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A Comparison of Gas Chromatographic and Immunochemical Methods for Quantifying Resin Acids
Published in Mark R. Servos, Kelly R. Munkittrick, John H. Carey, Glen J. Van Der Kraak, and PAPER MILL EFFLUENTS, 2020
Kai Li, Tao Chen, Paul Bicho, Colette Breuil, John N. Saddler
Resin acids are diterpenoid carboxylic acids present in most softwoods and are usually released from wood chips during pulping processes (Taylor et al. 1988; Rogers et al. 1979; McKague et al. 1977). They are of concern to the pulp and paper industry because of their acute toxicity towards fish and other aquatic life. For example, the 96 h LC50 of most resin acids for rainbow trout falls between 0.2 and 1.7 ppm (Rogers 1973; Walden and Howard 1981; Priha and Talka 1986; Taylor et al. 1988; McCarthy et al. 1990). It has been reported that resin acids may contribute to as much as 70% of the toxicity of whole effluents (Leach and Thakore 1977). The eight common resin acids usually detected in Canadian softwood pulp mill effluents are listed in Fig. 1. Dehydroabietic acid (DHA) is one of the most abundant resin acids found in pulp mill effluents and can form chlorinated derivatives by electrophilic substitution of chlorine on the aromatic ring during pulp bleaching when chlorine or chlorine dioxide is used. These chlorinated resin acids are reported to be more persistent and toxic than their parents (McLeay and Associates 1987; Taylor et al. 1988).
Treatment of Paper and Pulp Industry Effluents
Published in Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang, Treatment of Industrial Effluents, 2019
Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang
Resin acids are tricyclic diterpenes that occur naturally in the resin of tree wood and bark and are transferred to process waters during pulping operations. They are weak hydrophobic acids and are toxic to fish at concentrations of 200–800 µg/L in wood processing wastewaters (McFarlane and Clark, 1988). Resin acids have been measured in Chemi-Thermo Mechanical Pulping (CTMP) wastewaters at concentrations as high as several hundred parts per million, even though the aqueous solubilities of individual resin acids are in the range of 3–6 mg/L. According to Leach and Thakore (1976), 60%–90% of the toxicity in CTMP effluents can be attributed to resin acids alone. It has been observed that wastewater pH strongly affects the toxicity and solubility of these acids, with measured 96 h LC50s (50% lethal concentration) for resin acids ranging from 0.4 to 1.7 mg/L for rainbow trout (McLeay, 1987). The most commonly monitored resin acids in aqueous pulping discharges include abietic acid, dehydroabietic acid, neoabietic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, levopimaric acid, and palustric acid. Isopimaric acid is considered to be the most toxic amongst all resin acids.
Conifer Resins and Essential Oils: Chemical Composition and Applications
Published in Tatjana Stevanovic, Chemistry of Lignocellulosics: Current Trends, 2018
Nellie Francezon, Tatjana Stevanovic
As mentioned, resins are composed of diterpenes, which are mainly represented by resin acids, but hydrocarbon analogs along with their alcohol and aldehyde derivatives are also often identified in conifer resins. The resin acids belonging to abietadiene derivatives, are based on tricyclic system related to phenantrene skeleton, but containing just two conjugated double bonds. The examples are laevopimaric, palustric, neoabietic and abietic acids, presented in Fig. 1. The dehydroabietic acid with an aromatic ring, is also present in minor quantities, while it is usually generated in higher quantities by oxidative transformation of resins (exposure to air, aging). The presence of higher quantities of dehydroabietic acid in a given resin sample may indicate its exposure to oxidative agents. Another oxidative product of abietadiene type resin acids is 7-oxo-dehydroabietic acid, which has become particularly important as a transformation product from resins originally rich in abietadiene type acids (Fig. 1).
Effect of Calcium on the Phase Distribution of Resin and Fatty Acids in Pitch Emulsions
Published in Journal of Dispersion Science and Technology, 2011
Donald MacNeil, Anna Sundberg, Lari Vähäsalo, Bjarne Holmbom
The resin acids can be classified into two groups, pimarane-type and abietane-type, based on their hydrocarbon skeleton structure.[4] The pimarane-type acids (pimaric, isopimaric, and sandaracopimaric acid) have a methyl and ethynyl group at the C-13 position, while the abietane-type acids (abietic, neoabietic, levopimaric, palustric, and dehydroabietic acid) have an isopropyl or isoprenyl group (Figure 1). In addition, dehydroabietic acid has an aromatic ring in its structure. The fatty acids are carboxylic acids mostly with 16 or 18 carbon atoms, either saturated, or mono- or polyunsaturated.