Preparation and characterization of DNA hydrogel bead as selective adsorbent of dioxins

Salmon milt DNA hydrogel beads were synthesized by an inverse suspension polymerization of acrylamide in the continuous phase of cyclohexane. These DNA hydrogel beads in water medium are stable, more than 82% (w/w) of the DNA can be retained in the hydrogel after a sufficient soaking in water. Comparing with normal adsorbents such as activated carbon and alumina, this DNA matrix showed a selective adsorptivity for the dioxin derivatives with planar structure such as dibenzo- p-dioxin (DD), dibenzofuran (DF) and biphenyl (BP). Rinsing with hexane can regenerate the DNA beads after adsorption by the dioxin derivatives, even the adsorption–regeneration process repeated four times, no significant decrease in the dioxin removal capacity was observed.