DETECTION OF GLUCOSAMINE IN THE ACID-HYDROLYSIS SOLUTION OF HUMIC SUBSTANCES

Several humic substances isolated from water and soil have been charac terized applying acid hydrolysis to release defined components bound i n these high molecular organic compounds. The hydrolysis solution have been analyzed by HPLC after precolumn derivatization with o-phthalald ehyde and 9-fluorenylmethylchloroformate. Under these conditions the n itrogen containing carbohydrate glucosamine could be detected and sepa rated besides seventeen amino acids. The results show that 8.0 to 40.1 % of the total nitrogen content of the investigated samples contribute s to amino acids and up to 7.9% to the carbohydrate glucosamine. It co uld be deduced that defined amino acid carbohydrate building blocks we re bound in humic substances, because the glucosamine nitrogen content correlates with the calculated amino acid nitrogen. Furthermore the t otal amino acid nitrogen amount of natural organic matter can be estim ated from the results of the determination of glucosamine.