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1.
Environ Sci Pollut Res Int ; 31(21): 31224-31239, 2024 May.
Article in English | MEDLINE | ID: mdl-38632197

ABSTRACT

Driven by climate change and human activity, Sargassum blooming rates have intensified, producing copious amount of the invasive, pelagic seaweed across the Caribbean and Latin America. Battery recycling and lead-smelter wastes have heavily polluted the environment and resulted in acute lead poisoning in children through widespread heavy metal contamination particular in East Trinidad. Our study details a comprehensive investigation into the use of Sargassum (S. natans), as a potential resource-circular feedstock for the synthesis of calcium alginate beads utilized in heavy metal adsorption, both in batch and column experiments. Here, ionic cross-linking of extracted sodium alginate with calcium chloride was utilized to create functional ion-exchange beads. Given the low quality of alginates extracted from Sargassum which produce poor morphological beads, composite beads in conjunction with graphene oxide and acrylamide were used to improve fabrication. Stand-alone calcium alginate beads exhibited superior Pb2+ adsorption, with a capacity of 213 mg g-1 at 20 °C and pH 3.5, surpassing composite and commercial resins. Additives like acrylamide and graphene oxide in composite alginate resins led to a 21-40% decrease in Pb2+ adsorption due to reduced active sites. Column operations confirmed Alginate systems' practicality, with 20-24% longer operating times, 15 times lower adsorbent mass on scale-up and 206% smaller column diameters compared to commercial counterparts. Ultimately, this study advocates for Sargassum-based Alginate ion-exchange beads as a bio-based alternative in Trinidad and developing nations for dealing with heavy metal ion waste, offering superior heavy metal adsorption performance and supporting resource circularity.


Subject(s)
Alginates , Ion Exchange Resins , Lead , Sargassum , Sargassum/chemistry , Alginates/chemistry , Adsorption , Lead/chemistry , Ion Exchange Resins/chemistry
2.
J Environ Manage ; 347: 119142, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37804631

ABSTRACT

Macroporous ion exchange resin has excellent selectivity to nitrogen (N), phosphorus (P) and partially soluble refractory organic compounds contained in the secondary effluent of wastewater treatment plants (WWTP). In this study, macroporous ion exchange resins were chosen as an alternative to single biochemical nitrogen removal processes. Various conditions were examined to optimize adsorption performance, and the adsorption mechanism was explored through isotherm fitting, thermodynamic parameter calculation, and kinetic analysis. The experiment demonstrated that the resin exhibited strong selectivity for nitrate (NO3-) and achieved an equilibrium adsorption amount of 9.8924 mg/g and an equilibrium adsorption time of 60 min at 25 °C. The resin denitrification pilot plant demonstrated stable operation for two months and achieved COD<20 mg/L, TN < 1.5 mg/L, and NH4+-N<0.5 mg/L. The removal rates of COD, TP, NH4+-N, NO3--N, and TN were 41.65%, 42.96%, 55.37%, 91.8%, and 90.81%, respectively. After the resin was regenerated, the removal rates of NO3--N, TN and the regeneration recovery rate were above 90%. Through cost analysis, the treatment cost of the pilot plant is only 0.104 $/m3. This study presents a practical, low-cost, and efficient treatment method for the deep treatment of secondary effluent from WWTP in practical engineering, providing new ideas and theoretical guidance.


Subject(s)
Ion Exchange Resins , Nitrates , Ion Exchange Resins/chemistry , Kinetics , Organic Chemicals , Thermodynamics , Nitrogen
3.
Anal Biochem ; 676: 115226, 2023 09 01.
Article in English | MEDLINE | ID: mdl-37422062

ABSTRACT

Ion exchange chromatography is a method that uses the different surface charges of trypanosomes and blood cells to separate them. This makes it possible to use molecular and immunological methods to diagnose or study these protozoans. DEAE-cellulose resin is commonly used to perform this method. The goal of this study was to compare three novel chromatographic resins designated as PURIFICA™ (Y-C2N®, Y-HONOH®, and Y-CNC3®). The resins were evaluated based on their ability to isolate the parasite, purification time, examination of parasite viability and morphology, and trypanosome recovery potential after passing through the columns. In terms of the evaluated parameters, there was no significant difference between DEAE-cellulose and the three tested resins in most experiments. However, PURIFICA™ (Y-C2N®, Y-HONOH®, and Y-CNC3®) resins are less expensive and easier to prepare than DEAE-Cellulose, making them an alternative for the purification of Trypanosoma evansi.


Subject(s)
Ion Exchange Resins , Trypanosoma , Chromatography, Ion Exchange/methods , DEAE-Cellulose/chemistry , Ion Exchange Resins/chemistry
4.
AAPS PharmSciTech ; 24(5): 132, 2023 Jun 08.
Article in English | MEDLINE | ID: mdl-37291437

ABSTRACT

Taste masking is critical to improving the compliance of pediatric oral dosage forms. However, it is challenging for extremely bitter lisdexamfetamine dimesylate (LDX) with a long half-life and given in large dose. The present study aims to develop an immediate-release, taste-masked lisdexamfetamine chewable tablet. Lisdexamfetamine-resin complexes (LRCs) were prepared using the batch method. The molecular mechanism of taste masking was explored by PXRD, PLM, STA, and FT-IR. The results showed that taste masking was attributed to the ionic interaction between drug and the resin. The ion exchange process conformed to first-order kinetics. The rate-limiting step of drug release was the diffusion of ions inside the particles, and the concentration of H+ was the key factor for immediate release. The masking efficiency of the prepared LRCs in saliva exceeded 96%, and the drug could be completely released within 15 min in aqueous HCl (pH 1.2). Furthermore, the SeDeM expert system was used for the first time to comprehensively study the powder properties of LRCs and to quickly visualize their defects (compressibility, lubricity/stability, and lubricity/dosage). The selection of excipients was targeted rather than traditional screening, thus obtaining a robust chewable tablet formulation suitable for direct compression. Finally, the difference between chewable tablets containing LRCs and chewable tablets containing lisdexamfetamine dimesylate was compared by in vitro dissolution test, electronic tongue, and disintegration test. In conclusion, an immediate-released, child-friendly lisdexamfetamine chewable tablets without bitterness was successfully developed by the QbD approach, using the SeDeM system, which may help in further development of chewable tablets.


Subject(s)
Lisdexamfetamine Dimesylate , Taste , Humans , Child , Ion Exchange Resins/chemistry , Excipients , Spectroscopy, Fourier Transform Infrared , Solubility , Tablets , Drug Compounding/methods , Administration, Oral
5.
AAPS PharmSciTech ; 24(5): 114, 2023 May 01.
Article in English | MEDLINE | ID: mdl-37127745

ABSTRACT

The purpose of this investigation was to formulate and evaluate the interaction between cation exchange resins and verapamil hydrochloride. The uptake studies were conducted using the rotating bottle apparatus. The Langmuir-like equation was applied to the experimental data and the maximum drug loading was determined from the Langmuir-like parameters. The drug-resin complexes were evaluated using XRD, SEM, and particle size analysis. Release studies were performed using USP dissolution apparatus 2. The resin with the lowest percentage of cross-linking had the highest uptake capacity. The percent increase in particle size due to complexation was found to be associated with drug loading; the highest drug loading had the highest increase in particle size. The X-ray diffraction patterns of the resins and the drug-resin complexes showed that they were both amorphous. The maximum drug release was approximately 40% when conventional dissolution testing was used. Results showed that sink conditions could not be maintained using conventional dissolution methods. Maximum drug release increased dramatically by increasing the volume of samples withdrawn and fresh dissolution medium added. Excellent correlation was obtained between sample volume and drug release rate with an R-value of 0.988. Particle diffusion-controlled model and film diffusion-controlled model were both applied to the experimental data. The results indicated that the rate-limiting step is the diffusion of the exchanging cations through the liquid film. The modified release formulation was prepared successfully and correlated very well with the USP monograph for verapamil hydrochloride extended release capsules.


Subject(s)
Ion Exchange Resins , Verapamil , Delayed-Action Preparations , Verapamil/chemistry , Ion Exchange Resins/chemistry , Drug Liberation , Cation Exchange Resins
6.
Article in English | MEDLINE | ID: mdl-35051681

ABSTRACT

Polyallylamine (PAA) has been utilized as a salt tolerant anion exchange chromatography ligand in downstream processing of biopharmaceuticals. We have developed novel MMC resins based on PAA polymer ligand partially modified with hydrophobic butyl or phenyl group. The resulting hydrophobic modified PAA ligand reduced HCP level to 12% (21-23 ppm) under 6 mS/cm in a flow-through polishing step of mAb, while not modified PAA ligand showed only 79% (145 ppm). We also found that structure of hydrophobic groups in the ligand mainly influenced on mAb yield. That is 25% increase of phenyl group modification ratio reduces mAb yield from 95% to 90%. On the other hand, modification with butyl group kept mAb yield more than 95%. The optimized ligand structure displayed a wide operational conductivity range. Extended purification studies of mAb using the MMC resin in the flow-through polishing step were carried out under optimized pH and conductivity condition as determined in a DOE study. The study revealed that the MMC resin was effective for developing one-step flow-through polishing workflow for mAb purification. In addition, the MMC flow-through polishing step could be directly coupled with a specified CEX chromatography step to efficiently remove mAb aggregates from 2.3% to <1.0% to achieve a biopharmaceutical-grade quality and a high yield of mAb (>93%) with a high loading capacity around 1000 mg/mL-resin. This new MMC resin will be useful in future mAb manufacturing platforms comprising of a robust and cost-effective flow-through polishing step.


Subject(s)
Antibodies, Monoclonal/isolation & purification , Chromatography, Ion Exchange/methods , Ion Exchange Resins/chemistry , Polyamines/chemistry , Animals , Antibodies, Monoclonal/chemistry , CHO Cells , Chromatography, Ion Exchange/instrumentation , Cricetinae , Cricetulus , Hydrophobic and Hydrophilic Interactions , Ligands
7.
Molecules ; 26(13)2021 Jun 26.
Article in English | MEDLINE | ID: mdl-34206735

ABSTRACT

The impact of key classes of compounds found in wine on protein removal by the ion-exchange resin, Macro-Prep® High S, was examined by adsorption isotherm experiments. A model wine system, which contained a prototypical protein Bovine Serum Albumin (BSA), was used. We systematically changed concentrations of individual chemical components to generate and compare adsorption isotherm plots and to quantify adsorption affinity or capacity parameters of Macro-Prep® High S ion-exchange resin. The pH (hydronium ion concentration), ethanol concentration, and prototypical phenolics and polysaccharide compounds are known to impact interactions with proteins and thus could alter the adsorption affinity and capacity of Macro-Prep® High S ion-exchange resin. At low equilibrium protein concentrations (< ~0.3 (g BSA)/L) and at high equilibrium protein concentrations in model wines at various pH, the adsorption behavior followed the Langmuir isotherm, most likely due to the resin acting as a monolayer adsorbent. The resulting range of BSA capacity was between 0.15-0.18 (g BSA)/(g Macro-Prep® High S resin). With the addition of ethanol, catechin, caffeic acid, and polysaccharides, the protein adsorption behavior was observed to differ at higher equilibrium protein concentrations (> ~0.3 (g BSA)/L), likely as a result of Macro-Prep® acting as an unrestricted multilayer adsorbent at these conditions. These data can be used to inform the design and scale-up of ion-exchange columns for removing proteins from wines.


Subject(s)
Ethanol/chemistry , Ion Exchange Resins/chemistry , Proteins/chemistry , Serum Albumin, Bovine/chemistry , Wine/analysis , Adsorption , Caffeic Acids/chemistry , Catechin/chemistry , Hydrogen-Ion Concentration , Kinetics , Models, Chemical , Phenols/analysis , Polysaccharides/chemistry , Solutions/analysis , Solutions/chemistry , Spectrophotometry , Water/chemistry
8.
J Chromatogr A ; 1644: 462121, 2021 May 10.
Article in English | MEDLINE | ID: mdl-33845425

ABSTRACT

In this study, we present results obtained on the enantioseparation of some cationic compounds of pharmaceutical relevance, namely tetrahydro-ß-carboline and 1,2,3,4-tetrahydroisoquinoline analogs. In high-performance liquid chromatography, chiral stationary phases (CSPs) based on strong cation exchanger were employed using mixtures of methanol and acetonitrile or tetrahydrofuran as mobile phase systems with organic salt additives. Through the variation of the applied chromatographic conditions, the focus has been placed on the study of retention and enantioselectivity characteristics as well as elution order. Retention behavior of the studied analytes could be described by the stoichiometric displacement model related to the counter-ion effect of ammonium salts as mobile phase additives. For the thermodynamic characterization parameters, such as changes in standard enthalpy Δ(ΔH°), entropy Δ(ΔS°), and free energy Δ(ΔG°), were calculated on the basis of van't Hoff plots derived from the ln α vs. 1/T curves. In all cases, enthalpy-driven enantioseparations were observed with a slight, but consistent dependence of the calculated thermodynamic parameters on the eluent composition. Elution sequences of the studied compounds were determined in all cases. They were found to be opposite on the enantiomeric stationary phases and they were not affected by either the temperature or the eluent composition.


Subject(s)
Carbolines/chemistry , Chromatography, High Pressure Liquid/methods , Ion Exchange Resins/chemistry , Tetrahydroisoquinolines/chemistry , Acetonitriles , Cations , Methanol , Stereoisomerism , Structure-Activity Relationship , Temperature
9.
Food Chem ; 340: 128100, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33059268

ABSTRACT

A strongly basic ion-exchange resin catalyst was reported to exhibit a high catalytic activity in transesterification to produce a bio-based surfactant, sugar ester under mild condition. However, the side-reactions to decompose the reactant and the product were found to occur. This study was aimed to improve the selectivity of sugar ester synthesis by newly focusing on the basicity of the resin. A weakly basic resin (Diaion WA20) with a lower mass transfer resistance suppressed the decompositions while maintaining synthesis rate. Controlling molar ratio of the reactants in the intraparticle reaction field also increased the reaction selectivity, 72.1% and product yield, 57.5%. Both values were drastically increased compared to the reported values with the strongly basic resin (selectivity 50.9%, yield 14.3%). This is the first knowledge to show a high catalytic activity of weakly basic resin. These results suggest that a more efficient continuous production process would be possible.


Subject(s)
Esters/chemistry , Fatty Acids/chemistry , Ion Exchange Resins/chemistry , Sugars/chemistry , Catalysis , Esterification
10.
Biomolecules ; 10(12)2020 11 26.
Article in English | MEDLINE | ID: mdl-33256040

ABSTRACT

In the present work, was investigated the separation and purification procedure of the biogenic 1,3-propanediol (1,3-PD), which is a well-known valuable compound in terms of bio-based plastic materials development. The biogenic 1,3-PD was obtained as a major metabolite through the glycerol fermentation by Klebsiella pneumoniae DSMZ 2026 and was subjected to separation and purification processes. A strong acidic ion exchange resin in H+ form was used for 1,3-PD purification from the aqueous solution previously obtained by broth flocculation. The eluent volume was investigated considering the removal of the secondary metabolites such as organic acids (acetic, citric, lactic, and succinic acids) and 2,3-butanediol (2,3-BD), and unconsumed glycerol. It was observed that a volume of 84 mL of ethanol 75% loaded with a flow rate of 7 mL/min completely remove the secondary metabolites from 10 mL of concentrated fermented broth, and pure biogenic 1,3-PD was recovered in 128 mL of the eluent.


Subject(s)
Fermentation , Glycerol/metabolism , Ion Exchange Resins/metabolism , Klebsiella pneumoniae/chemistry , Propylene Glycols/isolation & purification , Flocculation , Glycerol/chemistry , Hydrogen-Ion Concentration , Ion Exchange Resins/chemistry , Klebsiella pneumoniae/metabolism , Propylene Glycols/chemistry , Propylene Glycols/metabolism
11.
J Chromatogr A ; 1633: 461627, 2020 Dec 06.
Article in English | MEDLINE | ID: mdl-33128970

ABSTRACT

A Poly (3,4-ethylenedioxothiophene) (PEDOT)/UiO-66 composite was electrodeposited on an etched stainless-steel wire as head-space solid-phase microextraction (HS-SPME) coating. A robust, well controlled thickness, and uniform coating of metal organic framework composites can be realized by the electrodeposited strategy. The incorporated UiO-66 not only enhanced the uniformity and stability of the composite coating, but also effectively decreased the stacking phenomenon of PEDOT and improved its extraction efficiency, which was over 100 times higher than that of the PEDOT coating without UiO-66. The composite coating was used to enrich seven types of volatile organic compounds (VOCs) in ion-exchange resins, including methyl cyclohexane, benzene, toluene, ortho-xylene, styrene, para-xylene and divinyl-benzene. The results of adsorption isotherm analysis showed that π stacking effect played dominant role between the composite coating and VOCs in the extraction process. The composite coating was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared and thermogravimetric analysis, respectively. A determination method for seven kinds of VOCs was established by HS-SPME coupled with gas chromatography-flame ionization detection (GC-FID). Under the optimal experimental conditions, the detection linear range (LRs) was 0.09-100 ng mL-1, and the detection limit (LODs) was 0.03-0.06 ng mL-1 (S/N = 3). The method was applied for the migration detection of VOCs in four types of ion-exchange resin, which showed satisfactory recovery (84.5-117.2%).


Subject(s)
Chemistry Techniques, Analytical/methods , Metal-Organic Frameworks/chemistry , Organometallic Compounds/chemistry , Phthalic Acids/chemistry , Polymers/chemistry , Thiophenes/chemistry , Volatile Organic Compounds/isolation & purification , Adsorption , Benzene/analysis , Benzene/isolation & purification , Chromatography, Gas , Flame Ionization , Ion Exchange Resins/chemistry , Limit of Detection , Solid Phase Microextraction , Stainless Steel/chemistry , Toluene/analysis , Toluene/isolation & purification , Volatile Organic Compounds/analysis , Xylenes/analysis , Xylenes/isolation & purification
12.
Int J Mol Sci ; 21(21)2020 Oct 23.
Article in English | MEDLINE | ID: mdl-33114195

ABSTRACT

This study examines the mechanisms of adsorption of anthocyanins from model aqueous solutions at pH values of 3, 6, and 9 by ion-exchange resins making the main component of heterogeneous ion-exchange membranes. This is the first report demonstrating that the pH of the internal solution of a KU-2-8 aromatic cation-exchange resin is 2-3 units lower than the pH of the external bathing anthocyanin-containing solution, and the pH of the internal solution of some anion-exchange resins with an aromatic (AV-17-8, AV-17-2P) or aliphatic (EDE-10P) matrix is 2-4 units higher than the pH of the external solution. This pH shift is caused by the Donnan exclusion of hydroxyl ions (in the KU-2-8 resin) or protons (in the AV-17-8, AV-17-2P, and EDE-10P resins). The most significant pH shift is observed for the EDE-10P resin, which has the highest ion-exchange capacity causing the highest Donnan exclusion. Due to the pH shift, the electric charge of anthocyanin inside an ion-exchange resin differs from its charge in the external solution. At pH 6, the external solution contains uncharged anthocyanin molecules. However, in the AV-17-8 and AV-17-2P resins, the anthocyanins are present as singly charged anions, while in the EDE-10P resin, they are in the form of doubly charged anions. Due to the electrostatic interactions of these anions with the positively charged fixed groups of anion-exchange resins, the adsorption capacities of AV-17-8, AV-17-2P, and EDE-10P were higher than expected. It was established that the electrostatic interactions of anthocyanins with the charged fixed groups increase the adsorption capacity of the aromatic resin by a factor of 1.8-2.5 compared to the adsorption caused by the π-π (stacking) interactions. These results provide new insights into the fouling mechanism of ion-exchange materials by polyphenols; they can help develop strategies for membrane cleaning and for extracting anthocyanins from juices and wine using ion-exchange resins and membranes.


Subject(s)
Anthocyanins/chemistry , Ion Exchange Resins/chemistry , Adsorption , Anion Exchange Resins/chemistry , Cation Exchange Resins/chemistry , Hydrogen-Ion Concentration , Molecular Structure , Static Electricity
13.
Pak J Pharm Sci ; 33(2(Supplementary)): 795-803, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32863254

ABSTRACT

Cupric ions are hazardous to human beings and their removal from the body is very necessary. The blends of IRP69H (AMBERLITE IRP-69 [H+] RESIN), DC20H (DOWEX™ 20 [H+] Resin), DMSCH (DOWEX™ MARATHON™ MSC [H+] Resin) and Kappa Carrageenan (κ-) were utilized for the removal of ions of Cu2+ from the blood. They were subjected to docking studies which showed that there is no significant interaction with the blood albumin. IER dose of 0.5 mg/10mL of IRP69H/κ-, DMSCH/κ-, and DC20H/κ- was essential for the 2+ ion removal. At pH 5.4, optimal 2+ ions adsorption efficiency was attained. The adsorption capacities of 2+ were in the order of IRP69H/κ->DC20H/κ->DMSCH/κ-. While the data fitted well to Freundlich, Langmuir and Dubinin-Radushkevich. Pseudo-second order was followed for 2+ adsorption for DMSCH/κ- and DC20H/κ- while the pseudo-first order was demonstrated well for IRP69H/κ-.


Subject(s)
Carrageenan/chemistry , Copper/chemistry , Ion Exchange Resins/chemistry , Ions/chemistry , Adsorption , Adult , Humans , Hydrogen-Ion Concentration , Kinetics , Resins, Synthetic/chemistry , Thermodynamics , Water Pollutants, Chemical/chemistry , Water Purification/methods , Young Adult
14.
Anal Chem ; 92(20): 13641-13646, 2020 10 20.
Article in English | MEDLINE | ID: mdl-32955253

ABSTRACT

In this letter, the innate ability of nitric oxide (NO) to inhibit platelet activation/adhesion/thrombus formation is employed to improve the hemocompatibility and in vivo accuracy of an intravascular (IV) potentiometric PCO2 (partial pressure of carbon dioxide) sensor. The catheter-type sensor is fabricated by impregnating a segment of dual lumen silicone tubing with a proton ionophore, plasticizer, and lipophilic cation-exchanger. Subsequent filling of bicarbonate and strong buffer solutions and placement of Ag/AgCl reference electrode wires within each lumen, respectively, enables measurement of the membrane potential difference across the inner wall of the tube, with this potential changing as a function of the logarithm of sample PCO2. The dual lumen device is further encapsulated within a S-nitroso-N-acetyl-DL-penicillamine (SNAP)-doped silicone tube that releases physiological levels of NO. The NO releasing sensor exhibits near-Nernstian sensitivity toward PCO2 (slope = 59.31 ± 0.78 mV/decade) and low drift rates (<2 mV/24 h after initial equilibration). In vivo evaluation of the NO releasing sensors, performed in the arteries and veins of anesthetized pigs for 20 h, shows enhanced accuracy (vs non-NO releasing sensors) when benchmarked to measurements of discrete blood samples made with a commercial blood gas analyzer. The accurate, continuous monitoring of blood PCO2 levels achieved with this new IV NO releasing PCO2 sensor configuration could help better manage hospitalized patients in critical care units.


Subject(s)
Biocompatible Materials/chemistry , Carbon Dioxide/analysis , Nitric Oxide/metabolism , Potentiometry/methods , Animals , Blood Vessels/chemistry , Electrodes , Ion Exchange Resins/chemistry , Potentiometry/instrumentation , S-Nitroso-N-Acetylpenicillamine/chemistry , Silicones/chemistry , Swine
15.
Molecules ; 25(18)2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32942756

ABSTRACT

Efficient separation technologies are crucial to the environment and world economy. The challenge posed to scientists is how to engineer selectivity towards a targeted substrate, especially from multicomponent solutions. Polymer-supported reagents have gained a lot of attention in this context, as they eliminate a lot of inconveniences concerning widely used solvent extraction techniques. Nevertheless, the choice of an appropriate ligand for immobilization may be derived from the behavior of soluble compounds under solvent extraction conditions. Organophosphorus compounds play a significant role in separation science and technology. The features they possess, such as variable oxidation states, multivalence, asymmetry and metal-binding properties, highlight their status as a unique and versatile class of compounds, capable of selective separations proceeding through different mechanisms. This review provides a detailed survey of polymers containing phosphoric, phosphonic and phosphinic acid functionalities in the side chain and covers main advances in the preparation and application of these materials in separation science, including the most relevant synthesis routes (Arbuzov, Perkow, Mannich, Kabachnik-Fields reactions, etc.), as well as the main stages in the development of organophosphorus resins and the most important achievements in the field.


Subject(s)
Ion Exchange Resins/chemistry , Phosphinic Acids/chemistry , Phosphoric Acids/chemistry , Phosphorous Acids/chemistry , Polymers/chemistry , Chelating Agents/chemistry , Organophosphorus Compounds/chemistry
16.
Int J Biol Macromol ; 161: 561-572, 2020 Oct 15.
Article in English | MEDLINE | ID: mdl-32522537

ABSTRACT

A starch-based ion exchange resin (SIR) was synthesized by copolymerizing raw starch with sodium methallyl sulfonate and styrene. The structural and surface properties of the SIR were characterized by 13C nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, gel permeation chromatography, scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis, Brunauer-Emmett-Teller surface area analysis, and laser particle size analysis. The SIR was physicochemically and thermally stable and resistant to acids, bases, and enzymes. In static adsorption tests, the SIR had decolorization ratios (DRs) for mixed dyestuffs in wastewater of up to 84.04%, which was higher than the DR for a synthetic ion exchange resin (001 × 7, DR 77.14%). In dynamic adsorption tests, the SIR bed had a DR of 99.85% and a wastewater handling capacity 25 times the column volume. After three adsorption-regeneration cycles, the DR of the resin bed had decreased by <7.5%. The properties of the SIR, particularly the adaptability of the SIR to continuous column adsorption, make the SIR suitable for removing dyestuffs from industrial wastewater and a potential substitute for traditional sorbents such as activated carbon and synthetic resins.


Subject(s)
Ion Exchange Resins/chemistry , Resins, Synthetic/chemistry , Starch/chemistry , Sulfonic Acids/chemistry , Adsorption , Hydrogen-Ion Concentration , Ion Exchange , Kinetics , Microscopy, Electron, Scanning/methods , Spectroscopy, Fourier Transform Infrared/methods , Surface Properties , Wastewater/chemistry , Water Pollutants, Chemical/chemistry
17.
Biotechnol Prog ; 36(5): e3024, 2020 09.
Article in English | MEDLINE | ID: mdl-32410373

ABSTRACT

In this study, an ion exchange resin-based downstream-processing concept for imine reductase (IRED)-catalyzed reactions was investigated. As a model reaction, 2-methylpyrroline was converted to its corresponding product (S)-2-methylpyrrolidine with >99% of conversion by the (S)-selective IRED from Paenibacillus elgii B69. Under optimized reaction conditions full conversion was achieved using a substrate concentration of 150 and 500 mmol/L of d-glucose. Seven commercially available cation- and anion-exchange resins were studied with respect to their ability to recover the product from the reaction solution. Without any pretreatment, cation-exchange resins Amberlite IR-120(H), IRN-150, Dowex Monosphere 650C, and Dowex Marathon MSC showed high recovery capacities (up to >90%). A 150-ml preparative scale reaction was performed yielding ~1 g hydrochloride salt product with >99% purity. Any further purification steps, for example, by column chromatography or recrystallization, were not required.


Subject(s)
Imines , Ion Exchange Resins/chemistry , Oxidoreductases , Adsorption , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Chromatography, Ion Exchange , Gas Chromatography-Mass Spectrometry , Imines/chemistry , Imines/metabolism , Oxidoreductases/chemistry , Oxidoreductases/metabolism , Paenibacillus/enzymology , Polystyrenes/chemistry , Pyrrolidines/chemistry , Pyrrolidines/metabolism
18.
Proc Natl Acad Sci U S A ; 117(13): 7004-7010, 2020 03 31.
Article in English | MEDLINE | ID: mdl-32179691

ABSTRACT

Protein mobility at solid-liquid interfaces can affect the performance of applications such as bioseparations and biosensors by facilitating reorganization of adsorbed protein, accelerating molecular recognition, and informing the fundamentals of adsorption. In the case of ion-exchange chromatographic beads with small, tortuous pores, where the existence of surface diffusion is often not recognized, slow mass transfer can result in lower resin capacity utilization. We demonstrate that accounting for and exploiting protein surface diffusion can alleviate the mass-transfer limitations on multiple significant length scales. Although the surface diffusivity has previously been shown to correlate with ionic strength (IS) and binding affinity, we show that the dependence is solely on the binding affinity, irrespective of pH, IS, and resin ligand density. Different surface diffusivities give rise to different protein distributions within the resin, as characterized using confocal microscopy and small-angle neutron scattering (length scales of micrometer and nanometer, respectively). The binding dependence of surface diffusion inspired a protein-loading approach in which the binding affinity, and hence the surface diffusivity, is modulated by varying IS. Such gradient loading increased the protein uptake efficiency by up to 43%, corroborating the importance of protein surface diffusion in protein transport in ion-exchange chromatography.


Subject(s)
Ion Exchange Resins/chemistry , Models, Chemical , Proteins/chemistry , Diffusion
19.
Methods Mol Biol ; 2127: 129-137, 2020.
Article in English | MEDLINE | ID: mdl-32112319

ABSTRACT

Biochemical, biophysical, and structural studies of membrane proteins rely on the availability of highly pure and monodisperse membrane protein samples. One of the most powerful methods for isolation of the membrane protein of interest is affinity purification. This methodology typically relies on engineering an affinity tag into the protein of interest and an affinity resin that specifically recognizes the tag, allowing one to purify the target protein in a single step. In some cases, the affinity purification procedure is combined with additional steps to increase the purity and homogeneity of the final protein sample. Here, we describe several protocols for affinity purification of TSPO, a small membrane protein. The techniques we use include immobilized metal affinity chromatography (IMAC) and strep-II tag-based streptavidin affinity chromatography.


Subject(s)
Chromatography, Affinity/methods , Membrane Proteins/isolation & purification , Recombinant Proteins/isolation & purification , Affinity Labels/chemistry , Amino Acid Sequence , Animals , Detergents/chemistry , Detergents/pharmacology , Escherichia coli , Eukaryotic Cells , Histidine/chemistry , Humans , Insecta , Ion Exchange Resins/chemistry , Membrane Proteins/chemistry , Membrane Proteins/genetics , Membrane Proteins/metabolism , Oligopeptides/chemistry , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/isolation & purification , Recombinant Fusion Proteins/metabolism , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Solubility/drug effects , Streptavidin/chemistry
20.
Chemosphere ; 244: 125589, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32050353

ABSTRACT

Radioactive Cs ions are extremely harmful to the human body, causing cancers and other diseases. Treatments were performed on radioactive Cs present in wastewater after use in industrial or medical fields. Prussian blue (PB) has been widely used for the removal of Cs ions from water but its colloidal structure hinders reuse, making it problematic for practical use. To solve this problem, we used a commercial macroporous polymer resin as a PB matrix. To provide an efficient anchor for PB, the surface of the polymer resin was decorated with sodium dodecylbenzenesulfonate to produce a negatively charged surface. The successful chemical binding between the polymer resin and PB prevented leakage of the latter during adsorption and crosslinked structure of the matrix provided regeneration of the adsorbent. The adsorbent maintained its removal efficiency after five repeats of the regeneration process. The PB-based, Cs ion-exchange resin showed excellent selectivity toward Cs ions and good reusability, maintaining its high adsorption capacity.


Subject(s)
Benzenesulfonates/chemistry , Cesium/chemistry , Ferrocyanides/chemistry , Ion Exchange Resins/chemistry , Water Pollutants, Chemical/chemistry , Adsorption , Humans , Wastewater/chemistry , Water Purification
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