The effects of salts on the nmr spectra of D 2 O in collagen fibers

The effects of two salts, MgCl 2 and MgSO 4 on the wide‐line nmr spectrum of D 2 O in oriented, undernatured collagen fibers have been examined at four different D 2 O contents. MgCl 2 was found to decrease the nmr doublet splitting, as compared with equal quantities of pure D 2 O while the major effect of MgSO 4 was to inhibit the adsorption of D 2 O without significantly affecting its nmr spectrum. The results, together with a few observations of KCl and LiCl solutions, indicate that even fairly high concentrations of salt have only small effects on the nmr spectrum of D 2 O in fibrous collagen. It is considered unlikely that either “two‐state” or “structured‐water” models can satisfactorily account for the D 2 O‐nmr doublet spectrum or the effects of salts on it, over the entire range of observed D 2 O content.