GAS-CHROMATOGRAPHIC DETERMINATION OF MURAMIC ACID, GLUCOSAMINE, MANNOSAMINE, AND GALACTOSAMINE IN SOILS

Muramic acid, glucosamine, mannosamine and galactosamine in soils may be useful for elucidating the microbial origin of soil organic nitroge n. Therefore, a method was developed to determine the aldononitrile ac etate derivatives of the four amino sugars simultaneously in the 6 hi HCl hydrolysates of soil samples by means of high resolution gas liqui d chromatography. This method was sensitive enough to detect less than 10 mu g muramic acid mi and less than 20 mu g ml(-1) of the other thr ee amino sugars. The maximum release of amino sugars was found after 6 to 8 h hydrolysis at 105 degrees C. Impurities in the acidic hydrolys ates were removed simply by neutralisation with KOH solution. The reco very of amino sugars after hydrolysis and purification was more than 9 0% on average. The method was applied to determine amino sugars in eig ht soils with different properties. The coefficients of variation aver aged 6.1% for glucosamine and galactosamine and 10.9% for muramic acid and mannosamine. Copyright (C) 1996 Elsevier Science Ltd