Influence of humic substances on results of the spectrophotometric (TPTZ) analysis of monosaccharides

A spectrophotometric method of monosaccharide analysis was assessed with regard to its non-selectivity towards humic substances. Analysis of model solutions showed that it responds positively to both marine and terrestrial humics. The systematic error in monosaccharide analysis (in glucose equivalents) was 0.18–0.20mg per 1 mg of Aldrich humic acid and 0.11–0.12 mg per 1 mg of humic substances isolated from Gulf of Gdańsk water.