Preparation and Properties of Rosin-based Anthraquinone Fluorescent Waterborne Polyurethane.

Fluorescent polyurethane has been widely used as fluorescent probes and switches due to its diverse structure and properties, but most of them are solvent-based and synthesized from petroleum-based products. A new type of rosin-based anthraquinone fluorescent waterborne polyurethane (WPU-DAAQ) with good and stable fluorescence properties was synthesized by reacting rosin modified ester (RAG) as a diol and 2, 6-diaminoanthraquinone (DAAQ) as a fluorescent agent with diisocyanate. The structure of WPU-DAAQ was characterized by Fourier transform infrared spectroscopy, UV-vis absorption spectroscopy, and hydrogen magnetic resonance spectroscopy. The fluorescence properties, water resistance, and solvent resistance of WPU-DAAQ were tested. The results showed that DAAQ was successfully grafted onto the polyurethane molecular chain. The fluorescence intensity of WPU-DAAQ increases and then decreases with increasing excitation wavelengths, and increases with the increase of solvent ether content, and is significantly enhanced compared to DAAQ. The dispersion stability was good with the increase of DAAQ. The introduction of DAAQ into polyurethane improved the thermal stability, hydrophobicity, and solvent resistance of WPU-DAAQ. Therefore, WPU-DAAQ is a new type of fluorescent waterborne polyurethane with stable dispersion properties, good fluorescent properties, heat resistance and water resistance.

Red Fluorescent Molecule with Aggregation-Induced Emission Based on Dehydroabietic Acid Diarylamine for Bioimaging.

In this paper, molecules with AIE red light properties were designed by coupling dehydroabietic acid diarylamine and 2,3-diphenylfumaronitrile, which were designated 2DTPA-CN and 2TPA-CN. The emission wavelengths were 683 nm and 701 nm, respectively. The 2DTPA-CN and 2TPA-CN showed typical AIE characteristics with large Stokes shifts of 7.4 × 104 cm-1 and 6.7 × 104 cm-1, respectively. The obvious solvatochromism and electron cloud distributions of HOMO/LUMO in the ground and excited states both reveal the intramolecular charge transfer (ICT) effect. The 2DTPA-CN, boasting exceptional biocompatibility, was successfully prepared into nanoparticles (NPs), which were applied to tumor cell imaging, showing good bioimaging effects both in vitro imaging in live cells and in vivo imaging in live mice. The results demonstrated that it possesses significant potential as an effective bioimaging reagent for the detection of tumor cells. Furthermore, the incorporation of 2,3-diphenylfumaronitrile moieties to dehydroabietic acid diarylamine emerged as a proficient approach to broaden the emission wavelengths of rosin-based fluorescent materials.

Rosin as a Natural Alternative for the effective disinfection of ESKAPE Pathogens and Clostridioides difficile spores.

AIM: Hospital-acquired infections (HAIs) caused by antimicrobial-resistant ESKAPE pathogens are a significant concern for the healthcare industry, with an estimated cost of up to ${\$}$45 billion per year in the US alone. Clostridioides difficile is an additional opportunistic pathogen that also poses a serious threat to immunocompromised patients in hospitals. Infections caused by these pathogens lead to increased hospital stays and repeated readmission, resulting in a significant economic burden. Disinfectants and sporicidals are essential to reduce the risk of these pathogens in hospitals, but commercially available products can have a number of disadvantages including inefficacy, long contact times, short shelf lives, and operator health hazards. In this study we evaluated the effectiveness of Rosin (a natural substance secreted by coniferous trees as a defence mechanism against wounds in tree bark) and its commercial derivative Rosetax-21 as disinfectants and sporicidal against the six ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) and spore preparations from Clostridioides difficile. METHODS AND RESULTS: Both Rosin and Rosetax-21 were tested under simulated clean and dirty conditions (with BSA) against the ESKAPE pathogens, and C. difficile spore preparations. In clean conditions, Rosin (5% weight/volume: w/v) demonstrated significant efficacy against five of the ESKAPE pathogens, with A. baumannii and E. faecium being the most susceptible, and K. pneumoniae the most resistant, showing only a one-log reduction after a 5 min treatment. However, in dirty conditions, all pathogens including K. pneumoniae exhibited at least a 3-log reduction to Rosin within 5 min. Rosetax-21 (5% w/v) was found to be less effective than Rosin in clean conditions, a trend that was exacerbated in the presence of BSA. Additionally, both Rosin and Rosetax-21 at 2.5% (w/v) achieved complete eradication of C. difficile spores when combined with 0.5% glutaraldehyde, though their standalone sporicidal activity was limited. CONCLUSIONS: The findings from this study highlight the potential of Rosin and Rosetax-21 as both bactericidal and sporicidal disinfectants, with their efficacy varying based on the conditions and the pathogens tested. This presents an avenue for the development of novel healthcare disinfection strategies, especially against HAIs caused by antimicrobial-resistant ESKAPE pathogens and C. difficile.

New device, 'old' allergens. Allergic contact dermatitis caused by the Dexcom G7 glucose sensor.

BACKGROUND: Allergic contact dermatitis (ACD) has been reported as an adverse effect from the use of several glucose sensors and insulin pumps from different manufacturers. Isobornyl acrylate (IBOA) has been identified as a major culprit sensitizer, but also other acrylates and (modified) colophonium have been reported as causes of ACD. OBJECTIVES: To report the two first cases diagnosed with ACD caused by the Dexcom G7 (DG7) glucose sensor. PATIENTS AND METHODS: Two children with suspected ACD from DG7 were patch tested with our medical device series with an addition of selected test preparations including two variants of modified colophonium - methyl hydrogenated rosinate (MHR) and glyceryl hydrogenated rosinate (GHR). Both patients were also tested with acetone extracts made from different parts of the DG7 sensor. The extracts were analysed by gas chromatography-mass spectrometry (GC-MS). RESULTS: Both patients tested positive to IBOA, hydroabietyl alcohol and GHR. In addition, patient 1 had a positive reaction to MHR and patient 2 had a positive reaction to colophonium. The GC-MS analyses showed the presence of IBOA and colophonium-related substances in the DG7 extracts. CONCLUSIONS: Both patients were diagnosed with contact allergy to well-known medical device-related sensitizers. The presence of IBOA and (modified) colophonium in a newly introduced (on the Swedish market in 2023) glucose sensor is remarkable and indicates an inadequate toxicological assessment of the materials used in the sensor.

Preparation and pH Detection Performance of Rosin-Based Fluorescent Polyurethane Microspheres.

Rosin-based fluorescent polyurethane emulsion (FPU) was prepared using isophorone diisocyanate, ester of acrylic rosin and glycidyl methacrylate, 1,5-dihydroxy naphthalene (1,5-DN), and 1,4-butanediol as the raw materials. Then, rosin-based fluorescent polyurethane microspheres (FPUMs) were successfully prepared by suspension polymerization method using FPU as the main material, azodiisobutyronitrile as the initiator, and gelatin as the dispersant. FPUMs were characterized by Fourier transform infrared spectra, thermogravimetric analysis, optical microscopy, scanning electron microscopy and fluorescence spectra, and the response performance of FPUMs to pH was studied. The results showed that FPUMs were successfully prepared. With the increase of the level of 1,5-DN, the particle size of FPUMs increased gradually, and the fluorescence intensity increased first and then decreased. When the level of 1,5-DN was 3 wt.%, the average particle size was 49.3 µm, the particle distribution index (PDI) was 1.05, and the fluorescence intensity was the largest (3662 a.u.). The fluorescence intensity of FPUMs increased linearly with the decrease of pH, which can be used for pH detection in solution. Furthermore, the FPUMs exhibited good thermal stability, anti-interference and recoverability.

Design, Synthesis, and Bioactivity Evaluation of Novel Rosin Diterpenoid Derivatives as Potential Anti-glioma Agents.

Glioma is the most common brain tumor and its treatment options are limited. Abietic acid and dehydroabietic acid are tricyclic diterpenoid oxygen compounds with strong lip solubility and anti-glioma activity. In this study, novel rosin diterpenoid derivatives were designed and synthesized using abietic acid and dehydrogenated abietic acid as lead compounds and their activities against T98G, U87MG, and U251 cells were evaluated by CCK-8 methods. The in vivo activity of compounds with stronger activity in vitro was preliminarily studied through the Zebrafish model. The results showed that the IC50 values of B6, B8, B10, and B12 were 11.47 to 210.6 µM, which were exhibited higher antiproliferative potency against T98G, U87MG, and U251. The scratch experiment showed that B12 inhibited the migration of T98G in a time-dependent and concentration-dependent manner. The results of in vivo activity further explained that B12 could inhibit the proliferation of the T98G. The pKa values of B6, B8, B10, and B12 were 7.17 to 7.35, which were within the ideal range of glioma drugs. The ADME predictions indicated that these derivatives could pass through the blood-brain barrier. In addition, molecular docking primarily explained interaction between compounds and protein. These results suggested that B12 should be a promising candidate that merits further attention in the development of anti-glioma drugs.

Design and Properties of Natural Rosin-Based Phosphoester Functional Surfactants.

As an important forestry biomass resource, rosin has a wide range of applications in medicine, adhesives, surfactants and other fields. Using natural dehydroabietic acid as a raw material, dehydroabietic acid-based phosphorus monoester (DPM) and diester (DPD) surfactants were designed and synthesized. The chemical structures and self-assembly properties were characterized by FT-IR, NMR and TEM, and the effects of pH on critical micelle concentration, γCMC, emulsifying properties, foam properties and micelle morphology were studied. The results showed that the CMC, γCMC value and aggregate morphology had certain pH responsiveness. The γCMC value under acidic conditions was smaller than γCMC under alkaline conditions, and the foaming performance and foam stability under acidic conditions were better than those under alkaline conditions. TEM micelle morphology studies have shown that DPM and DPD surfactants can self-assemble into rod-shaped and spherical micelle morphologies with a pH change in an aqueous solution. At the same pH, the foaming and emulsification properties of DPD were better than those of DPM. The best foaming and emulsification ability of DPD were 11.8 mL and 175 s, respectively. At the same time, the foaming ability of DPD is also affected by pH. DPD has excellent foaming properties in acidic conditions, but these disappeared in neutral conditions.

Sequential Esterification-Diels-Alder Reactions for Improving Pine Rosin Durability within Road Marking Paint.

Pine rosin, which is derived from Pinus merkusii resin, a natural product, has demonstrated potential as a road marking binder. Although pine rosin has an excellent shinning property, it has some limitations, such as instability and color change. To tackle these issues, modified rosin has been developed through sequential esterification and Diels-Alder reactions, and it has shown better properties than untreated rosin. In this study, from the evaluation of untreated and treated rosins, the treated rosin showed some improvements, such as a lower acid value and higher stability, as shown by the color consistency during the oxidation test at 150 °C for 24 h in open-air conditions. Additionally, as road marking paint, the modified rosin is blended with blending materials in the range of 18-28 wt.%. The modified rosin has a softening point of 170-210 °C, a hardness of 50-71 HD, and a weight loss of 1.33-5.12 mg during the wearing test. These results are comparable to or better than those of commercially available road marking products.

Rosin modified aminated mesoporous silica adsorbed tea tree oil sustained-release system for improve synergistic antibacterial and long-term antibacterial effects.

Tea tree oil, a natural antibacterial compound, cannot be used effectively because of its volatile nature. In this work, a biocompatible carrier was prepared and loaded with tea tree essential oil. The carrier was prepared via the electrostatic or chemical action of aminated mesoporous silica and sodium rosin for achieving a low volatilization rate of tea tree essential oil. A synergistic antibacterial effect was observed between sodium rosin and tea tree essential oil. This method utilized the positive charge of the amino group and the condensation reaction with the carboxyl group to achieve physical and chemical interactions with sodium rosin. Fourier Transform Infrared, Brunauer-Emmet-Teller, Zeta potential, SEM, TEM, and TG were performed to characterize the structure and properties of the samples. Compared to the electrostatic effect, the chemically modified system exhibited a longer sustained release, and the sustained release curve followed the Korsmeyer-Peppas release model. Also, the antibacterial properties of the chemically modified system exhibited better minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) respectively, the MIC and MBC forE. coliwere 0.3 mg ml-1and 0.6 mg ml-1respectively, forS. aureuswere 0.15 mg ml-1and 0.3 mg ml-1respectively. More strikingly, the sample also demonstrated long-term antibacterial performance. Therefore, this work provides a new way for the delivery of volatile antibacterial drugs to achieve sustained-release and long-lasting antibacterial effects.

Modeling the dynamic kinetics of microbial disinfection with dissipating chemical agents-a theoretical investigation.

The most notable microbial survival models of disinfection kinetics are the original and modified versions of the static Chick-Watson-Hom's (CWH) initially developed for water chlorination. They can all be viewed as special cases of the Weibull survival model, where the observed static curve is the cumulative form (CDF) of the times at which the individual targeted microbes succumb to the treatment. The CWH model time's exponent is the distribution's shape factor, and its concentration-dependent rate parameter represents the distribution's scale factor's reciprocal. Theoretically, the concentration- dependence of the Weibull model's rate parameter need not to be always in a form of a power-law relationship as the CWH model requires, and two possible alternatives are presented. Apart from being chemically reactive, most chemical disinfectants are also volatile, and their effective concentration rarely remains constant. However, the published dynamic versions of the original CWH model are mathematically incongruent with their static versions. The issue is nonexistent in the dynamic version of the Weibull or other distribution-based models, provided that the momentary inactivation rate is expressed as the static rate at the momentary concentration, at the time that corresponds to the momentary survival ratio. The resulting model is an ordinary differential equation (ODE) whose numerical solution can describe survival curves under realistic regular and irregular disinfectant dissipation patterns, as well as during the disinfectant dispersion and/or its replenishment. KEY POINTS: • The Chick-Watson-Home models are treated as special cases of the Weibull distribution. • Dynamic microbial survival curve described as ordinary differential equation solution. • Survival rate models of disinfectant dissipation and replenishment patterns presented.

Tracing colophonium in consumer products.

BACKGROUND: Colophonium (rosin) can cause allergic contact dermatitis, mainly due to autoxidation of abietic acid (AbA). Products containing ≥0.1% colophonium should be labeled with EUH208 - "Contains rosin; colophony. May produce an allergic reaction." How should this be measured? OBJECTIVE: To compare the results from different strategies for estimating colophonium levels in consumer products: (a) from AbA, and (b) the sum of all major resin acids. To investigate the ratio of 7-oxodehydroabietic acid (7-O-DeA)/AbA as indication of autoxidation. METHODS: Resin acids were extracted from consumer products, derivatized, and then separated by gas chromatography/mass spectrometry (GC/MS). RESULTS: Resin acids were detected in 9 of 15 products. No product contained colophonium ≥0.1%. Estimation based on AbA resulted in underestimation of the colophonium levels in four of nine products. For three products, the obtained levels from this strategy were only one of two compared to when estimating from the sum of all resin acids. The ratio 7-O-DeA/AbA varied from 74% to 1.4%. CONCLUSIONS: We propose to measure colophonium based on the sum of all detectable major resin acids, including 7-O-DeA. The ratio of 7-O-DeA/AbA should be used as a marker of autoxidation, indicating an increased risk of sensitization. The presented analytical method is simple to use and suitable for further screening studies.

The adjuvant effects of rosin and coconut oil on nicosulfuron and mesotrione to control weeds.

Natural adjuvants are novel options to reduce the doses of chemical herbicides. The aim of the current study was to examine the compositions and adjuvant effects of rosin and coconut oil on herbicides using a combination of indoor experiment and field trial. The GC-MS results showed that the main component of rosin was abietic acid (40.02%), and the main components of coconut oil were 2-pentanone, 4-hydroxy-4-methyl- (21.45%) and dodecanoic acid (14.59%). In greenhouse experiment, rosin showed a significant adjuvant effect on nicosulfuron against Digitaria sanguinalis and Amaranthus retroflexus, with the GR50 ratios of 1.47 and 1.69, respectively. The GR50 values of nicosulfuron in the present of coconut oil were 3.99 and 10.13 g a.i./hm2 against D. sanguinalis and A. retroflexus, lower than that of individual application. The adjuvant effect of rosin and coconut oil on mesotrione was also found. In field trial, the fresh weight control efficiency of nicosulfuron (45 g a.i./hm2) and mesotrione (112.5 g a.i./hm2) was significantly improved after the addition of rosin and coconut oil, similar with that of recommended dose. Rosin and coconut oil could reduce the contact angle of nicosulfuron, with the results of 56.68° and 53.90°, respectively, lower than that of individual application. Furthermore, rosin and coconut oil could decrease the surface tension, wetting and penetration time; and increase the spreading diameter and maximum retention. Both rosin and coconut oil have adjuvant effects on herbicides in the lab & field with multiple mechanisms. Thus, they have the potential to be developed into natural adjuvants for herbicide formulation to control weeds.

Weathering of Antibacterial Melt-Spun Polyfilaments Modified by Pine Rosin.

For many antibacterial polymer fibres, especially for those with natural functional additives, the antibacterial response might not last over time. Moreover, the mechanical performance of polymeric fibres degrades significantly during the intended operation, such as usage in textile and industrial filter applications. The degradation process and overall ageing can lead to emitted volatile organic compounds (VOCs). This work focused on the usage of pine rosin as natural antibacterial chemical and analysed the weathering of melt-spun polyethylene (PE) and poly lactic acid (PLA) polyfilaments. A selected copolymer surfactant, as an additional chemical, was studied to better integrate rosin with the molecular structure of the plastics. The results reveal that a high 20 w-% of rosin content can be obtained by surfactant addition in non-oriented PE and PLA melt-spun polyfilaments. According to the VOC analysis, interestingly, the total emissions from the melt-spun PE and PLA fibres were lower for rosin-modified (10 w-%) fibres and when analysed below 60 ℃. The PE fibres of the polyfilaments were found to be clearly more durable in terms of the entire weathering study, i.e., five weeks of ultraviolet radiation, thermal ageing and standard washing. The antibacterial response against Gram-positive Staphylococcus aureus by the rosin-containing fibres was determined to be at the same level (decrease of 3-5 logs cfu/mL) as when using 1.0 w-% of commercial silver-containing antimicrobial. For the PE polyfilaments with rosin (10 w-%), full killing response (decrease of 3-5 logs cfu/mL) remained after four weeks of accelerated ageing at 60 ℃.

Natural Deep Eutectic Solvents for the Extraction of Phenyletanes and Phenylpropanoids of Rhodiola rosea L.

The extraction of Rhodiola rosea rhizomes using natural deep eutectic solvent (NADES) consisting of lactic acid, glucose, fructose, and water was investigated. A two-level Plackett-Burman design with five variables, followed by the steepest ascent method, was undertaken to determine the optimal extraction conditions. Among the five parameters tested, particle size, extraction modulus, and water content were found to have the highest impact on the extrability of phenyletanes and phenylpropanoids. The concentration of active compounds was analyzed by HPLC. The predicted results showed that the extraction yield of the total phenyletanes and phenylpropanoids (25.62 mg/g) could be obtained under the following conditions: extraction time of 154 min, extraction temperature of 22 °C, extraction modulus of 40, molar water content of 5:1:11 (L-lactic acid:fructose:water, mol/mol), and a particle size of rhizomes of 0.5-1 mm. These predicted values were further verified by validation experiments in predicted conditions. The experimental yields of salidroside, tyrosol, rosavin, rosin, cinnamyl alcohol and total markers (sum of phenyletanes and phenylpropanoids in mg/g) were 11.90 ± 0.02, 0.36 ± 0.02, 12.23 ± 0.21, 1.41 ± 0.01, 0.20 ± 0.01, and 26.10 ± 0.27 mg/g, respectively, which corresponded well with the predicted values from the models.

Stability of Alum-Containing Paper under Alkaline Conditions.

The present contribution evaluates the methods of degradation and stabilization of alum-containing paper with a focus on the alkaline environment achieved by deacidification procedures. In terms of reviewed subjects, the contribution focuses on alum-rosin sized paper, which is still used as a carrier of knowledge and information; however, it also mentions cellulose itself and other brands of paper. The contribution summarizes the results on the homogeneity of the distribution of alum and rosin in the paper mass and on the paper surface. It provides the knowledge gained in the field of alkaline hydrolysis and oxidation with special regard to transition metal species. It shows the values of alkaline reserves achieved in the main mass-deacidification processes. On the basis of the acquired knowledge, the contribution emphasizes the procedures of paper stabilization. Criteria of "increased mechanical permanence and lifetime prolongation" adopted to evaluate and compare the efficacy of individual mass-deacidification processes were applied and corresponding data are introduced. The contribution also draws attention to the existence of open issues in the area of paper degradation and stabilization.

The Emulsifying Properties of Hydrogenated Rosin Xylitol Ester as a Biomass Surfactant for Food: Effect of pH and Salts.

The xylitol ester of hydrogenated rosin (XEHR) was obtained for the first time from biomass-based hydrogenated rosin and xylitol using an environmentally friendly, high-pressure CO2 catalytic synthesis. This compound is intended for use as an emulsifier for food. Analyses by ICP-AES showed the absence of heavy metal residues in the product, such that it met food standards. Fourier transform infrared and nuclear magnetic resonance spectroscopies together with gel permeation chromatography confirmed the successful esterification and the formation of a monoester and diester with molar masses of 427 and 772 g/mol. The emulsification of water/soybean oil mixtures by adding the XEHR was assessed at pH values of 4, 6.86, and 10 and in the presence of NaCl, KCl, MgCl2, and CaCl2. The XEHR was found to act as an emulsifier by reducing the interfacial tension of such mixtures to less than 2 mN/m under all conditions. The highest emulsifying activity index (9.52 m2/g) and emulsifying stability index (94.53%) were obtained after adding MgCl2 (100 mM). Particle size and confocal microscopy showed that the presence of salts gave a more uniform droplet size and a finer emulsion structure. The high viscosities of the emulsions containing salts also suggested a more cohesive oil droplet network.

Variability of Major Phenyletanes and Phenylpropanoids in 16-Year-Old Rhodiola rosea L. Clones in Norway.

Rhodiola rosea L. (roseroot) is an adaptogen plant belonging to the Crassulaceae family. The broad spectrum of biological activity of R. rosea is attributed to its major phenyletanes and phenylpropanoids: rosavin, salidroside, rosin, cinnamyl alcohol, and tyrosol. In this study, we compared the content of phenyletanes and phenylpropanoids in rhizomes of R. rosea from the Norwegian germplasm collection collected in 2004 and in 2017. In general, the content of these bioactive compounds in 2017 was significantly higher than that observed in 2004. The freeze-drying method increased the concentration of all phenyletanes and phenylpropanoids in rhizomes compared with conventional drying at 70 °C. As far as we know, the content of salidroside (51.0 mg g-1) observed in this study is the highest ever detected in Rhodiola spp. Long-term vegetative propagation and high genetic diversity of R. rosea together with the freeze-drying method may have led to the high content of the bioactive compounds observed in the current study.

Bacterial growth dynamics and corresponding metabolite levels in the extraction area of an Austrian sugar beet factory using antimicrobial treatment.

BACKGROUND: During the manufacture of sucrose from sugar beet, different microorganisms originating from the plant material as well as from the soil enter the process. Due to the formation of polysaccharide-based slimes, these contaminants may induce several adverse effects such as filtration problems during juice purification. Certain microorganisms also metabolize sucrose, leading to product losses with financial consequences. To better understand and to prevent these negative effects, the aim of the study was to investigate the evolution of relevant bacterial groups, including their metabolites appearing during the extraction process. For this purpose, one production cycle was monitored to identify the major contamination steps and to clarify how they relate to the processing conditions. Traditionally, different antimicrobial agents such as formaldehyde, sulfur dioxide, hypochlorous acid, sodium hypochlorite, and chlorine dioxide have been added to inhibit microbial growth. In the present study, a rosin-based product derived from pine trees was applied as an alternative to those substances. RESULTS: Press water, raw juice, and mid-tower juice were identified as being highly contaminated with bacteria, and processing conditions such as time, temperature and pH level significantly influenced bacterial levels and the corresponding metabolites. Among the contaminants identified, lactic acid bacteria, and mesophilic and thermophilic aerobic bacteria played a dominant role, whereas lactic acid, acetic acid, butyric acid, and ethanol were identified as typical metabolites. CONCLUSION: Bacterial growth during production could be reduced by shock dosing of the rosin-based material in the extraction area. © 2020 Society of Chemical Industry.

Particle size analysis of municipal solid waste for treatment process modeling.

Several unit operations used in municipal solid waste (MSW) processing facilities are based on physical properties of the waste materials, such as particle size, density and shape. Reliable expressions describing particle size distribution (PSD) of the different waste components present in MSW are not readily available in the context of process modeling. In this study, the characterization data for household wastes and construction and demolition (C&D) wastes were analysed with the purpose of selecting the most representative PSD expression for these waste streams. The Rosin-Rammler distribution was identified over the log-normal and the gamma distributions as the best-fitting PSD for the waste samples. This was demonstrated for both raw and processed waste samples. Parameters were derived and validated for every category of MSW materials considered in the characterization. A model for mixed household waste PSD was developed based on the summation of Rosin-Rammler expressions corresponding to each category of waste materials, as the composition was determined to be the main factor influencing particle size. A simplified model was also derived for mixed waste as a bimodal distribution since two main modes were observed in household waste - one for the "organic" fraction and one for the "inorganic" fraction.

Alkaloid purification using rosin-based polymer-bonded silica stationary phase in HPLC.

Alkaloids are important natural products that exhibit a wide spectrum of pharmacological activities. To efficiently separate and purify them, a rosin-based polymer-bonded silica stationary phase in high-performance liquid chromatography was synthesized via the surface radical polymerization of ethylene glycol maleic rosinate acrylate and methacrylic acid onto functionalized silica. The stationary phases, columns, optimization of chromatographic conditions for alkaloids, and thermodynamic behavior of the analytes on the column were fully studied. Under the optimized conditions, the prepared column efficiently purified natural camptothecine, caffeine, and evodiamine with the corresponding purities of 92, 96, and 97%. With this work, we have developed an efficient approach to isolate alkaloids and promoted the research on rosin-based materials in biomedicine and analytical chemistry.