Gas chromatographic separation of diterpene acids on glass capillary columns of different polarity

Mixtures of resin acids from tall oil distillation products and from naturally occurring rosins (colophony) were separated on WCOT glass capillary columns coated with SE 30, FFAP, DEGS and BDS, and the resin acids were identified by gas chromatography-mass spectrometry (GC-MS). In contrast to previous investigations, the identified diterpene acids are characterized by Kovats index values. These retention values are correlated with the different polarity of the stationary phase. The advantages of columns coated with FFAP for the separation of crude and distilled tall oil and fatty acid samples are discussed. Dedicated to Prof. Dr. Erich Ziegler at his 70th birthday     

Cyclopropenoid Fatty Acids in Malagasy baobab: Adansonia grandidieri (Bombacaceae) Seed Oil

Adansonia grandidieri (bombacaceae family) seed oil gives a positive Halphen test. Composition analysis of derivatized fatty acid methyl esters, in presence of silver nitrate in anhydrous methanol, after chromatography fractionation on silicagel column, were made by gas-liquid chromatography (GLC) using a packed DEGS column. Presence of malvalic and sterculic acids were detected. GLC analysis using glass capillary columns coated with Carbowax 20 M and BDS shows that A. grandidieri seed oil contains mainly palmitic (41%), oleic (22%) and linoleic (12%) acids. Cyclopropenic fatty acid concentration was 14% with 6% for malvalic and 8% for sterculic acids. A slight proportion of dihydrosterculic acid (1.5%) was observed. GLC fatty acid methyl esters analysis, without derivatization, on the two glass capillary columns coated with Carbowax 20 M and BDS gave the same results for cyclopropenic acids content.     

Capillary gas chromatography-mass spectrometry of resin acids in tall oil rosin

The resin acid composition of Finnish tall oil rosin was investigated by gas chromatography and mass spectrometry employing open tubular capillary columns. On a column coated with 1,4-butanediol succinate, 16 resin acids found in tall oil rosin samples were well resolved, and mass spectra could be recorded. All resin acids were confirmed to be of the pimaric and abietic types by gas chromatographymass spectrometry. Eight of the acids were not detected in the corresponding crude tall oils and evidently had been formed during the technical distillation process. The presence of 8,15-pimaradien-18-oic and 8,15-isopimaradien-18-oic acids in the rosin, but not in the crude tall oil, indicates that the pimaric type acids also undergo extensive isomerization during tall oil distillation. Additionally, three dihydroabietic acids and two acids with identical mass spectra, tentatively stereoisomers of 7,9(11)-abietadien-18-oic acid, were formed during the distillation process.     

Tall oil fatty acids

About 1949, with the advent of effective fractional distillation, the tall oil industry came of age, and tall oil fatty acids (TOFA), generally any product containing 90% or more fatty acids and 10% or less of rosin, have grown in annual volume ever since, until they amount to 398.8 million pounds annual production in the U.S. in 1978. Crude tall oil is a byproduct of the Kraft process for producing wood pulp from pine wood. Crude tall oil is about 50% fatty acids and 40% rosin acids, the remainder unsaps and residues; actually, a national average recovery of about 1–2% of tall oil is obtained from wood. On a pulp basis, each ton of pulp affords 140–220 pounds black liquor soaps, which yields 70–110 pounds crude tall oil, yielding 30–50 pounds of TOFA. Separative and upgrading technology involves: (a) recovery of the tall oil; (b) acid refining; (c) fractionation of tall oil; and occasionally (d) conversion to derivatives. TOFA of good quality and color of Gardner 2 corresponds to above 97% fatty acids with the composition of 1.6% palmitic & stearic acid, 49.3% oleic acid, 45.1% linoleic acid, 1.1% miscellaneous acids, 1.2% rosin acids, and 1.7% unsaponifiables.     

A study of the influence of storing wood on the yield and quality of tall oil

In 12 weeks of storage time pine roundwood lost approximately 11% in tall oil yield, while for the same length of time purchased slabwood chips (pine) lost 64%. Most of the loss in yield occurred within six weeks. The purchased chips lost more tall oil yield in one week than the roundwood in 12 weeks. The loss in yield from the roundwood was due entirely to the loss in yield of fatty acids. The loss in yield in the purchased slabwood chips was due predominantly to the loss in yield in fatty acids; however, there was, in addition, a small loss in resin acids, and a very small loss in unsaponifiables. As for tall oil quality, by the end of 12 weeks of storage the acid number of tall oil from both roundwood and purchased chips had dropped below 160. In correlating the yield of tall oil from the wood extractions with the yield of tall oil from the black liquor from digester cooks, it appears that on the average about 80% to 88% of the extracted tall oil can be found in the black liquor.     

Tallöl-Fraktionierung als Beispiel der Optimierung konventioneller Füllkörperkolonnen

Fractionation of Tall Oil as an Example of Optimization of Conventional Packed Columns The present communication records a simple calculation for optimization of packed columns in an example of layout of columns for fractional distillation of crude tall oil into the main products, i.e. fatty acids and resin acids. This calculation requires, apart from knowledge on the temperatures stability of the material, only the HETP value, which is the height of chosen packing material equivalent to one theoretical plate. An arrangement of three columns is necessary for complete separation of crude tall oil in continuous manner. In the example shown, calculation of the first column for a capacity of 20 000 t per year is given.     

The behavior of resin acids during tall oil distillation

The behavior of resin acids during tall oil distillation was studied by analyzing samples from six industrial-scale processes. The same artifact resin acids were formed in all processes. However, the proportion of artifact resin acids in tall oil rosins varied from 8.3 to 18.3% of the resin acids. The lowest values were found for two processes utilizing thin-film evaporators. The yield of resin acids in the tall oil rosin fraction varied from 62 to 80% of the resin acids in the crude tall oil feeds. Dehydroabietic acid was formed in all processes, the amount in rosin being 14-44% more than in the crude tall oil feed. Of the abietic acid, only 45-82% was recovered in the tall oil rosin fraction. The distribution of various resin acids and their reaction products during distillation was determined. Major resin acid impurities in tall oil fatty acids were 8,15-pimaradien-18-oic acid and 8,15-isoprimaradien-18-oic acid, both formed chiefly during distillation, and two secodehydroabietic acid isomers common in crude tall oils. The reactions of resin acids leading to new isomers or non-acidic products are discussed. Some results of this work were presented at the 173rd American Chemical Society Meeting, New Orleans, March 1977.     

Distillability of extracted mixed-birch tall oil

Chemical and physical properties of tall oil made in the CSR process and distillation results of three different types of distillation plants are presented. Chemically extracted, mixed-birch, tall oil differs remarkably from the normal Scandinavian crude tall oil. The extracted oil deviates from the normal, unextracted, mixed-birch tall oil with respect to the smaller unsaponifiable amount and the fatty acid esters. The amount of resin acid is small in extracted mixed-birch tall oil. The quantity of fatty acids, especially that of saturated fatty acids, is large. Distillation of extracted mixed-birch tall oil is most successful in a distillation plant where thin film evaporators are used.     

Tall oil fatty acid marketing

Once considered a low cost by-product of crude tall oil fractionation, tall oil fatty acids are now being used for their own distinctive and specific properties in special applications. Consumption of tall oil fatty acids in protective coatings, soaps, and ore flotation has declined in recent years, however, usage in chemical intermediates has increased significantly in the past 10 years. These intermediates are dimer acids, oleic and linoleic acids, epoxidized esters, amidoamines, and diacids. Static tall oil production during the mid 1970s caused by changes in paper mill operations (i.e., continuous digestion, waste recycling, increased usage of chips and hard wood) has increased the demand for higher priced oleic acid and other unsaturated fatty acids.     

Spectrophotometric analysis of tall oil rosin acids

Summary About half of the rosin acids in whole and distilled tall oil consist of abietic and neoabietic acids, as distinguished from hydroabietic acids, dehydroabietic acid, and the pimaric acids. In this respect the tall oil rosin acids are similar to those from gum or wood rosin. This was established by spectrophotometric analysis of the rosin acids from whole tall oil, double distilled tall oil, rosin acids crystallized from tall oil, and rosin acids separated from tall oil by fractional distillation. The rosin acids crystallized from tall oil contained the highest percentage of abietic acid, but the sum of abietic and neoabietic acids was only slightly higher. The rosin acids from acid refined tall oil contained appreciably less abietic and neoabietic acid than the others. Before spectrophotometric analysis the rosin acids were isolated from the tall oils in about 95% yield by cyclohexylamine precipitation.     

Extractive Profiles in the Production of Sulfite Dissolving Pulp from Eucalyptus Globulus WOOD

The profile of major families of extractives soluble in acetone and dichloromethane during the production of acid sulfite dissolving pulp from Eucalyptus globulus wood was assessed. Nearly 85% of total extractives were removed from wood during pulping and nearly 11% in the course of E-O-P pulp bleaching and secondary pulp screening. Unlike extractives of polyphenolic origin that were almost completely removed after the alkaline extraction stage (E), fatty acids were the main retained component in fully bleached pulp followed by sterols and fatty alcohols. Throughout the bleaching steps, the profiles of extractives were not necessarily decreasing and depended on their reactions with bleaching reagents and the presence of auxiliary chemicals (e.g. antifoams). In this context, the content of fatty acids and fatty alcohols was mostly vulnerable. It has been suggested that Fock reactivity of dissolving pulps is unaffected by extractives at concentrations up to 0.3%.     

On the formation of degradation products from the pyrolysis of tall oil fatty acids with kraft lignin

Mixtures of tall oil fatty acids and kraft lignin from southern pine wood were pyrolyzed at 160 C and 280 C with or without exclusion of oxygen. In addition to fatty acids of various chain lengths and aromatic degradation products from lignin, a number of homologousn-alkylbenzenes were formed (ca. 1.5%) and characterized by gas chromatography-mass spectrometry. The possible ways of formation of the latter from fatty acids are discussed briefly.     

Solvent extraction of fatty acids from natural oils with liquid water at elevated temperatures and pressures

The use of liquid water at elevated temperatures and pressures as an extractive solvent for separating mixtures of compounds which occur in natural oils has been studied. A southern pine tall oil and a distillate from the deodorization of soybean oil were extracted with liquid water at temperatures from 298 to 312°C and pressures between 103 and 121 bar. Results indicate that water can be used to extract fatty and resin acids from crude tall oil to obtain a product with a high acid content that produces less pitch during distillation. The process can also be used to extract fatty acids from vegetable oil deodorizer distillate.     

Diterpene resin acids: Major active principles in tall oil against Variegated cutworm,Peridroma saucia (Lepidoptera: Noctuidae)

Tall oil, a by-product of the kraft process for pulping softwood, has been shown to have insecticidal properties. In the present study, the active principles in tall oil against the variegated cutworm,Peridroma saucia Hübner, were investigated. GC-MS analysis showed that abietic, dehydroabietic, and isopimaric acids were major resin acid components of crude tall oil and depitched tall oil. When crude tall oil samples of differing resin acid composition were incorporated into artificial diet at a concentration of 2.0% fresh weight, they suppressed larval growth by 45–60% compared to controls. This suppression was significantly (P0.05) correlated with the equivalent contents of abietic, dehydroabietic, isopimaric, and total resin acids. These results were also evident from a diet choice test, showing that the second-instar larvae obviously selected diets with low levels of resin acids when different diets were randomly arranged in a Petri dish. Bioassays with pure resin acids (abietic, dehydroabietic, and isopimaric acids) demonstrated that all individual chemicals have similar bioactivity against this insect. Comparison of the bioactivities of depitched tall oil and an equivalent mixture of pure resin acids in thePeridroma chronic growth bioassay indicated that pure resin acids and depitched tall oil share a common mode of action to this insect. This study confirms that resin acids are major active principles in tall oil against the variegated cutworm, but other chemicals likely also contribute to the bioactivity of tall oil.     

Analyses of organic foulants in membranes fouled by pulp and paper mill effluent using solid-liquid extraction

Fouling of membranes is a serious problem in membrane technology. By characterizing the foulants in membranes it is possible to understand fouling and reduce it. However, the characterization of foulants, especially organic ones, is difficult. The purpose of this study was to find out whether there are any organic foulants such as extractives in the membranes, and if it is possible to identify them. Membranes of different materials and hydrophilicity were used in filtration of ground wood mill (GWM) circulation water during one month in an integrated pulp and paper mill, Solid—liquid extraction was employed to remove the extractives from the membranes and the characterization of them was carried out with a gas chromatograph. According to the results, there are extractives in the membranes and it is possible to characterize them. It seems that the fouling by extractives mainly comes from resin and fatty acids. In addition, some traces of lignans were found in the membranes. Moreover, the hydrophobic membranes contained more of these acids and lignans than the hydrophilic membranes.     

Chemical characterization of Cedrus deodara wood extracts using water and molybdenum catalysts

The effect of the presence of some molybdenum catalysts on the amount of extractives in cedar wood has been studied. Autoclave treatment of cedar wood in the presence of some molybdenum catalysts can increase the amount of extracts. While autoclave treatment of cedar wood in water gave 2.85% extractives, the same treatment in the presence of H₃PMo₁₂O₄₀ gave 7.51% extractives. In the presence of silica-supported MoO₃, the amount of extractives was 5.50%. The extractives obtained using water were partially soluble in chloroform (40.7%). Only 27.6% of the extractives obtained using H₃PMo₁₂O₄₀ was soluble in the same organic solvent. When cedar was treated with silica-supported MoO₃, 56.4% of the extractives was soluble in chloroform. The extracts can be a source of fatty acids for biodiesel production and simple carbohydrates. The analysis of the chloroform-soluble fraction showed that the autoclave treatment of cedar wood gave 49.7% of a mixture of 2-hydroxy-1-(hydroxymethyl)ethyl hexadecanoate, 2-hydroxy-1-(hydroxymethyl)ethyl octadecanoate, and 2,3-dihydroxypropyl octadecanoate. The extractives obtained in the presence of the polyoxometalate molybdenum derivative gave 95% of the same esters of fatty acids, while those obtained in the presence of silica supported MoO₃ showed the presence of 93% of the same esters. Gas chromatography–mass spectrometry (GC-MS) of water-soluble fraction showed the presence of some simple carbohydrates, mainly ribose, xylose, and arabinose.     

Operating variables in the analysis of tall oil acids by capillary gas chromatography

Factors influencing the analysis of fatty and resin acid methyl esters by capillary gas chromatography have been investigated. Methods to calculate equivalent chain length (ECL) values and their limitations are first discussed. Retention data, expressed as equivalent chain lengths (ECL) were determined on SE-30, SP-2100 and Carbowax 20M columns. The medium length (20–30-m) polysiloxane columns, SE-30 and SP-2100, provided overall better resolution and shorter retention times than the more polar Carbowax 20M column of similar length. The temperature dependence of ECL values was investigated for all three columns in the range 180–210 C. Retention times and ECL values were more temperature-dependent for the Carbowax 20M than for the other two stationary phases. The effects of split ratio and method of injection on the precision and accuracy of the analysis were also examined. Using optimal conditions of analysis established in this paper, the difference between measured and actual weights of an internal standard added to two tall oil samples was determined to be less than 3%.     

Effect of temperature on the separation of some Δ9-cis-trans isomers of methyl esters of fatty acids by open tubular gas chromatography

The influence of temperature on the gas chromatographic separation ofcis-trans isomers of the methyl esters of some monounsaturated fatty acids was studied on capillary columns coated with Apiezon L, BDS and DEGS. As far as methyl oleate and methyl elaidate are concerned, the separation is better at lower temperatures on Apiezon L (180–210 C) and at higher temperatures on polyester phases (BDS, DEGS; 150–180 C). The influence of temperature on the separation ofcis-trans isomers on the three stationary phases under study is explained by the higher values of δECL/δt forcis isomers. The variation of the equivalent carbon chain length with temperature can be used for the identification ofcis-trans isomers in natural mixtures.     

Study of color stability of tall oil fatty acids through isolation and characterization of minor constituents

Minor constituents in high quality tall oil fatty acids have been isolated successfully by liquid column chromatography, using silicic acid as the adsorbent. The minor constituents contained two types of compounds: those which were noneffective and those which were effective in causing the darkening of tall oil fatty acids during heating. The former consisted oftrans-3,5-dimethoxystilbene and rosin acids. The latter was separated into numerous fractions by the combination of chemical methods, silicic acid column chromatography, and low temperature fractional crystallization. The fractions were characterized by functional group analyses, chemical reactions, and UV and IR spectrometric methods. Most of the fractions contained two-three times as much oxygen in the molecule as the original sample and were highly oxidized fatty acids. They had mol wt ranging 300–551 and contained double bonds, carbonyl, ester, peroxide, and hydroxyl groups. The effect of these minor constituents upon the color stability of tall oil fatty acids during heating was postulated as being due to the hydroxyl groups located in the α-position to the double bond in the molecule.     

Identification of minor cyclic fatty acids in fractionated tall oil

The structure of several minor cyclic fatty acids present in Finnish tall oil fatty acids are elucidated by gas chromatography-mass spectrometry. The origin and mechanism of formation of these cyclic fatty acids are discussed. The cyclic fatty acids identified in tall oil fatty acids are: 4-(5-pentyl-3a,4,7,7a-tetrahydro-4-indanyl)butanoic acid,ω-(o-alkylphenyl)alkanoic acid, 2,6-dimethyl-9-(3-isopropylphenyl)-6-nonenoic acid, 4-(5-pentyl-4-indanyl)butanoic acid, and 4-(2-hexyl-1,2,4a,5,6,7,8,8a-octahydro-1-naphthyl)butanoic acid. In addition, three different branched or cyclic unsaturated C₁₉ fatty acids are reported to be present in tall oil.