Bound and free water determination by pulsed nuclear magnetic resonance.

Summary In the present paper the analysis of the transverse magnetization decay curves of water is discussed. Whenever the spin-echo decay curve of water does not show a single exponential behaviour and the apparent relaxation rates of bound and free component vary with the moisture content, an exchange process must be hypothesized. A method for obtaining the amount of bound and free water, in the presence of exchange, is reported. If the described procedure is applied, the amount of bound water as determined by pulsed nuclear magnetic resonance (NMR) is in good agreement with the amount of unfreezable water as determined by other techniques.