Sorptions on lignin, wood and celluloses. II. Nitrosamines

Sorption of N-diethylnitrosamine depends very characteristically on the mode of preparation of lignins. Some of the enzymatically prepared lignins are strong sorbers, similar to Kraft lignin. Lignins prepared by digesting the Hurricane pulverized wood show smaller nitrosamine binding than lignins obtained from wood treated in the Wiley-mill, for a given residual saccharide content. This difference is not due solely to the difference in iron contents. For lignins prepared from wood comminuted in the Wiley-mill the binding capacity is indirectly proportional to residual sugar content. N-nitrosamine adsorption involves different binding sites than that of bile acids. Appearance of two binding sites for some lignins indicates that nitrosamines might compete for some binding sites with metal (II) ions. Nevertheless, for sorption of N-nitrosamines accessibility of the binding sites also plays a role.