CHLORO-4,4,5,5-TETRAMETHYL-1,3,2-DIOXAPHOSPHOLANE, A REAGENT FOR THE ACCURATE DETERMINATION OF THE UNCONDENSED AND CONDENSED PHENOLIC MOIETIES IN LIGNINS

The use of -chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane as a pho sphitylation reagent in quantitative P-31 NMR analysis of the hydroxyl groups in lignins has been thoroughly examined, and an experimental p rotocol recommended for spectra acquisition has been developed. Quanti tative analysis of six ''standard lignins'' gave results comparable to those obtained by other methods of analysis. Excellent resolution of the various phenolic hydroxyl environments including those present in condensed moieties was observed. However, this was at the expense of r esolution in the aliphatic hydroxyl region, where no distinction betwe en primary, secondary, and the erythro and three forms of the secondar y hydroxyls of the beta-O-4 bonds can be made.