TLC Determination of Aquatic Humic Acids

Humic acids are mostly determined by spectroscopic methods, although they are not accurate enough, because humic acids possess no maximum absorption at any wavelength in the ultraviolet and visible spectrum. In this contribution the accurate and precise method for aquatic humic acids determination, using thin layer chromatography, was worked out. Previously, humic acids were separated and preconcentrated -from the river water, using macroreticular adsorption resin Amberlite XAD-4, and subsequently determined by TLC. The Chromatographie system was: silicagel HF254(Merck, precoated plates 20 × 20 cm) and NH3 -acetone (60:40,v/v) as a solvent system. Quantitative determination was made by Camag– Turner 111 Fluorimeter, by measuring UV–quenching.