Analysis of wood pulp extracts utilizing gas chromatography-mass spectroscopy
Wood pulp mill effluents continue to attract much attention due to environmental consequences. However, in comparison, very little work has been published on wood pulp extracts themselves.
In this investigation, chemithermomechanical (CTMP) pulps as well as Kraft (BKP) pulps were Soxhlet extracted with solvents of different polarity. These two types of pulp extracts were then compared qualitatively using GC-FID and GC-MSD as well as quantitatively based on the percent of extractives obtained. For all the pulps studied, the percent extractives of water > ethyl acetate > cyclohexane. The CTMP extracts exhibited many more components as compared to BKP extracts for all the extractions solvents. The presence of trace chlorinated phenolics in the above wood pulp extracts was also addressed utilizing GC-ECD, GC-EIMS and GC-NCIMS. 4-MCG, 4,5-DCG, 4,5,6-TCG, 3,4,5-TCG, 2,4,6- TCP, 2,3,4,6-TeCP, PCP and 6-MCVN were discovered. Due to a lack of knowledge of the complete history of the wood pulps studied, the exact causes for their discoveries are unknown.
Attempts were also made to study the feasibility of Supercritical Fluid Extraction of the above mentioned wood pulps due to the difficulties faced with Soxhlet extractions. The percent extractives obtained using SF-CO₂ and cyclohexane were found to be comparable.