scholarly journals Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
V. S. Anusuya Devi ◽  
V. Krishna Reddy
Keyword(s):  
Detection Limit ◽  
Cobalt Content ◽  
Molar Absorptivity ◽  
Order Derivative ◽  
Spectrophotometric Methods ◽  
Biological Water ◽  
Highly Sensitive ◽  
Beer's Law ◽  
Beer’S Law

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.

scholarly journals 2-Hydroxy-1-naphthaldehyde-P-hydroxybenzoichydrazone: A New Chromogenic Reagent for the Determination of Thorium(IV) and Uranium(VI)

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
V. S. Anasuya Devi ◽  
V. Krishna Reddy
Keyword(s):  
Detection Limit ◽  
Simultaneous Determination ◽  
Uranium Content ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Maximum Absorbance ◽  
Highly Sensitive ◽  
Beer's Law ◽  
Beer’S Law

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.

scholarly journals Redox-Reaction Based Spectrophotometric Assay of Isoniazid in Pharmaceuticals

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
N. Swamy ◽  
K. N. Prashanth ◽  
K. Basavaiah
Keyword(s):  
Prussian Blue ◽  
Redox Reaction ◽  
Molar Absorptivity ◽  
Spectrophotometric Assay ◽  
Commercial Formulation ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Beer's Law ◽  
Beer’S Law

Two spectrophotometric methods are described for the determination of isoniazid (INH) in pharmaceuticals. In the first method (FCR method), INH is reacted with Folin-Ciocalteu reagent in Na2CO3 medium and the resulting blue colored chromogen measured at 760 nm. Iron(II), formed as a result of reaction between INH and iron(III), is made to react with ferricyanide, and the resulting Prussian blue is measured at 760 nm, basing the second method (FFC method). The conditions for better performance are optimized. Beer’s law is obeyed in the concentration ranges 0.5–10 and 0.2–3.0 μg mL−1 for FCR method and FFC methods, respectively, with corresponding molar absorptivity values of 1.12×104 and 4.55×104 L mol−1 cm−1. The methods are validated for accuracy, precision, LOD, LOQ, robustness, and ruggedness as per the current ICH guidelines. The validated methods were successfully applied to quantify INH in its commercial formulation with satisfactory results; hence the methods are suitable for isoniazid determination in bulk drugs and pharmaceuticals.

scholarly journals 2-(4-Diethylaminostyryl)-1,3,3-trimethyl-5-thiocyanato-3H-indolium chloride as a new reagent for indirect spectrophotometric red-ox determination of Osmium (VI)

2008 ◽  
Vol 10 (2) ◽  
pp. 17-19
Author(s):  
Zholt Kormosh ◽  
Svitlana Korolchuk
Keyword(s):  
Complex Anion ◽  
Molar Absorptivity ◽  
Reaction Conditions ◽  
Spectrophotometric Detection ◽  
Highly Sensitive ◽  
Beer's Law ◽  
Beer’S Law ◽  
Redox Method

2-(4-Diethylaminostyryl)-1,3,3-trimethyl-5-thiocyanato-3H-indolium chloride as a new reagent for indirect spectrophotometric red-ox determination of Osmium (VI) A highly sensitive indirect spectrophotometric redox method for the determination of osmium is reported on. The method is based on the oxidation of iodide by osmium (VI) and the spectrophotometric detection of the liberated iodine in the form of complex anion associate with 2-(4-diethylaminostyryl)-1,3,3-trimethyl-5-thiocyanato-3H-indolium chloride reagent. The appropriate reaction conditions have been established. The molar absorptivity is (0.2-1.2)·105 dm3/mol·cm at 589.5 nm wavelength. The absorbance of the coloured extracts obeys the Beer's law in the range to 7.6 mg/dm3 of Os(VI).

scholarly journals Spectrophotometric Method for the Determination of Carboxin in its Formulations and Environmental Samples

2011 ◽  
Vol 8 (4) ◽  
pp. 1680-1685 ◽  
Author(s):  
C. Swarna ◽  
K. Purushotham Naidu ◽  
G. Nagendrudu ◽  
N. V. S. Naidu ◽  
K. Saraswathi
Keyword(s):  
Oxidative Coupling ◽  
Environmental Samples ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Beer's Law ◽  
Label Claim ◽  
Colored Product ◽  
Beer’S Law ◽  
Good Agreement

Simple, precise, rapid, sensitive and accurate spectrophotometric methods have been developed for the estimation of carboxin in pure form and in its formulations. The first method is based on oxidative coupling of carboxin with 1,10-phenonthrolin in presence of ferric chloride to form orange colored product with λmaxof 510 nm. The product obeyed Beer's law in the concentration range 1-10 mL (10 to 100 µg/mL) with molar absorptivity of 1.1425×103Sandell's sensitivity 0.2061. The second method is based on the reaction of carboxin with 2,2'-bipyridine to form orange red colored product exhibiting λmaxof 522 nm with molar absorptivity, Sandell's sensitivity 2.2605×103, 0.1041 respectively. It obeys Beer's law in the concentration range of 0.5-50 mL (5 to 50 µg/mL). The assay of results was found to be in good agreement with label claim.

scholarly journals Rapid Spectrophotometric Determination of Phenoxazine

2010 ◽  
Vol 7 (2) ◽  
pp. 1001-1005
Author(s):  
Baghdad Science Journal
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Acidic Medium ◽  
Absorption Maximum ◽  
Aqueous Samples ◽  
Economic Method ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Stability

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

Spectrophotometric Determination of Pyridoxine Hydrochlorine in Pharmaceutical Preparations and Foods

1997 ◽  
Vol 80 (6) ◽  
pp. 1368-1373 ◽  
Author(s):  
Kailasam Srtvidya ◽  
Natesan Balasubramanian
Keyword(s):  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Spectrophotometric Assay ◽  
Stable Complex ◽  
Pyridoxine Hydrochloride ◽  
Beer's Law ◽  
Rice Samples ◽  
Beer’S Law ◽  
Aqueous Volume

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.

scholarly journals New Spectrophotometric Determination of Cefdinir by Batch Method and Cloud Point Extraction

2019 ◽  
Vol 30 (1) ◽  
pp. 85
Author(s):  
Omar Qusay Mezhir
Keyword(s):  
Detection Limit ◽  
Correlation Coefficient ◽  
Cloud Point ◽  
Azo Dye ◽  
Cloud Point Extraction ◽  
Diazonium Salt ◽  
Molar Absorptivity ◽  
Purple Colour ◽  
Beer's Law ◽  
Beer’S Law

In this study, new spectrophotometric methods were developed for estimation of cefdinir (CFD); the research consists of two methods. The first method depends on the conversion of function group amine in cefdinir to diazonium salt and then combined with the 2, 5-Dimethylphenol (2, 5-DMP) reagent in the alkaline medium. The formed azo dye has a purple colour with absorption intensity at λmax 510 nm. Concentration range was obeyed Beer's law at (1-50 μg / ml), correlation coefficient was 0.9998, molar absorptivity was 1.54 × 104 L.mol-1.cm-1 and the detection limit was 0.04 μg.ml-1. The second method is including cloud point extraction (CPE) of a trace amount of the formed azo dye in the first method followed by measuring with a UV-visible spectrophotometer. Concentration range that obeyed the Beer's law was (0.2-6 μg / ml), correlation coefficient was 0.9998, molar absorptivity was1.48×105 L.mol-1.cm-1, detection limit was 0.004 μg.ml-1, Pre-concentration factor was 25 and Distribution coefficient was 125.The proposed methods were applied and proved their compatibility for estimating of ingredient compound in pure samples and pharmaceuticals by comparing them with previous studies. Keyword: cefdinir, diazotization, cloud point extraction, 2, 5-Dimethylphenol.

scholarly journals Micro Spectrophotometric Determination and Cloud Point Extraction of Sulphadimidine Sodium in Pure form and Pharmaceutical Drug

2019 ◽  
Vol 16 (2) ◽  
pp. 0332
Author(s):  
Dhahir Et al.
Keyword(s):  
Detection Limit ◽  
Cloud Point ◽  
Cloud Point Extraction ◽  
Pharmaceutical Preparation ◽  
Pure Form ◽  
Basic Medium ◽  
Limit Of Quantitation ◽  
Beer's Law ◽  
Beer’S Law

Two simple, rapid, and useful spectrophotometric methods were suggest or the determination of sulphadimidine sodium (SDMS) with and without using cloud point extraction technique in pure form and pharmaceutical preparation. The first  method was based on  diazotization of the Sulphdimidine Sodium drug by sodium nitrite at 5 ºC, followed by coupling with α –Naphthol in basic medium to form an orange colored product . The product was stabilized and its absorption was measured at 473 nm. Beer’s law was obeyed in the concentration range of (1-12) μg∙ml-1. Sandell’s sensitivity was 0.03012 μg∙cm-1, the detection limit was 0.0277 μg∙ml-1, and the limit of Quantitation was 0.03605μg∙ml-1.The second method was the cloud point extraction (CPE) using Trtion X-114 as surfactant. Beer’s law was obeyed in the concentration range of (1-12) μg∙ml-1. Sandell’s sensitivity was 0.02958 μg∙cm-1, the detection limit was 0.01745 μg∙ml-1, and the limit of quantitation was 0.028303 μg∙ml-1. All variables including the reagent concentration, reaction time, color stability period, and mole ratio were studied in order to optimize the reaction conditions. The mole ratio for the composition of product is (1:1). Both methods were effectively useful to the determination of sulphdimidine sodium in pharmaceutical dose form.  The attained results were in a good agreement with the official and other methods in the literature .No interference were observed from the commonly encountered additives and excipients.

scholarly journals Spectrophotometric assay of Nicotinamide in Pharmaceutical Dosages

2021 ◽  
Vol 2063 (1) ◽  
pp. 012017
Author(s):  
Basima A A Saleem ◽  
Raghad A M Hamoo ◽  
Ghassan Q Ismail
Keyword(s):  
Charge Transfer ◽  
Reduction Reaction ◽  
Molar Absorptivity ◽  
Charge Transfer Reaction ◽  
Colored Complex ◽  
Spectrophotometric Methods ◽  
Oxidation Reduction ◽  
Beer's Law ◽  
Beer’S Law ◽  
Transfer Method

Abstract The reaction of nicotinamide and alizarin reagent using charge transfer reaction at a pH of 5.54 lead to produce a red colored compound measured at 527 nm., while the blue colored complex was formed using the oxidation reduction reaction between nicotinamide and chromate at pH 3.49 in the presence of an indigo cochineal dye. Theses tow colored products were measured at 527 and 610 nm respectively using two simple, fast and an accurate spectrophotometric methods. The linearity of the charge transfer method was followed Beer’s law 0.4 - 32 μg while the oxidation reduction method was obeyed Beer’s law from 1.6 - 40 μg in depending on the concentration range. Molar absorptivity was 1.95×104 and 2.16×104 mol−1 cm−1 for the red and blue colored complex respectively. Finally, the values of Sandal’s sensitivity were 0.00626 and 0.00565 μg−2 cm−1 for the first and second methods respectively. These two methods have been applied to quantify the amount of nicotinamide in pharmaceuticals with good recovery.

New, simple and validated UV-spectrophotometric methods for the estimation of sodium usnate in preparations

2010 ◽  
Vol 29 (2) ◽  
pp. 157 ◽  
Author(s):  
Ivana Savić ◽  
Goran Nikolić ◽  
Ivan Savić ◽  
Saša Zlatković ◽  
Dragiša Djokić
Keyword(s):  
Phosphate Buffer ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Cost Effective ◽  
Sensitivity Coefficient ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Beer’S Law

New, simple, cost effective, accurate and reproducible UV-spectrophotometric methods were developed and validated for the estimation of sodium usnate in pharmaceutical preparations. Sodium usnate was estimated at 290 nm in water and phosphate buffer (pH 3):methanol (11:20 V/V). Beer’s law was obeyed in the concentration range of 0.1–5 μg·cm−3 (r = 0.997) in water and 1–12 μg·cm−3 (r = 0.999) in the phosphate buffer:methanol. The apparent molar absorptivity and Sandell’s sensitivity coefficient were found to be 3.16×104 dm3·mol−1·cm−1 and 11.58 ng·cm–2/0.001 A in water and 3.72×104 dm3·mol−1·cm−1 and 9.83 ng·cm–2/0.001 A in phosphate buffer:methanol, respectively, indicating the high sensitivity of the proposed methods. These methods were tested and validated for various parameters according to ICH guidelines. The detection and quantitation limits were found to be 0.0721 and 0.2163 μg·cm–3 in water and 0.163, 0.489 μg·cm−3 in phosphate buffer:methanol, respectively. The proposed methods were successfully applied for the determination of sodium usnate in pharmaceutical preparations. The results demonstrated that the procedure is accurate, precise and reproducible (R.S.D. < 2 %).

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