PROBLEMS WITH THE DETERMINATION OF LIGNIN DERIVATIVES IN EFFLUENTS FROM BLEACHED KRAFT PULPING
Most methods for determination of lignin derivatives in effluents and recipient waters are based on photometric measurements directly or after colour reactions with the phenolic hydroxyl groups. These methods are critically discussed. In applying the methods it is assumed that the character of lignin derivatives is aromatic. This is the case for lignin derivatives of low molar mass, but a large proportion of the derivatives with a molar mass greater than 1000 D is non-aromatic and will not react under the conditions of the tests and consequently are not included in the results.