Selective Separation Research Articles

Ligand content and driving force effects on ion-ion permselectivity in ligand-functionalized membranes

Ion-selective membranes could enable sustainable critical material separations processes because of their scalability, low energy consumption, and low chemical input. The effects of membrane water content and incorporation of ion-coordinating ligands have been studied via computation and experiment to develop structure-performance relationships. However, few studies systematically investigate the effects of membrane composition beyond monomer chemical identity or the balance of driving forces such as diffusion and electromigration. Here we synthesized a library of poly(ethylene glycol) acrylate membranes with varying percentages of ion-coordinating monomers (acrylic acid, 4-vinylpyridine) to investigate the influence of ligand content on cation permeabilities and permselectivities. Trends in membrane performance under electrodialysis and diffusion were compared to elucidate the relative effects of separation driving forces and to inform electrochemical operation. We observed order-of-magnitude permeability reductions with ligand content for ions capable of multidentate ligand complexation, especially for nickel in the pyridine-containing membranes. As a result, lithium/nickel permselectivity gradually increased by a factor of 1.65 × from 10 to 50 mol% pyridine membranes. We further demonstrated simultaneous improvements in lithium/nickel separation productivity (1.75 ×) and selectivity (2.99 ×) with increasing electric potential driving force. Ultimately, results from this study provide design insights for ligand-functionalized membranes in electrified ion-ion separations processes.

Introducing Phosphate Ester into DAPhen by Propyl Enhanced the Selectivity for UO22+ over Th4.

A new type of phenanthroline carboxamide(DAPhen)-phosphate ester ligand (L1/L2) was synthesized for the selective separation of U(VI) over Th(IV). Liquid-liquid extraction experiments showed that the introduction of phosphate ester could increase the extraction ability of ligands for U(VI), especially L2, which showed high selectivity for the separation of U(VI) over Th(IV). The slope analysis indicated that L1 could form 1:1 and 1:2 complexes with U(VI) and 1:1 complexes with Th(IV). NMR titration revealed that the DAPhen unit of ligands combined with one U(VI) to form 1:1 complexes, and then the phosphate ester unit of the 1:1 complexes further combined with another U(VI) to form 1:2 complexes. Ligands provide only the DAPhen unit to Th(IV) to form 1:1 complexes. The crystal structures found 1:2 complexes of L1 and U(VI), 1:1 complexes of L2 and U(VI), and 1:1 complexes of L1 and Th(IV). The larger stability constant (log β) of the 1:1 complexes of L2 with U(VI) than that of the 1:1 complexes of L1 with U(VI) showed that the binding ability of U(VI) with the DAPhen unit of L2 is stronger than that of U(VI) with the DAPhen unit of L1. This study provides new ideas for designing extractants with excellent properties.

Selective Separation of Thiophene Derivatives Using Metal-Organic Frameworks-Based Membranes.

The removal of sulfur compounds, particularly thiophene derivatives, from oil is crucial due to concerns about environmental issues. Therefore, the deep desulfurization of transportation fuels is currently an urgent problem, and numerous attempts have been made in this direction. Membrane-based desulfurization can be a good alternative to the traditional hydrodesulfurization method, which has several limitations. In this work, the use of membranes containing a metal-organic framework, MOF-5, doped with transition metals (Ag, Cu, Ni), in the adsorptive desulfurization process was studied. The efficiency of membranes was evaluated based on selective removal of thiophene and dibenzothiophene from model oil. Characterization techniques, including scanning electron microscopic (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), confirmed the successful synthesis and incorporation of metal-organic frameworks (MOFs) into mixed matrix membranes (MMMs). Desulfurization experiments showed that MOF-5/Ag exhibited the highest thiophene adsorption efficiency (86.8%), outperforming MOF-5/Cu and MOF-5/Ni. The enhanced performance is attributed to the strong interaction between silver and sulfur. These findings demonstrate the potential of MOF-based MMMs for efficient and selective desulfurization, offering a viable alternative to traditional hydrodesulfurization (HDS) methods.

Engineering of Covalent Organic Framework Nanosheet Membranes for Fast and Efficient Ion Sieving: Charge-Induced Cation Confined Transport.

Artificial membranes with ion-selective nanochannels for high-efficiency mono/divalent ion separation are of great significance in water desalination and lithium-ion extraction, but they remain a great challenge due to the slight physicochemical property differences of various ions. Here, the successful synthesis of two-dimensional TpEBr-based covalent organic framework (COF) nanosheets, and the stacking of them as consecutive membranes for efficient mono/divalent ion separation is reported. The obtained COF nanosheet membranes with intrinsic one-dimensional pores and abundant cationic sites display high permeation rates for monovalent cations (K+, Na+, Li+) of ≈0.1-0.3mol m-2 h-1, while the value of divalent cations (Ca2+, Mg2+) is two orders of magnitude lower, resulting in an ultrahigh mono/divalent cation separation selectivity up to 130.4, superior to the state-of-the-art ion sieving membranes. Molecular dynamics simulations further confirm that electrostatic interaction controls the confined transport of cations through the cationic COF nanopores, where multivalent cations face i) strong electrostatic repulsion and ii) steric transport hindrance since the large hydrated divalent cations are retarded due to a layer of strongly adsorbed chloride ions at the pore wall, while smaller monovalent cations can swiftly permeate through the nanopores.

Healable, Recyclable, and Upcyclable Gel Membranes for Efficient Carbon Dioxide Separation

AbstractIonic liquids (ILs) are prized for their selective dissolution of carbon dioxide (CO2), leading to their widespread use in ionogel membranes for gas separation. Despite their advantages, creating sustainable ionogel membranes with high IL contents poses challenges due to limited mechanical strength, leakage risks, and poor recyclability. Herein, we leverage copolymerized and supramolecularly bound ILs to develop ionogel membranes with high mechanical strength, zero leakage, and excellent self‐healing and recycling capabilities. These membranes exhibit superior ideal selectivity for gas separation compared to other reported ionogel membranes, achieving a CO2/nitrogen selectivity of 61.7 and a CO2/methane selectivity of 24.6, coupled with an acceptable CO2 permeability of 186.4 Barrer. Additionally, these gas separation ionogel membranes can be upcycled into ionic skins for sensing applications, further enhancing their utility. This research outlines a strategic approach to molecularly engineer ionogel membranes, offering a promising pathway for developing sustainable, high‐performance materials for advanced gas separation technologies.

Flotation of Copper Sulfide Ore Using Ultra-Low Dosage of Combined Collectors

Copper sulfide ores frequently co-occur with pyrite, presenting a significant challenge for their selective separation during beneficiation processes. Despite advancements in flotation technology, there remains a critical need for efficient methods to enhance copper recovery while suppressing pyrite interference, particularly without compromising the associated precious metals such as gold and silver. Current practices often struggle with achieving high selectivity and recovery while maintaining environmental sustainability. Here, we investigate the efficacy of a ternary collector mixture consisting of ammonium dibutyl dithiophosphate (ADD), butyl xanthate (BX), and ethyl xanthate (EX) for the selective flotation of copper sulfide from a complex ore containing 0.79% Cu and associated precious metals (0.233 g/t Au and 5.83 g/t Ag). A combination of lime and hydrogen peroxide as inhibitors was employed to suppress pyrite effectively under alkaline conditions (pH = 11.33). The results demonstrate that the optimized ternary collector system (ADD:BX:EX at a ratio of 1:0.5:0.5) significantly improves the copper grade and recovery at an ultra-low dosage of 10 g/t. The optimized flotation method using the combined collectors and inhibitors effectively separated chalcopyrite from pyrite, achieving a copper concentrate with 20.08% Cu content and a recovery of 87.73%. Additionally, the process yielded notable recoveries of gold (9.22%) and silver (26.66%). These findings advance the field by providing a viable and environmentally conscious approach to the beneficiation of sulfide ores, potentially serving as a blueprint for processing similar mineral deposits while minimizing reagent usage and costs.

Charge‐Sign‐Independent Separation of Mono‐ and Divalent Ions With Nanofiltration Membranes

AbstractAchieving precise selective separation of monovalent and divalent cations, as well as anions, is vital yet challenging in practical applications involving complex component treatments. Current membranes are typically effective for separating either cation pairs or anion pairs. To address this issue, a straightforward strategy for fabricating a nanofiltration (NF) membrane is developed that selectively permeates monovalent ions. This study focused on neutralizing the surface charge and tuning the pore size distribution of the polyamide membranes through a secondary interfacial polymerization using a zwitterionic copolymer consisting of 2‐methacryloyloxyethyl phosphorylcholine and 2‐aminoethyl methacrylate hydrochloride. The optimized NF membrane prepared in this study, with a near‐neutrally charged membrane surface and appropriate pore size distribution, demonstrates favorable performance in precisely separating monovalent and divalent ions, irrespective of the ion charge sign. The optimum NF membrane features high selectivity for both Cl−/SO42− (93) and Li+/Mg2+ (67) ion pairs, along with high water permeance of 8.5 L m−2 h−1 bar−1, making it competitive with many reported membranes. This study offers new insights into the ion‐selective mechanisms of polyamide membranes for monovalent/divalent ions and may guide the development of advanced membranes with single‐solute selectivity.

Oriental covalent immobilization of N-glycan binding protein via N-terminal selective modification

Lectin affinity chromatography is one of powerful tools for the study of protein glycosylation. Different lectin proteins can recognize different structures of monosaccharides or oligosaccharide units, allowing for the selective separation of glycopeptides or glycoproteins containing different polysaccharide structures. However, the N-glycans were only partially captured by most of common lectins, reducing the coverage rate of identifying N-glycoconjugates. Recently, it has been reported that the engineering variant of glycan binding protein Fbs1 has a high affinity for innermost Man3GlcNAc2 structure and is able to bind diverse types of N-glycans, which can be suitable for the analysis of protein N-glycosylation. However, efficient immobilization of protein to separation matrix is particularly challenging as it requires the functionality and integrity of the protein to be preserved. Herein, we describe a simple and robust strategy for oriental covalent immobilization of proteins on magnetic nanoparticles by N-terminal selective labeling techniques. We inserted the enterokinase cleavage site to produce the specific N- terminal glycine of protein. Under physiological conditions, the protein was immobilized on the surface of the MNPs by this glycine tag, and the enrichment process could be completed within 30 min. A whole enrichment and purification of glycan and glycopeptides were completed and analyzed by MALDI TOF-MS. The functional materials achieved stable enrichment of glycan structure in different enzyme digestion systems or complex samples, showing excellent anti-interference and applicability.

Construction of Ion-Imprinted Graphene Oxide Mixed-Matrix Membranes for Selective Adsorption and Separation of Tm3.

Efficient adsorption and separation of rare earth from other similar rare earth wastewater has become an urgent demand for resource utilization of ion-type rare earth minerals in China. Herein, thulium (Tm) ion-imprinted graphene oxide (GO)-doped polyether sulfone (PES) membranes (GO-TII/PES-2 membranes) were prepared, in which ion-imprinted graphene oxide was applied as an efficient Tm3+ ionic ligand in the imprinted layer and polyether sulfone was applied as a carrier in the membrane matrix to achieve the selective adsorption and separation of Tm3+ and neighboring rare earth ions. Combined with an ion rectifier, the separation and purification performances of Tm3+ were explored. The separation factors β(Tm3+/Tb3+), β(Tm3+/Sm3+), β(Tm3+/Nd3+), and β(Tm3+/Ce3+) in the dynamic adsorption process increased significantly from 1.22, 1.04, 1.04, and 1.02 for nonimprinting to 3.07, 3.91, 3.91, and 3.33 for imprinted membranes. The GO-TII/PES-2 membrane adsorbed about three times more Tm3+ than the nonionic-imprinted (GO-NII/PES) membrane by adding a color developer and quantifying Tm3+ based on a fast and easy UV-photometric method. After eight dynamic permeations, the adsorption of Tm3+ by the GO-TII/PES-2 membrane decreased by only 13%, indicating that the membrane has good reuse performance. Additionally, the investigation examined the influence of Tm3+ on wheat seed germination, underscoring its potential application in agriculture and the importance of adsorbing and separating rare earth ions.

Relationship between septic acute kidney injury and adiponectin: A retrospective study in patients undergoing continuous plasma exchange with dialysis.

Adiponectin (APN) is a multimeric protein with anti-inflammatory properties that is specifically secreted by adipocytes. Continuous plasma exchange with dialysis (cPED) is a blood purification therapy in which plasma exchange is performed using a selective membrane plasma separator while the dialysate flows outside the hollow fibers. Patients with sepsis were divided into two groups based on the presence or absence of acute kidney injury (AKI) complications: AKI and non-AKI group. Plasma APN levels significantly increased after cPED in both groups. The creatinine levels in the AKI group before cPED were significantly higher than those in the non- AKI group. The plasma APN levels in the AKI group before cPED were significantly higher than those in the non-AKI group. cPED increased APN levels in both patients with and without AKI. Therefore, cPED therapy may be a promising intervention for increasing APN levels in patients with sepsis.

Boosting selective Cs+ uptake through the modulation of stacking modes in layered niobate-based perovskites

Selective separation of 137Cs is significant for the sustainable development of nuclear energy and environmental protection, due to its strong radioactivity and long half-life. However, selective capture of 137Cs+ from radioactive liquid waste is challenging due to strong coulomb interactions between the adsorbents and high-valency metal ions. Herein, we propose a strategy to resolve this issue and achieve specific Cs+ ion recognition and separation by modulating the stacking modes of layered perovskites. We demonstrate that among niobate-based perovskites, ALaNb2O7 (A = Cs, H, K, and Li), HLaNb2O7 shows an outstanding selectivity for Cs+ even in the presence of a large amount of competing Mn+ ions (Mn+ = K+, Ca2+, Mg2+, Sr2+, Eu3+, and Zr4+) owing to its suitable void fraction and space shape, brought by the stacking mode of layers. The Cs+ capture mechanism is directly elucidated at molecular level by single-crystal structural analyses and density functional theory calculations. This work not only provides key insights in the design and property optimization of perovskite-type materials for radiocesium separation, but also paves the way for the development of efficient inorganic materials for radionuclides remediation.

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

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

Selective separation of light and heavy rare earth elements from acidic mine waters by integration of chelating ion exchange and ligand impregnated resin

This study addresses the potential of sourcing Critical Raw Materials (CRMs) using Acidic Mine Waters (AMWs) as a secondary resource. AMWs, often viewed as waste, contain valuable metals like zinc and copper, as well as critical metals like magnesium and cobalt. Moreover, recent studies also reported the presence of Rare Earth Elements (REEs) at concentrations (mg/L) that make their extraction both technically and economically viable. The research focuses on a circular process to recover these metals from AMWs, specifically from the Aznalcóllar open-pit mine, which contains 216 mg/L of Al, 47 mg/L of Fe, 547 mg/L of Zn, and 18.56 mg/L of REEs. The proposed method involves pre-treating the AMW to remove Fe and Al, achieving removals of over 99.9 % and 90 %, respectively, at pH 4.5. Following this, transition metals like Zn, Cd, and Cu were removed as sulphides with a removal efficiency exceeding 99 %. This pre-treatment step reduced the concentration of competing metals in the ion-exchange process, thereby enhancing the recovery and purity of REEs. To separate heavy and light REEs, two types of resins in series were used: an impregnated resin (TP272) and a chelating resin (S930), which can be regenerated using sulphuric acid (H2SO4). The final recovery of REEs as oxalates was achieved using oxalic acid and ammonia at pH 1, with further optimization of the elution process to minimize ammonia consumption and undesired precipitation of other oxalates. Finally, REE oxalates with purities exceeding 90 % were obtained. This research demonstrates a sustainable method for efficiently recovering valuable REEs from AMWs, while also addressing environmental concerns related to hazardous sludge generation.

Proton permeation and selective separation of hydrogen isotopes through fullerene nanocages (X12Y12): A DFT insights

To resolve the problem of mobile electrolytes for the permeation of hydrogen isotopes in fuel cells, we have studied herein heteronuclear fullerene nanocages (Al12N12, Al12P12, B12N12, and B12P12) for the separation and permeation of hydrogen isotopes. The separation and permeation of fullerene nanocages for hydrogen isotopes are studied at ωB97XD functional of DFT along with 6–31g (d,p) pople basis set. Zero-point energy (ZPE) is calculated for Protium (H+) and its heavier isotopes including deuterium (D+) and tritium (T+). The Arrhenius equation is employed to calculate the selectivity of protium to deuterium (H+/D+) and deuterium to tritium (H+/T+) isotopes. The selectivity is calculated by using the zero-point energy difference (ZPE) of protium (H+) to its heavier isotopes. The proposed fullerene nanocages estimated better selectivity for proton isotopes. The phosphide-based nanocages (Al12P12, B12P12) provide superior selectivity values of H+/D+ and H+/T+ compared to nitrogen-based nanocages (Al12N12, B12N12). This study provides insights into separation pathways for proton isotopes through nanocages for many industrial applications in the energy sector.

Adsorptive separation of anthracene and carbazole by carboxyl-functionalized carbon material derived from MAF-6

Anthracene and carbazole are high-value heavy carbon resources mainly found in the anthracene oil fraction of high-temperature coal tar. Because of their similar structures, traditional solvent crystallization methods are not capable of achieving the separation of high-purity anthracene and carbazole. In this study, MAF-6, a material that can be synthesized in large quantities at room temperature, was used as a sacrificial precursor, carbonized (MC-1000), and subsequently oxidized to form carboxyl-functionalized carbon material (CMC-1000). The presence of carboxyl groups, along with lactones, hydroxyl groups, and carbonyl groups in MC-1000 and CMC-1000, was confirmed through XPS spectra and Boehm titration. CMC-1000 showed an increase of 5.7 mmol/g in oxygen-containing functional groups. The adsorption and separation capacities of MAF-6, MC-1000, and CMC-1000 for anthracene and carbazole in model oil were investigated. FT-IR analysis and DFT calculations demonstrated that the major interaction between CMC-1000 and carbazole involved hydrogen bonding (N–H···O and N–H···N). The results show that CMC-1000 has a high separation selectivity for carbazole over anthracene, with a selectivity of up to 44.4. The formation of hydrogen bonds between the N–H group of carbazole and the oxygen-containing groups on CMC-1000 plays an essential role in achieving high adsorption capacity and selectivity. In addition, CMC-1000 showed strong regenerative capacity, maintaining a selectivity above 29.7 over five cycles.

Constructing CO2 capture nanotraps via tentacle-like covalent organic frameworks towards efficient CO2 separation in mixed matrix membrane

The structure and morphology of fillers are crucial factors in the process of CO2 separation within mixed matrix membranes (MMMs). In this study, the tentacle-like covalent organic framework (COF) as a filler was incorporated into the Pebax matrix for CO2/CH4 separation. The COF has abundant Lewis base sites (O atom and N atom) and porous pores, thereby constructing efficient CO2 capture nanotraps in the MMMs. The CO2 capture nanotraps facilitate the CO2 transport in the MMMs, and this can be verified by the Grand Canonical Monte Carlo (GCMC) simulation and density functional theory (DFT) calculation. Simultaneously, the CO2 capture nanotraps are distributed on the surface of tentacle-like COF, which is conducive to strengthening CO2 capture ability. Therefore, Pebax/COF MMMs exhibited superior CO2 gas separation performance compared to the pure Pebax membrane. Among them, the MMM with 3 wt% COF loading displayed the highest CO2 gas separation performance, exhibiting permeability and selectivity that were 73.4% and 32.9% higher than the pure Pebax membrane, respectively. Thus, CO2 capture nanotraps constructed in the MMMs via tentacle-like COF showed a promising potential for CO2 separation.

Water/oil interfacial photocatalysis of amphiphilic CdS/Bi2WO6 S-scheme heterojunctions for efficient production and spontaneous separation of H2O2 and value-added organics

The photocatalytic co-production of H2O2 and value-added organics in a suitable water/oil biphasic system offers an intriguing strategy to address the challenges encountered in a single liquid-phase solution, including the efficient separation of H2O2 and organic products as well as the mitigation of undesirable secondary reactions. For this, exploring amphiphilic photocatalysts with high performance is highly required. Herein, an amphiphilic CdS/Bi2WO6 S-scheme heterojunction photocatalyst is designedly synthesized through a two-step solvothermal process, aiming to achieve efficient interfacial photocatalytic reactions at the water/oil interface for simultaneous generation and selective separation of H2O2 and organic products. The CdS/Bi2WO6 heterojunction photocatalyst exhibits enhanced light absorption in UV–visible region, increased electron-hole separation efficiency, and powerful charge carriers with high redox abilities. Moreover, the formation of S-scheme heterojunction improves the catalyst stability by preventing CdS from photocorrosion. As a result, the production rate of H2O2 reaches up to 216.76 mmol g−1 h−1, accompanied by the generation of organic products (benzaldehyde: 104.91 mmol g−1 h−1, benzoic acid: 49.88 mmol g−1 h−1, and benzyl benzoate: 38.01 mmol g−1 h−1), in a water/benzyl-alcohol biphasic system under simulated sunlight irradiation. The photocatalytic mechanism is elucidated based on the results of comprehensive experiments and characterizations. This study highlights a rational construction of amphiphilic photocatalysts and their application in organic/water interfacial photocatalytic reactions.

Cu-trimesate and mesoporous silica composite as adsorbent showing enhanced CO2/CH4 and CO2/N2 selectivity for biogas and flue gas separation

Due to their diverse structure, high porosity, and tunable functionality, Metal-Organic Frameworks (MOFs) hold great potential as materials for diverse applications, including gas separation. Material science researchers are focusing on creating flexible materials that have special properties. Most of the latest research mainly concentrates on fabricating composite materials of MOFs and other functional materials. These MOF-based composites can mitigate the limitations of pure MOFs and may even perform better than the individual components. Here, we present a systematic study on the effect of solvent in synthesising a composite (Cu-BTC@SBA-15) of Cu-trimesate MOF (aka CuBTC) and ordered mesoporous silica SBA-15, showing considerable improvement in selectivity for CO2 adsorption from the flue gas and biogas. The pristine Cu-BTC, SBA-15 and the composites with different content of Cu-BTC were characterized by PXRD, BET, FT-IR, SEM, TEM and TGA techniques. The pure gas adsorption isotherms were measured for CO2, CH4, and N2 gases. Ideal Adsorbed Solution Theory (IAST) is used for the binary selectivity calculations for gas systems such as CO2/CH4 and CO2/N2 in the context of biogas and flue gas separation. The composite exhibited an increase in CO2/CH4 selectivity by 39 % compared to pure Cu-BTC and 85 % compared to pure SBA-15. For the CO2/N2 system, the composite showed 38 % higher selectivity than Cu-BTC. The work has significance in the design of effective MOF-based composites for CO2 separation. Our work might open up a new route to design multifunctional materials for worldwide applications through an adsorptive and or mixed matrix membrane route.

B-159 Fast Cleanup for 19 Steroid Analytes in Serum Using Supported Liquid Extraction (SLE)

Abstract Background Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful tool that holds promise in designing the future of steroid analysis in the clinical laboratory. It is already widely used in steroid analysis in endocrinology and is being utilized increasingly in newer applications for individual steroids and panels relevant in clinical research. LC-MS/MS is gaining user base owing to greater sensitivity and specificity and gradually even replacing some of the legacy test methods. Improved sample preparation, modern chromatography methods, and sensitive, faster scanning mass spectrometers have all played a role in improving LC-MS/MS. Steroid analysis for clinical research can require very low limits of detection which demand high recoveries and very clean extracted samples. Supported Liquid Extraction (SLE) can provide very clean extracted samples with less method development and a streamlined workflow compared to solid phase extraction (SPE). Laboratories desire high-throughput methods which consolidate analytes into one panel with fast chromatographic run times. Chromatographic separation of steroid isomers with the same m/z is necessary for accurate quantitation by LCMS/MS. Meeting these criteria can be challenging in a single LC-MS/MS method. Methods Each 200 µL serum sample was pretreated with 200 µL of pH 6 Ammonium Acetate buffer (aq) before being loaded onto a Novum™ PRO SLE, MAX 96-well plate, following the standard SLE protocol. Samples were eluted using 2 × 900 µL of Dichloromethane or Ethyl Acetate. After evaporation of the elution solvent, samples were reconstituted in 100 µL of 0.5 mM Ammonium Fluoride / Methanol (60:40, v/v). A Kinetex™ 2.6 μm C18, 50 x 3.0 mm column using a gradient of 0.5 mM Ammonium Fluoride (aq) and Methanol on an Agilent® 1290 Infinity UHPLC and SCIEX® 7500 Triple Quad™ were used for quantitation. Results Here, we present an effective sample extraction method and LC-MS/MS analysis method for the quantitation of a 19-analyte steroid panel from serum. The Kinetex 2.6 μm C18 column provided a fast 8-minute chromatographic separation and good selectivity for steroid analytes in both positive ion mode and negative ion mode. Calibration curves with a linear fit and 1/x weighting, showed good linearity with R2 of >0.99 for all analytes except 17-OH-Pregnenolone and DHEAS when using Dichloromethane as the elution solvent, and R2 of >0.980 for all analytes when using Ethyl Acetate as the elution the solvent. Accuracy of samples using Dichloromethane as the elution solvent were 80-112 %, except for 17-OH-Pregnenolone and DHEAS. Accuracy of all samples using the Ethyl Acetate elution solvent were 91-118 %. Conclusions The-96 well plate extraction method was robust, reproducible, and can be automated. SLE using Novum Pro MAX combined with a fast LC method provides a simple, rapid, high-throughput workflow for identification and quantitation of 19 steroids from serum.

Tailored microporous graphitic carbon adsorbents from the urea-assisted method for efficient selective gas adsorption and separation of CH4/N2 and CH4/H2

Currently, the adsorption and separation of methane (CH4) from CH4/N2 and CH4/H2 have attracted global attention as an essential technique for the utilization of unconventional natural gas and to meet energy demand. This technique completely relies on the adsorbent; the development of the adsorbent can achieve selective CH4 adsorption and separation. In this context, microporous graphitic carbon adsorbents were tailored using hydrothermal and calcination methods. The textural features of adsorbents were precisely tailored using a hydrothermal approach by optimizing the glucose-urea ratio, and they were then activated with the non-corrosive reagent K2CO3, which gives a specific pore structure that aids in performance. Adsorbents’ textural characteristics, such as surface area and porosity, were significantly influenced by the glucose-urea ratio, which plays an essential role in gas adsorption and separation. A series of tailored microporous graphitic carbon adsorbents named 0.5-HTAC, 1-HTAC, 1.5-HTAC, 2-HTAC, 1.5-HTAC-a, 1.5-HTAC-b, and 1.5-HTAC-c. Among them, 1.5-HTAC adsorbent displayed superior CH4 gas adsorption (36.86 cm3/g) and excellent selectivity of CH4/N2 (6.29) at room temperature, owing to its microporosity, good surface area, and morphological effect. Meanwhile, H2 gas adsorption was not detected at room temperature, indicating that the 1.5-HTAC adsorbent is extremely selective for CH4 gas. However, an additional study of H2 uptake performed at 77 K revealed excellent H2 adsorption of about 314.3 cm3/g. Furthermore, the 1.5-HTAC adsorbent exhibited a low heat of CH4 adsorption as well as impressive reversibility, indicating that it can be reused more effectively.