Complexation equilibria between uranium(VI) and 2-(2’-thiazolylazo)-4,6-dimethylphenol and 2-(4’,5’-dimethyl-2’-thiazolylazo)-4,6-dimethylphenol. Extraction-spectrophotometric determination of uranium

1988 ◽  
Vol 53 (2) ◽  
pp. 258-268 ◽  
Author(s):  
Brígida Santana ◽  
María J. Sánchez ◽  
Juan J. Arias ◽  
Francisco García-Montelongo
Keyword(s):  
Numerical Calculation ◽  
Sulphuric Acid ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Acid Leaching ◽  
Ionization Constants ◽  
Water Medium ◽  
Calculation Methods ◽  
Spectrophotometric Methods

2-(2’-Thiazolylazo)-4,6-dimethylphenol (TADMP) and 2-(4’,5’-dimethyl-2’-thiazolylazo)-4,6-dimethylphenol (DMTADMP) have been synthesized and their ionization constants determined by spectrophotometric methods and graphical and numerical calculation methods. Both reagents form UO2R+ and UO2R2 complexes with uranium (TADMP: log β101 = 9.18 ± 0.02, log β102 = 17.64 ± 0.01; DMTADMP: log β101 = 8.38 ± 0.02, log β102 = 18.78 ± 0.14) in a 40% (v/v) ethanol-water medium at I = 0.25 (NaClO4). An extraction-spectrophotometric method for the determination of 1.35-9.45 ppm uranium based on its extraction into toluene with TADMP from a pH 6.5 buffered medium has been developed ( ε = 1.6 . 104 l mol-1 cm-1 at 580 nm), and applied to its determination in sulphuric acid leaching residues.

scholarly journals Spectrophotometric Determination of Palladium(II) Ions Using a New Reagent: 4-(N’-(4-Imino-2-oxo-thiazolidine-5-ylidene)-hydrazino)-benzoic Acid (p-ITYBA)

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Oleksandr S. Tymoshuk ◽  
Orest S. Fedyshyn ◽  
Lesia V. Oleksiv ◽  
Petro V. Rydchuk ◽  
Vasyl S. Matiychuk
Keyword(s):  
Detection Limit ◽  
Complex Formation ◽  
Benzoic Acid ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Water Medium ◽  
Analytical Reagent ◽  
Optimal Ph

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.

Collaborative Study of the Spectrophotometric Determination of Procainamide Hydrochloride

1976 ◽  
Vol 59 (4) ◽  
pp. 807-810
Author(s):  
Jeffrey C Hamm
Keyword(s):  
Sodium Hydroxide ◽  
Acid Medium ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Dosage Forms ◽  
Standard Deviations

Abstract The USP analysis for procainamide HCl is titrimetric and relatively nonspecific, capsule and tablet dyes may interfere, and the method is not applicable to coated tablets. In the spectrophotofluorometric method the sample deteriorates when exposed to a xenon source. In the ultraviolet spectrophotometric method reported here, the sample is dispersed in acid medium, possible interferences are extracted in chloroform, base is added, procainamide is extracted in chloroform, the residue is dissolved in sodium hydroxide, and the compound is measured by absorption at 272 nm and comparison with a standard. Recoveries of standards added to capsule, tablet, and injection composites ranged from 99.3 to 102%. Twelve collaborators reported duplicate assay results for all 3 dosage forms with per cent standard deviations for 5 samples ranging from 1.01 to 1.27%. The method has been adopted as official first action.

DC Polarographic and Spectrophotometric Determination of Ampicillin Capsules

1980 ◽  
Vol 63 (5) ◽  
pp. 1049-1051
Author(s):  
Juan A Squella ◽  
Luis J Nunez-Vergara ◽  
Maximo Aros
Keyword(s):  
Absorption Band ◽  
Spectrophotometric Determination ◽  
Degradation Product ◽  
Uv Absorption ◽  
Acidic Hydrolysis ◽  
Average Recovery ◽  
Polarographic Wave ◽  
Spectrophotometric Methods ◽  
Hydrolysis Of

Abstract Polarographic and spectrophotometric methods are proposed for the determination of ampicillin in capsules. Acidic hydrolysis of ampicillin with 1% HCHO in 0.3N HCl yields a degradation product identified as 2-hydroxy-3-phenyl-6-methylpyrazine. This compound has a well defined UV absorption band at 380 nm and a polarographic wave at –0.55 V vs SCE, which can be used for analytical purposes. Individual capsule assays, composite assays, and recovery studies are described. The average recovery values and standard deviations (SD) for UV and polarographic determinations were 99.20% (SD 0.95) and 100.85% (SD 1.09), respectively

scholarly journals DETERMINATION OF TRACE NITRITE AS 4-(4-NITROBENZENAZO)- 1-AMINONAPHTHALENE COMPLEX BY EXTRACTION-SPECTROPHOTOMETRY

2010 ◽  
Vol 9 (2) ◽  
pp. 254-260
Author(s):  
Choirul Amri ◽  
Dwi Siswanta ◽  
Mudasir Mudasir
Keyword(s):  
Detection Limit ◽  
Organic Solvents ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Absorbance Unit ◽  
Extraction Spectrophotometry ◽  
Linear Concentration

A study of extraction-spectrophotometric method for the determination of trace nitrite as 4-(4-nitrobenzenazo)-1-aminonaphthalene complex using n-amylalcohol and chloroform as organic solvents has been done. Results of the study showed that extraction-spectrophotometric determination of nitrite using n-amylalcohol or chloroform was very sensitive and had low limit of detection. Extraction-spectrophotometric method of nitrite using n-amylalcohol gave range of linear concentration 0.000-0.054 mg/L NO2--N, detection limit of 2.09x10-4 mg/L NO2--N, and sensitivity of 34.514 ± 0.398 absorbance unit per mg/L of NO2--N. Meanwhile, extraction-spectrophotometric of nitrite using chloroform had range of linear concentration of 0.000-0.100 mg/L NO2--N, detection limit of 8.99x10-4 mg/L NO2--N, and sensitivity of 18.353 ± 0.456 absorbance unit per mg/L NO2--N.   Keywords: Nitrite Trace, 4-(4-Nitrobenzenazo)-1-Aminonaphthalene, Extraction-Spectrophotometry

scholarly journals Difference spectrophotometric method for the determination of Fluphenazine hydrochloride in tablets using peroxomonosulfate

2021 ◽  
Vol 9 (2) ◽  
pp. 64-71
Author(s):  
Mykola Blazheyevskiy ◽  
◽  
Valeriy Moroz ◽  
Olena Mozgova ◽  
◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Present Method ◽  
Molar Absorptivity ◽  
Limit Of Quantification ◽  
Derivatizing Agent ◽  
Sensitive Method

The oxidative derivatization method using potassium hydrogenperoxomonosulfate for the indirect spectrophotometric determination of Fluphenazine hydrochloride is presented. Potassium hydrogenperoxomonosulfate is introduced as a derivatizing agent for Fluphenazine hydrochloride, yielding the sulfoxide. This reaction product was successfully used for the spectrophotometric determination of the Fluphenazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Fluphenazine hydrochloride in the concentration range of 0.2-30 µg mL-1. The molar absorptivity at 349 nm is 5.6×103 (dm3cm-1mol-1). The limit of quantification, LOQ (10S) is 0.24 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Fluphenazine hydrochloride in tablets 5.0 mg was demonstrated. The present method is precise, accurate and excipients did not interfere. RSD for Fluphenazine Hydrochloride 5.0 mg tablets was 1.37 %.

scholarly journals Spectrophotometric Determination of Epinephrine in Pharmaceutical Preparations Using Praseodymium as Mediating Metals

2011 ◽  
Vol 8 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Relative Error ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Direct Methods ◽  
Orange Yellow ◽  
Sensitive Spectrophotometric Method

A simple, accurate and sensitive spectrophotometric method for the determinaion of epinephrine is described . The method is based on the coordination of Pr (III) with epinephrine at pH 6. Absorbance of the resulting orange yellow complex is measured at 482 nm . A graph of absorbance versus concentrations shows that beer 's low is obeyed over the concentration range (1-50)mg.ml-1 of epinephrine with molar absorpitivity of ( 2.180x103 L.mol-1.cm-1 ), a sandell sensitivity of (0.084 mg.cm-2 ), a relative error of (-2.83%) , a corrolation coffecient (r= 0.9989) and recovery % ( 97.03 ± 0.75 ) depending on the concentration.This method is applied to analyse EP in several commercially available pharmaceutical preparations using direct methods .All statistical calculations are implemented via a Minitab software version 11.

The Direct Spectrophotometric Determination of Protein in Cerebrospinal Fluid

1963 ◽  
Vol 9 (3) ◽  
pp. 283-295 ◽  
Author(s):  
Roman L Patrick ◽  
Ralph E Thiers
Keyword(s):  
Cerebrospinal Fluid ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Gel Filtration ◽  
Spectrophotometric Measurement ◽  
Separation Chamber ◽  
Cerebrospinal Fluid Protein

Abstract A rapid and sensitive direct spectrophotometric method for the determination of cerebrospinal fluid protein which uses as little as 0.1 ml. of sample has been described. The result is not affected by the ratio of albumin to globulin in the sample. Interfering substances are removed prior to spectrophotometric measurement with an automatic separation chamber employing the principle of gel filtration. Slight alterations of the procedure described for the measurement of protein enable one to obtain the nonprotein moiety for study or to measure proteins in other biologic fluids.

Spectrophotometric Determination of Aminacrine Hydrochloride in Creams, Jellies, and Suppositories: Interlaboratory Study

1987 ◽  
Vol 70 (3) ◽  
pp. 560-565
Author(s):  
Elaine A Bunch
Keyword(s):  
Thin Layer ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Coefficient Of Variation ◽  
Visible Spectrum ◽  
Interlaboratory Study ◽  
Commercial Products ◽  
Absorbance Maximum

Abstract A previously reported visible spectrophotometric method for the analysis of aminacrine hydrochloride in creams, jellies, and suppositories was studied collaboratively by 8 laboratories. Aminacrine hydrochloride was extracted into acidic ethanol and its visible spectrum recorded. The amount present was calculated by determining the net absorbance between the absorbance maximum at about 402 nm and one-half the sum of the absorbance of the minima at about 389 and 412 nm. Each collaborator received 4 creams (0.2%), 1 jel (0.2%), 1 molded suppository (6 mg/3.198 g), and 2 gelatin-encapsulated suppository samples (12 mg/6.661 g and 14 mg/6.863 g). The cream samples included blind duplicates prepared to contain 0.212% aminacrine hydrochloride, 15% sulfanilamide, and 2% allantoin. Mean recovery for the authentic cream was 104.7% with a coefficient of variation (CV) of 9.22%. The commercial products contained these respective amounts (CVs): creams, 100.0% (2.48%) and 101.5% (2.16%); jel, 118.0% (9.58%); molded suppository, 102.7% (1.88%); and gelatin encapsulated suppositories, 93.1% (1.0%) and 94.3% (1.60%). Standard aminacrine hydrochloride provided for the study was 99.6% pure by nonaqueous titration. Thin layer chromatographic identification of aminacrine hydrochloride was also tested collaboratively. The method was not adopted by AOAC.

Improved Spectrophotometric Determination of Cyclopiazonic Acid in Poultry Feed and Corn

1990 ◽  
Vol 73 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Ivan Chang-Yen ◽  
Keshore Bidasee
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Cyclopiazonic Acid ◽  
Poultry Feed ◽  
Reaction Conditions ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Feed Samples

Abstract An improved visible spectrophotometric method has been developed for cyclopiazonic acid in poultry feed and corn. The method Is based on the reaction of cyclopiazonic acid with Ehrlich reagent and detection at 580 nm. Reaction conditions were optimized with respect to reaction and measurement times and acid and Ehrlich reagent concentrations. Calibration curves were linear from 1 to 20 μg cyclopiazonic acid in 3 mL Ehrlich reagent, with a lower detection limit of 0.08 mg/kg for 50 g samples of poultry feed and corn. Recoveries from 50 g samples of poultry feed spiked with cyclopiazonic ranging from 0.16 to 1.20 mg/kg averaged 93.8%. Moldy corn and poultry feed samples analyzed by this method contained between 1 and 4 mg/kg cyclopiazonic acid.

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