Colorimetric determination of vanadium with 5,7-dibromo-8-hydroxyquinoline after paper-chromatographic separation from interfering ions

1968 ◽  
Vol 237 (3) ◽  
pp. 172-178 ◽  
Author(s):  
I. I. M. Elbeih ◽  
M. A. Abou -Elnaga
Keyword(s):  
Chromatographic Separation ◽  
Colorimetric Determination ◽  
Interfering Ions ◽  
Paper Chromatographic Separation

scholarly journals A colorimetric micro method for the determination of formyl groups

1969 ◽  
Vol 111 (4) ◽  
pp. 401-406 ◽  
Author(s):  
S. Usha Lakshmi ◽  
L. K. Ramachandran
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Chromatographic Separation ◽  
Quantitative Method ◽  
Standard Procedure ◽  
Formyl Group ◽  
Alumina Column ◽  
Purple Colour ◽  
Paper Chromatographic Separation

The characteristic purple colour formed by N-formyl-N′-2,4-dinitrophenyl-hydrazine in the presence of piperidine and acetone was made the basis of a new quantitative method for the determination of formyl groups. Samples containing N-formyl groups (up to 0·4μmole) are hydrazinolysed at 97–98° for 1hr. and are dinitrophenylated after the removal of excess of hydrazine. Interference from 2,4-dinitrophenylhydrazine is eliminated by subjecting the dinitrophenylated samples to chromatography on an alumina column. Interference arising from the formation of N-acetyl-N′-2,4-dinitrophenylhydrazine, when determining formyl groups in samples containing acetyl, can be avoided by a paper-chromatographic separation before analysis. A standard procedure is described. The method gives satisfactory results when applied to N-formyl-amino acids. Gramicidin, when analysed by this method, was found to contain 0·89 mole of formyl group/mole for a molecular weight of 1880. The method indicated the absence of formyl groups from lysozyme, a protein known not to contain such groups. Generally, the analytical values obtained by the method are within 100±4% of theory.

Paper Chromatographic Separation, Identification, and Determination of Diglycerols.

1964 ◽  
Vol 36 (3) ◽  
pp. 502-505 ◽  
Author(s):  
Herbert. Siegel ◽  
A. B. Bullock ◽  
G. B. Carter
Keyword(s):  
Chromatographic Separation ◽  
Paper Chromatographic Separation
Sign in / Sign up

Export Citation Format

Share Document