Abstract This work introduces a novel, cost-effective, and sustainable ionic liquid–assisted cloud point extraction (IL-CPE) technique for the enrichment and spectrophotometric quantification of trace copper(II) at 436 nm. The method employs the complexation of Cu(II) with (Z)-4-bromo-2-(((2-hydroxyphenyl)imino)methyl)phenol at pH 6.5, succeeded by extraction with 1-butyl-3-methylimidazolium hexafluorophosphate and Triton X-114. Under optimal circumstances, the approach exhibited remarkable linearity (2.0–300 µg L⁻¹, R2 = 0.9997), substantial sensitivity with a preconcentration and enrichment factors 100 and 12.5, respectively, and a minimal detection limit of 0.6 µg L⁻¹. Precision and reliability of the novel IL-CPE method was validated by low relative standard deviation for 100 and 200 µg L⁻¹ (n = 10) was 1.6% and 2.0%, respectively, and accuracy was substantiated by the use of certified reference materials and actual environmental samples, encompassing water and food matrices. Moreover, the method’s environmental effect was meticulously assessed utilizing several Green Analytical Chemistry metrics (AGREE, AGREEprep, ComplexMoGAPI, AGSA) and practical indices (BAGI, CACI). The evaluation via the RGB algorithm and Carbon Footprint Reduction Index (CaFRI) verifies that this method is a sustainable, eco-friendly, and very dependable option for regular trace metal detection.

. A comprehensive eco-friendly stability-indicating RP-HPLC method has been developed and validated for the determination of molnupiravir in dosage forms. Molnupiravir quantification was carried out on the Luna C8 column (4.6 mm x 250 mm, 5 mu m, 100 & Aring;) from Phenomenex, USA, and set at 25 degrees C. The mobile phase consists of water: ethanol (60:40 v/v), at a flow rate of 0.5 mL/min. The injection volume was 20 mu L, and detection was implemented at 236 nm. The devised method was validated in accordance with ICH requirements and was discovered to be linear within the range of 0.25-100 mu g/mL with a regression coefficient (R2) equal to 0.9999. Molnupiravir was exposed to acidic, basic, oxidative, thermal, and photolytic stress conditions. The accuracy was about 100.69 +/- 0.11%, the limits of detection and quantification are 0.0086 and 0.026 mu g/mL, respectively, and the intra- and inter-day precision with RSD% did not exceed 1.0%. The total analysis time was less than 7.0 minutes, establishing this method as proper for regular quality control evaluations of molnupiravir. The inclusion of absolute ethanol was required in order to obtain a sufficient resolution. Three methods were used to assess the sustainability.

A novel trisphosphorylated Schiff-base adsorbent (PTREN) was developed and statistically validated for targeted samarium(III) recovery from leachates of spent SmCo permanent magnets. Structural and physicochemical characterization via Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS), thermogravimetric and derivative thermogravimetric analysis (TGA/DTG), x-ray diffraction (XRD), scanning electron microscopy (SEM), and N-2-sorption confirmed successful phosphonate functionalization (Brunauer-Emmett-Teller [BET]), thermal stability up to approximately 430 degrees C, and a hierarchical microporous-mesoporous architecture with a BET surface area of 68.47 m(2) g(-1). Batch adsorption studies demonstrated pronounced pH sensitivity, with maximum Sm(III) removal at pH 5.0-proximate to the point of zero charge-and rapid equilibrium within 45 min using 0.05 g adsorbent, yielding a maximum uptake capacity of 456.4 mg g(-1). Kinetic modelling confirmed pseudo-second-order behaviour (R-2 = 0.9938), supported by Elovich and intraparticle diffusion analyses, indicating chemisorption dominance with multi-stage mass-transfer contributions. Equilibrium data conformed to the Langmuir isotherm (R-2 = 0.9948; q max = 454.55 mg g(-1); R L = 0.011-0.060), while Dubinin-Radushkevich analysis yielded a mean adsorption energy of 28.87 kJ mol(-1), corroborating inner-sphere Sm-O-P coordination. Thermodynamic parameters indicated a spontaneous (negative Delta G degrees), endothermic (Delta H degrees = +9.097 kJ mol(-1)), and entropy-driven (Delta S degrees = +40.152 J mol(-1) K-1) process. Response-surface methodology and ANOVA yielded a robust quadratic predictive model (R-2 = 0.9874; CV% = 2.85%), identifying initial Sm(III) concentration and adsorbent dosage as dominant variables, with a non-significant lack-of-fit. Stripping with 0.5 mol L-1 HNO3 enabled crystalline Sm2O3 recovery, while PTREN retained above 85% capacity over nine regeneration cycles, confirming its viability for closed-loop, industrially scalable samarium recovery.

Monothioglycerol predominantly acts as an antioxidant in injectable solutions, inhibiting the oxidation and degradation of medications that are sensitive to oxygen, alongside other formulation ingredients. It scavenges free radicals and ceases the chemical chain reactions that result in instability. A thorough, swift, straightforward, and eco-friendly stability-indicating liquid chromatography (LC) method has been developed and validated, facilitating the measurement of monothioglycerol concentrations in injectable solutions. The antioxidant was studied through several tests in accordance with ICH guidelines, including characteristics such as forced degradation studies. Through isocratic separation, monothioglycerol and its related degradants were effectively resolved. The antioxidant was determined using an end-capped octadecylsilyl (C18) column, and the method was validated under room temperature conditions. The isocratic mobile phase operates at a flow rate of 1.0 mL/min and consists of fixed ratios of filtered water, acetonitrile, and orthophosphoric acid. The overall AES grade of 86, AGREE grade of 0.64, MoGAPI grade of 76, BAGI grade of 75.0, and ultimate whiteness of 95.8 all highlight the ecological advantages of the HPLC method. The current research indicates that the proposed methodology is unique, precise, accurate, stable, and environmentally beneficial at a microscale, making it suitable for routine quality control analysis.

Developing and validating a stable, environmentally friendly technology to quantify the amounts of nicotinamide and cocarboxylase, in addition to adenosine triphosphate, in bulk and in dosage form for freeze-dried injections through micro-scale sample preparation is the main goal of the intended study. The green mobile phase used was 0.025 M potassium dihydrogen phosphate at pH 6.0. The adenosine triphosphate concentration range was 20.24–202.4 µg/mL, the cocarboxylase concentration range was 101.04–1010.4 µg/mL, and the nicotinamide concentration range was 40.24–402.4 µg/mL with correlation coefficient R2 ≥ 0.999. The final AES of 84, CACI grade of 74, AGSA grade of 77.78, score of AGREEprep = 0.76, score of MoGAPI = 76, score of BAGI = 82.5, and whiteness of 85.8 all showed how sustainable the system was. ICH validation parameters, cost-effectiveness, and environmental friendliness, in contrast with the published techniques as stated below, are some of the distinctive qualities of the approach being offered.

This work seeks to develop and validate a straightforward, rapid, economical, sensitive, and extractive spectrophotometric technique for the quantification of bromocriptine mesylate (BMC) in both pure form and pharmaceutical formulations. The devised methods rely on the production of ion-pair complexes between bromocriptine mesylate and three dyes: bromocresol purple (BCP), methyl orange (MO), and alizarin red S (ARS) in acidic buffer solutions. The various parameters influencing the response between bromocriptine mesylate and the dyes were examined and optimized. The synthesized complexes were extracted using methylene chloride and analyzed at 409, 424, and 428nm with BCP, MO, and ARS, respectively. Beer’s law was adhered to within the ranges of 1.0–16, 1.0–24, and 1.0–20μg mL-1 while employing BCP, MO, and ARS, respectively, under optimal conditions. The ion pairs were determined to have a 1:1 composition. The molar absorptivity, Sandell’s sensitivity, and the limits of detection and quantification were computed. Additional method validation metrics, including intra-day and inter-day accuracy and precision, robustness, ruggedness, and selectivity, have been assessed. The proposed methodologies have been effectively utilized for the analysis of bromocriptine mesylate in both its pure form and pharmaceutical formulations. The methods' reliability was further confirmed through recovery trials utilizing the usual addition technique. A statistical comparison of the results with the reported approach was conducted using Student's t-test and F-test, revealing no significant statistical differences.

A straightforward and validated vortex-assisted dispersive microsolid-phase extraction method for the separation and preconcentration of cobalt and nickel ions in real samples (water, juice, and food) prior to their determination by flame atomic absorption spectrometry (FAAS) was developed. The suggested technique utilizes adsorbent, modified multiwalled carbon nanotubes, in conjunction with a new complexing agent, 3-benzyl-4-p-nitrobenzylidenamino-4,5-dihydro-1,2,4-triazole-5-thiol, which complexes with cobalt and nickel ions at pH 7.0. The impact of various parameters has been examined and refined. The calibration curves exhibited linearity throughout the ranges of 2.0-500 and 5.0-400 mu g L-1, with limit of detections of 0.60 and 1.5 mu g L(-1 )for cobalt and nickel ions, respectively, under optimal circumstances. The preconcentration factor was 200. Cobalt and nickel have maximum sorption capacities of around 400 and 450 mg g(-1), respectively. The recovery rates of the analytes varied between 95.0% and 100%. Additionally, the relative standard deviation (RSD%) for intra-day (1.80% and 2.40%) and inter-day (1.50% and 2.0%) measurements indicates the repeatability for determination of cobalt and nickel ions, respectively. Certified reference materials were employed to validate the precision of the suggested preconcentration process. The suggested method effectively determined the concentrations of cobalt and nickel ions in several real environmental samples.

Antioxidants can maintain the medication's quality throughout production and storage, with acceptable limits during shelf life potentially being lower than release limits, provided that other quality attributes are met; they may reach to be NLT 5 % (or lower) from the target amount in the medication formula at shelf life which may reach to be totally consumed within a short period of time like within a month from the manufacturing process time. Sodium bisulfite (SBS) is used as a chemical preservative and antioxidant in oral suspensions containing nystatin, methylparaben sodium, and propylparaben sodium. SBS itself isn't the active therapeutic ingredient, its role as a preservative/antioxidant is therapeutically critical for maintaining the efficacy and safety of the drug product. By developing and validating a complete, innovative, fast, gradient, and green shelf life liquid chromatography methodology, sodium bisulfite levels in oral suspensions can now be measured. The challenges that were faced during the method development are; the matrix interference effect with the SBS main peak while considering isocratic method and the long run time, so we relied on the current gradient mode, moreover the reliance on usage of the current specific column with the low particle size was the best choice to get the well resolved SBS peak, additionally the preclusion of ethanol which is greener than acetonitrile was owing to the high back pressure of ethanol on the column's small particle size and the interference that was resulted with the sample matrix with ethanol. A number of tests were performed on the antioxidant compound in accordance with ICH and US FDA guidelines. Sodium bisulfite and its related degradants were effectively separated via gradient separation. At room conditions, the Shim-pack C-18 stationary phase was used to quantify and validate the antioxidant. The gradient mobile phase runs at a flow rate of 1.0 mL/min. It includes varying concentrations of phosphate buffer at pH 2.5 and acetonitrile. The positive environmental impacts of the LC technique are demonstrated by the combined Eco Scale (AES) grade of 90, Analytical Greenness Metric technique (AGREE) grade of 0.63, Analytical Greenness Metric for Sample Preparation (AGREEprep) rating of 0.62, Click Analytical Chemistry Index (CACI) rating of 64, Analytical Green Star Area (AGSA) rating of 63.89, Modified Green Analytical Procedure Index (MoGAPI) rating of 82, Blue Applicability Grade Index (BAGI) rating of 77.5, and final whiteness rating of 95.8. Concerning the current paper, the proposed methodology is unique and true, with a recovery percentage range of 97.67 to 99.1 %; linear within the range of 10-200 mu g/mL with a correlation coefficient R-2 of 0.99978; strong, with an average inter-day precision of 100.62 % and a pooled RSD% < 2 %, and an average intra-day precision of 100.67 % with a pooled RSD% < 2 %; sensitive, with a detection limit of 3.22 mu g/mL and a quantitation limit of 9.77 mu g/mL; and environmentally beneficial, making it suitable for regular quality control inspections.

The current research focuses on creating and validating two straightforward, sensitive, precise, and cost-effective spectrophotometric techniques for detecting an irreversible inhibitor of monoamine oxidase: selegiline hydrochloride in its pure form and in pharmaceutical formulations. The methods rely on creating a charge transfer complex between selegiline hydrochloride as the n-electron donor and either quinalizarin or alizarin red S as the π-acceptor in methanol. This results in the formation of highly colored chromogens with absorption peaks at 567 and 530 nm for quinalizarin and alizarin red S, respectively. The study examined the optimization of reaction parameters. Beer's law is followed within the concentration ranges of 1.0–18 μg mL-1 using quinalizarin and 1.0–20 μg mL-1 using alizarin red S under ideal conditions. This is supported by a high correlation coefficient (r2 ≥ 0.9996) and a low relative standard deviation (RSD% ≤ 1.10). The detection and quantification limits were determined to be 0.30 and 1.0 μg mL-1 for quinalizarin and 0.29 and 0.97 μg mL-1 for alizarin red S. The results obtained using the proposed approaches for the pure selegiline hydrochloride and commercial tablets closely matched those obtained using the reported method. KEY WORDS: Alizarin red S, Charge transfer reaction, Dosage forms, Quinalizarin, Selegiline hydrochloride, Spectrophotometry Bull. Chem. Soc. Ethiop. 2026, 40(9), 1975-1988. DOI: https://dx.doi.org/10.4314/bcse.v40i9.11

A novel organic bis-azo reagent, 2,2′-(2,4-dioxopentane-3,3-diyl)bis(diazene-2,1-diyl)dibenzoic acid (DBDA), was synthesized using lanthanum hydroxide nanorods (LHNRs) as a nanocatalytic support, reducing reaction time to 2 min. The LHNRs were comprehensively characterized by FT-IR, SEM-EDX, TEM, XRD, and surface area analyses. DBDA formed a stable green complex with Cu(II) (Cu-DBDA) with maximum absorbance at 421 nm. Under optimized conditions, the method obeyed Beer–Lambert's law over 1–22 µg mL⁻¹, with a molar absorptivity of 0.23 × 10⁴ L mol⁻¹ cm⁻¹, Sandell's sensitivity of 0.029 µg cm⁻², LOD of 0.31 µg mL⁻¹, LOQ of 0.94 µg mL⁻¹, and RSD of 0.71%. The complex developed within 5 min and remained stable for 3 days, with high selectivity for Cu(II) over numerous interfering ions. The method was successfully applied to copper determination in water, food, and urine samples; its greenness was confirmed by ComplexMoGAP and BAGI metrics. Both DBDA and the solid Cu–DBDA complex were fully characterized by FT-IR, SEM-EDX, TEM, XRD, ¹H/¹³C NMR, mass spectrometry, thermal analysis, and elemental analysis. DFT calculations supported the formation of a distorted square-planar Cu(II) complex with an N₂O₂ coordination environment. TD-DFT analysis revealed a reduced frontier orbital gap and ligand-to-metal charge-transfer contributions, consistent with the experimentally observed bathochromic shift from 370 to 421 nm upon complexation. In vitro cytotoxicity assays revealed selective anticancer activity against PC-3 and HCT-116 cell lines, with enhanced potency for Cu-DBDA and reduced toxicity toward normal WI-38 cells, corroborated by molecular docking studies showing superior binding affinity of Cu-DBDA to key cancer targets.

The present study aimed to develop, optimize, and validate a novel, cost-effective, environmentally sustainable, and stability-indicating HPLC method for the determination of remifentanil in both bulk drug substance and lyophilized parenteral dosage forms. The mobile phase consisted of double-distilled water and ethanol (750:250 V:V), delivered at a flow rate of 1.0 mL/min. The method demonstrated excellent linearity over the concentration range of 10–100 μg/mL, with a correlation coefficient (R2) of 0.9995. Chromatographic detection was performed at 210 nm using a 10 μL injection volume, and the total analysis time was less than 6 min.The proposed method exhibited outstanding environmental and analytical performance, achieving an Analytical Eco-Scale (AES) score of 90 with other greenness metrics. These metrics collectively demonstrate the method's high level of sustainability, greenness, whiteness, and cost-effectiveness. Furthermore, the method was successfully validated in accordance with the current ICH, EMA, USP, BP, and US FDA guidelines. Compared with more sophisticated techniques, such as UPLC-MS, the proposed method offers several advantages, including shorter analysis time, reduced solvent consumption, lower operating costs, and suitability for routine quality control.

The sustainable recovery of rare earth elements (REEs) from secondary resources is essential as demand rises and primary ores face economic and environmental constraints. Here, a tris-phosphorylated Schiff-base ligand (PTREN) is rationally constructed as a molecular adsorbent for highly selective uptake of Sm3+ from spent SmCo magnet leachates. The three phosphonic acid groups create a pre-organized, multidentate O-donor pocket tailored for inner-sphere Sm3+ coordination. PTREN was thoroughly characterized by FTIR, NMR, XPS, TGA, BET, and MALDI-TOF, confirming its discrete structure and stable phosphonate functionality. Batch experiments show fast kinetics (equilibrium in 45 min) and a high Langmuir capacity of 469.4 mg g-1 at pH 5.0. Isotherm, kinetic, and thermodynamic analyses collectively indicate monolayer chemisorption, a spontaneous and endothermic process, and increased interfacial disorder upon binding. Sm3+ is efficiently desorbed with 0.5 M HNO3 and converted to high-purity Sm2O3 nanoparticles, closing the material loop. PTREN maintains over 85% of its initial capacity after nine adsorption - desorption cycles, evidencing excellent structural robustness and regenerability. This work introduces a tunable phosphonate-based molecular platform that couples selective Sm recovery from complex waste streams with direct generation of value-added oxide products, advancing circular REE recycling. A full list of abbreviations and acronyms used throughout this manuscript is provided in Table S-1 of the Supporting Information.

A high-sensitivity potentiometric iodide sensor was fabricated using tricaprylylmethylammonium chloride (TCMACl) as an ion exchanger incorporated into a PVC matrix. The constructed electrode demonstrated high performance characteristics toward I-ion, with a Nernstian slope of-59.2 +/- 0.17 mV/decade, a wide dynamic working range extending from 5 x 10-7to 5 x 10-2 M, and a low detection limit of 5.0 x 10-7 M. The proposed electrode was characterized by its fast response time of 4 s toward the analyte during calibration and the evaluation of iodide in samples. The surface of the prepared membrane was examined using SEM-EDX analysis, supported by mapping, and the stability of TCMACl in the membrane was studied using a mass loss method. The responsive sensor successfully determined the iodide concentration in antiseptic pharmaceutical drugs, achieving an average recovery of 96 % with a relative standard deviation (RSD) of 1.81 %. Additionally, the constructed sensor was applied as an indicator electrode in the potentiometric titration of AgNO3 against KI solution.