1.3 Organic analysis

Abstracts1 General analytical chemistry

     

1.3 Organic analysis

Abstracts1 General analytical chemistry

1.3 Organic analysis     

1.3 Organic analysis

Abstracts1 General analytical chemistry

1.3 Organic analysis     

1.3 Organic analysis

Abstracts1 General analytical chemistry

     

1.3 Organic analysis

Abstracts1 General analytical chemistry

1.3 Organic analysis     

Organic analysis by luminescence methods

This review presents the major features of luminescence methods relating to the estimation of organic compounds in solution. A notation for reporting fluorimetric determinations is proposed. The outstanding factors affecting the fluorescence of solutions are briefly reviewed, and determinations of compounds offering a native fluorescence are illustrated by selected examples. Special attention is paid to functional fluorimetry and to the determination of non-fluorescent compounds by means of chemical reactions giving rise to fluorescent species. Some enzymatic reactions are described, as far as they allow the estimation of definite chemicals. Phosphorimetry and chemiluminescence are exemplified. An appendix presents some new functional fluorimetric determinations developed by the authors.     

Organic azo-dyes in quantitative analysis

Summary Eliamina blue FFL is used as indicator in the complexometric titration of thorium in the p_H range 2.5–3.5. The end-point is sensitive, sharp and obvious. Solutions containing from 20 g to 20 mg thorium — in the nitrate form — per 10 ml aliquot can be easily titrated. Fe³⁺, Zr, Cu²⁺, Ni and Al interfere while Sb⁵⁺, Sn⁴⁺, As⁵⁺, Ce⁴⁺, U⁶⁺, Ca, Pb, Cd Na, K, Co, Mn²⁺ and Cr⁶⁺ do not.     

Organic azo-dyes in quantitative analysis

Summary Chrom red brown 5RD was used as an indicator for complexometric titration of thorium. The change in the colour at the end-point was from wine-red to yellow. It is recommended that the thorium buffered aliquot should not contain less then 200 g thorium per 10 ml for a precise estimation. A range of p_H from 2.5 to 3.5 has been found satisfactory for such a titration. Ferri, ferro and zirconium ions interfere; they should be separated beforehand.Part I: Zaki, M. R., and K. Shakir: Z. analyt. Chem. 174, 274 (1960).     

Organic azo-dyes in quantitative analysis

Summary Chrom Red Brown 5 RD has been found as a sensitive reagent for the spectrophotometric determination of thorium. Concentrations as low as 1 g thorium/1 ml can be easily determined at wave length 485 nm. Sulphate, chloride, ferric and zirconium ions badly interfere, while Li, Na, K, Ni, Co, Cu²+, Cd, Ca, Mg and Cr³⁺ do not. U⁶⁺ and Ce⁴⁺ are permissible as traces.Part II: Zaki, M. R., and K. Shakir: Z. analyt. Chem. 177, 196 (1960).