Elution Agent Research Articles

Bio-analytical Methodology for Exploring Ripretinib’s Pharmacokinetic Profile in Rat Plasma Employing Bosutinib as an Internal Standard Utilizing LC-MS/MS

A robust, consistent, straightforward, swift, and precise liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was tailored for the bioanalytical analysis of ripretinib, with bosutinib serving as the comparative standard. This article provides a synopsis of recent developments in bioanalytical LC-MS/MS techniques utilizing a phenyl column (150x4.6 mm, 3.5 μ) and an eluting agent composed of ammonium formate at a pH of 2.5, which was altered in a 50:50 ratio with formic acid and acetonitrile. The chromatogram was utilized to analyse ripretinib, and the MS detector was equipped with electrospray ionization (ESI) method functioning in positive ionization conditions with multiple reactions monitoring (MRM). This allowed for the recording of transition m/z values of 531.4465→170.9638 for ripretinib and 511.4230 → 160.7133 for BTB. In the chromatographic analysis, ripretinib was retained for approximately 2.433 minutes, whereas BTB was retained for around 3.608 minutes. The validity of the approach extends across a linearity scale of 5 to 100 ng/mL for ripretinib, boasting a correlation index of 0.9999. In the realm of biological matrices, the extraction procedure employing the protein precipitation technique yields recovery rates of 99.6, 99.2, and 98% at the lower, middle, and higher quality control levels, respectively. The obtained results for accuracy, precision, matrix effect, and stability were determined to be within the acceptable range. To observe the investigated analyte in bodily fluids, pharmacokinetic studies yielded key parameters, including a half-life of 10 hours and a time to reach a maximum drug level of 4 hours. This thorough assessment affirms that the method satisfies rigorous criteria for system suitability and specificity well within predefined acceptance limits. Such performance positions it as an indispensable asset in the realm of bioanalysis, significantly broadening its clinical applicability.

Innovative Sol-gel functionalized polyurethane foam for sustainable water purification and analytical advances.

Nanomaterial combined polymeric membranes such as polyurethane foams (PUFs) have garnered enormous attention in the field of water purification due to their ease of management and surface modification, cost-effectiveness, and mechanical, chemical, and thermal properties. Thus, this study reports the use of novel Sol-gel impregnated polyurethane foams (Sol-gel/PUFs) as new dispersive solid phase microextractors (d- µ SPME) for the efficient separation and subsequent spectrophotometric detection of Eosin Y (EY) textile dye in an aqueous solution with a pH of 3-3.8. The Sol gel, PUFs, and Sol gel-impregnated PUFs were characterized using scanning electron microscopy (SEM), goniometry measurements, dynamic light scattering (DLS), energy dispersive spectroscopy (EDS), UV-Visible, and FTIR spectra. Batch experiment results displayed a remarkable removal percentage (96% ± 5.4%) of the EY from the aqueous solution, with the total sorption time not exceeding 60min. These data indicate rate-limited sorption via diffusion and/or surface complex ion associate formations after the rapid initial sorption steps. A pseudo-second order kinetic model thoroughly explained the sorption kinetics, providing a sorption capacity (qe) of 37.64mgg-1, a half-life time (t1/2) of 0.8 ± 0.01min, and intrinsic penetration control dye retention. The thermodynamic results revealed a negative value for ΔG⁰ (-78.07kJmol-1 at 293K), clearly signifying that the dye uptake was spontaneous, as well as a negative value for ΔH⁰ (-69.58kJmol-1) and a positive value for ΔS⁰ (147.65Jmol-1 K-1), making clear the exothermic nature of EY adsorption onto the sorbent, with a growth in randomness at the molecular level. A ternary retention mechanism is proposed, involving the "weak base anion exchanger" of {(-CH2-OH+ -CH2-) (Dye anion)-}Sol-gel/PUF and/or {(-NH2 + -COO-) (Dye anion)-}Sol-gel/PUF via solvent extraction and "surface adsorption" of the dye anion on/in the Sol-gel/PUFs membranes in addition to H-bonding, including surface complexation and electrostatic π-π interaction, between the dye and the silicon/zirconium oxide (Si-O-Zr) and siloxane (Si-O-Si) groups on the sorbent. Complete extraction and recovery (93.65 ± 0.2, -102.28 ± 2.01) of EY dye with NaOH (0.5M) as a proper eluting agent was achieved using a sorbent-packed mini column. In addition, the established extractor displayed excellent reusability and does not require organic solvents for EY enrichment in water samples, making it a talented nominee as a novel sorbent for EY sorption from wastewater. This study is of great consequence for expanding the applicatio1n of Sol-gel/PUFs in developing innovative spectrophotometric sensing strategies for dye determination. In view of this, it would also be remarkable to perform future studies to explore the analytical implications of this extractor regarding safety and environmental and public health issues associated to the pollutant.

Elution of Divalent Cations from Iron Ore Mining Waste in an Indirect Aqueous Mineral Carbonation for Carbon Capture and Storage

Mining waste is generated in vast quantities globally, which can have negative environmental consequences. This study highlights the utilization of iron ore mining waste as feedstock material in the preparatory step of an indirect aqueous mineral carbonation for carbon sequestration. The role of reactive cations (Ca2+, Mg2+, and Fe2+) was investigated in view of their elution behavior to improve carbonation efficiency. An elution experiment was carried out for the divalent cations using different acids (oxalic, HCl, acetic, and formic acid) at different concentration solutions (up to 1.5 M) and times (up to 100 min) at ambient temperature. The initial analysis confirmed the presence of divalent cations in the sample. The elution approach at ambient temperature resulted in the elution efficiency of Fe2+ (30.4%), Mg2+ (54%) using oxalic acid, and Ca2+ (98%) using HCl at a relatively short time between 50 and 100 min. It was found that for the iron ore mining waste, oxalic acid and HCl were best suited as elution agents for the Fe2+ and Mg2+, and Ca2+, respectively. The CO2 sequestration potential was calculated to be 131.58 g CO2/kg residue. A further carbonation step using a complexing agent (1,10 phenanthroline) confirmed the formation of siderite and magnesite along with phenanthroline hydrates. Findings have shown that the indirect mineral carbonation of the iron mining waste with complexing agent might improve carbonation efficiency, thus indicating that this material is useful for long-term carbon capture and storage applications.

Sequential separation of uranium and plutonium in urine sample using UTEVA resin

This article describes the process of separating uranium (U) and plutonium (Pu) sequentially in urine samples through the use of UTEVA resin. The manuscript optimizes several parameters, including the concentration of nitric acid in the loading solution, the repeatability of results across the multiple uses of the column, and most significantly, implementation of distinctive eluting agents. These eluting agents encompass a combination of 0.002M sulfamic acid and 0.002M ascorbic acid in 2M HNO3, as well as 1.5M NH2OH, HCl (hydroxylamine hydrochloride) in 2M HCl, all aimed at enhancing recovery percentages. The selection of 0.002M sulfamic acid and 0.002M ascorbic acid in 2M HNO3 have been observed to be exceptionally effective in achieving higher radiochemical recoveries. The standardized methodology presented here is characterized by its swiftness and robustness, particularly when compared to the traditional ion exchange method and numerous other published works related to extraction chromatography materials. Radiochemical recoveries for spiked urine samples of 232U and 242Pu consistently fall within the range of 93%–100% and 71%–96%, demonstrating an average recovery percentage with a standard deviation of 96.2% ±2.4% and 82.4% ±10.1%, respectively.

Hybrid membrane distillation and ion exchange process for resources recovery from mining wastewater

This work aims to achieve a process intensification through the hybridization of direct contact membrane distillation (DCMD) and ion exchange (IX) to increase resource recovery (water, H2SO4, Copper (Cu), Nickel (Ni), and Cobalt (Co)) from a gold mining wastewater. An increase in maximum recovery rate was achieved by the DCMD in the hybrid configurations – from 34 to 52 %. Recovery of Cu, Ni and Co is best achieved by NH4OH (4 mol/L), however with considerable carryover. Conversely, selective recovery can be achieved by different eluting agents H2SO4 0.1 mol/L to recover Co (~80 %), H2SO4 1 mol/L to recover Ni (~47 %), and NH4OH 4 mol/L to recover Cu (~26 %), with a lower carryover of other ions (<14 %). Scale-up calculations showed that the Amberlyst A26 mass required for the hybrid IX (batch) is 2.4× lower than the Dowex M4195, which resulted from the exchange capacity and selectivity. Conversely, the estimated Amberlyst A26 mass required for the hybrid IX (fixed-bed) was higher due to the higher initial concentration of H₂SO₄. Lastly, CapEX ranged from 0.2 to 5.6 M US$, and OpEX from 2.61 to 11.42 US$/m3. Considering earnings with the recovered resources the hybrid fixed-bed configurations are a clear choice due to the lowest payback times (<4 years).

A crescent-shaped imprinted microgel adsorbent with near-infrared light-responsive performance for selective adsorption of Lead(II)

Smart hydrogel adsorbent with high selectivity and“on–off”switching ability is vital for the effective elimination of heavy metal pollution, but its simple fabrication remains a serious task. To address this, a facile strategy via an oil-in-water-in-oil (O1/W/O2) droplet microreactor was proposed to prepare polydopamine-coated imprinted microgel adsorbents (DMHIIPs) with crescent shape, and then as-prepared smart adsorbent with near-infrared (NIR) light-responsive performance was used to selectively remove lead ions (Pb(II)) from aqueous solution. The critical solution temperature (LCST) of DMHIIPs is 44.2 °C, resulting from the increase of thermal change and decrease of entropy change during swelling. DMHIIPs have high photothermal conversion efficiency and stability, and the temperature of DMHIIPs dispersion (0.5 mg/L) can be rapidly heated to above 50 °C under NIR (808 nm, 1.0 W cm−2) irradiation for 10 min. The adsorption capacity of Pb(II) on DMHIIPs elevates from 128.0 mg g−1 to 135.2 mg g−1, when the solution temperature increases from 20 °C to 40 °C, but this value significantly reduces to 59.2 mg g−1 at 60 °C. Pseudo-second-order can be well described the kinetic results of DMHIIPs, confirming chemisorption is the rate-limiting step. Desorption ratio of DMHIIPs is 36.5% in 30 min under NIR irradiation, and it can be increased to 63.2% When combining NIR irradiation with the using of elution agent. In addition, the obtained DMHIIPs has excellent selectivity coefficient (k) for competitive Cu(II) (7.20), Cd(II) (23.31), and Ni(II) (39.33), respectively. This work demonstrates a new strategy to NIR-responsive imprinted microgel adsorbent provides a new perspective for controlling the adsorption process of heavy metal pollution.

Adsorption of radioactive cesium using synthesized chitosan-g-poly(acrylic acid/N-vinylcaprolactam) by γ-irradiation

To remove radioactive cesium ions from wastewater, graft copolymer of chitosan-g-poly(acrylic acid/N-vinylcaprolactam) [CTS-P(AA/VC)] was synthesized. The shape, thermal stability, and structure of the graft copolymer were all successfully characterized by SEM, TGA, and FT-IR. Batch sorption experiments were carried out in order to evaluate the effects of various parameters such as pH, contact time, adsorbate initial concentration, and temperature. The kinetics data of batch interaction were also extensively covered with various (linear and non-linear) models of sorption kinetic such as pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. Langmuir and Freundrich equations isotherm models were studied by linear and non-linear equations. To determine the best-fitting equations, the correlation coefficient (R2) and the normalized standard deviation Δq (%) were used as error analysis methods. It appeared briefly that the linear and non-linear forms of pseudo-second order and the Langmuir model are better fitted for kinetic and isotherm models, respectively. The elimination capability for cesium-134 radionuclides was ∼115 mg g-1. Thermodynamic parameters showed exothermic, spontaneous nature and decreased randomness during the adsorption process. After the adsorption studies, the elution process was successfully proceeds by using different eluting agents. The findings suggested that CTS-P(AA/VC) graft copolymer could be a useful material for treating cesium-134 ions-containing liquids.

Development and validation of HPLC-FLD method for aflatoxin M1 determination in milk and dairy products

Abstract Milk and dairy products are the most consumed foods in human diet and their safety is in the attention centre of control authorities. Aflatoxin M1 (AFM1) is a dangerous toxin that can occur in milk and dairy products as a metabolite formed from aflatoxin B1 contained in contaminated animal feed. Therefore, the aim of this study was to develop and validate a reliable method for the determination of AFM1 content in milk and dairy products based on HPLC with fluorescence detection employing immunoaffinity columns (IAC) pre-treatment. Optimal chromatographic separation of AFM1 was achieved using a water/acetonitrile mixture (80/20, v/v) as a mobile phase, column with C18 stationary phase maintained at 25 °C, and fluorescence detection at excitation wavelengths of 360 nm and emission of 440 nm. Efficacy of AFM1 extraction from the samples was found to be influenced by the elution agent composition. The best results were obtained using 1.25 mL of acetonitrile/methanol (3/2, v/v) and 1.25 mL of water. Validation parameters of the proposed method met the criteria set by the European legislation with the limits of detection and quantification at 0.002 and 0.007 µg/kg, respectively. Also, suitability of the method was confirmed by its application for AFM1 determination in certified reference material. Finally, the method was applied for AFM1 determination in 25 milk and dairy products collected in Slovakia; the AFM1 content was below the limit of quantification. It was concluded that the method is suitable for AFM1 content monitoring in milk and dairy products.

Separation of Minor Actinides from High-Level Liquid Waste Using Novel Silica-Based Butyl-BTP Adsorbents

To separate the long-lived minor actinides (MA = Am, Cm) from high-level liquid waste (HLLW), we have been studying an advanced separation process via selective adsorption that uses minimal amounts of organic solvent and compact equipment. The process consists of two separation columns packed with a CMPO (octyl(phenyl)-N,N-diisobutylcarbamoyl-methyl phosphine oxide) adsorbent for elemental group separation and a soft-donor named the R-BTP (2,6-bis-(5,6-dialkyl-1,2,4-triazine-3-yl) pyridine) adsorbent for the isolation of MA from lanthanides (Ln). In this work, the effects of nitrate ion (NO3-) on the adsorption behavior of Am(III) and a typical fission product Ln(III) onto the isoBu-BTP/SiO2-P adsorbent were studied experimentally. Then, the desorption properties of the adsorbed element were examined using different eluting agents. A hot test for the separation of MA from the fission product Ln in a genuine MA containing effluent from the irradiated MOX-fuel treatment process was carried out using a nBu-BTP/SiO2-P packed column. It was found that the separation factor between Am(III) and Ln(III)-FP is over 100 in the measured 0.5-4 M NO3-. The adsorbed elements could be effectively eluted off using a complexing agent such as DTPA or pure water. Complete separation between MA and Ln was achieved in the column results, indicating that the proposed MA separation process is feasible in principle.

Carboxylate-functionalized dragon fruit peel powder as an effective adsorbent for the removal of Rhodamine B (cationic dye) from aqueous solution: adsorption behavior and mechanism

In this study, we used a simple and low-toxicity chemical treatment to make a carboxylate-functionalized dragon fruit peel powder (CF-DFPP) from dragon fruit peel to improve its capacity for adsorbing Rhodamine B (RhB) from an aqueous medium. Field Emission-Scanning Electron Microscopy/Energy-Dispersive X-ray (FE-SEM/EDX), point of zero charges (pHPZC), Brunauer-Emmett-Teller (BET), and Fourier Transform Infrared (FT-IR) analyses were performed to characterize the adsorbent materials. The adsorption performance and mechanism for the removal of RhB were examined. The kinetic, isotherm and thermodynamic parameters were employed to evaluate the adsorption mechanism. Compared to other models, the Langmuir isotherm and PSO kinetic models better defined the experimental data. CF-DFPP adsorbent exhibited a maximum adsorption efficiency of 228.7 mg/g at 298 K for RhB adsorption. Thermodynamic analysis revealed that the adsorption of RhB by CF-DFPP was spontaneous (ΔGo < 0) and exothermic (ΔHo < 0) nature of the process. Different eluting agents were used in desorption tests, and NaOH was revealed to have greater desorption efficiency (96.8%). Furthermore, regeneration examinations revealed that the biosorbent could effectively retain RhB, even after six adsorption/desorption cycles. These findings demonstrated that the CF-DFPP might be a novel material for removing RhB from an aqueous medium.

Desorption of Coffee Pulp Used as an Adsorbent Material for Cr(III and VI) Ions in Synthetic Wastewater: A Preliminary Study.

Some of the diverse agro-industrial waste generated in primary or secondary stages have proved to be promising biomaterials for treating aqueous effluents contaminated, in this case, with heavy metals. Therefore, it is necessary to know their optimal operating conditions and the regeneration or reusability of the solid by-product, an aspect related to desorption. Considering the above, this article presents the findings of a preliminary study related to the desorption process of coffee pulp without physicochemical modification (Castilla variety), an agricultural waste used as a sorbent of Cr(III and VI) ions in synthetic wastewater. The desorption efficiency of four eluting agents at defined concentrations (0.10M)—HC1, HNO3, H2SO4, and EDTA—was evaluated in a time interval of 1 to 9 days. Likewise, the proposals for the sorption and/or desorption mechanisms proposed and reported in the literature with respect to the use of biosorbents derived from the coffee crop are presented. With respect to the results, the coffee pulp used in previous studies of the adsorption of chromium species mentioned (optimal conditions in synthetic water of particle size 180 μm, dose 20 g·L−1, agitation 100 RPM, room temperature, time of 90 to 105 min) showed efficiencies in the removal of Cr(III) and Cr(VI) of 93.26% and 74.80%, respectively. Regarding the extracting substances used, H2SO4 0.10 M was the one that presented the highest desorption percentage in both chromic species, with a desorption of 45.75% Cr(VI) and 66.84% Cr(III) in periods of 5 and 9 days, respectively, with agitation of 100 RPM and room temperature. Finally, the dissemination of preliminary results on the desorption of coffee pulp contaminated with chromic species without physicochemical modification is novel in this study, as similar work with this specific material has not yet been reported in the literature. On the other hand, the limitations of the study and future research are related to the evaluation at different concentrations and of other extractor solutions that allow improving the efficiency of desorption of these chemical species in a shorter time from the coffee pulp (with and without modification) as well as the reuse cycles. As a result, the desorption of coffee pulp used as an adsorbent material in real water could help researchers identify the possible interfering factors that affect the process (foreign anions and cations, organic matter, environmental conditions, among others).

Vitellogenin-derived fragment in embryos of Japanese flounder Paralichthys olivaceus with binding and bactericidal activities against an infectious bacterium via an interaction with saccharides

Thirty- and 90-kDa proteins with binding ability to Edwardsiella tarda, a causative bacterium of Edwardsiellosis in fish, were purified from the embryo of Japanese flounder Paralichthys olivaceus. The proteins were isolated with affinity chromatography, in which the bacterium was used as a ligand and galactose, mannose, and ethylenediaminetetraacetic acid (EDTA) were used as elution agents, followed by gel filtration chromatography. N-terminal amino acid sequencing and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry (LC/Q-TOF-MS) analysis revealed that the 90-kDa protein was lipovitellin heavy-chain (LvH), which is one of the proteolytically cleaved products of maternal vitellogenin (Vg) and represents the main precursor of the egg yolk in teleosts, and the 30-kDa protein was an N-terminal bit of LvH. On the other hand, Vg in the serum of the mother fish did not bind to E. tarda. While the 90-kDa protein did not show anti-bacterial activity, the 30-kDa protein strongly exhibited activity toward E. tarda, with a minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) below 0.06 μM, suggesting that the latter protein plays an important role during embryogenesis in the flounder. This is the first report showing that Vg-derived products have monosaccharides-binding activity and a fragment derived from LvH exhibits bactericidal activity.

SILVER(I) PRECONCENTRATION USING m-AMINOPHENOL CONTAINING SORBENT FROM AQUEOUS SOLUTIONS

The influence of sorption characteristics on the removal of silver(I) has been examined. The sorption capacity of chelating polymeric sorbent, based on maleic anhydride styrene copolymer modified with m-aminophenol, towards Ag(I) ions was studied. The pH of sorption was maximum at the value 6. With the increasing of initial metal concentration, sorption of silver(I) increases and reached maxima at val-ue 80∙10-3 M. At the final stage, the elution process of Ag(I) was established and find that HNO3 1 M is the best elution agent. Multiple use of the regenerated sorbent for sorption process is possible. This study shows that using of mentioned sorbent modified with m-aminophenol is effective for removal of silver(I) ions from aqueous solutions

Desorption of chromium (VI) and lead (II) ions and regeneration of the exhausted adsorbent

The desorption characteristics of previously adsorbed hexavalent chromium [Cr(VI)] and divalent lead [Pb(II)] ions on groundnut husk were tested by various desorption eluents such as tap water, de-ionized water, NaOH, HCl and H2SO4. Among them, HCl and H2SO4 were chosen as the best desorbing agents for Cr(VI) and Pb(II) ions, respectively, due to their high desorption efficiency. The desorption efficiency of HCl and H2SO4 for Cr(VI) and Pb(II) ions was about 76.1% and 82.1%, respectively, at a concentration of 0.1 M for both elution agents. The exhausted groundnut husk was regenerated up to five cycles, and the removal efficiency of Cr(VI) and Pb(II) ions on the recycled groundnut husk could be maintained at 53.5% and 54.6%, respectively, in the third cycle. The successive regeneration cycles resulted in the reduction of the desorption efficiency by 20.0% and 26.7% for Cr(VI) and Pb(II) ions, respectively, after the third cycle. The results show that groundnut husk could be recycled when used to remove Cr(VI) and Pb(II) ions from Cr(VI) and Pb(II)-polluted water and wastewaters.

Influence of competitive eluting agents on REEs recovery from silica gel adsorbent with immobilized aminodiphosphonic acid

It was demonstrated that traces of rare earth elements (REEs) can be quantitatively preconcentrated from contaminated water with pH ≥ 3 on a silica-based adsorbent with covalently immobilized amino-di(methylenephosphonic) acid (SiO2-AdPA). However, recovery of REEs from the adsorbent required utilization of a strong mineral acid. In order to reduce environmental impact and increase the reusability of the adsorbent, a ligand-exchange approach that includes treatment of the adsorbent with strong complexing ligands was used. The eluting potential of several ligands was investigated, namely EDTA, 5-sulfosalicylic acid (SSA), citric acid (CiA), aminosulfonic acid (AmSA), α-hydroxyisobutyric acid (HBA), oxalic acid (OxA) and ascorbic acid (AsA). The results were compared to those obtained by acidic treatment (HCl or HNO3). It was demonstrated that the complete desorption of all REEs can be achieved by using 10−2 mol L-1 EDTA solution with pH = 8.0, while acidic treatment requires 1.0 mol L-1 HNO3. Reusability tests demonstrated complete stability of the adsorbent for at least five consecutive adsorption/desorption cycles with no decrease in its adsorption characteristics.

Development of new organic-inorganic, hybrid bionanocomposite from cellulose and clay for enhanced removal of Drimarine Yellow HF-3GL dye

Cellulose/clay composites were prepared and applied for the adsorption of Drimarine Yellow HF-3GL direct dye. The prepared composites were characterized by FTIR, TGA, EDX, SEM and XRD techniques. Bagasse was used as a cellulose source, while clay was obtained from local source, which was modified chemically before composite preparation. Adsorption efficiencies were compared of composite I and II as a function of contact time, temperature, pH, initial dye concentration and composite dose. Non-linear kinetic and equilibrium isotherm employed and dye adsorption data fitted well to pseudo-second order kinetics model. Among isotherms, the Redlich-Peterson isotherm well defined the sorption process of dye on to composites. Thermodynamic factors (ΔS°, ΔH° and ΔG°) revealed that the sorption process was spontaneous, exothermic and feasible. Cellulose/clay composite I and II removed 88.64% and 89.95% dye with 60 min at pH 2 and 30 °C, respectively. For reusability, desorption was performed using different eluting agents and NaOH showed higher desorption efficiency. For the treatment of wastewater, the developed composites were applied to textile effluents and color removal of (90–96.07%) and (97–98.23%) was achieved using cellulose/clay composite I and II, respectively. The results showed that cellulose/clay composite are efficient for the removal dyes and could possibly be used for the treatment of textile effluents.

Efficient tetracycline hydrochloride removal by encapsulated phosphotungstic acid (PTA) in MIL–53 (Fe): Optimizing the content of PTA and recycling study

The performance of tetracycline hydrochloride (TC.HCl) adsorption by MIL–53 (Fe), PTA/MIL–53 (Fe) (phosphotungstic acid impregnating via post modification) and four different contents of PTA in PTA@MIL–53 (Fe) (phosphotungstic acid encapsulating via one–pot method) were investigated. The results proved that the comparison adsorption capacity of the adsorbent in high concentration of TC.HCl is: PTA(10 wt%)@MIL–53 (Fe) > PTA(16 wt%)@MIL–53 (Fe) > PTA(6 wt%)@MIL–53 (Fe) > PTA(30 wt%)@MIL–53 (Fe) > PTA/MIL–53 (Fe) > MIL–53 (Fe). The maximum adsorption capacity of TC.HCl on to PTA(10 wt%)@MIL–53 (Fe) using Langmuir equation was 1250 mg/g which is extremely high. The isotherm adsorption data were found to fit Langmuir model and the adsorption process was matched by pseudo–second–order kinetics model. The thermodynamic assessments expressed that the process is spontaneous and endothermic. The regeneration experiments by 0.1 M HCl/ethanol (10/90, v/v) as elution agent showed that the adsorption capacity was not changed significantly even after 3 times reusing. PTA (10 wt%)@MIL–53 (Fe) showed a great potential to be a good adsorbent for TC.HCl removal from an aqueous media and also capable of being regenerated.

Fast and efficient copper-mediated 18F-fluorination of arylstannanes, aryl boronic acids, and aryl boronic esters without azeotropic drying

BackgroundCopper-mediated radiofluorination is a straightforward method to produce a variety of [18F]fluoroarenes and [18F]fluoroheteroarenes. To minimize the number of steps in the production of 18F-labelled radiopharmaceuticals, we have developed a short and efficient azeotropic drying-free 18F-labelling method using copper-mediated fluorination. Our goal was to improve the copper-mediated method to achieve wide substrate scope with good radiochemical yields with short synthesis time.ResultsSolid phase extraction with Cu (OTf)2 in dimethylacetamide is a suitable activation method for [18F]fluoride. Elution efficiency with Cu (OTf)2 is up to 79% and radiochemical yield (RCY) of a variety of model molecules in the crude reaction mixture has reached over 90%. Clinically relevant molecules, norepinephrine transporter tracer [18F]NS12137 and monoamine transporter tracer [18F]CFT were produced with 16.5% RCY in 98 min and 5.3% RCY in 64 min, respectively.ConclusionsCu (OTf)2 is a suitable elution agent for releasing [18F]fluoride from an anion exchange cartridge. The method is fast and efficient and the Cu-complex is customizable after the release of [18F]fluoride. Alterations in the [18F]fluoride elution techniques did not have a negative effect on the subsequent labelling reactions. We anticipate this improved [18F]fluoride elution technique to supplant the traditional azeotropic drying of [18F]fluoride in the long run and to concurrently enable the variations of the copper-complex.

Effective adsorption of Co2+ and Sr2+ ions by 10-tungsten-2-molybdophosphoric acid supported amine modified magnetic SBA-15

The presence of heavy metals in water sources have created serious environmental concerns. In this study, 10-tungsten-2-molybdophosphoric acid supported amine-functionalized magnetic SBA-15 with core–shell morphology was prepared and its applicability as effective inorganic adsorbent for Co2+ and Sr2+ removal was investigated. The adsorbent was characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometer, inductively coupled plasma analysis and N2 physical adsorption–desorption technique. The effective parameters including dosage of adsorbent, contact time, initial concentration of metal ion, pH of solution, temperature and elution agent were investigated. Batch adsorption studies depicted higher adsorption affinity for Co2+ than Sr2+ ions. The synthesized adsorbent has an adsorption capacity of 87.72 mg g−1 and 80.01 for Co2+ and Sr2+ respectively. This research highlights the source of difference between their adsorption capacity. EDTA had more desorption performance as elution agent than HCl that attributed to larger chelating stability constant of EDTA. Moreover, the results showed the good recyclability and excellent stability of adsorbent after 4 successive cycles.

Preparation and characterization of chitosan/clay composite for direct Rose FRN dye removal from aqueous media: comparison of linear and non-linear regression methods

In the present study, sorption efficacy of chitosan (β-(1→4)-linked d-glucosamine and N-acetyl-d-glucosamine) composite for synthetic direct Rose FRN dye removal from aqueous media was investigated. Chitosan and clay were subjected to chemical modifications to prepare chitosan/clay composite. Batch sorption affecting parameters like pH, composite dose, volume, initial dye concentration, time and temperature were optimized. Maximum sorption capacity (17.18mg/g) was found within first 40min of contact. Point of zero charge was found to be 7.0. Linearized and non-linearized regression forms of pseudo 1st and 2nd order kinetic models were used to predict the nature of rate limiting steps involved in the sorption process. Sorption equilibrium data was revealed by applying linear and non-linear equilibrium Langmuir, Freundlich and Redlich–Peterson isotherm models. Calculated values of thermodynamic factors showed that sorption process is exothermic, spontaneous and feasible. Desorption studies were performed for the regeneration of chitosan/clay composite by using different eluting agents. The synthesized composite were characterized by X-ray diffraction (XRD), surface analysis (Brunauer, Emmett and Teller: BET), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The developed method was also applied on the real textile effluent for the efficient removal of dyes.