Ion-exchange Separation Research Articles

Upregulation of BRCA1 and 2 protein expression is associated with dysregulation in amino acids profiles in breast cancer

BackgroundThe prevalence of breast cancer (BC) is high among cancers in Egypt, ranking it the most common cause of cancer mortality in women. BRCA1 and BRCA2 tumor suppressors proteins have a specific relationship with BC. Plasma free amino acids levels (PFAAs) have been reported to exhibit altered profiles among cancer patients. Thus, the present study aims to examine the alteration of the PFAAs profiles and investigate their association with BRCA1 and 2 circulating levels in Egyptian females diagnosed with BC and in females with family history of BC to establish potential early detection strategies for BC.Methods and resultsThis study included 26 BC patients, 22 females with family history of BC (relatives) in addition to 38 healthy females as control group. Quantitative measurement of PFAAs was determined by the ion exchange separation method through high performance liquid chromatography. BRCA1 and BRCA2 concentrations were determined using ELISA. Our results showed PFAAs profiles in BC patients and in females with BC family history with significant upregulation in mean plasma levels of Alanine, Phenylalanine, Glutamate and Cysteine and downregulation of Taurine, Threonine, Serine, Glycine, Valine, Methionine and Histidine levels compared to controls. Also, a significant positive correlation was observed between plasma BRCA1 and Valine levels while a significant negative correlation was observed between BRCA2 and Lysine plasma levels.ConclusionPFAAs profile can potentially be used in early screening for BC patients and for susceptible females.

Exploring Strategies for Copper Removal from Nickel Anolytes: A Review

Various methods, such as electrochemical purification, chemical precipitation, solvent extraction, and ion-exchange resins, have been extensively employed for the removal of copper from nickel anolytes. However, these methods exhibit several significant drawbacks when applied in industrial settings. For instance, electrochemical purification fails to efficiently manage nickel anolyte solutions with low copper content. Chemical precipitation presents challenges in residue management and incurs high production costs for precipitants. Solvent extraction raises concerns related to toxicity, while the use of ion-exchange resins demands meticulous selection of suitable materials. In this review, we present a comprehensive review of the nickel removal methods used for nickel anolyte purification, electrochemical purification, chemical precipitation, solvent extraction, and ion-exchange resins. We also examine the suitability and benefits of each technique in industrial settings. The ion-exchange method has drawn significant attention due to its strong selectivity and small adsorption quantity. The ion-exchange separation process does not generate any slag, and the ion-exchange resin can be recycled and reused; this method has great potential in a wide range of applications.

Promising method of ion exchange separation of anions before reverse osmosis

Promising method of ion exchange separation of anions before reverse osmosis

Analysis of iron-rich hydrochloric acid solutions for uranium, thorium, rare-earth elements and other heavy metals

A simple solvent extraction method is described for the separation of trace elements including uranium (U), thorium (Th) and rare-earth elements (REEs) from industrially processed iron-rich hydrochloric acid solutions. Iron (Fe) causes severe spectral interference during the analysis of trace elements using inductively coupled plasma optical emission spectrometer (ICP-OES) and U by light-emitting diode (LED)-based fluorimeter (LEDF). The spectral interferences of Fe on trace elements are studied and documented. Sequential solvent extractions using methyl isobutyl ketone (MIBK) effectively removed the highly interfering Fe from these processed acid solutions, thereby enabling accurate and sensitive determination of Cd, Zn, Pb, Co, Ni, Cr, V, Cu, Sr, Zr, Ti, REEs including radioactive elements like U and Th. Solvent extraction parameters like the number of extractions, aqueous-organic ratio and acidity have been optimized for removal of Fe. The accuracy of the method has been established by analyzing synthetically prepared hydrochloric acid solutions by spiking-recovery method. Ion exchange separation of REEs using Dowex 50 × 8 cation exchange resin has been also studied and reported. The precision obtained has been well within ± 10% RSD for elements having concentration above 10 mg L−1 and ± 15% for elements having concentration below 10 mg L−1 for replicate (n = 5) measurements.

Seasonal Changes in Qualitative and Quantitative Characteristics of Humic Substances in Waters of Different Genesis: Membrane Technologies and Equilibrium Processes

Membrane filtration methods were applied in this study to research natural waters specification (and speciation). Lysimetric waters (soil waters) of background territories in different seasons are considered. Features of the change in molecular weights, elemental composition, and zeta potential of organic matter during fractionation from 8 μm to 100 kDa were found. The number of labile and non-labile speciation of some elements obtained by membrane filtration and ion-exchange separation methods were found and compared. The highest molecular weights of organic substances were found in summer samples of lysimetric waters (more than 100 kDa) with a predominance of the aromatic component in the IR spectra of the samples. Several maxima were also found in the molecular weight distribution, including the increase in autochthonous organic substances. The most stable negative zeta potential, as a stabilized colloid matter, are represented in summer (near -26 mV) and in autumn (near -22 mV) lysimetric water. A slight increase in metal ions bound into organic complexes is typical for summer and autumn samples.

Sugary solutions

Sugary solutions

Recovery of Calcium from Reaction Fly Ash

Reaction fly ash contains a large number of harmful substances, so it is usually solidified and buried in landfills. To improve the problem of insufficient landfill space, this study recovers CaOH from reaction fly ash to achieve mass and volume reduction. The leachate obtained by leaching the reaction fly ash with de-ionized water and 2N hydrochloric acid was used in the experiments, respectively. The volume reduction with 2N hydrochloric acid had better performance than de-ionized water, representing more than 90%. The leaching efficiency of Ca reached 21.06% with de-ionized water for 20 min at a condition of 25 °C and 7 mL/g pump density. The chemical precipitation with NaOH was conducted immediately after the completion of the leaching experiment, with a precipitation efficiency of CaOH reaching 98.55%. The leaching efficiency of Ca reached 70.26% with 2N hydrochloric acid for 30 min at a condition of 25 °C and 10 mL/g pump density. The chemical precipitation with NaOH and ion exchange with IRC748 were conducted, respectively, after the completion of the leaching experiment. After two precipitations, the precipitation efficiency of CaOH was 99.93%. The precipitation efficiency and purity of Ca after ion exchange separation were 99.90% and 98.91%, respectively. This work provided an effective approach to recover CaOH from reaction fly ash and accomplished volume reduction at the same time.

Stripping of hafnium and zirconium from chelating ion-exchange resin

Separation of hafnium from zirconium on Diphonix® resin is very successful. However, the chemical affinity of these elements to the Diphonix® resin is very strong. Therefore, the aim of the present study was to develop a method that would permit the desorption of these metals and the regeneration of the resin. For this purpose, solutions of various ligands such as citrate, oxalate, EDTA, tiron, and carbonate were examined. The lowest weight distribution coefficients of hafnium and zirconium on Diphonix® resin were obtained using a 0.25 M ammonium oxalate solution. Its use gave satisfying results with a very good level of the metals recovery in dynamic studies. Due to difficulties in the processing of the obtained zirconium(IV) (hafnium(IV)) oxalate into zirconium(IV) (hafnium(IV)) sulfate, some modification of the stripping method was proposed. The elution of the studied elements by ammonium oxalate solution was preceded by elution with 2 M sulfuric acid. It permitted the removal of 70% of the adsorbed zirconium(IV) as a sulfate solution, ready for returning into the Zr and Hf ion-exchange separation process.

Application of Ultrafiltration and Ion Exchange Separation Technology for Lysozyme Separation and Extraction

In this study, the fermentation broth of the recombinant Pichia pastoris strain ncy-2 was studied. After pretreatment, separation, and purification, lysozyme was optimized using biofilm and ion exchange separation. Finally, lysozyme dry enzyme powder was prepared by concentrating and vacuum drying. The removal rate of bacterial cells was 99.99% when the fermentation broth was centrifuged at low temperature. The optimum conditions were: transmembrane pressure of 0.20 MPa, pH 6.5, 96.6% yield of lysozyme, enzyme activity of 2612.1 u/mg, which was 1.78 times higher than that of the original enzyme; D152 resin was used for adsorption and elution. Process conditions were optimized: the volume ratio of resin to liquid was 15%; the adsorption time was 4 h; the concentration of NaCl was 1.0 mol/L; the recovery rate of lysozyme activity was 95.67%; the enzyme activity was 3879.6 u/mL; and the purification multiple was 0.5, 3.1 times of the original enzyme activity. The enzyme activity of lysozyme dry enzyme powder was 12,573.6 u/mg, which had an inhibitory effect on microsphere lysozyme. Its enzymatic properties were almost the same as those of natural lysozyme, which demonstrated good application prospects and production potential.

Binary separation control in preparative gradient chromatography using iterative learning control

Purification of biopharmaceuticals has shifted toward continuous and integrated processes, in turn bringing along a need for monitoring and control to maintain a desired separation between the target pharmaceutical and any impurities it may carry. In this study, a cycle-to-cycle control of the retention volumes of two compounds in a chromatographic, ion exchange purification step was developed, allowing the process to maintain the desired retention volumes in the separation. The controller made use of a model-based, multivariate iterative learning control (ILC) algorithm that used a quadratic-criterion objective function for optimal set point control, along with feed-forward control based on direct model inversion for preemptive control of set point changes. The model was calibrated using 3 experiments, allowing for fast setup. The controller was tested by introducing three different disturbances to a sequence of otherwise identical ion exchange separation processes: a change in the salt concentration of the elution buffer, a change in set point, and a change in the pH of the elution buffer. It was capable of correcting for all disturbances within at most 3 cycles, proving its efficacy. The successful application of ILC for separation control in biopharmaceutical purification paves the way for the development of further ILC-based control strategies within the field, as well as combination with other control strategies.

Volumetric Scale-Up of a Packed-Bed Ion-Exchange System to Extract Phytate from Thin Stillage.

Phytate is the main form of phosphorus in corn ethanol coproducts and poses digestion issues in monogastric-animal feed. Extracting phytate as a commodity chemical will bring extra revenue to the corn ethanol industry and reduces potential phosphorus pollution from livestock waste management. We assessed a simplified scale-up approach of an ion-exchange separation system applied to extract phytate from thin stillage using volumetric parameters and simplifications of the van Deemter model. Thin stillage is one of the main byproducts generated on dry-grind corn-to-ethanol plants and accounts for the liquid portion of the bottom product generated in the ethanol distillation process. Thin stillage is rich in dissolved phytate, which served as the basis for an ion-exchange extraction system developed with a scalability factor of 50. Under the evaluated conditions, similar breakthrough profiles were obtained when similar Péclet and Stanton numbers were maintained for the scales studied, demonstrating that a simple and straightforward scale-up can be attained if special attention is given to maintaining both parameters as the basis of calculations of the plate numbers of ion-exchange columns.

MRNA Purification: Technology Aspects and Impurities TFF, Chromatography, UF/DF (Resins, Magnetic Beads, Monoliths)

m RNA VACCINE production like other biopharmaceutical need various purification stages in the manifacturing process. In this process are used techniques like: (TFF) tangential flow filtration followed by different chromatographic procedure (affinity and ion exchange separation) with various kinds of resin and then UF/DF technique (Ultrafiltration-diafiltration). So it is of interest to verify that the materials used for this kind of procedure is solid phases or for the membrane and if released impurity in the final product. For Silica-based Reversed-Phase packing’s, a carbon load percentage indicates the amount of functional bonded phase attached to the Silica-base material. Aim of this work is to investigate the role played by these characteristics in the separation process of mRNA. Because this parameter influence the retention time it is interesting to evaluate the use in separation technique of biopharmaceuticals and this also is for the carbon coated silica columns. Silica gel for chromatography can be produced by systemic process but also form Rice treated at high temperature. What kind of effect can be played using an high level of carbon coated silica material on the final purified product? The graphitic particle can be found as impurity during the manufacturing process of these resins? And what is the role played by carbon (graphene-quantum dots) membrane as reported in various research application?

The role of pH in the separation of Lu and Yb by ion-exchange explained by novel chemical structures of lanthanide complexes

The individual separation of lanthanides is very complex due to the similarities between these elements. Ion-exchange separations with carboxylic acids are widely studied, but the importance of pH is overlooked. This study used citric acid to evaluate Lu and Yb separation with Dowex 50W-X8. The separation was monitored by X-ray fluorescence. Five new structures of Lu and Yb citrates are proposed. Better separation occurs when the pH of the ligand is pH 4.5, where a mononuclear structure is formed. Conversely, polynuclear structures are formed at higher pH, and separation fails. X-ray diffraction reveals different phases at each pH value, and FTIR results support the proposed structures.

Thorium ion exchange separation from rare earth elements ore samples following a combined attrition and dissolution procedure

Autogenous grinding (without grinding media) may provide some advantages if satisfactory lixiviation efficiency can be achieved on larger grain sizes. This grinding strategy requires less energy and offers important cost savings and reduction of GHG emissions in the mining industry compared to other commonly used approaches. Two attrition cells (1.2 L, 12 L) were designed to conduct a wet autogenous grinding. The combined grinding and leaching experiments were performed using six Canadian rare earth elements (REEs) ore samples to solubilize the REEs while grinding the ore in a modified attrition mill. Sulfuric, hydrochloric and nitric acids were compared under various operating conditions on three different types of ore samples (carbonatite, sedimentary, peralkaline). The addition of an alkaline step was also investigated. Metals dissolution in the 1.2 L attrition mill with or without NaOH addition (T = 20 °C, solid/liquid ratio = 20%, acid concentration [HNO3] = 7.5 M, time = 1 h) was found effective for the carbonatite ore (solubilization efficiencies of 91–99% Th, 29–32% U, 85–91% LREEs, 84–94% HREEs) and the sedimentary ore (solubilization efficiencies of 89–99% Th, 98–99% U, 22–83% LREEs, 48–99% HREEs). Actinide elements often comprise a significant component in REEs ore samples and are considered impurities. Their presence in primary REE mineral resources is problematic from a regulatory and health physics perspective. To overcome these issues, anionic, cationic and chelating resins were tested to remove Th from the nitric leaching liquor. Best separation results were obtained with the impregnated resin Lewatit VPOC 1026. To the best of our knowledge, this is the first time that Lewatit VPOC 1026 was reported in the literature for Th separation from REEs.

Mining value from waste: Scandium and rare earth elements selective recovery from coal fly ash leach solutions

Global demand for rare earth elements (REEs) has been on the rise due to recent rapid technological advancements. Even though most REEs are mainly recovered from rich ores and mineral deposits, recovery of REEs from secondary sources has attracted attention. However, low metal concentration, complex matrices and high levels of other impurities in mine wastes and tailings have remained the toughest challenges to overcome. The presence of low amount of valuable metals such as Sc requires utilization of very selective separation techniques such as ion exchange. A series of ion exchange resins (chelating, solvent impregnated and strongly acidic) were studied in the recovery of Sc from synthetic and actual pregnant leach solutions obtained from acid-leaching of coal fly ash. To the best of our knowledge, this paper exhibits the first attempt in selective recovery (from other REEs as well as major Fe and Al contaminations) of Sc in coal fly ash using ion exchange separation technique. With maximum capacity of ∼24 mg Sc/g resin, Sc was adsorbed quickly on phosphorus containing Lewatit® VP OC 1026 and TP 272 resins even in the presence of high levels of potentially interfering Fe3+ and Al3+ ions. Full elution of the adsorbed REEs from VP OC 1026 was achieved with 5 M H2SO4, with only minor Sc removal. While elution of Sc from these chelating resins has been reported to be challenging, Sc could be eluted almost completely with 2 M NH4F. Recovery of REEs with 5 M H2SO4 from TP 272 resulted in co-elution of only 7% of the adsorbed Sc while the rest could be eluted efficiently with 6 M HNO3.

Low-pressure chromatographic separation and UV/Vis spectrophotometric characterization of the native and desialylated human apo-transferrin

Low-pressure pH gradient ion exchange separation provides a fast, simple and cost-effective method for preparative purification of native and desialylated apo-transferrin. The method enables easy monitoring of the extent of the desialylation reaction and also the efficient separation and purification of protein fractions after desialylation. The N-glycan analysis shows that the modified desialylation protocol successfully reduces the content of the sialylated fractions relative to the native apo-transferrin. In the optimized protocol, the desialylation capacity is increased by 150 %, compared to the original protocol provided by the manufacturer. The molar absorption coefficients in the near-UV region for the native and desialylated apo-transferrin differ by several percent, suggesting a subtle dependence of the glycoprotein absorbance on the variable sialic acid content. The method can easily be modified for other glycoproteins and is particularly appropriate for quick testing of sialic acid content in the protein glycosylation patterns prior to further verification by mass spectrometry.

Hydrothermal Synthesis and Characterization of Zeolite A from Corn (Zea Mays) Stover Ash.

This study deals with the impact of calcination, alkalinity, and curing time parameters on the hydrothermal synthesis of zeolite A. The zeolite A sample, produced from corncob-stalk-and-leaves (corn stover) ash was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that calcination, alkalinity, and curing time have significant effects on the crystallization and the morphology of zeolite A. In addition, these parameters also impacted the cation exchange capacity. Furthermore, the synthesized zeolite A was obtained using a calcination temperature of 500 °C within two hours of airflow, which is much lower than the temperatures previously reported in the literature for an agricultural waste and other waste materials. A fusion ratio of corn stover ash:NaOH of 1.0:1.5 and a curing time of nine hours were achieved. This is a major result as this curing time is much lower than those featured in other studies, which can reach up to twenty-four hours. In this paper, cubic crystal with rounded edge of zeolite A, having a cation exchange capacity of 2.439 meq Na+/g of synthesized anhydrous zeolite A, was obtained, which can be a good candidate for ion-exchange separation.

Selective separation of neptunium on macroporous bifunctional anion exchange resin aided by redox speciation

Pyridinium and methyl ammonium based macroporous bifunctional anion exchange resin was synthesized from commercially available resin, Reillex™ 402 and investigated for selective extraction of neptunium(IV) from nitric acid medium. Acid stability of the resin was found to be satisfactory. Due to the possibility of existence as multiple oxidation states of Np, UV–Vis spectrophotometry and electrochemical methods were used to probe the redox speciation and warrant ion exchange separation of Np(IV). Ferrous sulphamate was used for simultaneous reduction of Np(V), (VI) and Pu(IV) to (IV) and (III), respectively. Batch sorption studies revealed fast kinetics (1 h.) of uptake having KD,NP(IV) of 425 at 4 M and capacity of 42 mg g−1. Stripping with ascorbic acid yielded quantitative results. Simultaneous determination of Np and Pu was standardized by electrochemical method. Selective separation of Np(IV) by column operation was carried out successfully for a mixture of (Np + Pu) and also (Np + Pu + U) corresponding to waste stream.

Application of Ion Exchange and Adsorption Techniques for Separation of Whey Proteins from Bovine Milk

Background:The world production of whey was estimated to be more than 200 million tons per year. Although whey is an important source of proteins with high nutritional value and biotechnological importance, it is still considered as a by-product of the dairy industry with low economic value due to low industrial exploitation. There are several challenges in the separation of whey proteins: low concentration, the complexity of the material and similar properties (pI, molecular mass) of some proteins.Methods:A narrative review of all the relevant papers on the present methodologies based on ion-exchange and adsorption principles for isolation of whey proteins, known to the authors, was conducted.Results:Traditional ion-exchange techniques are widely used for the separation and purification of the bovine whey proteins. These methodologies, based on the anion or cation chromatographic procedures, as well as combination of aforementioned techniques are still preferential methods for the isolation of the whey proteins on the laboratory scale. However, more recent research on ion exchange membranes for this purpose has been introduced, with promising potential to be applied on the pilot industrial scale. Newly developed methodologies based either on the ion-exchange separation (for example: simulated moving bed chromatography, expanded bed adsorption, magnetic ion exchangers, etc.) or adsorption (for example: adsorption on hydroxyapatite or activated carbon, or molecular imprinting) are promising approaches for scaling up of the whey proteins’ purification processes.Conclusion:Many procedures based on ion exchange are successfully implemented for separation and purification of whey proteins, providing protein preparations of moderate-to-high yield and satisfactory purity. However, the authors anticipate further development of adsorption-based methodologies for separation of whey proteins by targeting the differences in proteins’ structures rather than targeting the differences in molecular masses and pI. The complex composite multilayered matrices, including also inorganic components, are promising materials for simultaneous exploiting of the differences in the masses, pI and structures of whey proteins for the separation.

Titanium isotope fractionation in solar system materials

New methods to determine the titanium (Ti) mass-dependent isotope fractionation of solar system materials to high precision were developed by combining internally normalised Ti isotope data with double-spike analyses utilising a 47Ti-49Ti double spike. The procedure includes a three-stage ion-exchange separation procedure to isolate Ti from the sample matrix that provides high-purity Ti fractions that are necessary for high-precision Ti isotope analyses. Analyses of sample aliquots that were spiked before and after the ion-exchange separation procedure demonstrate that Ti isotope fractionation can be induced by the separation procedure. This outcome requires the addition of the double spike before the ion exchange separation procedure in order to accurately determine the natural mass-dependent Ti isotope fractionation of samples. Multiple double spike analyses of an Alfa Aesar Ti standard performed over eight months yielded a reproducibility (2σ standard deviation) of 0.033‰ for δ49/47Ti (differences in 49Ti/47Ti relative to the OL-Ti standard). Terrestrial sample analyses display a 2σ reproducibility of 0.018 to 0.031‰ for δ49/47Ti. Titanium isotope results for three terrestrial USGS magmatic reference samples (AGV-2, BHVO-2 and BCR-2) agree well with literature data and therefore demonstrate the accuracy and precision of the presented methodologies. Achondritic meteorites display an overall range of 0.75‰ for δ49/47Ti. The ungrouped achondrite NWA 7325 has a more positive composition by 0.64‰ for δ49/47Ti compared to all other investigated samples likely reflecting Ti isotope fractionation induced by magmatic differentiation associated with highly reducing conditions and potentially associated with oxide and plagioclase formation. In contrast, eucrites with δ49/47Ti of -0.020 ± 0.070 and -0.003 ± 0.033 and the first mass-dependent Ti isotope data for an acapulcoite (Dhofar 125; δ49/47Ti = 0.094 ± 0.033) show only limited magmatic Ti isotope fractionation. Chondrites also display a relatively restricted range of 0.085‰ for δ49/47Ti, including one calcium‑aluminum rich inclusion (CAI) from Allende and the first mass-dependent Ti isotope data for two Rumuruti chondrites (NWA 753 and NWA 755). Furthermore, the mass-dependent Ti isotope composition of chondrites overlaps with that of eucrites and the acapulcoite Dhofar 125 indicating that nebular processes induce only limited Ti isotope fractionation. Additionally, the Ti isotope data indicate that thermal metamorphism also produced marginal Ti isotope fractionation at the bulk sample scale for chondrites. Small mass-dependent Ti isotope variations between different bulk meteorite samples are also evident, which might reflect sample heterogeneity. Importantly, the mass-dependent Ti isotope composition of the Earth and Moon overlap with the composition of the investigated chondrites, eucrites and acapulcoites within the 2 standard deviation uncertainties.