg/cm2respectively. The stability constant of Cu(II)-HMBO complex is found to be 6.13×109. Gibb’s free energy change for complex formation reaction was found to be -13.93 Kcal/mol. The reagent can be used for the analysis of brass.


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.


2008 ◽  
Vol 59 (1) ◽  
pp. 3-7
Author(s):  
Aurora Reiss ◽  
Mihaela Mureseanu ◽  
Nicolae Muresan

5-Hydroxy-6-mercapto-benzo [a] phenazine (HMBP) is proposed as a sensitive and selective analytical reagent for the extractive spectrophotometric determination of copper (II). Copper reacts with HMBP to give a dark red complex which is soluble in chloroform. The composition of the CuII � HMBP complex is established as 1:2 by Job�s continuous variation method and molar ratio method. The instability constant of the complex calculated by Job�s relation for nonisomolar series is 4.65 . 10-9, at room temperature. The CuII-HMBP complex in chlorophorm shows a maximum absorbance at 495 nm, with molar absorptivity and Sandell�s sensitivity values of 7.39 . 103dm3 mol-1 cm-1 and 0.012 mg cm-2, respectively. Beer�s law is obeyed in the concentration range 0.67 - 26.90 mg mL-1 and the detection limit is 0.59 mg mL-1. A repetition of the method is checked by finding the relative standard deviation (RSD) at 1.00 mg mL-1 CuII of 0.6%. The method is successfully employed for the determination of copper (II) in environmental samples. The reliability of the method is assured by analysing the standard alloys and by inter-comparison of experimental values, using an atomic absorption spectrometer.


Author(s):  
Salwa Fares Rassi

A simple, rapid and sensitive spectrophotometric method was developed for the determination of Se (IV) using 5,6-diaminouracil hydrochloride (DAUH) as an analytical reagent. The reagent has been synthesized and characterized using IR, 1H NMR. The metal ion in aqueous medium forms yellow colored complex with DAUH showing maximum absorbance at 343 nm. Hence, analytical studies were further carried out at 343 nm. The reagent reacts with selenium in acidic medium to form yellow colored 1:1 (M:L) complex . The color reactions are instantaneous and absorbance values remain constant for one week. The composition of the Se (IV) complex with DAUH was studied by the method of job’s continuous variation and molar ratio method. Beer’s law was obeyed in the range 0.2-15.0 μg mL−1of Se (IV). The molar absorptivity and Sandell’s sensitivity of the method were found to be 0.5×10+4 L.mol-1.cm-1and 0.031μg.cm-2 respectively. Since DAUH method is more sensitive, it was applied for the determination of selenium in samples.


Author(s):  
Sebastian Satya ◽  
Pravin U. Singare ◽  
R.S. Lokhande

2,2'-[1,2-phenylenebis(nitrilomethylidene)]bisphenol (BSOPD) is synthesized in the laboratoryand characterized by NMR, IR and elemental analysis for its purity. This reagent forms a yellowcomplex with U(VI) which can be quantitatively extracted into chloroform at pH 10. This complex inchloroform shows an intense absorption peak at 413.0 nm. It is observed that Beer’s law is obeyed inthe range of 2.0-10.0 ppm of metal solution. It gives a linear and reproducible graph under appropriateconditions, the complex having a molar absorptivity of 3.69 x 104 L mol-1·cm-1. Sandell’s sensitivitycalculated was found to be 4.4 x 10-3μg·cm-2. Nature of the extracted complex, determined by Job’scontinuous variation method, Slope ratio method and Mole ratio method shows that the compositionof U(VI) : BSOPD complex is 1:4. Interference by various ions is studied and masking agents usedwhere required. The proposed method has been applied for the determination of U(VI) in monazite sand and synthetic samples. The results of the analysis are found to be comparable with those obtained by standard method.


2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Kudige N. Prashanth ◽  
Basavaiah Kanakapura ◽  
Madihalli S. Raghu ◽  
Kanakapura B. Vinay

Studies were carried out to use the charge-transfer reactions of sumatriptan (SMT), extracted from neutralized sumatriptan succinate (STS), as n-electron donor with the π-acceptor, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and σ-acceptor, and iodine (I2). The formation of the colored complexes was utilized for the development of simple, rapid, and accurate spectrophotometric methods for the determination of SMT in pure form as well as in its tablets. The quantification of colored products was made spectrophotometrically at 585 nm for the CT complex formed between SMT and DDQ (DDQ method) and at 375 nm for the CT complex formed between SMT and I2 (I2 method). Beer’s law is obeyed over the concentration ranges of 4.0–56.0 μg mL−1 and 2.0–28.0 for DDQ and I2, respectively, with correlation coefficients () of 0.9997 and 0.9998. The analytical parameters such as apparent molar absorptivity, Sandell’s sensitivities, and limits of detection (LOD) and quantification (LOQ) are also reported for both methods. The described methods were successfully applied to the determination of SMT in tablets. No interference was observed from the common excipients present in tablets. The reaction stoichiometry in both methods was evaluated by Job’s method of continuous variations and was found to be 1 : 1 (donor : acceptor).


2000 ◽  
Vol 83 (1) ◽  
pp. 231-236 ◽  
Author(s):  
Hong-Wen Gao ◽  
Sheng-Yi Zhang ◽  
Su-Mei Ye

Abstract Determination of the mercury complex formed with Thiomicher's ketone (TMK) was improved by β-correction spectrophotometry in the presence of a nonionic surfactant at pH 5. The complex formed was Hg(TMK)2, and its true molar absorptivity is reported for the first time: εHg(TMK)2560 = 1.04 × 105 L/mol·cm. In addition, the stability constant of Hg(TMK)2 was equal to 3.64 × 1010 at an ion strength of 0.01 at 20°C. Results from analyses of wastewater samples showed that the relative standard deviations were ≤8.3%, and the recoveries of mercury ranged from 90 to 110%.


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