A rapid, sensitive and reliable thin-layer chromatography/spectrophotometry screening procedure was developed for quantitative determination of diuretics associated in pharmaceutical dosage forms. The chromatographic method employed microcrystalline cellulose and butanol : acetic acid : water (4:1:1) or amilic alcohol : ammonium hydroxide 25% (9:1) as mobile phases and detection by U.V. light. The drugs were extracted using a simple procedure and were quantified by U.V. spectrophotometry. Results varied from 97.5 to 102.5% and are similar to those obtained by conventional methods. This method of quantification of diuretics is promising for quality control of drugs.

Os autores estudaram o comportamento cromatográfico de preparações farmacêuticas comerciais contendo o íon Fe (II). Utilizando celulose microcristalina/Propanol: ácido clorídrico 4 N: ácido acético concentrado: ácido nítrico concentrado: clorofórmio (40: 5: 5: 10: 10), como sistema cromatográfico e alizarina como reagente de detecção, Fe (II), Mn (II), Mg (II), Cu (II), Zn (II) e Ca (II) foram separados e identificados pela Cromatografia Planar. O Fe (II) foi determinado pela reação com a ortofenantrolina, resultando em solução adequada para quantificação colorimétrica.

The authors have studied the chromatographic behavior of pharmaceutical preparations obtained from commercial sources containing the ferrous ion. Using microcrystalline cellulose , propanol: 4 N, H Cl, acetic acid, nitric acid, chloroform mixture (40: 5: 5: 10: 10) as chromatographic system and and Alyzarin as the detection reagent Fe (II), Mn (II), Mg(II), Zn (II) and Ca (II) were separated and identificated by Planar Chromatography. Fe (II) cation was determined by reaction with 1, 10-Phenanthroline, resulting in an appropriate solution for colorimetric quantitation.