Physicochemical Analysis of a Spent Sulfite Liquor from a CMP Pulp

The lignosulfonates (LS) of an industrial spent sulfite liquor originated from a chemimechanical pulping process (CMP) of softwood have been examined by different physicochemical and spectroscopic methods. Gel permeation chromatography shows an average MW of 1600 daltons. Analytical data reveal the characteristics of sulfonated guaiacylpropyl units. FABMS analysis gives some additional structural features of a typical LS model. This work also shows that sugars react with NaHS03 and prevent their detection by GLC as silylated derivatives.