Adducts were prepared by reacting wood cell wall polysaccharide, lignin and model compounds of these polymers with chromium(vi) ions. Magnetic susceptibilities of these adducts were measured using a Gouy balance. It was shown that under the reaction conditions used, (polysaccharide, lignin, etc. in molar excess), the adducts were paramagnetic. This implies that the chromium in the adducts is in the tervalent state.