Chemical Science International Journal

Controlled Preparation of δ-Al\(_2\)O\(_3\) Nanoparticles Using Oil-in-Water Microemulsion method (O/W)

N’guessan Nicaise Eny, Aimé Serge Ello, Yann Aman, Ossonon Benjamin Diby — Tue, 19 May 2026 00:00:00 +0000

Alumina nanoparticles have attracted considerable attention as advanced materials due to their promising properties for applications in catalysis, electronics, adsorption, and biomedicine. Traditional synthesis methods for alumina particles show several limitations, such as irregular morphology, low dispersibility, and a narrow range of application. The oil-in-water (O/W) microemulsion process was used to synthesize alumina. The effect of the amount of alumina precursor, aluminum isopropoxide, and surfactant, Tween 40, was investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) coupled with EDX. The results of the structural analysis indicate that the synthesized alumina powders are δ-Al₂O₃ and showed spherical nanoparticles. A decrease in particle size was observed as the amount of Tween 40 varied from 2.72% to 5.44% and increased with the amount of aluminum isopropoxide. These results demonstrated that the oil-in-water microemulsion method provided an effective route for controlling the morphology, size and dispersibility of good purity alumina nanoparticles.

High Performance Thin Layer Chromatography (HPTLC) Method Development and Validation for Determination of Empagliflozin

Wed, 20 May 2026 00:00:00 +0000

Background: Empagliflozin is an antidiabetic drug used in the management of type 2 diabetes. Reliable and cost-effective analytical methods are required for its quality control in pharmaceutical formulations. This study focuses on developing and validating an HPTLC method for its accurate determination.

Aims: An SGLT2 inhibitor reduces glucose levels by increasing its excretion through the kidneys in the form of urine. Besides reducing the chances of death due to heart problems, it treats conditions such as chronic kidney disorders, heart failure, and type 2 diabetes mellitus. The estimation of pharmaceutical formulations of the recent formulation of empagliflozin that has been approved and marketed can be achieved through an HPTLC procedure that has been developed and validated.

Methodology: Precoated silica gel 60 F254 TLC plates were used in chromatography using toluene as a solvent system. The mobile phase is methanol:ethyl acetate (6:2:2 v/v/v). Detection was performed at 254 nm.

Results: Guidelines from the ICH were considered in validating the technique. For empagliflozin, the calibration curve was linear in the range 100-600 ng/band. The LOD and LOQ of empagliflozin were found to be 10.11 ng/band and 30.56 ng/band, respectively. Accuracy and precision of the proposed method were evaluated through recovery studies (the % recovery of empagliflozin was 99.88%), and intra-day and inter-day precision studies (the standard deviation values of precision studies were determined as 0.23-0.85 and 0.21-0.71, respectively).

Conclusion: This method is well-validated according to ICH guidelines, and from the statistical analysis we conclude that it is accurate, precise, sensitive, specific, and reproducible. Commercial form and bulk powder of empagliflozin can be analyzed routinely for quality control purposes.

Chemical Study of Cassane-type Diterpenoid Isomers from the Root Bark of Erythrophleum ivorense A. Chev. (Fabaceae)

Thu, 28 May 2026 00:00:00 +0000

Cassane-type diterpenoid alkaloids are among the major secondary metabolites reported in the genus Erythrophleum and are known for their important biological activities. In the present study, the methanolic extract of the root bark of Erythrophleum ivorense was investigated in order to isolate and characterize cassane-type diterpenoid isomers. Successive chromatographic separations of the ethyl acetate extract led to the isolation of two diterpenoid alkaloid isomers. Their structures were elucidated by combining IR, HR-ESI-MS, 1D and 2D NMR analyses. The two compounds exhibited the same molecular formula, C₂₅H₃₉NO₇, and were identified as N,N-dimethyl-3β,6α-dihydroxy-nor-cassane and N,N-dimethyl-3β,7α-dihydroxy-nor-cassane. These compounds had previously been reported in the genus Erythrophleum, but this work constitutes their first isolation from the root bark of Erythrophleum ivorense. This study contributes to the phytochemical knowledge of the species and confirms the richness of its root bark in cassane-type diterpenoid alkaloids.

Influence of the Drying Method on the Phytochemical Composition of Ethanolic Extracts of Avocado Seeds (Persea americana)

Sat, 30 May 2026 00:00:00 +0000

Plants constitute an important source of bioactive compounds that confer various medicinal and pharmacological properties. Due to this potential, their valorization represents a major challenge in the fields of scientific research, pharmacology, and industry. Interest in avocado has continued to grow in recent years, and although studies on its phytochemical composition are becoming increasingly numerous, those dedicated to the seed are still in their early stages. From the perspective of agro-food by-product valorization, a phytochemical screening was carried out on ethanolic extracts of avocado seeds obtained after sun drying and shade drying. The analyses revealed the presence of flavonoids, tannins, and saponins in both extracts. However, the absence of anthocyanins was observed in the shade-dried samples, whereas sterols and triterpenes were absent in the sun-dried samples. A complete absence of coumarins, alkaloids, and carotenoids was also noted in all extracts. Although the phytochemical composition of avocado seeds may be influenced by processing conditions, it nevertheless highlights a richness in relatively stable phenolic compounds, reflecting a strong antioxidant potential. These results therefore suggest a possible valorization of avocado seed extracts in industry, particularly as a source of natural antioxidants for the preservation of edible oils. In pharmacology, these extracts could also constitute a promising source of bioactive compounds exhibiting anti-inflammatory, cardioprotective, and insulin-regulating activities, thereby opening perspectives for the development of pharmaceutical products.

Groundwater Contamination by Iron, Manganese, and Antimony in the Bangéli Canton (Northern Togo): Speciation, Seasonal Mobility, and Health Risk Assessment

Tue, 09 Jun 2026 00:00:00 +0000

Background: Borehole groundwater is the primary source of drinking water in Bangéli canton, northern Togo, but increasing contamination by iron (Fe), manganese (Mn), and antimony (Sb), partly linked to geological conditions and past mining activities, raises concerns about water quality and human health.

Aims: This study investigated the speciation, mobility, seasonal variability, and health risks of antimony (Sb), iron (Fe), and manganese (Mn) in borehole groundwater from Bangéli canton, northern Togo.

Methodology: Four contaminated boreholes were monitored during dry and rainy seasons from 2024 to 2025. Physicochemical parameters (pH and Eh) were measured in situ. Total concentrations of Fe, Mn, and Sb were determined using ICP-OES, while trace-level confirmation and analytical validation were performed using ICP-MS. Metal speciation was interpreted using hydrogeochemical conditions and Pourbaix diagrams. Groundwater quality and health risks were assessed using the Heavy Metal Pollution Index (HPI) and the USEPA risk assessment model.

Results: Mean concentrations ranged from 1082.99 ± 685.38 to 1291.20 ± 980.42 µg/L for Fe, 184.21 ± 99.56 to 216.22 ± 133.15 µg/L for Mn, and 60.83 ± 21.57 to 248.49 ± 61.91 µg/L for Sb, exceeding WHO guideline values in most samples. Concentrations were generally higher during the rainy season, particularly for antimony. The dominant species were Sb(V), Fe²⁺, and Mn²⁺, indicating high mobility under prevailing hydrogeochemical conditions. Health risk assessment revealed significant non-carcinogenic risks, especially for children, with antimony as the major contributor. Hazard Index (HI) values exceeded acceptable limits.

Conclusion: Groundwater contamination is mainly controlled by hydrogeochemical processes and past mining activities, highlighting the need for continuous monitoring and improved water management strategies.

Assessment of Groundwater Quality for Drinking Purposes Using Water Quality Index (WQI) in Fianga Region, South-Western Chad

Al-Djazouli Ouchar Mahamat — Mon, 22 Jun 2026 00:00:00 +0000

Groundwater is an important source of water for domestic use in the town of Fianga, south-western Chad, but local information on its suitability for drinking remains limited. This study assessed groundwater quality using the Water Quality Index (WQI) approach and selected physicochemical parameters from 21 boreholes. The parameters considered were total dissolved solids, electrical conductivity, temperature, pH, Mg²⁺, Ca²⁺, K⁺, Na⁺, Cl⁻, HCO₃⁻, SO₄²⁻ and NO₃⁻. The results were compared with the drinking-water quality standards applied in the manuscript, and WQI values were calculated to classify the sampled boreholes. The borehole waters were generally acidic to neutral, and most measured parameters were within the recommended limits for drinking purposes. However, one borehole showed a nitrate concentration above the recommended threshold, indicating a possible localised influence of pollution. The WQI values ranged from 43.09 to 78.37. On the basis of the WQI classification, 57.14% of the sampled boreholes were classified as having excellent water quality, while 42.86% were classified as having good water quality. No borehole was classified as poor, very poor or unsuitable according to the WQI categories used in the study. These findings indicate that the groundwater sampled in Fianga is generally suitable for human consumption, although the borehole with elevated nitrate requires attention. The study provides baseline information for groundwater monitoring, planning and management in the area and highlights the need for continued assessment using a broader set of physicochemical parameters and a larger number of boreholes. The results can support local decision-making where groundwater is used for household supply.