Resin Acids Research Articles

Emissions of organic compounds from western US wildfires and their near-fire transformations

Abstract. The size and frequency of wildfires in the western United States have been increasing, and this trend is projected to continue, with increasing adverse consequences for human health. Gas- and particle-phase organic compounds are the main components of wildfire emissions. Some of the directly emitted compounds are hazardous air pollutants, while others can react with oxidants to form secondary air pollutants such as ozone and secondary organic aerosol (SOA). Further, compounds emitted in the particle phase can volatize during smoke transport and can then serve as precursors for SOA. The extent of pollutant formation from wildfire emissions is dependent in part on the speciation of organic compounds. The most detailed speciation of organic compounds has been achieved in laboratory studies, though recent field campaigns are leading to an increase in such measurements in the field. In this study, we identified and quantified hundreds of gas- and particle-phase organic compounds emitted from conifer-dominated wildfires in the western US, using two two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC ToF-MS) instruments. Observed emission factors (EFs) and emission ratios are reported for four wildfires. As has been demonstrated previously, modified combustion efficiency (MCE) was a good predictor of particle-phase EFs (e.g., R2=0.78 and 0.84 for sugars and terpenoids, respectively), except for elemental carbon. Higher emissions of diterpenoids, resin acids, and monoterpenes were observed in the field relative to laboratory studies, likely due to distillation from unburned heated vegetation, which may be underrepresented in laboratory studies. These diterpenoids and resin acids accounted for up to 45 % of total quantified organic aerosol, higher than the contribution from sugar and sugar derivatives. The low volatility of resin acids makes them ideal markers for conifer fire smoke. The speciated measurements also show that evaporation of semi-volatile organic compounds took place in smoke plumes, which suggests that the evaporated primary organic aerosol can be a precursor of SOAs in wildfire smoke plumes.

From Flask to Mill: Reductive Functionalization of Fluoroacetamides as a Case Study for Transferring Solvent-Based Reactions to the Solid State

The development of sustainable methods is a central focus of modern organic synthesis and has applications in various areas of the chemical industry. Mechanochemistry is a highly desirable green synthetic method as it departs from traditional solution-based reactions and their concurrent generation of waste solvent. Here, we report results of the adaptation of a solution-based method for the reductive functionalization of fluoroacetamides to a mechanochemical protocol as a case study. This greener solid-state, one-pot strategy is based on the partial reduction of amides by an in situ mechanochemically generated zirconocene chloride hydride (Schwartz’s reagent) and tandem nucleophilic addition of indole to afford high-value functionalized fluorinated amines in moderate to good yields. In addition to it being the first time this reductant has been mechanochemically generated, the sustainable approach was complemented by operationally simple purification by an acidic resin. Significant improvements in green metrics (E factor and EcoScale) were observed by this adaptation of the methodology.

Synthesis and evaluation of diterpenic Mannich bases as antiviral agents against influenza A and SARS-CoV-2.

A chemical library was constructed based on the resin acids (abietic, dehydroabietic, and 12-formylabietic) and its diene adducts (maleopimaric and quinopimaric acid derivatives). The one-pot three-component CuCl-catalyzed aminomethylation of the abietane diterpenoid propargyl derivatives was carried out by formaldehyde and secondary amines (diethylamine, pyrrolidine, morpholine, and homopiperazine). All compounds were tested for cytotoxicity and antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells and SARS-CoV-2 pseudovirus in BHK-21-hACE2 cells. Among 21 tested compounds, six derivatives demonstrated a selectivity index (SI) higher than 10, and their IC50 values ranged from 0.19 to 5.0 μM. Moreover, two derivatives exhibited potent anti-SARS-CoV-2 infection activity. The antiviral activity and toxicity strongly depended on the nature of the diterpene core and heterocyclic substituent. Compounds 12 and 21 bearing pyrrolidine moieties demonstrated the highest virus-inhibiting activity with SIs of 128.6 and 146.8, respectively, and appeared to be most effective when added at the time points 0–10 and 1–10 h of the viral life cycle. Molecular docking and dynamics modeling were adopted to investigate the binding mode of compound 12 into the binding pocket of influenza A virus M2 protein. Compound 9 with a pyrrolidine group at C20 of 17-formylabietic acid was a promising anti-SARS-CoV-2 agent with an EC50 of 10.97 µM and a good SI value > 18.2. Collectively, our data suggested the potency of diterpenic Mannich bases as effective anti-influenza and anti-COVID-19 compounds.

Dehydration of levoglucosan to levoglucosenone over solid acid catalysts. Tuning the product distribution by changing the acid properties of the catalysts

The effect of the catalytic properties of various types of solid acids, including oxides (ZrO2, SOX/ZrO2, WOX/ZrO2, Nb2O5, NbOPO4, Al2O3, TiO2), silica–aluminas (ZSM5 and USY zeolites) and acidic ion-exchange resins (Amberlyst-70 and Dowex 50wx8) were investigated for liquid-phase levoglucosan (LGA) conversion. H2SO4 was also evaluated as a reference catalyst. The concentration of both Brønsted and Lewis acid sites in the catalysts was measured by FTIR of adsorbed pyridine and titration with NaOH. The catalysts were tested under different reaction conditions (110–170 °C and 30–60 bar of N2) for 1 h using tetrahydrofuran (THF) as solvent. The product distribution obtained from the LGA conversion can be tuned depending on the type of acid site of the catalyst or the reaction conditions used. Catalysts containing only Bronsted acid sites were selective to LA while those with both Bronsted and Lewis acid sites favored the formation of 5-hydroxymethylfurfural (HMF). LGO was mainly produced by the homogeneous catalyst. The USY and HZM5 (SiO2/Al2O3 ratio of 23) promoted the production of HMF and glucose, respectively. A reaction mechanism was proposed taking into account the acid properties of the catalysts. The reactions of dehydration of LGA to LGO or hydration of glucose requires Brønsted acid sites. Catalysts with only Lewis acid sites produced only humins. For the catalysts containing both Brønsted and Lewis acid sites, LGA is mainly hydrated to glucose on the Bronsted acid sites. Then, glucose is preferentially isomerized to fructose on the Lewis acid sites, followed by its dehydration to HMF. The low LA formation shows that the hydration of HMF to LA requires a higher concentration of Brønsted acid sites.

Production of biodiesel and water conservation through conversion of free fatty acids from a domestic wastewater drain

ABSTRACT Wastewater discharge from restaurants, hotels, household kitchens, confectionaries, meat, fruits, and vegetable processing units contain free fatty acids (FFAs) from fats, oils, and greases (FOG). These FFAs are one of the major causes of sewer overflows and blockages that cause health and environmental issues. This study has investigated the use of sewer wastewater as a source of lipids for the production of alkyl esters (Biodiesel) and provides a characterization of the resulting processed water. Amberlyst A21 basic resin in a column reactor was used to recover the FFAs by adsorption from an oily layer collected from the domestic wastewater drain (Chakri drain, Rawalpindi, Pakistan) having a 33.0 ± 2.08% oily fraction with 59.7 ± 1.1% FFAs. The recovered ethanol washed FFAs from the Amberlyst A21 surface were then turned into Fatty Acid Ethyl Esters (FAEEs) in the presence of an acidic resin catalyst Amberlyst 15. The esterification reaction was studied at temperatures 50, 60, and 70°C, molar ratios of 1:2 to 1:3, acidic resin weight % of 2 to 6, and reaction time of 2 to 8 hr, respectively. A maximum FFAs conversion into esters of 91.38 ± 1.13% was noted at an esterification temperature of 70°C, molar ratio of 1:3, acidic resin weight of 6%, and a reaction time of 8 h. The fractional distillation of the esterified reaction product at 100°C improved the ester content in the reaction mixture up to 96.6 ± 0.18%, with a distilled biodiesel yield of 95.52 ± 0.21%. The collected top oily layer from sewer drain wastewater was found to have a density 947.31 kg/m3, kinematic viscosity 32.69 mm2/sec, flash point 283°C, and LHV and HHV of 26 and 28 MJ/kg, respectively, while for the produced biodiesel the density was 886 kg/m3, kinematic viscosity 4.3 mm2/sec, flash point 137°C, and LHV and HHV of 39 and 41 MJ/kg was noted, respectively. Only oily layer free wastewater after passing through PAC was found to meet Pakistan NEQS, with COD <150 mg/L, pH 6–8, Alkalinity <1000 mg/L, and Ammonia-nitrogen <40 mg/L. For every 1000 gallons of domestic sewer drain wastewater treated per 8 h work shift or 3 work shifts in a day with FFAs recovered and their conversion into biodiesel, a net profit of 54.89 and 93.32 million Pakistani rupees can be gained in the first year and then in successive years, respectively. Thus, this research provides a way to produce renewable energy fuel, biodiesel from the waste lipids (FFAs) of wastewater drains to meet the energy requirements and a solution for the conservation of water bodies.

Study on Construction and Reinforcement Technology of Dolomite Sanding Tunnel

The No. 2 conduit of the Xiaopu Tunnel in the Yuxi section of central Yunnan’s water diversion project is taken as the research object, starting from the geological conditions along with the characteristics, formation mechanism and evolutionary model of dolomite sanding. This paper discusses the engineering problems of the project’s tunnels with dolomite sanding in the water-rich section, and its corresponding engineering reinforcement plan. It was found that in the tunnel section with normal level of dolomite sanding, there was no water seepage, where measures such as advanced small conduit, mechanical excavation, short grubbing and strong support could all be adopted for safe passage. Even in the water seepage section of the weak dolomite sanding tunnel, the surrounding rock was found in close interlock with strong self-stability. The excavation and support were implemented according to the category of normal surrounding rock. In the water-rich sections with strong and intense dolomite sanding, gushing of water and sand were quite frequent, with developed fissures, broken rock masses and rich waters. During the engineering operation, phosphoric acid and sodium silicate slurry in addition to urea formaldehyde resin and oxalic acid slurry plus Malisan and liquid catalyst slurry were first prepared for water plugging. Then, pure water slurry was used for surrounding rock reinforcement, which exerted an excellent effect. This method can provide reference for reinforcing tunnels of sandy dolomite in other areas of projects.

Effect of ferrate pretreatment on anaerobic digestibility of primary sludge spiked with resin acids.

Resin acids are mixtures of high molecular weight carboxylic acids found in tree resins. Due to higher hydrophobicity and low solubility, they tend to adsorb on the suspended solids in pulp and paper (P&P) mill wastewater and accumulate in primary sludge through settling. Anaerobic digestion (AD) is a common practice stabilizing sludge; however, high concentration of resin acids affects the AD process. The aim of this research was mainly to determine the impact of ferrate (Fe (VI)) oxidation on selected resin acids and anaerobic digestibility of ferrate-treated primary sludge (PS) spiked with the resin acids. First, batch control oxidation of model resin acids with Fe (VI) was conducted to identify an optimum dosage, pH and contact time using a Box-Behnken design approach. Thereafter, anaerobic treatability studies of primary sludge spiked with resin acids both under control condition and optimum ferrate pretreatment were conducted. Up to 97% oxidation of resin acids occurred in pure water, while only 44%-62% oxidation of resin acids occurred in PS with an increasing Fe (VI) dosage from 0.034 to 0.137mg Fe (VI)/mg tCODfed. The pretreatment did not affect the anaerobic biodegradability of resin acids; however, it lowered their negative influences on the PS digestibility. About 0.076mg Fe (VI) dosage/mg tCODfed solubilized the sludge increasing the methane production by 40% compared to the untreated digester. The potential benefits of ferrate pretreatment of P&P primary sludge include resin acids oxidation and subsequent toxicity reduction, higher sludge solubilization enhancing methane production and enabling anaerobic digestion at higher COD loading.

HPLC analysis of β-caryophyllene in copaiba oleoresin: Development, validation and applicability

Copaiba oil (CO) is an oleoresin containing resinous acids, comprising mainly of diterpenes, and volatile compounds, comprising of sesquiterpenes. CO has been used for many years as a therapeutic agent and cosmetic, being the β-caryophyllene (CAR) one of the main sesquiterpene markers found in CO samples. During the last years, some analytical methods have been developed for analysis of sesquiterpenes like CAR from CO. However, these methods are based on gas chromatography, and requiring additional steps, such as derivatization or extraction of the essential fraction of the CO for sesquiterpenes analysis. Liquid chromatography methodologies have been proposed only for analysis of diterpenes. Therefore, the aim of this study was to develop a high-performance liquid chromatography (HPLC) assay for CAR analysis in CO samples (Copaifera reticulata Ducke) and in emulsion systems containing CO. The HPLC system suitability was determined through the capacity factor, repeatability, relative retention, resolution, tailing factor, theoretical plate number and the height of the theoretical plate; where the method developed showed the efficiency for separation of CO compounds. The method was validated displaying specificity, linearity, precision, accuracy, and robustness. Moreover, it showed to be of utmost importance to analyze CO in emulsion systems, displaying versatile and applicability.

Enhancing phosphorus recovery from efficient acidogenic fermentation of waste activated sludge with acidic cation exchange resin pretreatment: Insights from occurrence states and transformation

Achieving phosphorus (P) recovery during treatment and disposal of waste activated sludge (WAS) by anaerobic-based processes has received increasing attention. To solve the problem of low phosphorus release efficiency, anaerobic fermentation (AF) combined with acidic cation exchange resin (ACER) pretreatment was first proposed in this study. Results showed that the isoelectric point pretreatment with ACER increased the recoverable phosphorus content by 2.3 times compared to that without ACER pretreatment. Phosphorus transformation was systematically analyzed from a whole-process perspective, and the results visually revealed that the release of phosphorus during the conventional AF process (without ACER pretreatment) was limited by insufficient phosphorus release from extracellular polymeric substances (EPS) and mineral precipitation, as well as the reprecipitation of soluble phosphorus with metals. ACER enabled effective dissolution of mineral phosphorus by acidifying WAS. On the other hand, ACER adsorbed metals to promote EPS disintegration and hydrolysis, thereby enhancing the release of EPS-bound P, which also reduced the reprecipitation of soluble phosphorus during AF. Furthermore, ACER pretreatment increased volatile fatty acids production by >2-fold with enhanced sludge hydrolysis. This finding has important implications for both non-renewable phosphorus recovery and sludge resource recovery.

3D-printed biological habitats for the protection and persistence of &lt;em&gt;Rhizobia&lt;/em&gt; species in compacted soils

Microorganisms in soils are responsible for many ecosystem services. However, in degraded soils microbial abundance and function are limited which compromises several biologically facilitated processes. Inoculating soils with desirable microbes can help to re-instate or initiate a viable functioning microbial community. However, establishment success is reliant on the survival of the microorganism in an adverse environment. In this proof-of-concept study, artificial microbial refugia have been developed using resin and light-emitting diode array (LED) 3D printing technology. We assessed whether the artificial refugia, termed a Rhiome, would support better microbial growth in degraded soils. Soil compaction, a form of soil degradation, and Rhizobium, an important microorganism for global agriculture, were both selected as the use case application for this assessment. Different materials together with resin were assessed for their suitability as a 3D printing material and for supporting rhizobial growth. The best result was found in materials constructed with a combination of polylactic acid (PLA) resin, yeast extract and mannitol. In a soil compaction experiment with inoculation of rhizobia, the addition of Rhiome significantly increased bacterium survival in the compacted soil to a level similar to, or higher than, the rhizobial loading in non-compacted soils. Augmentation of the resin with yeast extract and mannitol increased Rhizobium growth significantly compared with the Rhiome constructed only with resin. These results indicate that the Rhiome was highly beneficial for instigating and maintaining significant rhizobia survival and growth in compacted soils. Further work, including near-to-field assessments, are required to assess Rhiome performance in a range of applications and to refine material properties relative to important context-specific performance metrics such as degradation rate. We propose the Rhiome concept as a promising asset in the toolbox for soil ecological restoration as a means of improving soil resiliency.

Green Synthesis of Starch Nanoparticles (SNPs) by Esterification with Rosin Acid Catalyzed by Maghnite-H+ (Algerian Montmorillonite) with Enhanced Antioxidant Activity

Green Synthesis of Starch Nanoparticles (SNPs) by Esterification with Rosin Acid Catalyzed by Maghnite-H+ (Algerian Montmorillonite) with Enhanced Antioxidant Activity

Hydrodeoxygenation of C3–4 polyols to C3–4 diols over carbon-supported bimetallic MgCu@C catalysts prepared from ion exchange resin

The selective hydrodeoxygenation (HDO) of C3–4 polyols (glycerol and erythritol) to value-added diol products was investigated over a series of Cu-based catalysts, namely, carbon-supported monometallic Cu@C and bimetallic MgCu@C prepared by using a weakly acidic cation-exchange resin as the carbon support precursors. High metal loading (> 50 wt%) and small metal particle size (< 15 nm) were realized by the catalyst prepared from ion-exchange resin. The addition of Mg decreased Cu particle size (10.0–13.5 nm) and improved metal dispersion. The largest metal surface area was achieved for the MgCu@C catalyst with Mg/Cu molar ratio of 1/9. Furthermore, HDO of C3–4 polyols was performed over the prepared catalysts at relatively low temperature (180 °C) under low initial H2 pressure (1.2 MPa). Over the MgCu@C catalyst with a nominal Cu/Mg atomic ratio of 9/1, a C3 polyol conversion of 94.0 C mol% was obtained with a high selectivity towards 1,2-propanediol (94.3 C mol%), while a low erythritol conversion of 18.75 C mol% with a selectivity toward butanediols of 43.0 C mol% was achieved after 360 h reaction. The different effects of the Mg addition on catalytic activity to C3 and C4 polyol HDO were likely attributed to the different reaction mechanism. The dehydration-hydrogenation mechanism was proposed for C3 HDO over Cu@C and MgCu@C, in which the addition of Mg species promoted the dehydration of glycerol to produce hydroxyacetone followed by the hydrogenation of hydroxyacetone to 1,2-propanediol.

Coupling between acid precipitation and resin adsorption for purifying alkaline extracted hemicellulose from sugarcane bagasse

Hemicellulose is considered the second most renewable component in lignocellulosic biomass after cellulose, and can be used in value-added industrial applications including medical dressing, packaging materials and hydrogels. Hence, the purification methods of different acid precipitation conditions, ethanol precipitation and resin adsorption were investigated. In this paper, the results showed that most of the lignin was removed by acid precipitation. With the adjustment of pH value from 6 to 2 by acid precipitation, the less lignin remains in hemicellulose samples, the higher the purity of hemicellulose. After resin adsorption treatment, the molecular weight of hemicellulose increased slightly and the weight average molecular weight of Ha2 (Ha2 is hemicelluloses precipitated at pH = 2) is 7.91 × 104 g/mol among, the branching degree of hemicellulose decreased slightly, the thermal stability of hemicellulose increased slightly. It can be shown from 2D HSQC NMR that the structure of hemicellulose did not change significantly before or after adsorption and at different pH values. Trace lignin-carbohydrate complexes (LCCs) structures were remained in hemicellulose sample. The slight loss of hemicellulose caused by resin adsorption is due to LCCs. The sensitivity of XAD-16N resin to phenyl glycoside bond (PhGlc) of different forms was different.

Foams Stabilized by AquivionTM PFSA: Application to Interfacial Catalysis for Cascade Reactions (Adv. Mater. Interfaces 19/2022)

Foams Stabilized by AquivionTM PFSA In article number 2200380, Andong Feng, Marc Pera-Titus, and co-workers demonstrate that AquivionTM perfluorosulfonic acid (PFSA) resin can generate particle-stabilized (Pickering) foams based on water (blue) and organic protic solvents (yellow). The foams are efficient platforms for engineering gas-liquid-solid catalytic reactions with enhanced triphasic contact.

Response Surface Optimization of Lipase‐Catalyzed Surface Esterification for Modification of Cassava Starch with Rosin Acid

The rosin acid starch (RAS) is prepared under the catalysis of lipase, by esterification on the starch particles' surface in a two-phase reaction system, using rosin acid and native cassava starch as starting materials. The effects of reaction time, solvent types, substrate ratio, reaction temperature, and lipase dosage on the degree of substitution (DS) of RAS are investigated. Based on the single factor experiments, the reaction conditions are optimized according to the principle of the combination Box-behnken centered design and response surface methodology analysis. The mathematical model of the influence of reaction temperature, material ratio, and enzyme addition amount on DS is established. The optimum synthesis conditions are determined as follows: solvent, trichloromethane; reaction time, 10 h; reaction temperature, 59 °C; substrate ratio (mRosin acid:mstarch), 4.1; and lipase dosage, 264 µL. Under these conditions, it is found that the DS is 0.0608. The analysis of variance and verification experiments show that the mathematical model has good fit degree and high credibility. Compared with the native cassava starch, RAS has improved contact angle, emulsion capacity, and emulsion stability.

The mechanisms and molecular properties about isomerization of resin acids, synthesis of acrylopimaric acid based on density functional theory calculation

AbstractAcrylopimaric acid is considered a possible substitute for petroleum‐based polymeric monomers. Resin acids were isomerized to form levopimaric acid(4), which reacted with acrylic acid to synthesize isomers of acrylopimaric acid. Density functional theory calculations were carried out to investigate the reaction mechanisms with seven reaction paths. In terms of dynamics, the energy barrier in the isomerization of palustric acid(2) to levopimaric acid(4) was the lowest, whereas the highest energy barrier was the isomerization of neoabietic acid(3) to levopimaric acid(4). The addition reaction of levopimaric acid(4) and acrylic acid(5) to acrylopimaric acid c(8) was the optimal reaction path dynamically. However, the energy of acrylopimaric acid c(8) was higher than that of acrylopimaric acid d(9). Highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO–LUMO) were analyzed for eight kinds of molecules. For acylpyimaric acid, the nonplanar six‐memed ring and the C–C double bonds were easily attacked by nucleophile, whereas the nonplanar six‐memed ring and the carboxyl group are easily reacted with electrophiles. The electrostatic surface potential were analyzed for molecules.

Beta zeolite as an efficient catalyst for the synthesis of diphenolic acid (DPA) from renewable levulinic acid

The solvent-free production of diphenolic acid (DPA) from levulinic acid (LA) and phenol is studied using readily accessible commercial acid zeolites like Beta, ZSM-5 and USY. Acid zeolites are cost-effective catalysts, and they are herein benchmarked against the sulfonic acid resins Amberlyst-15 and Nafion®, and sulfonic acid-functionalized SBA-15 silicas. Beta zeolite with a moderate aluminum content (H-Beta 19, Si/Al=23) presents the best catalytic performance, owing to the right combination of the shape selectivity effect conferred by the BEA structure, and the adequate balance of acidity (Al content and speciation). The optimization of the reaction conditions is tackled by the response surface methodology using as optimization factors the temperature, the PhOH:LA molar ratio, and the catalyst loading. Thus, under the optimized reaction conditions (12 mmol LA, 140 ᵒC, 0.30 g catalyst loading, PhOH:LA = 6:1 mol), over 70% yield to DPA with LA conversion around 77% is obtained after 72 h. Despite the catalyst shows a progressive activity decay in successive uses because of fouling, removal of the formed organic deposits by calcination in air allows restoring the starting catalytic performance.

Production of an EP/PDMS/SA/AlZnO Coated Superhydrophobic Surface through an Aerosol-Assisted Chemical Vapor Deposition Process.

In this study, a superhydrophobic coating on glass has been prepared through a single-step aerosol-assisted chemical vapor deposition (AACVD) process. During the process, an aerosolized precursor containing polydimethylsiloxane, epoxy resin, and stearic acid functionalized Al-doped ZnO nanoparticles was deposited onto the glass at 350 °C. X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy showed that the precursor was successfully coated and formed a nano/microstructure (surface roughness: 378.0 ± 46.1 nm) on the glass surface. The coated surface had a water contact angle of 159.1 ± 1.2°, contact angle hysteresis of 2.2 ± 1.7°, and rolling off-angle of 1°, indicating that it was superhydrophobic. In the self-cleaning test of the coated surface at a tilted angle of 20°, it was shown that water droplets rolled and washed out dirt on the surface. The stability tests showed that the surface remained superhydrophobic after 120 h of exposure to ultraviolet (UV) irradiation and even after heat exposure at 350 °C. In addition, the surface was highly repellent to water solutions of pH 1–13. The results showed that the addition of the functionalized nanoparticles into the precursor allowed for the control of surface roughness and provided a simplified single-step fabrication process of the superhydrophobic surface. This provides valuable information for developing the manufacturing process for superhydrophobic surfaces.

Ultra High-Performance Supercritical Fluid Chromatography for the Quantitation of Diterpene Resin Acids in Norway Spruce Samples.

Picea abies (L.) H. Karst. (Pinaceae) is native to Northern, Central and Eastern Europe. The fast-growing tree reaches up to 50 m in height, has modest nutritional requirements and depends on sufficient water supply. The conifer, commonly called Norway spruce, produces exudates which are traditionally used to treat skin wounds in Northern European countries. Major bioactive constituents of the conifer oleoresin are diterpene resin acids (DRAs) of the abietane and the pimarane type. To assure consistent pharmaceutical quality of Norway spruce balm and commercial products thereof, an analytical method for the quantitation of DRAs is the prerequisite. However, high structural similarity among DRAs and their poor UV absorption makes chromatographic separation and detection challenging: Conventional liquid chromatography systems often fail to achieve sufficient separation, moreover, they are not sustainable. Gas chromatography on the other hand requires time-consuming derivatization prior to unacceptably long analyses (>60 min). These drawbacks prompted the development of the first validated supercritical fluid-based protocol for the separation and quantitation of eight DRAs, i.e., pimaric acid (1), sandaracopimaric acid (2), palustric acid (3), isopimaric acid (4), levopimaric acid (5), abietic acid (6), dehydroabietic acid (7), and neoabietic acid (8). By using an ultra high-performance supercritical fluid chromatography (UHPSFC) device hyphenated to a quadrupole mass detector, the DRAs were separated in less than 20 min on a Torus 2-Picolylamin (2-PIC) column (3.0 mm × 100 mm; 1.7 µm particle size) applying supercritical CO2 and ethanol as mobile phase. Regarding selectivity, accuracy (recovery rates: 87–108%), intermediate precision (between 6.6 and 11.1%), and linearity (R2 ≥ 0.99; linear between 0.75 μg/ml and 2.5 mg/ml), results were obtained in line with ICH guidelines. The lowest limit of detection (LOD) was at 0.75 μg/ml (7) and the lowest limit of quantitation (LOQ) at 2 μg/ml (8). As application examples, 22 Norway spruce balm samples and five commercial products were analyzed. The here presented protocol not only simplifies and shortens the analytical workflow, but also reduces the amount of organic solvent waste by about two thirds compared to conventional liquid chromatographic set-ups. These advantages qualify this fast and efficient method as an ideal tool for an environmentally friendly quality control of traditionally used wound-healing Norway spruce balm products.

Features of application of alkylketene dimer emulsions and modified resin acids in cellulosic and waste suspensions for obtaining high-quality types of paper and cardboard

The features of the use of sizing emulsions of alkyl ketene dimers (AKD) and resin acids modified with monoethyl cellosolve maleate (TM) and monoethanolamine (TMAS-3N) for hydrophobization of fibrous suspensions containing primary (sulphate cellulose (unbleached and bleached) from coniferous and hardwood) and secondary (waste paper) semi-finished products, differing in fractional composition and degree of grinding (25-70 °SR). The content of particles of the dispersed phase of the emulsions varied from 0.08 to 0.30 % for the AKD emulsion and from 0.20 to 2.00 % for TM and TMAS-3N. It has been established that the hydrophobic effect of AKD, TM and TMAS-3N emulsions increases when secondary fibrous semi-finished products are replaced with primary ones; it depends on the grinding degree of the fibrous suspension and its fractional composition. A feature of the use of alkyl ketene dimers emulsion lies in the ability of its particles to form hydrophobic β-ketoether bonds with hydroxyl groups of fibers, the number of which increases singnificantly when cellulose fibers are used instead of recycled ones. A feature of the use of TM and TMAS-3N rosin emulsions is their ability to form sizing complexes in the presence of electrolyte, which makes it possible to ensure their electrostatic interaction with the surface of fibers (cellulose and waste paper). The advantage of the TMAS-3N emulsion as compared to TM is the possibility of reducing the content of particles of the dispersed phase by 1.8-6.6 times while achieving high hydrophobicity (absorption with one-sided wetting does not exceed 21 g/m2) and maintaining the original strength of paper and cardboard.