Quantification of resin acids in CTMP (chemithermomechanical pulping) effluents using an enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay (ELISA) based on polyclonal antibodies was used to quantify resin acids in the effluents from a chemithermomechanical pulp (CTMP) mill. Using a direct ELISA format, with polyclonal antibodies immobilized on the plate, the assay had a 50% inhibition concentration (I₅₀) of 49.7 ppb and a detection limit of 4.5 ppb. Good recoveries were obtained from DHA spiked buffer. CTMP effluents with different levels of resin acids were quantified and the ELISA data were shown to compare favourably with both total abietic type resin acids and total resin acids as determined by gas chromatography (GC).