Spectrophotometric determination of zinc with 5-methyl-1,3,4-thiadiazolyl-(2-azo-1)-2-naphthol

1983 ◽  
Vol 48 (2) ◽  
pp. 464-470 ◽  
Author(s):  
Juan Cacho ◽  
Cristina Nerin

The reaction of Zn(II) with 5-methyl-1,3,4-thiadiazolyl-(2-azo-1)-2-naphthol (MTDAN) and extraction of the complex formed in chloroform is studied. The optimum pH range for the extraction and formation of the complex is 10-11.2 and Beer's law is obeyed in the interval of 0-2 ppm of Zn(II) in the organic phase. The molar absorptivity is 5.9 . 104 l mol-1 cm-1 at 568 nm. The stoichiometry of the complex corresponds to the type ML2. Some interferences are studied and an easy way is given to eliminate them. The results are compared with those corresponding to TAN. The reaction is applied to the analysis of synthetic samples of bronzes with satisfactory results.

Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan

A spectrophotometric method has been developed for the determination of Fe(III) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into ethyl acetate at pH 6. The method obeys Beer’s law over arrange from 1 to 7 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.31 × 104 L mol-1cm-1 and 0.13 μg cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.


Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan

A spectrophotometric method has been developed for the determination of Cu(II) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into n-butanol at pH 9.2. The method obeys Beer’s law over arrange from 1 to 10 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.97 × 104 L mol-1cm-1 and 0.26 µg·cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.


2013 ◽  
Vol 10 (3) ◽  
pp. 898-906
Author(s):  
Baghdad Science Journal

This paper describes the development of a simple spectrophotometric determination of bismuth III with 4-(2-pyridylazo) resorcinol (PAR) in aqueous solution in the presence of cetypyridinium chloride surfactant at pH 5 which exhibits maximum absorption at 532 nm. Beer's law is obeyed over the range 5-200 µg/25 mL. i.e. 0.2-8 ppm with a molar absorptivity of 3×104 l.mol-1.cm-1 and Sandell's sensitivity index of 0.0069 µg.cm-2. The method has been applied successfully in the determination of Bi (III) in waters and veterinary preparation.


2010 ◽  
Vol 7 (2) ◽  
pp. 1001-1005
Author(s):  
Baghdad Science Journal

A rapid high sensitive and inexpensive economic method has been developed for the Determination of phenoxazine by using molecular spectrophotometry. The method is based on the oxidation of phenoxazine by potassium (meta)periodate in acidic medium. The oxidation conditions were selected to enhance the sensitivity and the stability of the pink colored species which shows an absorption maximum at 530 nm. The Beer’s law was obeyed for phenoxazine concentration range from 1 to 6 µg mL-1 with 0.003 µg mL-1 detection limit and provided variation coefficients between 0.4 to 1.7 %. This method was successfully applied for the determination of phenoxazine in aqueous samples


1997 ◽  
Vol 80 (6) ◽  
pp. 1368-1373 ◽  
Author(s):  
Kailasam Srtvidya ◽  
Natesan Balasubramanian

Abstract An easy and sensitive spectrophotometric assay of pyridoxine is described. The procedure is based on formation of an azo dye by the reaction of pyridoxine with diazotized 2,4-dinitroaniline followed by the reaction of the dye with Hg2+ ions to form a stable complex with maximum absorbance at 545 nm. The system obeys Beer’s law for 4–75 μg pyridoxine hydrochloride in an overall aqueous volume of 25 mL (correlation coefficient, 0.9998). On extraction into 5 mL butan-1-ol, the system obeys Beer’s law in the range 0.8–15 μg pyridoxine hydrochloride at 545 nm. The color is stable for 60 min in both aqueous and organic phases (molar absorptivity, 3.7 × 104 L/mol · cm; coefficient of variation, 3.1%, n = 10). The pyridoxine contents of pharmaceutical preparations, a processed foodstuff, and 2 rice samples were determined by using the proposed method. Assay reliability was established by recovery studies and parallel determination using a reported method.


2002 ◽  
Vol 85 (1) ◽  
pp. 146-148
Author(s):  
Ashok Kumar Malik ◽  
Avasarla L J Rao

Abstract A method was developed for the determination of zinc(II) dimethyldithiocarbamate by converting it into the copper(II) dithiocarbamate complex, which is then extracted into molten naphthalene. The absorbance is measured at 430 nm versus a reagent blank. Beer's law is obeyed for concentrations of 0.63 × 10−3 to 17.2 × 10−3 g/L in the final solution. The method is sensitive and was applied to the determination of ziram in a commercial sample and in wheat grain.


2014 ◽  
Vol 675-677 ◽  
pp. 1429-1432
Author(s):  
Xing Xin Chen ◽  
Kui Liu ◽  
Li Fang Kuang ◽  
Hua Long

Determination of lanthanum in the raffinate by spectrophotometry was studied, using tribromoarsenazo as chromogenic reagent. The addition of ascorbic acid can mask the interference of other metal cations in the solution. Under the conditions of ascorbic acid (10g·L-1) 5 mL, hydrochloric acid 0.04 mol·L-1 and tribromoarsenazo (0.5g·L-1) 2 mL, Beer’s law is obeyed in the range of 0-10 μg·(25mL)-1 for lanthanum, with correlation coefficient higher than 0.99. Beer’s law can be applicable for the wavelength range of 580-660 nm. There is no linear relation at too high or too low acidic environment.


2004 ◽  
Vol 72 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Marwa S. Elazazy ◽  
Abdalla Shalaby ◽  
M. N. Elbolkiny ◽  
Hawa M. Khalil

A simple, rapid, sensitive and accurate method for the determination of aciclovir, cefepime HCI, etamsylate and metoclopramide HCI in pure form and in pharmaceutical formulations is developed.The method is based on the fomabon of tris(o-phenanthroline) iron(ll) complex (Ferroin) upon the reaction of the ated drugs wrth iron(lll )-o- phenanthroline mixture. The ferroin complex is colorimetncally measured at λmax 510 nm against a reagent blank. 0ptimization of the experimental conditions is described. Beer's law is obeyed in the concentration range from 0.25–30 µg ml−1 with molar absorpitivities (ε) ranging from 4.796 x 103–9.51 2 x 104 L.mol−1.cm−1 and Sandell sensitivities (S) of 2.129 x 10−3–34.5 x 10−3 µg cm−2. The developed method is applied successfully for the determination of the cited drugs in pure forms and in the corresponding pharmaceutical formulations without any interferences from common excipients.


2007 ◽  
Vol 4 (1) ◽  
pp. 50-52 ◽  
Author(s):  
M. Vamsi Krishna ◽  
P. V. Madhavi Latha ◽  
D. Gowri Sankar

A simple, sensitive spectrophotometric method for the determination of Famciclovir and Racecodotril is developed. It is based on the formation of a colored oxidative coupling product between 2,6-dichloroquinone-chlorimide and the drug is described. The method has been extended to pharmaceutical preparations. The absorption maxima and Beer’s law limits for Famciclovir are 500 nm, 20-100 µg/mL and for Racecodotril are 460 nm, 12.5-62.5 µg/mL.


1982 ◽  
Vol 65 (1) ◽  
pp. 141-143
Author(s):  
Madiha B Sidhom ◽  
Michel E El-Kommos

Abstract A spectrophotometric method is described for the determination of menadione and menadione sodium bisulfite in bulk and in solution for injection. The method measures the intensity of the violet color (λmax 540 nm) developed when menadione reacts with thiosemicarbazide in alkaline medium. Beer's law is obeyed in the concentration range 4-40 μg/m L (r = 0.9995). The method is simple, sensitive, and particularly suited for routine analysis of official menadione sodium bisulfite injection. Results are comparable with the USP method.


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