The determination of 10–100 μmg. quantities of hexosamine

Abstract

The hexosamine is separated from other sugars by shaking with an ion-exchange resin, deaminated and treated with pyrrole and hydrochloric acid to produce a yellow color having Emax at 433 m[mu]; and E433 m[mu] of hexosamine = 4.3 x 104. The method is applicable to a range of 10-100 pumg, which can be determined with an overall accuracy of + 5% for duplicate samples. The basic reaction is six times more sensitive than the Dische and Borenfreund (1950) reaction, and three times more sensitive than the most sensitive modification of the Elson and Morgan (1933) method. Scaling down the quantities to ultramicro level raises the sensitivity over previous methods to 1000-fold. It is specific for hexosamine. The method was used in comparison with an ultramicro modifica tion of the method of Elson and Morgan to determine the hexosamine content of less than 1 ul amounts of biological fluids. Excellent agreement between the two methods was found, and the significance of this is discussed with regard to complete hydrolysis and interference from sugars and amino acids. The method is readily applicable to the usual micro scale (1-10 [mu]g), when conventional apparatus can be used.