Keywords : III


Spectrophotometric Assay of Yttrium(III) with Alizarin Red S in the Presence of etyltrimethylammonium Bromide -Application to Water Samples

Salim A. Mohammad; Sammei Y. Zebary

Rafidain Journal of Science, 2018, Volume 27, Issue 2, Pages 127-137
DOI: 10.33899/rjs.2018.145397

A simple, accurate and sensitive procedure for spectrophotometric determination of yttrium (III) in aqueous solution has been developed. The method is based on the reaction of yttrium (III) with alizarin red S (ARS) reagent in the presence of cetyltrimethylammonium bromide (CTAB) and triton-X-100 surfactants at pH 4.7 to form a red carmine complex which has maximum absorption at 520 nm. Beer's law is obeyed over the concentration range 2.5-75 µg yttrium (III) /20 ml, (i.e. ,0.125-3.73 ppm) with a determination coefficient of (0.9954) and molar absorptivity of 1.16×104 l.mol-1.cm-1. The limit of detection (LOD) and the limit of quantification (LOQ) are 0.1009 and 0.323 g.mL-1, respectively. Under optimum conditions, the stoichiometry of the reaction between yttrium (III), alizarin red S and CTAB is found to be 1:2:2, respectively. The recoveries are obtained in the range of 98.07 - 100.63% and the relative standard deviation is better than ±2.33%. The method has been successfully applied to the determination of yttrium(III) in natural waters

Analytical Use of Prussian Blue to the Assay of Hydroxyurea in Capsule

Kasim M. Al-Abbasi; Rasha N. Mahmood

Rafidain Journal of Science, 2014, Volume 25, Issue 4, Pages 104-121
DOI: 10.33899/rjs.2014.88664

The research involves a simple and sensitive spectrophotometric method for the determination of hydroxyurea in aqueous solution by two steps. The first step depends on the reduction of ferric ions by hydroxyurea to ferrous ions, and in the second step the later reacts with potassium ferricyanide to form a stable prussian blue. This dye is soluble in water and gives absorption maxima at 700 nm. Beer's law was obeyed over the range 1-100 µg of hydroxyurea per 20 ml (i.e 0.05 – 5 ppm) with a corresponding molar absorptivity of 2.4×1041.mol-1.cm-1, Sandell's sensitivity index of 0.0032 µg cm-2 and average relative standard deviation of ± 0.33%, depending on the concentration level, and the t-test value comes to be (0.91) which is less than its table value (2.361) at a confidence level of 95% for 8 degrees of freedom which applies credibility to the suggested method.
The method had been applied successfully to determination of hydroxyurea in capsule.

Spectrophotometric Determination of Bismuth with Alizarine Red S and Cetylpyridinium Chloride - Application to Water Samples, Urine and Veterinary Preparation

Salim A. Mohammed; Mohammed M. Mohammed

Rafidain Journal of Science, 2013, Volume 24, Issue 9, Pages 52-63
DOI: 10.33899/rjs.2013.78759

A simple, accurate, sensitive and reliable method for spectrophotometric determination of Bismuth(III) is developed. The method is based on the reaction of bismuth (III) with alizarine red S (ARS) and cetylpyridinium chloride (CPC) in the presence of Triton X-100 at pH 3 to form a pink, water soluble ternary complex which shows a maximum absorption at 507 nm with a molar absorptivity of 1.4 x104 L.mol-1cm-1. The calibration curve is linear in the concentration range 5– 150 μg of bismuth (III) in a final volume of 20mL (i.e. 0.25-7.5 μg mL-1) with a determination coefficient of (R2) (0.9974). The limit of detection (LOD) and the limit of quantification (LOQ) are 0.0671 and 0.2235 g.mL-1, respectively. Under optimum conditions, the stoichiometry of the reaction between bismuth (III), alizarine red S and cetylpyridinium chloride is found to be 1:3:6, respectively. The recoveries are obtained in the range of 98.8- 102.1% and a relative standard deviation (RSD) of ± 0.93 to ±3.07% depending on the concentration level. The proposed method has been applied successfully to the determination of bismuth (III) in various samples such as, natural waters, urine and veterinary preparation

Spectrophotometric Determination of Cerium (III) with Arsenazo III: Application to Sea Water and Synthetic Alloys

Sadallah T. Sulaiman; Ghaydaa K. Hanna; Wadala A. Bashir

Rafidain Journal of Science, 2013, Volume 24, Issue 5, Pages 37-50
DOI: 10.33899/rjs.2013.74510

The detailed investigation of a sensitive and selective spectrophotometric method for the determination of trace amounts of cerium is described. The method is based on the reaction of cerium(III) with arsenazo ш in the presence of sodium dodecyl sulphate surfactant at pH 3.0 to form a blue-greenish coloured chelate absorbing maximum at 653 nm. Beer’s law is obeyed over the range (5-70) µg /25 ml, with a molar absorptivity of (4.99×104) l.mol-1.cm-1 and the coefficient of determination (r2) is 0.9994, Sandell’s sensitivity index is (28.08×10-4) µg.cm-2, a relative error of (0.0-0.2%) and a relative standard deviation of (0.0 to +2.1)%, depending on the concentration levels in the calibration curve. The method has been applied successfully to determine cerium in sea water and some synthetic alloys.

Spectrophotometric Assay of Metoclopramide Hydrochloride in Pharmaceutical Preparations via Arsenazo III-Cerium (III) Reaction

Najih H. Shekho; Thura Z. Al-Sarraj

Rafidain Journal of Science, 2013, Volume 24, Issue 1, Pages 70-83
DOI: 10.33899/rjs.2013.67502

A simple, rapid, accurate and precise spectrophotometric method is proposed for determining metoclopramide – hydrochloride (MCPH) in pure form and in pharmaceutical preparations .The method is based on oxidation - reduction reaction between metoclopramide - hydrochloride and cerium (IV) ion, then the subsequent reaction of cerium (III) and arsenazo III reagent in acidic medium to produce a blue-violet complex which is stable, water-soluble and has a maximum absorption at 654nm with a molar absorptivity of 9.36x104 l.mol-1.cm-1 and Sandell's sensitivity of 0.0038 µg.cm-2. Beer's law is obeyed in concentration range from 1-30 µg metoclopramide - hydrochloride in final volume of 25 ml, (0.04-1.2) ppm with a relative standard deviation (RSD) ( ±1.80% - ±3.98%) and the limit of detection (LOD) is 0.0095 µg/ml and the limit of quantitation (LOQ) is 0.0317 µg/ml . The method is suitable for the determination of metoclopramide - hydrochloride in the presence of other ingredients that are usually present in dosage forms and the recoveries are obtained in the range of 97.6-101.0 % . The proposed method has been applied successfully to the determination of the intended compound in its pharmaceutical preparations ( tablet and injection).