Based on the nitrogenous base or quaternary ammonium moiety in isoxsuprine hydrochloride (ISX), two highly accurate and selective titrimetric methods are proposed f or the determination of ISX in spiked human urine, injection and tablets. Non aqueous titration (Method A) involves removal of protonated amine using mercuric acetate for enhanced basic nitrogen prior to titration with perchloric ac...

Ethambutol tablets of 200 and 400 mg denominations were assayed by the standard non-aqueous titration method and a simpler calorimetric method. With the titrimetric method, assay values, appreciably higher than the stated content (117% or more), were obtained with the products of 4 companies, while all the values were within 6% of the stated content by the calorimetric method. Rifampicin and py...

0

*Correspondence: T. D. Silva. Departamento de Farmácia. Faculdade de Ciências Biológicas e da Saúde. Universidade Federal dos Vales do Jequitinhonha e Mucuri, Campus JK. Rodovia MGT 367, Km 583, n° 5000, 39100-000, Diamantina, MG, Brasil. E-mail: [email protected] Development and validation of alternative methods by non-aqueous acid-base titration and derivative ultraviolet spectrophoto...

2,10-Disubstituted phenothiazines are the best drugs in psychiatry. Several methods for their analysis have been reported in the literature. The official methods are based on non-aqueous titration or spectrophotometry. Various oxidizing agents have been used for the spectrophotometric determination of 2,10-disubstituted phenothiazines, e.g. Ce(SO4)2, NH4VO3, K2S208, KIO4, KIO3, KBrO3, FeCl3, Na...

A PVC-based membrane of 12-crown-4 exhibits good response for Zn2+ in a wide concentration range (7.08  10-5-1.00  10-1 M) with a non-nernstian slope of 20.5 mv per decade of concentration of Zn2+. The response time of sensor is <10 s and the membrane can be used for more than 3 months without observing any divergence. In addition, the proposed sensor exhibits very good selectivity for Zn2+ o...

the acidity constants of some amino acids (am) were determined by potentiometric ph titration. the stability constants of the 1:1 complexes formed between m2+: ca2+, mg2+, mn2+, co2+, ni2+, cu2+ or zn2+ and am2-, were determined by potentiometric ph titration in aqueous solution (i = 0.1 m, nano3, 25°c). the order of the stability constants was reported. it is shown that the stability of the bi...

In the determination of P-oxybutyric acid through oxidation to acetone by the Shaffer bichromate method’ with subsequent estimation of the acetone by Messinger’s iodimetric titration,” difficulty was experienced in obtaining the t,heoretical amount of acetone from known amounts of pure P-oxybutyric acid. It was suspected that either the Messinger titration was inaccurate or that the acetone was...