In recent years, green analytical chemistry has become essential in pharmaceutical research, aiming to mitigate environmental hazards associated with conventional analytical practices. The current focus lies in optimizing analytical methods to achieve both environmental and economic sustainability. In this framework, three environmentally sustainable spectrophotometric methods were developed for simultaneous analysis of three co-formulated drugs: acetaminophen, dextromethorphan hydrobromide, and pseudoephedrine hydrochloride, which are often used to alleviate symptoms associated with COVID-19. The employed spectrophotometric methodologies include the double divisor-ratio spectra derivative method, the mean centering of double divisor ratio spectra method, and the dual wavelength in ratio spectrum method. The innovative techniques displayed good linearity within 25–350 µg/mL for dextromethorphan hydrobromide, 2–24 µg/mL for acetaminophen, and 100–1400 µg/mL for pseudoephedrine hydrochloride. The environmental sustainability of the proposed methods was evaluated using the Analytical Eco-Scale, analytical greenness metric, and the Green Analytical Procedure Index. Furthermore, complementary evaluations of blueness and whiteness were conducted through the Blue Applicability Grade Index and the Red Green Blue 12 metric, respectively. The collective outcomes of all evaluation metrics clearly demonstrated that the proposed methods possess enhanced environmental compatibility and sustainability relative to the existing techniques. The proposed methods were fully validated according to the International Conference on Harmonization recommendations. The developed methods offered a cost-effective and eco-friendly approach for concurrent determination of acetaminophen, dextromethorphan hydrobromide, and pseudoephedrine hydrochloride in their bulk substances, and pharmaceutical formulations.
This study evaluated the performance of chicken manure-based biochar (CMBC), produced using a large-scale pyrolysis system (15 tons/day), for Zn removal from real zinc smelter wastewater. CMBC exhibited a maximum experimentally observed Zn adsorption amount of 36.37 mg/g. Kinetic and equilibrium data were better described by the Elovich and Langmuir models, respectively. Physicochemical characterization indicated that Zn removal involved multiple processes. Ion exchange accounted for an estimated 37.4
This study reports the development of a magnetically recoverable biosorbent based on Fusarium oxysporum (F. oxy) biomass functionalized with CuFe₂O₄ (CFO) nanoparticles and ZIF-67 for Cd²⁺ removal from synthetic solutions and real industrial wastewaters. Structural characterization using SEM, EDX-mapping, BET, VSM, and XRD confirmed the successful formation of the F. oxy/CFO/ZIF-67 composite, with the specific surface area increasing from 1.569 to 123 m² g⁻¹ after magnetic and MOF modification. FTIR analysis revealed the presence of hydroxyl, carboxyl, amine, and metal–oxygen functional groups, while the point of zero charge (pHpzc ≈ 6.5) indicated favorable electrostatic interactions with Cd²⁺ at near-neutral pH. The composite exhibited saturation magnetization of 11.179 emu g⁻¹, enabling rapid magnetic separation. Process optimization using response surface methodology based on a central composite design (RSM–CCD) showed excellent predictive accuracy of the quadratic model (R² = 0.9994, Adjusted R² = 0.999, Predicted R² = 0.9982), achieving Cd²⁺ removal efficiencies up to 99.17
Biochar can be used as soil amendment to improve crop growth. The production of biochar through pyrolysis and the composting process of Cow Dung and Sawdust were carried out, and the resulting products were characterized using Fourier Transform Infrared Spectroscopy (FTIR, Spectrum), proximate analysis, and physicochemical analysis. The determination of heavy metal concentrations was carried out using an Atomic Absorption Spectrophotometer (AAS, PerkinElmer 800). Results were compared with WHO and USEPA standard for soil quality and analyzed using descriptive and one-way ANOVA statistical analysis. The results obtained for proximate analysis; volatile matter gave mean values of 24.00–55.00
A multifunctional magnetic mesoporous carbon derived from polyethylene terephthalate (PET) waste plastic bottles and acid mine drainage (AMD-mag@PET-MPC) was employed for the adsorptive removal of perfluorooctanoic acid (PFOA) and perfluoroundecanoic acid (PFUnDA) in water systems. Under optimised conditions, the equilibrium data were best described by the Langmuir isotherm model with maximum adsorption capacities of 356 and 225 mg g−1 for PFOA and PFUnDA, respectively. The kinetic data best fit the pseudo-second-order kinetic model, suggesting that chemisorption is involved. The thermodynamic data suggested the feasibility of the random and spontaneous nature of the adsorption process. The adsorption mechanism involves hydrogen bonding, π–π interactions and electrostatic interactions. The AMD-mag@PET-MPC adsorbent was further applied as the extraction phase in the magnetic solid phase extraction (MSPE) of PFOA and PFUnDA in surface water and wastewater samples. Under optimised conditions, the analytical characteristics, such as linear range (1.7–5000 and 0.6–5000 ng/L), with a correlation coefficient (R2) above 0.99, were attained for both analytes. The limit of detection (LOD = 0.19–0.5 ng/L) and limit of quantification (LOQ = 0.6–1.7 ng/L) were achieved. The relative standard deviations (
