Parameters Characterizing Chromatographic Spots and Separation Effects Determined by Visual and Densitometric Methods

Abstract

Phloroglucinol (P), niclosamide (N), salicylanilide (S) and thymol (T) were chromatographed on silica gel TLC plates with n‐hexane‐acetone in different volume proportions as mobile phases. Comparison and characterization of chromatographic spots of examined compounds on the basis of resolution (R _S ), separation factor (α), constant of the pair separation (R ^α _F ), and ΔR _F values were discussed. The R _S parameter, serving to evaluate the substance separation, was determined by visual and densitometric methods. It was proven that the R _S parameter determined by the visual method for two adjacent substances is always larger than that determined by the densitometric method. It was stated that the densitometric method is correct, objective, and assures standard conditions for the parameter R _S determination.

Keywords:

• Normal phase thin layer chromatography
• Densitometry
• Spectrodensitometry
• Separation parameters
• Selected phenol drugs

Acknowledgment

This research was financed by the Ministry of Science and Information Technologies by resources reserved for science in the years 2005–2008 as research project No. T09A 155 29.