Adsorption of Heterocyclic Aromatic Amines by Low Molecular Weight Cellulose

This study was carried out to determine the in vitro binding of heterocyclic aromatic amines (HAAs), IQ, MeIQ, Trp-P-1, and Trp-P-2, to low molecular weight cellulose using HPLC assay and bacterial mutagenicity assay. Eight types of low molecular weight cellulose (degree of polymerization (DP): 125-180, particle size: 8-80μm, settling volume in water (SV): 3.2-6.6mL/g) were used in this study. All types of DP 180 cellulose showed higher adsorptive capacity for IQ, MeIQ, Trp-P-1 and Trp-P-2 than the DP 125 and DP 130.The 4 HAAs showed no significant difference in adsorption by cellulose from 10 to 80μm in particle size. In the case of 2 types of cellulose with the same DP (180) and particle size (40μm) but different SV (5.4mL/g, 4.0mL/g), Trp-P-1, Trp-P-2 and MeIQ showed no difference in adsorption but IQ was adsorbed at a higher rate (1.3 times) by the cellulose of larger SV. Highly hydrophobic compounds among the 4 HAAs (Trp-P-1 and Trp-P-2) were adsorbed by cellulose in large quantities, strongly and quickly. The results of the two assays seemed to show similar patterns in the adsorption of the 4 HAAs by the 8 types of cellulose. Based on the HPLC assay, Trp-P-1 and Trp-P-2 were adsorbed by the 8 types of cellulose at rates of 81-95%and 71-95%. Similarly, the numbers of revertants per plate induced by Trp-P-1 and Trp-P-2 treated with these celluloses were 0.7-2.1% and 0.4-5.0% of the control, respectively. From these results, it has been clarified that low molecular weight cellulose with a DP about 24 to 80 times smaller than the native value can adsorb HAAs.