Determination of organic pharmaceuticals with N-bromosuccinimide. Part IV. Some pyrazolone derivatives by back-titration

The Analyst ◽  
1982 ◽  
Vol 107 (1279) ◽  
pp. 1272 ◽  
Author(s):  
M. M. Amer ◽  
B. A. El-Zeany ◽  
A. M. Taha ◽  
O. A. El-Sawy
Keyword(s):  
Pyrazolone Derivatives ◽  
Back Titration

Titrimetric Determination of Iodine-Bromine Numbers of Some Edible Oils Using Three N-Chloroimides

1987 ◽  
Vol 70 (4) ◽  
pp. 762-763
Author(s):  
Narayanan Jayasree ◽  
Parameswaran Indrasenan
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Solid State ◽  
Palm Olein ◽  
Edible Oils ◽  
Aqueous Acetic Acid ◽  
Acetic Acid Medium ◽  
Back Titration ◽  
Titrimetric Determination

Abstract Three simple titrimetric methods have been developed to determine iodine-bromine numbers of some edible oils, such as coconut, gingelly, groundnut, mustard, olive, palm olein, and sunflower, using 3 N-chloroimides. The 3 N-chloroimides are N-chlorophthalimide, N-chlorosuccinimide, and N-chlorosaccharin, all of which have recently been developed as potential oxidimetric titrants for use in aqueous acetic acid medium. The proposed excess back-titration methods have advantages over existing methods in terms of ease of extraction into aqueous acetic acid layer, shorter reaction time of NCSA method, and stability of N-chloroimides in solid state.

scholarly journals Sensitive and rapid titrimetric and spectrophotometric methods for the determination of stavudine in pharmaceuticals using bromate-bromide and three dyes

2008 ◽  
Vol 80 (2) ◽  
pp. 253-262 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Veeraiah Ramakrishna ◽  
Chikkaswamy Somashekar ◽  
Urdigere R. Anil Kumar
Keyword(s):  
Dosage Forms ◽  
Linear Increase ◽  
Thymol Blue ◽  
Fixed Amount ◽  
Rapid Methods ◽  
Spectrophotometric Methods ◽  
Back Titration ◽  
Bulk Drug ◽  
Hcl Medium

Four sensitive and rapid methods for the determination of stavudine (STV) in bulk drug and in dosage forms were developed and optimized. In titrimetry, aqueous solution of STV was treated with a known excess of bromate-bromide in HCl medium followed by estimation of unreacted bromine by iodometric back titration. Spectrophotometric methods involve the addition of a measured excess of bromate-bromide in HCl medium and subsequent estimation of the residual bromine by reacting with a fixed amount of methyl orange, indigocarmine or thymol blue followed by measurement of absorbance at 520 nm (method A), 610 nm (method B) or 550 nm (method C). In all the methods, the amount of bromate reacted corresponds to the amount of STV. Calculations in titrimetry were based on a 1:0.666 (STV:KBrO3) stoichiometry and the method was found to be applicable over 3.5-10 mg range. A linear increase in absorbance with concentration of STV was observed in the spectrophotometric methods, and the Beer's law was obeyed over the concentration ranges 0.125-1.75, 1-10 and 1-9.0 µg mL-1 STV for method A, method B and method C, respectively. The methods when applied to the determination of STV in tablets and capsules were found to give satisfactory results.

Determination of Chloride Concentration in Cheese: Collaborative Study

1982 ◽  
Vol 65 (6) ◽  
pp. 1350-1356
Author(s):  
L J Poortvliet ◽  
William Horwitz
Keyword(s):  
Collaborative Study ◽  
Chloride Concentration ◽  
Potentiometric Method ◽  
Three Samples ◽  
Back Titration ◽  
Gouda Cheese

Abstract Three samples of ground Gouda cheese containing 1-2% chloride were analyzed by 7 laboratories by 3 methods: oxidation with KMnO4 and HNO3 followed by a Volhard titration; the same but with filtering off the precipitated AgCl before back-titration; and the general potentiometric method without ashing or oxidation. The data were analyzed by ISO statistics (ISO-R 5725) and by AOAC statistics (Youden), the major differences being the rejection of different values as outliers and in the statement of the precision parameters. The within-laboratory variability (repeatability) is comparable for all 3 methods; the between-laboratory variability (reproducibility) is comparable for the Volhard method with filtration and the potentiometric methods, but the direct Volhard method is inferior. Because of its generality and simplicity, the potentiometric method has been adopted official first action; the Volhard method with filtration has been reinstated official final action as an alternative.

Determination of fluorine in glass crystallite using complexometric back titration

1988 ◽  
Vol 45 (9) ◽  
pp. 349-351
Author(s):  
T. I. Danilevich ◽  
V. V. Abramov
Keyword(s):  
Back Titration

Determination of organic pharmaceuticals with N-bromosuccinimide. Part III. Some pyrazolone derivatives by direct titration

The Analyst ◽  
1982 ◽  
Vol 107 (1278) ◽  
pp. 1054 ◽  
Author(s):  
B. A. El-Zeany ◽  
M. M. Amer ◽  
A. M. Taha ◽  
O. A. El-Sawy
Keyword(s):  
Direct Titration ◽  
Pyrazolone Derivatives

scholarly journals Micro-determination of organic fluorine using EDTA back-titration of lanthanum

1972 ◽  
Vol 21 (5) ◽  
pp. 631-635 ◽  
Author(s):  
Kingo MIZUNO ◽  
Noriko MIYAJI
Keyword(s):  
Back Titration ◽  
Organic Fluorine

scholarly journals Application of Cerium (IV) as an Oxidimetric Agent for the Determination of Ethionamide in Pharmaceutical Formulations

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Nagib A. S. Qarah ◽  
Sameer A. M. Abdulrahman
Keyword(s):  
Quality Control ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Sample Solution ◽  
Standing Time ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Back Titration ◽  
Bulk Drug

Two simple methods are described for the determination of ethionamide (ETM) in bulk drug and tablets using cerium (IV) sulphate as the oxidimetric agent. In both methods, the sample solution is treated with a measured excess of cerium (IV) solution in H2SO4 medium, and after a fixed standing time, the residual oxidant is determined either by back titration with standard iron (II) solution to a ferroin end point in titrimetry or by reacting with o-dianisidine followed by measurement of the absorbance of the orange-red coloured product at 470 nm in spectrophotometry. In titrimetry, the reaction proceeded with a stoichiometry of 1 : 2 (ETM : Ce (IV)) and the amount of cerium (IV) consumed by ETM was related to the latter’s amount, and the method was applicable over 1.0–8.0 mg of drug. In spectrophotometry, Beer’s law was obeyed over the concentration range of 0.5–5.0 μg/mL ETM with a molar absorptivity value of 2.66 × 104 L/(mol·cm). The limits of detection (LOD) and quantification (LOQ) calculated according to ICH guidelines were 0.013 and 0.043 μg/mL, respectively. The proposed titrimetric and spectrophotometric methods were found to yield reliable results when applied to bulk drug and tablets analysis, and hence they can be applied in quality control laboratories.

Titrimetric determination of cobalt, nickel and lanthanoids in alloys for novel permanent magnets using ion selective electrodes

1981 ◽  
Vol 46 (4) ◽  
pp. 982-986
Author(s):  
Dagmar Kalavská ◽  
Adam Košturiak ◽  
Svetozár Kalavský
Keyword(s):  
Permanent Magnets ◽  
Copper Ion ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Fluoride Ions ◽  
Cobalt Nickel ◽  
Back Titration ◽  
Titrimetric Determination ◽  
Fluoride Ion Selective Electrode

A procedure of chelatometric determination of cobalt, nickel and lanthanoids based on back titration with Cu(II) ions using copper ion selective electrode has been developed and applied to alloys for novel type permanent magnets. In addition, a method has been worked out for direct titrimetric determination of lanthanoids with solution of fluoride ions in 75% ethanol using fluoride ion selective electrode.

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