Indonesian Journal of Chemical Analysis (IJCA)

From Mesoporous Silica to MOF–Silica Composites: Advancements in Nanostructured Drug Delivery Systems

2025-12-31T01:20:20+00:00

Recent advances in nanotechnology have enabled the development of versatile drug delivery systems (DDS) using nanoscale carriers, offering significant improvements over conventional therapies. Mesoporous silica nanoparticles (MSNs) and metal–organic frameworks (MOFs) are highly porous nanomaterials with tunable structures and large surface areas, making them promising platforms for drug delivery. MSNs provide controllable particle size, pore size, and surface functionality, allowing efficient loading and controlled release of both hydrophilic and hydrophobic drugs. MOFs, with their high surface area, adjustable pore structures, and chemical versatility, enable high drug loading capacity and stimuli-responsive release. Integrating MOFs with silica to form MOF–silica composites further enhance structural stability, biocompatibility, and drug delivery efficiency. Stimuli-responsive composites can minimize premature drug release and enable targeted delivery in response to environmental triggers, such as pH or near-infrared irradiation. This review highlights the structural and functional differences among MSNs, MOFs, and MOF–silica composites, and discusses their applications in delivering model therapeutic agents, including curcumin, quercetin, and doxorubicin. The advantages, limitations, and future perspectives of these nanocarriers for precision medicine are also addressed, emphasizing their potential to improve therapeutic efficacy while reducing off-target effects.

Microalgae for CO₂ Capture Under Extreme Conditions and Its Biomass: A Mini Review

2026-02-06T02:59:57+00:00

The continuous increase in carbon dioxide (CO₂) emissions has raised atmospheric CO₂ concentrations to over 420 ppm. This has become one of the main drivers of global climate change, underscoring the need for efficient, sustainable mitigation strategies. Microalgae offer great potential for CO₂ capture. As photosynthetic organisms, microalgae use CO₂ for growth. They are reported to have photosynthetic efficiencies 10–50 times higher than those of terrestrial plants and to grow in various media, making them superior for carbon utilization. However, most conventional microalgae cannot thrive under extreme conditions, such as low pH (<4), high temperatures (>35 °C), high CO₂ levels (>10%), or the presence of pollutants like sulfur dioxide (SO₂) and nitrogen oxides (NOₓ). Extremophilic microalgae are species capable of surviving in highly acidic conditions, elevated temperatures, and environments contaminated with SO₂ and NOₓ. This makes them highly promising candidates for CO₂capture under extreme conditions. Furthermore, microalgae capture CO₂ and convert it into high-value biomass, thereby enhancing their value as CO₂ capture agents.

A Review on the Potential of UiO-66-NH₂ Metal-Organic Framework as a Proton Exchange Membrane in Microbial Fuel Cells

2026-02-23T15:00:05+00:00

The escalating global demand for energy has accelerated the development of efficient and environmentally sustainable renewable energy technologies. Among these, Microbial Fuel Cells (MFCs) have emerged as a promising bioelectrochemical system capable of converting chemical energy derived from organic substrates into electrical energy through microbial metabolism. A critical component influencing MFC performance is the Proton Exchange Membrane (PEM), which facilitates the selective transport of H⁺ ions from the anode to the cathode while preventing substrate crossover. Conventional PEM materials, such as Nafion, exhibit several limitations, including high cost and suboptimal performance under specific operational conditions. Consequently, recent research has increasingly focused on the development of Mixed Matrix Membranes (MMMs) that integrate polymer matrices with inorganic fillers, particularly Metal–Organic Frameworks (MOFs), to enhance membrane properties. Among various MOFs, UiO-66-NH₂ has attracted considerable attention due to its exceptional chemical and thermal stability, as well as the presence of amine (-NH₂) functional groups that improve hydrophilicity and facilitate proton transport pathways. This review evaluates the potential application of UiO-66-NH₂ as a functional filler in polyvinylidene fluoride (PVDF)-based membranes to enhance PEM performance in MFC systems. Evidence from recent studies indicates that incorporating UiO-66-NH₂ into PVDF matrices can significantly improve proton conductivity while maintaining adequate mechanical strength, positioning this composite membrane as a promising and sustainable alternative for advanced bioelectrochemical energy technologies.

Total Alkaloid Determination in Ethanolic Extract of Cocoa (T. cacao) and Robusta Coffee (C. canephora) Beans using TLC-Densitometric Method

2025-06-18T02:00:51+00:00

Alkaloids are a major class of bioactive secondary metabolites commonly found in various natural products, including cocoa (Theobroma cacaoL.) and robusta coffee (Coffea canephora). These compounds have been widely reported to exhibit important pharmacological activities, including antioxidant, antidiabetic, antifungal, and antibacterial effects, making them valuable candidates for the development of pharmaceutical and functional herbal products. This study aimed to provide reliable quantitative data on the total alkaloid content of ethanolic extracts from cocoa (Theobroma cacao L.) and robusta coffee (Coffea canephora) beans using the TLC-densitometric method, thereby supporting the standardization, quality control, and potential pharmaceutical applications of these natural materials. However, alkaloid was extracted and fractioned from cocoa and robusta coffee beans using ethanol and chloroform. The total alkaloids in the ethanolic extracts of cocoa and robusta coffee beans were identified by TLC-Densitometry, with average Retardation factors (Rf) of 0.321 and 0.771, respectively. Caffeine was used as a standard. The quantification of total alkaloid in the ethanolic extract of cocoa and robusta coffee beans was 2.003% per 50 mg and 11.713% w/w per 10 mg extract, respectively. In summary, cocoa and robusta coffee beans show promising potential as herbal medicines because they contain substantial levels of pharmacologically active alkaloid compounds.

Biodiesel Synthesis with Different Feedstock Oils: Free Fatty Acid Analysis and Fuel Properties Characterization

2026-01-04T11:39:19+00:00

The present study evaluates the feasibility of non-edible and waste oils as sustainable feedstocks for biodiesel production through a two-step esterification–transesterification process. Waste cooking oil, Calophyllum inophyllum oil, and sunflower oil were employed as raw materials, with sodium hydroxide used as the base catalyst during transesterification. The initial free fatty acid content varied significantly among the feedstocks, ranging from 29.38% in Calophyllum inophyllum oil to 3.20% in waste cooking oil and 1.28% in sunflower oil. Acid-catalyzed esterification effectively reduced the free fatty acid levels, enabling efficient conversion during the subsequent transesterification step. Fourier transform infrared spectroscopy confirmed the successful formation of fatty acid methyl esters, indicated by the presence of characteristic ester functional group absorption bands. Methyl oleate is the dominant component in all biodiesel samples, reaching 83.12% in sunflower oil biodiesel. The produced biodiesel exhibited kinematic viscosities of 4.61-5.63 cSt and flash points of 164-175 °C, meeting ASTM D6751 specifications.

Phytochemical Characterization and Quantification of Phenolic, Flavonoid, and Tannin Contents in Ethanol Extract of Medicago sativa

2026-01-24T11:41:41+00:00

Medicago sativa (alfalfa) leaves are known to contain diverse bioactive phytochemicals, particularly phenolic and flavonoid compounds that are commonly associated with antioxidant activity. This study aimed to characterize the phytochemical profile of the ethanol extract of alfalfa leaves and quantify its major phenolic constituents to provide chemical evidence supporting its antioxidant potential. Dried alfalfa leaves were extracted using maceration with ethanol 70%, followed by qualitative phytochemical screening, Fourier Transform Infrared (FTIR) analysis, and spectrophotometric determination of total phenolic, flavonoid, and tannin contents. Phytochemical screening confirmed the presence of alkaloids, phenolics, tannins, flavonoids, and triterpenoids, while saponins were not detected. Quantitative analysis showed that the extract contained a high total flavonoid content (136.25 ± 3.165 mg quercetin equivalents/g extract), along with appreciable levels of total phenolics (19.32 ± 0.814 mg gallic acid equivalents/g extract) and tannins (66.49 ± 0.927 mg tannic acid equivalents/g extract). These findings demonstrate that alfalfa leaf extract is a rich source of polyphenolic compounds, which are widely associated with antioxidant properties, thereby providing a scientific basis for further evaluation of antioxidant activity.

UV-Visible Spectrophotometric Determination of Ni(II) Using a Schiff Base Ligand Derived from 1,5-Diphenylcarbazone and Aniline

2026-01-27T14:23:30+00:00

UV-Visible spectrophotometric approach for Ni(II) determination was developed using a Schiff base ligand synthesized from 1,5-diphenylcarbazone and aniline. The ligand was isolated with a yield of 64.98% and exhibited absorption bands at 239 and 278 nm, confirming the formation of the azomethine group. Ni(II) complexation at a metal to ligand molar ratio of 1:3 was carried out through complex formation without crystallization and with crystallization, affording a solid complex with a 57.11% yield. The complex formed without crystallization showed a maximum absorbance at 532 nm, whereas the crystalline complex exhibited a maximum absorbance at 535 nm, indicating identical chromophoric behavior in solution. Coordination was additionally verified by FTIR, as evidenced by the shift of the C=N stretching band toward lower wavenumbers and the emergence of characteristic Ni–N vibrations. The maximum analytical response was obtained at pH 6, and the absorbance remained stable for at least 120 min, demonstrating sufficient complex stability for routine measurements. The addition of Co(II) did not result in statistically significant changes in absorbance, confirming negligible interference under the studied conditions. Overall, the Ni(II)-Schiff base system provides a reproducible and selective spectrophotometric response suitable for nickel determination in aqueous media.

Chemical Composition GC/MS analysis, antioxidant and Antimicrobial Activity of Hibiscus, Baobab, and Buckhorn Seed Oil’s

2025-12-31T01:16:56+00:00

This study explores the chemical composition and bioactive potential of Baobab, Hibiscus, and Buckthorn seed oils, focusing on their antioxidant and antimicrobial activities for cosmetic and functional food applications. GC/MS analysis revealed distinct profiles: Hibiscus oil was rich in 10(E),12(Z)-conjugated linoleic acid (32.87%) and cis-13-Octadecenoic acid (31.54%), Baobab oil contained high levels of cis-Vaccenic acid (24.59%) and n-Hexadecenoic acid (17.57%), and Buckthorn oil was characterized by significant concentrations of gamma-Sitosterol (12.78%) and gamma-Tocopherol (11.5%). The antioxidant capacity, measured using the DPPH assay, showed Buckthorn oil as the most active (IC₅₀ = 7.2 mg/mL), followed by Hibiscus (IC₅₀ = 11.7 mg/mL) and Baobab (IC₅₀ = 24.9 mg/mL), highlighting their potential as natural antioxidants, with Buckthorn oil demonstrating superior efficacy. Antimicrobial testing against Staphylococcus aureus, Escherichia coli, and Candida albicansrevealed limited activity. Baobab and Buckthorn oils showed weak inhibition against S. aureus (9.3 mm and 9.0 mm, respectively). In contrast, Hibiscus oil had no effect, and none of the oils inhibited E. coli or C. albicans. One-way ANOVA confirmed no significant differences in inhibition zones against S. aureus (p = 0.204), indicating that the antimicrobial effects are weak and not statistically meaningful. These findings demonstrate that while the tested oils have strong antioxidant potential, particularly Buckthorn oil, their antimicrobial activity in crude form is limited. Future studies incorporating MIC determination and formulation optimization could enhance their practical applications in cosmetics, pharmaceuticals, and functional foods.

Enhancement of Pineapple Industrial Waste Delignification Through the Effect of Microwave Irradiation Duration with Alkali Assistance.

2026-02-23T15:07:29+00:00

Delignification is an important step for removing lignin, increasing the accessibility of cellulose and hemicellulose for various industrial applications. This study investigated the effect of microwave irradiation duration on the alkaline-assisted delignification of pineapple peel waste using a Completely Randomized Design (CRD) with irradiation times of 0, 15, 30, and 45 minutes at a constant power of 45 W. Compositional analysis was performed using the Chesson–Datta method, while structural and chemical modifications were evaluated through Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The results indicated that increasing irradiation time significantly improved delignification efficiency (P < 0.05), with the highest lignin reduction of 57.6% achieved at 45 minutes, accompanied by increases in cellulose and hemicellulose contents of 62.79% and 55.8%, respectively. FTIR spectra confirmed the removal of lignin through the reduction of characteristic functional group intensities. Moreover, SEM analysis revealed pronounced structural disruption, increased surface irregularity, and enhanced porosity after treatment, indicating effective breakdown of the lignocellulosic matrix and improved exposure of cellulose fibers. These findings demonstrate that microwave-assisted alkaline treatment is a promising approach for enhancing the valorization of pineapple industry waste.

Synthesis of Deep Eutectic Solvent (DES) Based on Glycerol and Propylene Glycol as a Medium for Anthocyanin Extraction from Senduduk Flowers (Melastoma sp.)

2026-03-12T14:38:06+00:00

Environmental concerns related to the extensive use of conventional organic solvents have driven the development of greener extraction technologies, including the application of deep eutectic solvents (DES) as environmentally friendly alternatives. This study aimed to evaluate the effectiveness of choline chloride–based DES combined with glycerol and propylene glycol as green solvents for anthocyanin extraction from Senduduk flowers (Melastoma sp.) using the ultrasound-assisted extraction (UAE) method. DES were synthesized at a 1:2 molar ratio and characterized based on density, viscosity, pH, moisture content, and functional group analysis using FTIR spectroscopy. The results confirmed the successful formation of DES with suitable physicochemical properties for extraction applications. Both DES systems were able to extract various bioactive compounds, including flavonoids, alkaloids, terpenoids, saponins, and tannins. The highest total anthocyanin content was obtained using choline chloride/glycerol DES (93.29 mg/L), followed by choline chloride/propylene glycol DES (89.06 mg/L). Total flavonoid contents were 86.97 mg QE/g and 85.78 mg QE/g, respectively. Antioxidant activity analysis indicated strong radical scavenging capacity with IC₅₀ values of 70.82 ppm and 72.61 ppm. These findings demonstrate that glycerol- and propylene glycol-based DES are effective green solvents for anthocyanin extraction and show potential for sustainable applications in food, pharmaceutical, and cosmetic industries.