Sur la détermination du poids moléculaire des polysaccharides. Recherches sur l'amidon 54

The determination of the mean degree of polymerization of polysaccharides with one reducing group by the action of 3,5‐dinitrosalicylic acid has been restudied. In order to assure complete reduction the heating period of the reaction mixture has been prolonged to 4 1/2 hours, especially for starch grains and for amylopectine. In spite of the reproductibility of the results of this rapid and simple method, they are only valid to a certain extent: the resulting degrees of polymerization can only be considered as an inferior limit, and the magnitude of the error increases with the real degree of polymerization.