In this study, a simple and sensitive spectrophotometric method was developed for the determination of ceftriaxone based on an oxidative coupling reaction with the reagent N,N-diethyl-p-phenylenediamine, using sodium periodate as the oxidizing agent in an acidic medium. The reaction produced a red-colored compound with a maximum absorption at 562 nm. The method showed good linearity within the concentration range of 6–60 µg/mL, characterized by a high correlation coefficient (r = 0.9999) and a molar absorptivity of 6488.58 liters · mol⁻¹·cm⁻¹, whilst the limit of detection (LOD) and limit of quantification (LOQ) were 0.37 and 1.11 µg/mL, respectively. The method also demonstrated good precision and reproducibility, with a relative standard deviation (RSD) not exceeding 0.57 percent, and the results of the interference and standard-addition studies confirmed its suitability for determining ceftriaxone in pharmaceutical preparations. The results indicate that the proposed method provides a simple, reliable, and sensitive analytical tool for the routine analysis of pharmaceutical preparations.
This study investigated the effect of the TiO₂/ZnO ratio on the functional groups, crystalline phases, and morphology of TiO₂/ZnO–HAp composites derived from blood cockle shell waste, Anadara granosa. Hydroxyapatite (HAp) was synthesized from blood cockle shells by a precipitation method and subsequently combined with TiO₂ and ZnO at TiO₂:ZnO:HAp mass ratios of 1:2:1 (Sample A) and 2:1:1 (Sample B). The composites were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The FTIR results indicated the presence of O–H and PO₄³⁻ groups characteristic of HAp, together with metal–oxygen vibrational bands in both samples. XRD analysis showed that Sample A consisted of 40.4% zincite (ZnO), 38.5% HAp, and 21.1% anatase (TiO₂), whereas Sample B consisted of 53.2% anatase, 23.5% HAp, and 23.3% zincite. SEM analysis showed that Sample A formed relatively regular aggregates ranging from 1.5–5.0 µm, with an average size of 2.85 ± 0.72 µm, whereas Sample B exhibited more irregular aggregates ranging from 2.0–12.0 µm, with an average size of 5.42 ± 1.85 µm. These results indicate that variation in the TiO₂/ZnO ratio was associated with differences in the crystalline-phase distribution and morphology of the TiO₂/ZnO–HAp composites, with the increased TiO₂ proportion in Sample B was accompanied by a higher relative contribution of the anatase phase.
Oil palm empty fruit bunch (OPEFB) is a cellulose-rich lignocellulosic residue generated in large quantities by the palm oil industry, particularly in Malaysia and Indonesia, yet remains substantially underutilized. Converting OPEFB into cellulose nanocrystals (CNC) provides an opportunity to valorize this waste into high-value materials. This systematic review synthesized the literature on OPEFB-derived CNC following the PRISMA 2020 framework. Structured searches covering 2015–2026 combined OPEFB, cellulose nanocrystal/nanocrystalline cellulose, and extraction-technology terms. Thirty-nine eligible primary and secondary sources were synthesized through narrative analysis, comparative tables, and a PRISMA flow diagram. Sulfuric acid hydrolysis remains the most extensively studied extraction route, generally producing rod-like CNC with nanometre-scale diameters and crystallinity indices of approximately 55–70%. Emerging deep eutectic solvent (DES) approaches, particularly choline chloride-based systems combined with process intensification or solvent recovery, demonstrate promising reductions in production cost and global warming potential. TEMPO oxidation, enzymatic and ionic-liquid pretreatments, and ultrasonic- or microwave-assisted processes provide alternative advantages in selectivity, mild processing, or energy efficiency. However, trade-offs in yield, processing time, and complexity remain. OPEFB-derived nanocellulose has been explored for cementitious composites, polymer nanocomposites, adsorption, drug delivery, and flexible energy-storage applications. Key gaps include inconsistent reporting of yield and crystallinity, limited OPEFB-specific techno-economic and life-cycle assessments, and scarce pilot-scale validation. Future research should emphasize standardized reporting, solvent-recycling-integrated green extraction, continuous biorefinery processing, and integrated techno-economic and life-cycle assessments to support the development of a circular bioeconomy in palm-oil-producing regions.
Colored peat water containing high concentrations of humic substances poses a significant challenge for conventional water treatment processes. In this work, a magnetically recoverable Fe3O4/UiO-66 composite was synthesized from zircon sand processing residues and magnetic waste as precursors and evaluated as a photo-Fenton catalyst for humic acid degradation. Magnetite (Fe3O4) was prepared from magnetic residues, while UiO-66 was synthesized from zircon-derived precursors, followed by solvothermal fabrication of Fe3O4/UiO-66 composites with different mass ratios. Structural and morphological characterization using FTIR, XRD, and SEM confirmed the formation of a crystalline magnetite integrated with a porous UiO-66 framework, indicating a heterogeneous architecture favorable for catalytic applications. Photo-Fenton performance tests under UV irradiation demonstrated that the Fe3O4/UiO-66 composite with a 1:2 mass ratio exhibited the highest humic acid removal efficiency, reaching approximately 93.6%, outperforming pristine Fe3O4 and UiO-66. Optimization of hydrogen peroxide dosage revealed that volumes between 0.75-1.0 mL provided optimal radical generation without noticeable scavenging effects. Kinetic analysis indicated that the degradation process followed a pseudo-second-order model, suggesting that surface-mediated radical interactions governed the reaction. Overall, the results demonstrate the feasibility of converting zircon-processing residues into a functional and magnetically recoverable Fe3O4/UiO-66 catalyst for humic acid treatment.
The purpose of this study was to explore the potential of pigment components from matoa fruit peels from Manokwari, West Papua, as dye sensitizers and to analyze the resulting electrical characteristics. Pigments were extracted via maceration, and the DSSC was fabricated using titanium dioxide as the photoanode. The electrical characteristics were determined by measuring the open-circuit voltage (Voc) and short-circuit current (Isc) under direct sunlight exposure. Additional analyses included phytochemical screening to identify secondary metabolites, UV-Vis spectroscopy to determine absorption wavelengths and pigment absorbance, and IR spectroscopy to identify functional groups. The results showed that the purple matoa fruit peel pigment can be used as a dye sensitizer for DSSC. The DSSC prototype showed a positive response to changes in solar radiation and generated Voc and Isc for 70 minutes (measurement duration). The measured Voc ranged from 19.8 mV to 74.6 mV, with a mean ± SD of 49.77 ± 14.54 mV within a solar radiation range of 135.2–1072.0 Wm⁻². Meanwhile, the measured Isc ranged from 1.6 μA to 5.5 μA, with a mean ± SD of 4.05 ± 1.29 μA within a solar radiation range of 137.3–1172.0 Wm⁻². The presence of water may influence the relatively low Voc and Isc values obtained.
