Factors affecting gas chromatographic analysis of resin acids present in pulp mill effluents

Publisher Website
Google Scholar
Abstract
The resin acid content of various pulp mill effluents was determined by traditional liquid‐liquid extraction followed by gas chromatography. Factors influencing the extraction efficiency in the liquid‐liquid extraction of resin acids were investigated using ethyl acetate and methyl t‐butyl ether (MTBE) at different pHs. The extraction efficiencies were influenced by both pH and the nature of the effluents. Higher extraction efficiencies were obtained for effluents from chemithermo‐mechanical pulp (CTMP) when they were adjusted to lower pHs prior to extraction. However, for untreated bleached kraft mill effluents (BKME), extraction at pH 9 was more effective. Use of a commercially available NH2 type solid‐phase extraction cartridge in sample clean‐up improved the GC performance significantly. The presence of high molecular weight material or humic acids influenced the extraction efficiency of resin acids in BKME