Analysis of Wood Extractives

Wood extractives

Wood extractives are well-known to cause problems in the production process e.g. by formation of deposits on process equipment or foaming. The extractives may also give rise to spots in the pulp or paper, as well as negatively influence several paper properties. Isolated and modified wood extractives are also compounds with a very high added value in various fields as biochemicals (e.g., pharmaceuticals and cosmetics).

What can we do?

RISE has very long experience in analysis of wood extractives. We can offer a wide range of extraction and characterization techniques which, in combination, offer a detailed characterization of the extractives in various types of samples, for example:

• Extractive content (gravimetric) in all types of samples.  

• Chemical composition and quantification of Extractives in wood and bark, extractives in pulp and paper, tall oil in black liquor and Extractives in liquors and filtrates.  

• Characterization of deposits and spots.  

• Molecular weight distribution of extracts.  

Methods, Intrumentation and Expertise

Extracts are derivatized and analyzed by GC/MS: Typically, individual fatty acids, resin acids, sterols, fatty alcohols, hydroxy acids etc. are quantified.  

Molecular mass distribution: The molecular mass of an extract is determined by size-exclusion chromatography (SEC), THF (tetrahydrofuran) or water-based systems. Detection with ultraviolet detector and/or refractive index detector and/or light scattering detector (MALS). 

Analysis with LC/MS: Water soluble compounds can be investigated and quantified by liquid chromatography combined with mass spectrometer. 

Phenolic groups: Sum of phenolic groups are determined using the Folin-Cocialteau spectrophotometric method. 

Characterization of extracts with Pyrolysis-GC/MS: The results are given in the form of chromatograms (pyrograms) with identification of seen compounds e.g. lignin, carbohydrates, tannins, extractives etc. Semi quantitative analysis. Very small samples (about 1 mg) can be analysed. 

Delivery

Results are compiled in an analysis report.