XAD-2 Resin Research Articles

Mutagenic drinking water and different levels of emerging micropollutants in Southern Brazil: A new challenge

This study investigated the presence of mutagenic compounds in raw and treated waters at four water treatment plants (WTP01 to WTP04), in southern Brazil. Samples were concentrated using Amberlite XAD4 resin and the acidic and neutral pH fractions tested by mutagenesis in Salmonella/microsome assay, using TA98, TA100 and YG7108 strains in presence and absence of metabolic activation (in vitro human S9). Mutagenesis in raw water was found only by strain TA98 at WTP03, with and without S9. In treated water, significant results were found for TA98 and TA100 strains, the latter being the most sensitive, with prevalence in acidic extract tests without S9. A chemical analysis was performed in the water samples, prioritizing the investigation of the presence and concentration of globally used Emerging Micropollutants (EMs). These compounds in water sources have the potential to contaminate drinking water due to the inefficiency of the conventional treatment employed and can generate disinfection by-products. WTP04 site had the highest total EMs in raw and treated waters, followed by WTP03 in treated water. These WTPs expressed an EMs removal capacity of 45% and only 23%, respectively. Some pharmaceuticals and caffeine showed the highest concentrations, and the latter was directly related to the disposal of domestic sewage in the aquatic ecosystem. The presence of EMs in water after treatment for all WTPs investigated suggests the importance of expanding guidelines that include EMs to establish better standards for the protection of aquatic life and better quality of the drinking water supplies.

Efficient separation of Th(IV) from highly acidic solution by microporous resin materials containing two novel phenanthroline phosphonates

Seeking the cost-effective, highly efficient functional materials with simple preparation procedures have always been a goal in the field of nuclides separation. Due to the effects of protonation and stability, the recovery of actinides like Th(IV) from molar concentrations of acidic solutions for most present materials still a challenge. Herein, we have combined the recently reported phenanthroline phosphonate (POPhen) ligands holding strong selective affinity for actinides in molar concentrations of HNO3 and the commonly used macroporous resin XAD-7 to develop two novel POPhen ligands functionalized XAD-7 composites for the highly efficient removal of Th(IV) from molar concentrations of HNO3 solutions via a simple but effective method. The results of SEM, N2 adsorption/desorption isotherms, FT-IR, solid state 13C/31P NMR and XPS spectra studies confirmed that two phenanthroline phosphonates nBu-POPhen (n-butyl) and iBu-POPhen (isobutyl) were successfully loaded onto the pore structures of XAD-7 carrier through physical interactions. Both two adsorbents showed strong sorption ability, high selectivity and fast sorption rates for Th(IV) in 3–4 M HNO3 solutions. The sorption capacities of Th(IV) by nBu-POPhen/XAD-7 and iBu-POPhen/XAD-7 (around 25 % ligand loading) were 167.5 and 161.4 mg/g respectively at 298 K in 3.0 M HNO3. Dynamic adsorption-stripping experiments, TOC and radiation stability studies further validated the practical application potential of the as-synthesized adsorbents. The sorption mechanism of Th(IV) was deeply elucidated by EDS-STEM, AC-HAADF imaging, XPS survey spectra, EXAFS analysis and DFT theoretical calculations.

Fractionation of phenolic aldehydes by liquid–liquid extraction and polymer resin adsorption

ABSTRACT The extraction and adsorption characteristics of three phenolic aldehydes with high physicochemical similarity in lignocellulosic biomass hydrolyzate, which are fermentation inhibitors, were investigated. The extraction process considered both physical extraction with two organic solvents and reactive extraction with five basic extractants. In physical extraction, n-hexane was found to be the most suitable organic solvent for selectively separating 4-hydroxybenzaldehyde from the three phenolic aldehydes, and in reactive extraction, trioctylphosphine oxide was identified as the most suitable basic extractant for the selective separation of syringaldehyde. In the adsorption process, various neutral polymer resins and anion-exchange polymer resins were employed. Among them, the neutral polymer resin XAD16 was found to be the most suitable for selectively separating 4-hydroxybenzaldehyde. To efficiently separate and concentrate the three phenolic aldehydes with equal mass percentages, a proposed five-step fractionation process included the aforementioned extraction and adsorption techniques. By implementing n-hexane-based physical extraction in step 4 and NaOH solution-based back-extraction in step 5 of the fractionation process, the purities of 4-hydroxybenzaldehyde, vanillin, and syringaldehyde in the final solution increased from their initial 33.3% each to 67.6%, 69.8%, and 76.4%, respectively, at a volume ratio of the aqueous phase to the organic phase of 1:15.

The Late Middle and Early Upper Palaeolithic in Crimea (Ukraine)—A Review of the Neanderthal Refugium Hypothesis

The Crimean Peninsula contains numerous important Palaeolithic sites. It has been considered a potential Neanderthal refugium in Eurasia prior to their disappearance or assimilation, and subsequent replacement by Homo sapiens. This understanding is primarily drawn from lithic technological analysis and radiocarbon dating. However, recent developments in the latter suggest that many of the previously obtained radiocarbon dates from Crimean sites may be too young. The chronological sequence from the site of Kabazi II is a case in point, where differences between dates of bulk collagen and those of single amino acids range up to 10,000 radiocarbon years. These discrepancies are argued to arise from sample contamination and its lack of removal in bulk collagen dating. In this paper, we undertake a critical re-evaluation of results from seven Palaeolithic archaeological sites in the Crimean Peninsula: Kabazi II, Siuren I, Buran-Kaya III, Zaskalnaya V and Zaskalnaya VI, Kabazi V and Starosel’e. Our analysis of radiocarbon results from various sites supports the view that radiocarbon dates obtained so far tend to be too young, which has been indicated in the stratigraphy and lithic assemblages. By harnessing robust radiocarbon protocols in future chronometric work, such as the extraction of hydroxyproline, ninhydrin derivatisation or the purification of amino acids using XAD-2 resin, there is potential for constructing accurate chronologies. Furthermore, improved dating accuracy holds the promise of significant additional insights into the prehistoric sequence of the Crimean Peninsula and its potential role as a refugium for Neanderthals prior to their disappearance.

A novel strategy for sequential separation of Th(IV) from highly acidic wastewater based on solid phase extraction

The potential applications and advantages of thorium(Th) in the development of the nuclear industry make the effective separation of Th(IV) crucial for depleted fuel management and environmental safety. However, selectively capturing of Th(IV) from high-concentration nitric acid remains a challenging task. In this work, a novel solid-phase extraction resin (TOPO/XAD-7) was successfully synthesized by vacuum impregnation of trioctylphosphine oxide (TOPO) into an acrylic-based polymer (XAD-7 resin). It exhibited excellent adsorption abilities for Th(IV), including wide highly concentration acid tolerance (0.01–6 mol L−1 HNO3), high adsorption capacity of 59.79 mg g−1, fast adsorption kinetic (< 60 min) and super elevated selectivity. The adsorption mechanism of the resin involves neutral chelation extraction, with the PO group being the main adsorption binding site. Additionally, the resin was demonstrated good reusability and stability under extreme conditions (high acidity, high temperature and high radiation). Furthermore, dynamic column experiments conducted using an automated separation system validated the practical application of TOPO/XAD-7 resin for the separation of Th(IV) and U(VI)/Th(IV) in wastewater, achieving high element recovery (> 99.5%) and a high U(VI) decontamination factor (3.5 × 105). This work confirms the excellent potential of TOPO/XAD-7 resin for the separation and enrichment of Th(IV) in nuclear wastewater.

Personal air sampling for pesticides in the California San Joaquin Valley.

California is a leading agricultural state and with that, has significant applications of pesticides. Levels of exposure have been measured to be higher among residents in agricultural areas, but measures of personal inhalation exposure to a wide range of pesticides are lacking. Community members in the San Joaquin Valley have expressed concern over pesticide exposures. Working with community members, a wide range of pesticides in personal air samples were measured. Adult and school-aged participants were recruited from small agricultural towns in the San Joaquin Valley. Participants wore a backpack sampler for 8-14 h on 1-3 days. Samples were collected on two tubes, one with Tenax-TA resin and the other with XAD-2 resin. In total, 21 pesticides were analyzed using both LC/MS and GC/MS methods. Thirty-one adult participants and 11 school aged participants were recruited, and sampling occurred on a total of 92 days. Seven adults, 22% of adult participants, and one school child had detectable levels of at least one pesticide. Pesticides detected above the limit of detection were 1,3-dichloropropene, chlorpyrifos, pyrimethanil, burprofezin and penthiopyrad. When these samples were collected, chlorpyrifos was not permitted to be used in California. California, a leading agricultural state, has significant pesticide use, leading to concern about exposures among community members. Thirty-one adult and 11 school aged participants wore personal air sampling backpacks from 1-3 days. Twenty-two percent of adult participants had detectable levels of at least one pesticide. Two pesticides with established toxicity, 1,3-dichloropropene and chlorpyrifos were detected, along with first time measurements of pyrimethanil, burprofezin and penthiopyrad in the United States, which all have potential indications of toxicity. This study suggests the need to expand which pesticides are measured in agricultural communities.

Preparation and Characterization of Five Amino-Modified Hyper-Crosslinked Polymers and Performance Evaluation for Aged Transformer Oil Reclamation

Adsorption is intensively considered to be the most feasible and economical option for aged transformer oil treatment. In this work, five aminated hyper-crosslinked polymers were prepared from chloromethylated polystyrene–co-divinylbenzene (Cl-PS-DVB) through a two-stage modification of crosslinking and five different reagents aminating. After modification, the specific surface area (SBET) and nitrogen content (CN) of prepared resins were greatly improved. To evaluate the reclamation performance of resins for removing oxides and contaminants from aged transformer oils, the total acid number (TAN) and color of oils were mainly examined. The results shown that the prepared resins have superior oil reclamation capacity compared to commercial resin XAD-4 due to their higher microporous specific surface area (Smic) and surface polarity. Among them, the NHC-R3, which used dimethyltriamine (DETA) as an aminating agent, had the best deacidification and decolorization performance. A series of experiments were designed to investigate the optimal regeneration program conditions for NHC-R3, and the additional electrical characteristics of the reclaimed oil, including breakdown voltage, dielectric dissipation factor (DDF), and interfacial tension, were measured as evidence that aged oil was successfully reclaimed.

Engineering Streptomyces albus B4 for Enhanced Production of (R)-Mellein: A High-Titer Heterologous Biosynthesis Approach.

The natural compound (R)-(-)-mellein exhibits antiseptic and fungicidal activities. We investigated its biosynthesis using the polyketide synthase encoded by SACE_5532 (pks8) from Saccharopolyspora erythraea heterologously expressed in Streptomyces albus B4, a chassis chosen for its fast growth, genetic manipulability, and ample large short-chain acyl-CoA precursor supply. High-level heterologous (R)-(-)-mellein yield was achieved by pks8 overexpression and duplication. The precursor supply pathways were strengthened by overexpression of SACE_0028 (encoding acetyl-CoA carboxylase) and four genes involved in β-oxidation (fadD, fadE, fadB, and fadA). Cell growth inhibition by (R)-(-)-mellein production at high concentration was relieved by in situ adsorption using Amberlite XAD16 resin. The final strain, B4mel12, produced (R)-(-)-mellein at 6395.2 mg/L in shake-flask fermentation. Overall, this is the first report of heterologous (R)-(-)-mellein synthesis in microorganism with a high titer. (R)-(-)-mellein prototype in this study opens a possibility for the overproduction of valuable melleins in S. albus B4.

Urban air PCDD/Fs: Dry deposition fluxes and mass transfer coefficients determined using a water surface sampler

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) cause significant environmental concerns. Atmospheric PCDD/Fs permeate water bodies and other ecosystems through wet and dry deposition. In an urban site, dry deposition flux samples of gaseous phase PCDD/Fs were collected by a water surface sampler (WSS) operated between June 2022 and June 2023. There is a conspicuous absence of literature on the direct measurement of dry deposition flux levels in the gaseous phase of PCDD/Fs. In the study, PCDD/Fs in the gas phase reaching the WSS dissolved in the water according to Henry's Law. The PCDD/Fs in the water were transferred to an XAD-2 resin column, sorbing the dissolved PCDD/Fs. The average monthly gas phase dry deposition flux was 34.07 ± 9.35 pg/m2-day (7.35 ± 2.16 pg I-TEQ/m2-day). The highest flux was measured in March (49.53 pg/m2-day), and the lowest was in August (18.64 pg/m2-day). These values indicated the direct flux from air to water. The atmospheric concentration of the gas-phase ranged from 68.38 to 126.88 fg/m3 (13.22–25.01 fg I-TEQ/m3). Dry deposition fluxes and concentrations of atmospheric PCDD/Fs were bigger in the colder months than in the warmer months. This was probably due to a significant increase in residential heating during the colder months, decreased photochemical reactions, and lower mixing heights. Regarding congeners in the dry deposition flux and concentration values in I-TEQ units, 2,3,7,8-TCDD compound predominated with the proportions of 31.61 ± 7.76% and 29.09 ± 12.34%, respectively. Concurrently measured dry deposition flux (Fg) and ambient air concentration (Cg) of PCDD/Fs were considered in the determination of mass transfer coefficient (MTC = Fg/Cg) calculation for each PCDD/F congener. The average MTC for targeted 17 PCDD/Fs was 0.45 ± 0.15 cm/s, and it fluctuated between 0.89 ± 0.30 cm/s for 2,3,7,8-TCDF and 0.2 ± 0.16 cm/s for OCDD.

Quercetin as the primary xanthine oxidase inhibitor compound in Maclura tricuspidata leaf

Maclura tricuspidata (MT) leaf demonstrated various health benefits, notably the inhibition of xanthine oxidase (XOD) activity, which is crucial in the management of hyperuricaemia and many diseases related to oxidative stress. This study aimed to identify the primary compound responsible for this inhibitory effect. Through a systematic investigation, MT leaf extracts were subjected to solvent-solvent partitioning using ethyl acetate, n-hexane, n-butanol, and dichloromethane. Further purification involved adsorption and desorption using Amberlite XAD-2 resin, followed by column chromatography on Silica Gel and Sephadex LH-20. The purified compounds were analysed using UPLC-QTOF-MS coupled with NMR spectroscopy. Our findings identified quercetin, a phenolic compound, as the most significant inhibitor of XOD activity in MT leaf, with an IC50 value of 212.92 μg/ml. This is the first report of purifying and identifying a single compound responsible for XOD inhibition in MT.

Native Mexican black bean purified anthocyanins fractionated by high-performance counter-current chromatography modulate inflammatory pathways

In addition to their pigment properties, the potential health benefits of anthocyanins have made them a subject of interest in recent years. This study aimed to obtain purified anthocyanin fractions from native Mexican black bean cultivars using Amberlite XAD-7 resin column and HPCCC and evaluate their anti-inflammatory properties using RAW 264.7 cells. The major anthocyanins in the purified anthocyanin fractions were delphinidin 3-glucoside (61.8%), petunidin 3-glucoside (25.2%), and malvidin 3-glucoside (12.2%). Purified anthocyanin fractions at 12.5 μg/mL effectively prevented LPS-induced ERK1/ERK2 phosphorylation and reduced the protein expression of COX-2 and mRNA expression of iNOS. Results showed that purified anthocyanin fractions have the potential to modulate the inflammatory response by inhibiting the production of pro-inflammatory mediators through the ERK1/ERK2 and NF-κB pathways. This study suggests that anthocyanins from black beans could be used as a natural strategy to help modulate inflammation-associated diseases.

Effect of Temperature on the Removal of Interferences in the Voltammetric Procedure for the Determination of Cr(VI).

The aim of this paper was to investigate the effect of temperature on the removal efficiency of surfactant-induced interferences. Surfactants were removed as a result of mixing with XAD-7 resin. The study was carried out using the example of Cr(VI) determination by adsorption stripping voltammetry (AdSV). Measurements were carried out using a solution containing Cr(VI), acetate buffer (pH = 6.2), DTPA, KNO3, and different surfactants. Ten mL of the solution was mixed with 0.5 g of XAD-7 resin at different temperatures for 5 min prior to voltammetric measurement. The effect of the mixing temperature of the sample with the resin on the voltammetric Cr(VI) signal in the presence of different surfactants was studied in the range from 20 to 60 °C. The proposed method of removing interference from surfactants by mixing the sample with the XAD-7 resin at 60 °C was used for the determination of trace amounts of Cr(VI) in river water containing non-ionic, anionic, cationic surfactants, and biosurfactants.

Tracking Aromatic Amines from Sources to Surface Waters.

This review examines the environmental occurrence and fate of aromatic amines (AAs), a group of environmental contaminants with possible carcinogenic and mutagenic effects. AAs are known to be partially responsible for the genotoxic traits of industrial wastewater (WW), and AA antioxidants are acutely toxic to some aquatic organisms. Still, there are gaps in the available data on sources, occurrence, transport, and fate in domestic WW and indoor environments, which complicate the prevention of adverse effects in aquatic ecosystems. We review key domestic sources of these compounds, including cigarette smoke and grilled protein-rich foods, and their presence indoors and in aquatic matrices. This provides a basis to evaluate the importance of nonindustrial sources to the overall environmental burden of AAs. Appropriate sampling techniques for AAs are described, including copper-phthalocyanine trisulfonate materials, XAD resins in solid-phase extraction, and solid-phase microextraction methods, which can offer insights into AA sources, transport, and fate. Further discussion is provided on potential progress in the research of AAs and their behavior in an aim to support the development of a more comprehensive understanding of their effects and potential environmental risks.

Anticandidal Activity of a Siderophore from Marine Endophyte Pseudomonas aeruginosa Mgrv7.

An endophytic symbiont P. aeruginosa-producing anticandidal siderophore was recovered from mangrove leaves for the first time. Production was optimal in a succinate medium supplemented with 0.4% citric acid and 15 µM iron at pH 7 and 35 °C after 60 h of fermentation. UV spectra of the acidic preparation after purification with Amberlite XAD-4 resin gave a peak at 400 nm, while the neutralized form gave a peak at 360 nm. A prominent peak with RP-HPLC was obtained at RT 18.95 min, confirming its homogeneity. It was pH stable at 5.0-9.5 and thermally stable at elevated temperatures, which encourages the possibility of its application in extreme environments. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) against Candida spp. Were in the range of 128 µg/mL and lower. It enhanced the intracellular iron accumulation with 3.2-4.2-fold (as judged by atomic absorption spectrometry) with a subsequent increase in the intracellular antioxidative enzymes SOD and CAT. Furthermore, the malondialdehyde (MDA) concentration due to cellular lipid peroxidation increased to 3.8-fold and 7.3-fold in C. albicans and C. tropicalis, respectively. The scanning electron microscope (SEM) confirmed cellular damage in the form of roughness, malformation, and production of defensive exopolysaccharides and/or proteins after exposure to siderophore. In conclusion, this anticandidal siderophore may be a promising biocontrol, nonpolluting agent against waterborne pathogens and pathogens of the skin. It indirectly kills Candida spp. by ferroptosis and mediation of hyperaccumulation of iron rather than directly attacking the cell targets, which triggers the activation of antioxidative enzymes.

Development of an analytical method for the determination of more than 300 pesticides and metabolites in the particulate and gaseous phase of ambient air

Pesticides can enter the atmosphere during spraying or after application, resulting in environmental or human exposure. The study describes the optimisation and validation of analytical methods for the determination of more than 300 pesticides in the particulate and gaseous phases of the air. Pesticides were sampled with high-volume air samplers on glass-fibre filters (GFFs) and glass columns filled with polyurethane foam (PUF) and XAD-2 resin. Comparing different extraction methods, a QuEChERS extraction with acetonitrile was selected for the GFFs. For the PUF/XAD-2 columns, a cold-column extraction with dichloromethane was used. Instrumental determination was performed using liquid chromatography/electrospray ionisation-time-of-flight mass spectrometry (LC/ESI-QTOF) and gas chromatography/electron impact ionisation-tandem mass spectrometry (GC/EI-MS/MS). Recovery experiments showed recovery rates between 70 and 120% for 263 compounds on the GFFs and 75 compounds on the PUF/XAD-2 columns. Semi-quantitative determination was performed for 39 compounds on the GFFs and 110 compounds on the PUF/XAD-2 columns. Finally, 27 compounds on the GFFs and 138 compounds on the PUF/XAD-2 columns could be determined only qualitatively. For the determination of the PUF/XAD-2 samples, signal suppression (LC) or signal enhancement (GC) due to matrix effects were determined. Method quantification limits of the optimised methods ranged from 30 to 240 pg/m3 for the target compounds on the GFFs, and from 8 to 60 pg/m3 on the PUF/XAD-2 columns. The applicability of the method was demonstrated by means of environmental air samples from an agricultural area in the Netherlands.

Uptake behavior of polycyclic aromatic compounds during field calibrations of the XAD-based passive air sampler across seasons and locations

Abstract. Polycyclic aromatic compounds (PACs) continue to demand attention due to their widespread presence and well-established health implications. Given that incomplete combustion is a major contributor to PACs and inhalation constitutes a crucial human exposure pathway, a comprehensive understanding of the concentrations, spatial distributions, and fates of a broad range of PACs in the atmosphere is important. Passive air samplers (PASs) are a commonly utilized technique for PAC sampling and monitoring. In this study, we present the results from two 1-year calibration experiments, one starting in summer and the other in winter, using a passive air sampler equipped with XAD resin as the sorbent (XAD-PAS). Throughout both experiments, PACs were consistently sorbed during the initial 6-month period. However, the sorbed amounts for many PACs exhibited a decrease after half a year of deployment. Three hypotheses to explain this phenomenon were explored, including the uptake of atmospheric particles, evaporation from the sorbent, and reactions with photo-oxidants. All had to be rejected based on the obtained data, additional laboratory experiments, and model results. Model simulations were further used to (i) confirm that a loss process must be invoked to explain the observed uptake behavior and (ii) estimate the kinetics of that loss process for different PACs. Sampling rates (SRs) for 28 PACs derived from the linearized uptake curves during the first 6 months of deployment were comparable to those of other semi-volatile organic compounds obtained during the same calibration experiment, and they also demonstrate a consistent negative correlation with volatility.

Relation between hydrophilic/hydrophobic characteristics of sludge extracellular polymeric substances and sludge moisture-holding capacity in hot-pressing drying

Sludge poses a serious threat to the environmental health. Hot-pressing drying has been proven efficient in sludge treatment because of the reduced thermal contact resistance, rapid increase in sludge temperature, and high drying rate. Sludge extracellular polymeric substances (EPS) significantly influence moisture transfer. However, whether in hot-pressing or traditional thermal drying, the effect of EPS on sludge moisture-holding capacity is rarely reported. Thereby, this study investigated the relationship between hydrophilic/hydrophobic characteristics of EPS and sludge moisture-holding capacity at various drying time and mechanical compression using XAD resin fractionation. Thermodynamic analysis indicated that sludge moisture desorption isotherms, net isosteric heat of desorption, and differential entropy presented a downward trend with the increase in drying time and mechanical compression, suggesting reduced sludge moisture-holding capacity. EPS analysis showed that at the same drying time, applying 25 kPa mechanical compression increased sludge temperature by 16 % and protein content by 13.8 %. At the same sludge temperature, protein content rose by 7.3 % compared to the drying without mechanical compression. It was concluded that the fast rise in sludge temperature and the mechanical extrusion facilitated the destruction of sludge microbial flocs, accelerating the release of intracellular and EPS-bound moisture and contributing to the decrease in moisture-holding capacity. Besides, tryptophan protein-like substances were the major source of hydrophilic/hydrophobic organic matter, compared to polysaccharide and humic acid-like substances. The gradually reduced sludge moisture-holding capacity was divided into three stages. Below 67 °C, the moisture desorption was dominated by the release of intracellular moisture. Below 85 °C, the increase in protein and the enhanced exposure of hydrophobic functional groups in protein improved the hydrophobicity of EPS. Above 85 °C, protein consumption due to thermal decomposition and browning reaction facilitated the desorption of EPS-bound moisture. Hence, this study provided novel insights into the mechanism of sludge drying.

Effective production of β‐sitosteryl oleate using a highly thermal‐tolerant immobilized lipase in a solvent‐free system

Abstractβ‐Sitosteryl oleate, renowned for its diverse beneficial bioactivities, holds significant promise as a potential ingredient in functional foods. This study reports the superior performance of β‐sitosteryl oleate facilitated by lipase UM1 (lipase from marine Streptomyces sp. W007, immobilized on XAD1180 resin) as a biocatalyst in a solvent‐free system, in comparison to commercial enzymes Novozym 435 (lipase B from Candida antarctica, immobilized on a macroporous acrylic resin), Lipozyme TL IM (lipase from Thermomyces lanuginosus, immobilized on a non‐compressible silica gel carrier), and Lipozyme RM IM (lipase from Rhizomucor miehei, immobilized on a macroporous acrylic resin). Remarkably, an over 98% yield was achieved under the optimal conditions: a substrate molar ratio of β‐sitosterol to oleic acid of 1:4, lipase loading of 150 U, and a reaction temperature of 60°C. The process exhibited substantial resilience and effectiveness, maintaining a degree of esterification above 95% even after five recycles. Following this, the synthesis was successfully scaled up by 100‐fold, with the product isolated through molecular distillation and confirmed using ultra‐performance liquid chromatography mass spectrometry (UPLC‐MS) and Fourier transform infrared spectroscopy (FT‐IR) analytical techniques. These results underscore lipase UM1 as a promising catalyst for the industrial‐scale synthesis of β‐sitosteryl oleate, fostering expanded avenues for its utilization in the functional food industry.

Isolation of Polyphenols from Aqueous Extract of the Halophyte Salicornia ramosissima.

Polyphenols from residual non-food grade Salicornia ramosissima have health-promoting effects in feed, food, or nutraceutical applications. Therefore, the isolation of polyphenols is of interest from a series of environmentally friendly isolation methods with recyclable solvents. The isolation of polyphenols from non-food grade S. ramosissima was investigated using sequential membrane filtration with and without acid pretreatment, liquid-liquid extraction, resin adsorption, and centrifugal partition chromatography (CPC); analyzed by the Folin-Ciocalteu assay for total polyphenols; and finally analyzed using UPLC-TQMS in negative ion-spray mode for detection of 14 polyphenols. Sequential membrane filtration and acid hydrolysis indicated the polyphenols forming complexes with other compounds, retaining the polyphenols in the retentate fraction of large molecular weight cut-off membrane sizes. Conventional liquid-liquid extraction using sequential ethyl acetate and n-butanol showed most polyphenols were extracted, apart from chlorogenic acids, indicating a low isolation efficiency of higher polarity polyphenols. Analysis of the extract after resin adsorption by Amberlite XAD-4 resin showed high efficiency for separation, with 100% of polyphenols adsorbed to the resin after 13 bed volumes and 96.7% eluted from the resin using ethanol. CPC fractionations were performed to fractionate the concentrated extract after resin adsorption. CPC fractionations of the 14 polyphenols were performed using an organic or aqueous phase as a mobile phase. Depending on the mobile phase, different compounds were isolated in a high concentration. Using these easily scalable methods, it was possible to comprehensively study the polyphenols of interest from S. ramosissima and their isolation mechanics. This study will potentially lead the way for the large-scale isolation of polyphenols from S. ramosissima and other complex halophytes. The compounds of the highest concentration after CPC fractionation were isoquercitrin and hyperoside (155.27 mg/g), chlorogenic acid (85.54 mg/g), cryptochlorogenic acid (101.50 mg/g), and protocatechuic acid (398.67 mg/g), and further isolation using CPC could potentially yield novel polyphenol nutraceuticals.

Preconcentration and determination of Cu(II) and Cd(II) ions from wastewaters by using hazelnut shell biosorbent immobilized on Amberlite XAD-4 resin

Hazelnut shell biosorbent immobilized on Amberlite XAD-4 polymer resin as solid phase extraction method was developed and used for preconcentration of Cu(II) and Cd(II) ions from aqueous solutions. Concentrations of analytes in solutions were determined by Flame Atomic Absorption Spectrometry after extraction with column technique. Functional groups of nutshell biosorbent immobilized on resin were characterized by Fourier transform infrared spectrometry. Optimized critical parameters for preconcentration of Cu2+ and Cd2+ ions from sample solutions with nutshell immobilized on the resin were the pH value of solution, type of eluent solutions, the flow rate of sample solution, quantities of nutshell biosorbent, Amberlite XAD-4 resin, and enrichment factors, respectively. Detection limits of Cu2+ and Cd2+ ions found were 0.29 μg L-1 and 0.25 μg L-1, respectively. The method proposed was applied for determinations of Cu2+ and Cd2+ ions in standard reference material (BCR-670 aquatic plant sample) for accuracy and applied to real water samples such as wastewater and Van lake water. At the 95% confidence level, relative standard deviations (RSDs) were found as 1.44% for Cd2+ and 1.21% for Cu2+ ions with three replicate measurements.