Simultaneous Separation Research Articles

Simultaneous CO2 mineral sequestration and nickel separation from laterite leachate: Thermodynamic and experimental study

Global warming resulting from escalating CO2 emissions and rising nickel demand present dual challenges to the sustainable development. In this study, a process for simultaneous nickel separation and CO2 mineral sequestration was proposed by using the leachate derived from the process of roasting laterite with copperas followed by water leaching. From the thermodynamic study, it was found that nickel can dissolve in the leachate in the form of nickel-ammonium complexes, while magnesium precipitated as carbonates. Furthermore, Eh-pH (potential vs. pH) results demonstrated that the conditions for the formation of nickel-ammonium complexes closely resemble those for magnesium carbonates. Under optimized conditions with the initial solution pH of 10.8, CO32–/Mg molar ratio of 2, reaction temperature of 30 °C, and reaction time of 1 h; over 95 % of Mg and 100 % of Fe can be converted into carbonates or hydroxides, with no more than 1 % Ni loss. Higher pH and CO32–/Mg molar ratios, along with lower temperatures, facilitated the separation of nickel from the magnesium and iron. The phase and microstructure of the precipitates were significantly influenced by the reaction temperature. At 30 °C, the precipitation product was MgCO3·3H2O, exhibiting a microstructure resembling porous spherical flowers; whereas at 80 °C, the precipitated phase was Mg5(OH)2(CO3)4·4H2O, also displaying a microstructure akin to porous spherical flowers. Efficient separation of nickel and magnesium in NH3–(NH4)2CO3-H2O was achieved by leveraging their distinct reaction properties, simultaneously sequestering CO2. This process achieved the maximum selective Ni recovery and CO2emission reduction in one step.

Rational design double S-scheme heterosystem based Photo-Electrocatalytic membrane device for continuous phytotoxin remediation

Today, the escalating contamination of water sources with phytotoxins poses a significant danger to both ecosystems and human health. Consequently, the implementation of advanced and sustainable remediation technologies becomes imperative for the effective removal of toxins. This study introduces a pioneering method for continuous phytotoxin remediation by integrating a photoelectrocatalytic membrane reactor, which utilizes a ZnCdFeSe heterojunction photocatalyst with a double S-scheme, is derived from the ZnCd prussian blue analog. This design capitalizes on the unique electronic structure and synergistic effects of the catalyst enabling efficient photo-electrocatalysis in the device. The proposed system attains an impressive phytotoxin rejection efficiency of 98.39%, accompanied by enhanced membrane permeation and anti-fouling performance. The obtained results are noteworthy for an emerging process that combines the simultaneous degradation and separation of toxic species, enabling prolonged and uninterrupted remediation processes. Experimental and density function theory (DFT) results demonstrate that, under optimal conditions, the well-stabilized double S-scheme ZnCdFeSe heterojunction achieves a mineralization rate of 85.67%. Even after six cycles of the photocatalytic membrane, the removal rate of ricin remains high at 78.96%, indicating the membrane’s commendable reusability and stability. This research not only contributes to the advancement of innovative environmental remediation strategies but also provides valuable insights for designing and optimizing photoelectrocatalytic systems for the persistent removal of toxins in water treatment applications.

Minor limonoid constituents from Swietenia macrophylla by simultaneous isolation using supercritical fluid chromatography and their biological activities.

This study reports simultaneous isolation of three new limonoids (1-3), six known regio isomers (6, 7, 9-12), and three more known limonoids (4, 5, 8) from Swietenia macrophylla (S. macrophylla) seeds. Structures of these compounds were determined via extensive study of their 1D/2D-NMR and mass spectral data. Known limonoids (4-12) were identified by comparing their physical and spectroscopic data with literature values. A novel environmentally friendly supercritical fluid chromatography (SFC) technique facilitated simultaneous and rapid separation of these compounds. The pharmacological activities of the new limonoids were investigated.

Three-Layered Composite Scintillator Based on the Epitaxial Structures of YAG and LuAG Garnets Doped with Ce3+ and Sc3+ Impurities.

In this study, we propose novel three-layer composite scintillators designed for the simultaneous detection of different ionizing radiation components. These scintillators are based on epitaxial structures of LuAG and YAG garnets, doped with Ce3+ and Sc3+ ions. Samples of these composite scintillators, containing YAG:Ce and LuAG:Ce single crystalline films with different thicknesses and LuAG:Sc single crystal substrates, were grown using the liquid phase epitaxy method from melt solutions based on PbO-B2O3 fluxes. The scintillation properties of the proposed composites, YAG:Ce film/LuAG:Sc film/LuAG:Ce crystal and YAG:Ce film/LuAG:Ce film/LuAG:Sc crystal, were investigated under excitation by radiation with α-particles from a 239Pu source, β-particles from 90Sr sources and γ-rays from a 137Cs source. Considering the properties of the mentioned composite scintillators, special attention was paid to the ability of simultaneous separation of the different components of mixed ionizing radiation containing the mentioned particles and quanta using scintillation decay kinetics. The differences in scintillation decay curves under α- and β-particle and γ-ray excitations were characterized using figure of merit (FOM) values at various scintillation decay intensity levels (1/e, 0.1, 0.05, 0.01).

Structural changes and grading mechanism of lignin during solid alkali-active oxygen extraction and grading

Cooking with active oxygen and solid alkali (CAOSA) is an efficient pretreatment method for biomass. For better grading of the lignin yellow liquor, the different lignin fractions and the recovered solid alkali were obtained using a simultaneous acid-alkali graded separation method. The results indicated that the recovery rate of solid alkali was 67.25 %, and the grading of lignin components was characterized by smaller dispersion coefficients, and more stable properties and structure. Lignin fractions with low dispersion coefficients possess more key structures, including the Phenol hydroxyl group (ArOH), Methoxy (OMe), and β-aryl ether (β-O-4), and have better thermal properties. The low molecular weight L4 has the highest ArOH content (2.1 mmol/g), which provides better antioxidant properties. The CAOSA process destroyed the S-unit and prevented lignin from condensation. Furthermore, the CAOSA process protected carbohydrates, which could effectively prevent them from dehydrating and re-polymerizing into pseudo-lignin. This allowed the pulp to remain natural, which was beneficial for subsequent transformation and utilization. Overall, the efficient separation of biomass components and lignin grading method proposed by combining the CAOSA process with the acid-alkali grading separation method has a strong application prospect and provides a theoretical basis for the high-value utilization of biomass and lignin.

Preparation of catalytic ceramic nanofiber membranes with MnFe dual-active sites enhancing catalytic ozonation of sulfamethoxazole

Membrane-based catalytic ozonation has recently attracted significant attention for its simultaneous boosted contaminant degradation and separation. In this work, catalytic ceramic nanofiber membranes ((MnFe0.05)@CNM) with MnFe dual-active site are prepared by anchoring FeOx nanoparticles onto Mn@CNM via an impregnation and in-situ precipitation method. The (MnFe0.05)@CNM coupled with catalytic ozonation was applied to the degradation of sulfamethoxazole (SMX), achieving a removal rate of up to 99.2 %. The catalytic degradation of SMX is verified by reactive oxygen species (ROS) quenching and EPR detection experiments, which shows that the 1O2, ·OH and O2·- are involved. Furthermore, (MnFe0.05)@CNM demonstrates superior catalytic stability, redox properties, and an abundance of acidic sites, as are revealed by H2-TPR and NH3-TPD analysis. The boosted performance is attributed to the synergistic catalysis by Mn and Fe bimetals under nano-confinement effect of membrane pores through facilitated electron transfer between Mn2+, Mn3+, Mn4+, Fe2+, and Fe3+, and promoting the decomposition of ozone and the generation of ROS. The nano-confinement effect of (MnFe0.05)@CNM also reduces the mass transfer distance between ROS and SMX, promoting ROS to attack the SMX molecules. This study presents a novel approach to developing catalytic ceramic membranes for the enhanced degradation of emerging contaminants in water.

Copper, Zinc, and Lead Recovery from Jarosite Pb–Ag Tailings Waste (Part 2)

The present paper describes the technological solution for obtaining Cu, Zn, Pb, and Ag from jarosite waste raw material, with its simultaneous separation from In and Fe. By roasting at low temperatures, iron was transformed from the Fe2(SO4)3 form into Fe2O3, which is insoluble in water and slightly soluble in acid. Copper sulfate and zinc sulfate are present in jarosite as sulfates. During temperature roasting, the copper and zinc were still in the form of CuSO4 and ZnSO4, i.e., they were easily dissolved in water. This procedure led to good selectivity of Cu and Zn compared to Fe. After water leaching, PbSO4 and Ag2SO4 remained in the solid residue. By treating jarosite with a content of 0.7% Cu, 5.39% Zn, and 5.68% Pb, products of commercial quality were obtained. By roasting jarosite in an electric furnace and leaching the roasted sample in water, leaching degrees of 91.07%, 91.97%, and 9.60% were obtained for Cu, Zn, and Fe, respectively. Using 1 M NaOH in the leaching solution, 99.93% Fe was precipitated to pH = 4. Cu in the form of CuSO4 was further treated by cementation with Zn, after which cement copper was obtained as a commercial product. Zn in the form of ZnSO4 was further treated by precipitation with Na2CO3 to obtain ZnCO3 concentrate of commercial grade. The total recovery of Pb and Ag, which were treated by chloride leaching, was 96.05% and 87.5%, respectively. The resulting NaPbCl3 solution was further treated with Na2CO3 solution, whereby PbCO3 was obtained as a commercial product. The produced PbCO3 could be further subjected to roasting to obtain soluble PbO. In these investigations, PbCO3 was smelted where a Pb anode was obtained; this was electrolytically refined to a Pb cathode. The proposed process does not pollute the environment with As and Cd.

Identification of 3-hydroxyaspartate with two chiral centers by capillary electrophoresis-mass spectrometry and vibrational circular dichroism independent of single enantiomer standard

Background3-Hydroxyaspartate(3-HA) is a non-proteinaceous amino acid whose four stereoisomers have different biological functions, making it meaningful to separate and analyze them. A combination of capillary zone electrophoresis-mass spectrometry (CZE-MS) and electron circular dichroism enables the separation and analysis of the four stereoisomers of 3-HA, but relies on enantiomeric standards. In contrast, the new method based on vibrational circular dichroism (VCD) can successfully confirm the peak order of the four enantiomers simultaneously without a single enantiomeric standard. This method is suitable for molecules without UV absorption, as well as for molecules with polychiral centers, and does not require enantiomeric standards. ResultsWe present a new analytical method based on CZE-MS coupled with VCD for the simultaneous determination of four stereoisomers of 3-HA with two chiral centers (D-threo-3-hydroxyaspartate, D-THA; L-threo-3-hydroxyaspartate, L-THA; D-erythro-3-hydroxyaspartate, D-EHA; L-erythro-3-hydroxyaspartate, L-EHA) in the absence of an optically pure single enantiomeric standard. The semipreparations of the non-racemic mixtures of DL-THA and DL-EHA were performed using high performance liquid chromatography (HPLC), with enantiomeric excess values reaching 90 %. By comparing the experimental VCD spectra of the DL-THA/DL-EHA mixture with the theoretical VCD spectra of the single L-THA/L-EHA enantiomer, the configuration of the dominant enantiomer in the nonracemic mixture was determined, where the two characteristic peaks in the 1250-1750 cm−1 spectral range fitted well. Finally, combined with the comparison of CE peak areas, the four stereoisomers were identified successfully. SignificanceThis is the first combined CZE-MS and VCD method for the simultaneous separation and analysis of four stereoisomers of 3-HA without relying on enantiomeric standards. This method is simple and reliable, and provides a new idea for the separation and analysis of chiral compounds with polychiral centers, which are difficult to obtain from enantiomeric standards.

Modeling and simulation of bi‐continuous jammed emulsion membrane reactors for enhanced biphasic enzymatic reactions

AbstractBi‐continuous jammed emulsion (bijel) membrane reactors, integrating simultaneous reaction and separation, offer a promising avenue for enhancing membrane reactor processes. In this study, we present a comprehensive macroscopic‐scale physicochemical model for tubular bijel membrane reactors and a numerical solution strategy for solving the governing partial differential equations. The model captures the co‐continuous network of two immiscible phases stabilized by nanoparticles at the liquid–liquid interface. We present the derivation of model equations and an efficient numerical solution strategy. The model is validated with experimental results from a conventional enzymatic biphasic membrane reactor for oleuropein hydrolysis, already reported in the literature. Simulation results indicate accurate prediction of reactor behavior, highlighting the potential superiority of bijel membrane reactors over current technologies. This research contributes a valuable tool for scale‐up, design, and optimization of bijel membrane reactors, filling a critical gap in this emerging field.

Paper Strips Functionalized with a Mixture of ZnO Nanotubes and Mn3O4 Nanoparticles for Simultaneous Separation of Blood Plasma and Detection of Physiological Iron Levels

Paper Strips Functionalized with a Mixture of ZnO Nanotubes and Mn₃O₄ Nanoparticles for Simultaneous Separation of Blood Plasma and Detection of Physiological Iron Levels

Simultaneous analysis of DL-Amino acids in foods and beverages using a highly sensitive chiral resolution labeling reagent

Amino acids with various functions are abundant in living organisms and foods. Recent advances in analytical technology show that trace amounts of D-amino acids exist in living organisms and foods. In addition, studies show that these amino acids are involved in various physiological functions that differ from those of L-amino acids. Thus, a technique for analyzing DL-amino acids is required. However, the simultaneous separation and highly sensitive detection of DL-amino acids are complicated; therefore, highly sensitive analytical methods that can rapidly separate and identify compounds are required. We previously developed our original chiral resolution labeling reagents for the separation and highly sensitive detection of DL-amino acids. Here, we developed a simple method for the rapid separation and highly sensitive detection of DL-amino acids in various foods and beverages by liquid chromatography–mass spectrometry (LC–MS) using an octadecyl (C18) column after labeling with 1-fluoro-2,4-dinitrophenyl-5-D-leucine-N,N-dimethylethylenediamineamide (D-FDLDA; enantiomeric excess > 99.9 %). In addition, we synthesized a stable isotope (13C6)-labeled D-FDLDA (13C6-D-FDLDA) and established an analytical method that can accurately identify the peak of each DL-amino acid. MS sensitivity of DL-amino acids labeled with our labeling reagent was higher than that of conventional labeling reagents (Marfey’s reagents). The labeling reagent was neither desorbed from each DL-amino acid nor degraded for at least 1 week at 4 °C. Furthermore, we determined the DL-amino acid contents in foods and beverages using the proposed method, and differences in the total amino acid content and D/L ratio in each food and beverage were observed.

Energy expenditure in the Z-type plate heat and mass exchanger based on the concept of heat-integrated distillation column

Thermal separation of substances typically involves the use of rectification columns equipped with condensers and reboilers. This conventional method is notably energy-intensive, necessitating substantial heat input to the reboiler and leading to significant waste heat discharge through the condenser into the environment. This paper presents our further study on an innovative alternative technology for thermal separation. The proposed approach involves conducting thermal separation within flow channels of a Heat and Mass Exchanger (HME), which are composed of plates with intricate geometries. In this system, heat distribution is maintained through the diaphragm, i.e., the channel walls, facilitating both heat exchange and simultaneous thermal separation of substances.This paper focuses on both laboratory and numerical investigations of two-phase flow within various channel geometries. Experimentally, four distinct channel designs were examined using an air–water mixture, aiming to identify a new geometry that facilitates countercurrent flow patterns in this challenging substance combination. The experimental phase led to the selection of a channel geometry that demonstrated the most effective countercurrent flow for intensive cases, then used for ethane-ethylene mixture. Subsequently, this selected geometry was subjected to numerical calculations using the mathematical model of the Heat and Mass Exchanger (HME). These calculations encompassed flow dynamics, thermal behavior, and the sizing of the HME, tailored specifically for the newly identified channel geometry.

Rapid and ecofriendly ultra performance liquid chromatographic analytical methodology for the simultaneous determination of four drugs included in COVID-19 treatment protocol

The global spread of COVID-19 disease has increased the demand for new therapeutic approaches. The clinical studies revealed that remdesivir and molnupiravir have been effective against COVID-19. Remdesivir (REM) is the first FDA-approved antiviral drug for COVID-19, while molnupiravir is the first oral antiviral drug for SARS-CoV-2 infections. In addition to antivirals, anticoagulants such as apixaban (APX) and antibiotics such as levofloxacin (LVF) are also included in the treatment protocols. This study suggests and validates a rapid and selective method for the determination of the four drugs involved in the COVID-19 treatment protocol. The simultaneous separation and determination of REM, MLP, LVF, and APX in human plasma were achieved using UPLC with a fluorophenyl column and a mobile phase composed of acetonitrile and water acidified with formic acid (pH = 3) in the ratio of 45: 55, v/v, at a flow rate of 0.1 mL/min. The PDA detector was adjusted at 254 nm. The method could simultaneously determine the four drugs in a single run in less than 6 min. The method exhibited linearity over the concentration ranges of 1.0–15.0 µg/mL, 0.1–5.0 µg/mL, 0.1–2.0 µg /mL, and 0.1–5.0 µg/mL, for LVF, MLP, APX and REM, respectively. The proposed method was validated following the International Council on Harmonization Q2(R1) guidelines and the findings were compared statistically to previously reported methods. The recovery rates of the drugs from spiked human plasma were satisfactory. The greenness of the suggested method was evaluated using three metrics, namely, Analytical Eco-scale, Green Analytical Procedure Index (GAPI) metric, and the Analytical GREEnness measure approach (AGREE).

Functionality-type and chemical-composition separation of poly(lactide-co-glycolide) using gradient elution normal-phase liquid chromatography with basic and acidic additives

End groups of poly(Lactide-co-glycolide) (PLGA) play an important role in determining the properties of polymers for use in drug delivery systems. For instance, it has been reported that the encapsulation efficiency in PLGA microspheres varies significantly between ester-terminated and acid-terminated PLGA. More importantly, the in-vivo degradation time of such polymer excipients is influenced by the functional end-group of the copolymer used.The end group distribution in PLGA polymers has been studied using electrospray and matrix-assisted laser-desorption/ionization – high-resolution mass spectrometry. In both cases, the application of these methods is typically limited to PLGA having a molecular weight of up to 4 kDa. 13Carbon-nuclear-magnetic-resonance has also been reported as a method to differentiate and quantify PLGA end groups with a molecular weight up to 136 kDa. However, reported NMR methods take over 12 h per sample, limiting throughput.Cryoprobe NMR can reduce the time required for the process, however such NMR equipment is costly, which makes it unsuitable for the quality control of PLGA.Here, we present a normal-phase liquid chromatography method capable of resolving functionality type distribution (FTD) and, partially, chemical composition distribution (CCD) in commercial PLGA polymers obtained from ring opening polymerization. This method can separate PLGA polymers with a molecular weight of up to 183.0 kDa while also enabling the simultaneous separation of the difference of Lactic acid (LA)/Glycolic acid (GA) ratios.To achieve this, a cross-linked diol column was used with a ternary gradient from HEX to 0.1 % v/v TEA in EA to 0.1 % v/v FA in THF to allow first for the elution of mono-ester terminated PLGA, followed by the di-acid terminated. In addition, a separation of ester-terminated PLGA in the difference of the LA/GA ratio was achieved.This method is expected to aid in understanding the correlation between PLGA's FTD, CCD, and physical properties, facilitating product development and quality control.

A Novel UHPLC-MS/MS Based Method for Isomeric Separation and Quantitative Determination of Cyanogenic Glycosides in American Elderberry.

LC-MS/MS analyses have been reported as challenging for the reliable separation and quantification of cyanogenic glycosides (CNGs), especially (R)-prunasin and sambunigrin isomers found in American elderberry (Sambucus nigra L. subsp. canadensis (L.) Bolli). Hence, a novel multiple reaction monitoring (MRM)-based ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated in the present study for simultaneous separation and quantification of five CNGs, including amygdalin, dhurrin, linamarin, (R)-prunasin, and (S)-prunasin (commonly referred to as sambunigrin). Initially, the role of ammonium formate was investigated as an aqueous mobile-phase additive in developing MRM-based UHPLC-MS/MS. Later, chromatographic conditions for the resolved separation of (R)-prunasin and sambunigrin were identified. Validation studies confirmed that the developed method has good linearity and acceptable precision and accuracy. A noticeable matrix effect (mainly signal enhancement) was observed in leaf samples only. This method was used to detect and quantify CNGs, including (R)-prunasin and sambunigrin, in leaf and fruit samples of American elderberry. Among the studied CNGs, only (R)-prunasin was detected in the leaf samples. Interestingly, (S)-prunasin (sambunigrin) was not detected in the samples analyzed, even though it has been previously reported in elderberry species.

Chip collection of hepatocellular carcinoma based on O2 heterogeneity from patient tissue

Hepatocellular carcinoma frequently recurs after surgery, necessitating personalized clinical approaches based on tumor avatar models. However, location-dependent oxygen concentrations resulting from the dual hepatic vascular supply drive the inherent heterogeneity of the tumor microenvironment, which presents challenges in developing an avatar model. In this study, tissue samples from 12 patients with hepatocellular carcinoma are cultured directly on a chip and separated based on preference of oxygen concentration. Establishing a dual gradient system with drug perfusion perpendicular to the oxygen gradient enables the simultaneous separation of cells and evaluation of drug responsiveness. The results are further cross-validated by implanting the chips into mice at various oxygen levels using a patient-derived xenograft model. Hepatocellular carcinoma cells exposed to hypoxia exhibit invasive and recurrent characteristics that mirror clinical outcomes. This chip provides valuable insights into treatment prognosis by identifying the dominant hepatocellular carcinoma type in each patient, potentially guiding personalized therapeutic interventions.

Simultaneously Selective Separation of Zearalenone and Four Aflatoxins From Rice Samples Using Co-Pseudo-Template Imprinted Polymers With MIL-101(Cr)-NH2 as Core.

A novel approach for the simultaneous separation of zearalenone (ZEN) and four types of aflatoxins (AFB1, AFB2, AFG1 and AFG2) from rice samples was presented. This approach utilized modified MIL-101(Cr)-NH2 as core, with molecularly imprinted polymers (MIPs) serving as the shell. The MIL-101(Cr)-NH2 was prepared via ring-opening reaction, while the imprinted polymers were synthesized using warfarin and 4-methylumbelliferyl acetate as co-pseudo template, ethylene glycol dimethacrylate as the cross-linker and azobisisobutyronitrile as initiator. The resulting co-pseudo-template-MIPs (CPT-MIPs) were thoroughly characterized and evaluated. Adsorption studies demonstrate that the adsorption process of CPT-MIPs follows a chemical monolayer adsorption mechanism, with imprinted factors ranging from 1.24 to 1.52 and selective factors ranging from 1.29 to 1.52. Self-made columns were prepared, and the method for separation was developed and validated. The limit of detections ranged from 0.12 to 2.09μg/kg, and the limit of qualifications ranged from 1.2 to 6.25μg/kg. To assess the reliability of the method, ZEN and AFs were spiked at three different levels, and the recoveries ranged from 79.53 to 94.58%, with relative standard deviations of 2.90-5.78%.

Validated chromatographic approach for determination of two ternary mixtures in newly approved formulations for helicobacter pylori eradication: assessment of greenness profile and content uniformity

A new, sensitive, and rapid isocratic reversed phase chromatographic method (RP-HPLC–UV) was developed for simultaneous separation of two newly co-formulated antiulcer mixtures; Amoxicillin, Vonoprazan and Clarithromycin [Mixture (I)], and Amoxicillin, Lansoprazole and Clarithromycin [Mixture (II)]. Analytical separation was performed using a Promosil C18 column and ultraviolet detection at 210 nm. The separation was achieved within only 8 min. For both mixtures, an aqueous solution, composed of (Acetonitrile: Methanol: 0. 2 M phosphoric acid) within ratio of (30: 30: 40) adjusted to final pH 3.0, was the mobile phase. This method was validated as per the International Conference on Harmonization guidelines. The linearity ranges of these proposed method of the (Mixture (I)) were 25.0–400.0 µg/mL Amoxicillin, 0.5–8.0 µg/mL Vonoprazan, and 12.5–200.0 µg/mL Clarithromycin. And the linearity ranges of the (Mixture (II)) were 10.0–300.0 µg/mL Amoxicillin, 0.3–9.0 µg/mL Lansoprazole and 5.0–150.0 µg/mL Clarithromycin. This method was firstly applied for effective separation of Amoxicillin, Vonoprazan and Clarithromycin [Mixture (I)]. It fulfilled good repeatability, sensitivity, and accuracy (R.S.D. < 2.0%). The mean recoveries of the analytes in their Tri-Pak formulations were acceptable. The greenness of the developed chromatographic methods was assessed using an Eco-scale method and it was applied for content uniformity testing as per the United States Pharmacopoeia (USP) and the acceptance value of Amoxicillin, in Mixture (I) was 2.88, the acceptance values for Amoxicillin, Lansoprazole in Mixture (II) were 2.592, 2.424, respectively.

HPLC-DAD method for concurrent estimation of netarsudil, latanoprost and benzalkonium chloride: Stability indicating study, impurity separation, assay of ophthalmic preparations and greenness/whiteness valuation

A validated, stability indicating, multiuse and sustainable HPLC-DAD method was developed for simultaneous determination and separation of the ophthalmic ternary mixture of netarsudil (NTS), latanoprost (LTP) and benzalkonium chloride (BZC) in presence of four related compounds and suspected impurities. Effectual liquid chromatographic separation was accomplished by using a Zorbax-SB Phenyl column with gradient elution of a mobile phase consisting of buffer mixture solution of phosphate and sodium pentane sulfonate (pH 3.0) and acetonitrile at flow rate 1.5 mL/min. DAD was tuned at 254 nm for measuring peak area of NTS and 210 nm for LTP and BZC. The proposed procedure showed to be effective in the stability investigation of the cited drugs. The suggested HPLC procedure was validated based on the International Council for Harmonization (ICH) guiding principles. The three analytes were determined within linearity ranges of 1–100 µg/mL, 5–200 µg/mL and 10–200 µg/mL for NTS, LTP and BZC respectively with excellent analytical performance. Assay of several ophthalmic preparations was successfully carried out using the validated method, which was further appraised together with some relevant reported methods in regard to green and white analytical chemistry aspects using AGREE and RGB-12 tools. Very few published analytical records were found for NTS/LTP mixture. After surveying the scientific literature, no documentation was retrieved for a similar inclusive stability-indicating impurity-profiling separative method for the synchronized quantitation of NTS, LTP together with co-formulated preservative BZC.

A Janus membrane with electro-induced multi-affinity interfaces for high-efficiency water purification.

Drinking water with micropollutants is a notable environmental concern worldwide. Membrane separation is one of the few methods capable of removing micropollutants from water. However, existing membranes face challenges in the simultaneous and efficient treatment of small-molecular and ionic contaminants because of their limited permselectivity. Here, we propose a high-efficiency water purification method using a low-pressure Janus membrane with electro-induced multi-affinity. By virtue of hydrophobic and electrostatic interactions between the functional interfaces and contaminants, the Janus membrane achieves simultaneous separation of diverse types of organics and heavy metals from water via single-pass filtration, with an approximately 100% removal efficiency, high water flux (>680 liters m-2 hour-1), and 98% lower energy consumption compared with commercial nanofiltration membranes. The electro-induced switching of interfacial affinity enables 100% regeneration of membrane performance; thus, our work paves a sustainable avenue for drinking water purification by regulating the interfacial affinity of membranes.