Current Analytical Chemistry - Volume 21, Issue 2, 2025

Essential oils are utilized in various food applications and are a rich source of naturally occurring volatile components. The extraction of essential oils has used conventional techniques for several years, but these methods require a long duration of time, more solvent, and high energy. However, recent advancements have led to novel and eco-friendly techniques that significantly enhance the essential oil yield while minimizing the use of resources.

This study describes the recent research on the extraction of essential oils and their components, focusing on microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE).

This review explores the instrumentation, mechanism, and applications behind MAE and UAE. It also describes the emerging technologies for the extraction of essential oils, along with their optimized conditions.

These techniques represent a more sustainable and efficient approach for the extraction of essential oil from various plant sources, aligning with the principles of green chemistry.

Rodents and many wild and domestic animals, including cattle, donkeys, goats, hares, ostriches, and sheep, spread the Crimean-Congo Hemorrhagic Fever Virus (CCHFV), acting as hosts for infected ticks primarily of the Hyalomma genus, which serve as vectors and reservoirs of the virus. CCHF is a severe, potentially lethal, and widespread disease, making it a serious public health issue. Environmental changes impacting rodent populations affect their global distribution and, therefore, play a role in the spread of CCHFV.

This study aims togain a deeper understanding of the envelope glycoproteins expressed by the CCHFV.

Multiple computational algorithms determined the Intrinsic Disorder Predisposition (PIDP), Polarity Index, and genomic profiles of each sequence of the glycoproteins.

When examining the Polarity Index Method Profile, 3.0v profile, and the PIDP profile, the envelope glycoproteins of the CCHFV showed different patterns. With these patterns, it was possible to identify structural and morphological similarities.

With the PIM 3.0v profile, our computer programs were able to identify isolated CCHFV envelope glycoproteins. We believe that this research provides a deeper understanding of this virus.

Flavonoid is a type of active constituent in herbs and always used as the quality control markers of herbal medicines. Owing to the extensive diversity of flavonoids, numerous reference compounds are necessitated for the analysis of flavonoids, and some are usually very expensive, which engenders challenges in the analysis of flavonoids in herbal medicines. Consequently, the development of a simple, rapid, and reference compounds saving method is important for the determination of flavonoids in herbal medicines.

In order to develop a high-performance liquid chromatography (HPLC) method for the determination of 5 flavonoids (mangiferin, hesperidin, baicalin, buddleoside, and rutin) in five herbal medicines (Anemarrhenae rhizome, Sophorae flos, Citri reticulatae pericarpium, Scutellariae radix, and Chrysanthemi indici flos) with rutin.

Five herbal medicine samples were prepared according to the Chinese Pharmacopoeia which includes ultrasound and reflux methods. The separation of the sample was performed on a PoroShell 120 EC-C18 (4.6 mm×100 mm, 2.7 μm) by gradient elution with 0.1% formic acid and acetonitrile at a flow rate of 1.0 mL/min. The wavelengths were set as follows: Anemarrhenae rhizome (363 nm), Sophorae flos (256 nm), Citri reticulatae pericarpium (236 nm), Scutellariae radix (263 nm), Chrysanthemi indici flos (354 nm).

The method validation showed that the established HPLC method was accurate and stable for quantitative analysis of flavonoids in five herbal medicines. The comparative analysis revealed that the determination results of the current HPLC method and Chinese Pharmacopoeia method are consistent, exhibiting less than 1% relative error. Remarkably, the developed HPLC method needs one cheapest reference compound (rutin) and costs 8 min for sample HPLC analysis.

The developed HPLC method for quantitative analysis of five flavonoids in five herbal medicines is simple, rapid, and reference compound saving, which provides a good alternative method for quality control of flavonoids in herbal medicines.

In desalination, addressing fouling challenges, particularly concerning silica, is pivotal for generating pure water from seawater and brackish sources. Efficient silica removal is vital for various applications, including power generation and electronics. Electrodeionization (EDI) has proven highly effective in achieving a high removal rate for silica.

Optimize silica removal through a combined membrane approach—water-soluble polymer-enhanced ultrafiltration and Electrodeionization (EDI)—for efficient water treatment and improved water quality.

The study utilized a 400 mL stirred Amicon cell for Ultrafiltration (UF) in combination with a water-soluble polymer. Additionally, a microflow EDI cell is employed, filled with Porolite A600 anion exchange resin and SST60 cation exchange resin, to optimize silica removal.

The water-soluble polymer-enhanced ultrafiltration achieved a 25% removal of SiO2, with the remaining silica effectively removed by EDI, resulting in a concentration of 11 µg/L.

The combined approach of water-soluble polymer-enhanced ultrafiltration and Electrodeionization (EDI) demonstrated effective silica removal.

This study aimed to demonstrate the practical and sensitive lead detection using biogenic silver nanoparticles in dark chocolate samples and silver nitrate was reduced using Syzygium cumini aqueous seed extract as a reducing agent to produce nanoparticles. The obtained NPs were characterized via spectrometry and scanning electron microscopy.

Silver nitrate was reduced using Syzygium cumini aqueous seed extract as a reducing agent to produce nanoparticles. The obtained NPs were characterized via spectrometry and scanning electron microscopy. The formation of NPs was confirmed by a shift in lambda max to 430 nm and the observation of 2 nm-sized particles in SEM. Data on change in lambda max as a function of time must be shown in a figure. Silver nanoparticles mixed with lead induce a red shift from the original 430 nm to 434 nm absorption maximum, confirming the efficiency of silver nanoparticles in finding a lead.

We evaluated that the limit of detection (LOD) was to be 0.8715 µg/mL, and the limit of quantification (LOQ) was found to be 150 µg/ mL.

The prepared biogenic silver nanoparticles have been used to detect lead in spiked diluted chocolates.

The study aimed to evaluate the cytotoxicity and anticancer potential of gold nanorods (GNRs) synthesized using hexadecyltrimethylammonium bromide capped seed (CTAB) on L929 fibroblast cells and glioma cells.

Gold nanorods were synthesized through the CTAB method, and their characterization was conducted using UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and scanning electron microscopy (SEM). The MTT cell viability assay was employed to assess the cytotoxic and anticancer effects of the synthesized gold nanorods on L929 fibroblast cells and glioma cells.

Analysis results revealed that the synthesized gold nanorods had an average size of 6.4 nm and rod-like morphology, with an absorbance peak of 836 nm. The quantity of synthesized GNRs was calculated to be 3.63 µM. Cytotoxicity analysis showed an IC50 value of 1.29 µM for L929 fibroblast cells and 1.26 µM for C6 glioma cells, indicating significant cytotoxic effects. Treatment with GNRs induced apoptosis in glioma cells and inhibited their proliferation, suggesting potential anticancer activity.

The findings suggest that GNRs hold promise as effective agents for cancer therapy. Further research is warranted to elucidate the precise mechanisms underlying their anticancer effects and to explore their potential clinical applications in cancer treatment.

Vitamins are needed for the healthy functioning of the body. When these vitamins are not in sufficient amounts in the body, they are usually taken externally with pharmaceutical preparations. Taking vitamins into the body in the right amounts is possible by analyzing the amounts in pharmaceutical preparations with validated methods.

In this study, a fast, simple, easily applicable, and selective normal-phase HPLC method was developed for the simultaneous determination of fat-soluble A, D3, E, and K1 vitamins in pharmaceutical preparations from syrup and tablets. Separation of the vitamins was carried out on a Zorbax CN column (250 x 4.6 mm, 5 µm) using a mixture of hexane-isopropyl alcohol (98:2, v/v) at 30°C column temperature and 1 ml/min flow rate. The detection wavelength is 280 nm. The developed method has been validated according to ICH Harmonised Tripartite Guideline Validation of Analytical Procedures: Text and Methodology Q2(R1) rules.

Calibration graphs are linear over the range of 10-1000 µg ml^-1, 1-50 µg ml^-1, 10-2000 µg ml^-1, 0.5-20 µg ml^-1, and the limit of detection values were found to be 1.496, 0.280, 1.388 and 0.040 µg ml^-1 for A, D3, E and K1 vitamins, respectively. Relative standard deviation values, which express within-day and between-day repeatability, were found below 2.54%. Average recovery values were also found at about 100.28, 101.46, 100.65, and 100.29% for A, D3, E, and K1 vitamins, respectively.

The developed and validated method was successfully applied to the simultaneous analysis of fat-soluble vitamins A, D3, E, and K1 in pharmaceutical preparations in syrup and tablet form.

In recent years, low-cost biomaterials have been used for sustainable applications to reduce the impact of wastewater treatment. The preparation of bio-based materials with a strong affinity for chromate plays a crucial role in the adsorption process.

In this study, chitosan-halloysite nanotubes composite hydrogel beads (Ch-HNTs) were prepared for the removal of hexavalent chromium (Cr⁶⁺) from aqueous solutions. Ch-HNTs hydrogel beads were generated by incorporating HNTs into chitosan using a glutaraldehyde solution to achieve efficient crosslinking. The structure of the Ch-HNTs was characterized by SEM and FTIR analysis. These novel adsorbents were then tested for the adsorption of Cr⁶⁺ in serial batch experiments. For this purpose, the effect of pH, contact time, temperature, concentration of adsorbate, and adsorbent concentration on the extent of adsorption were investigated.

The adsorption rate for Cr⁶⁺ was maximum at an initial pH of 2 in 60 minutes of contact time. The experimental data were fitted to Langmuir adsorption isotherm. The adsorption data were fitted to the Langmuir adsorption isotherm. The maximum adsorption capacity of 72.22 mg Cr^6+/g for Ch-HNTs was obtained according to the Langmuir adsorption isotherm.

It is proposed that Ch-HNTs can be potential adsorbents for Cr⁶⁺ removal from dilute solutions. Nonetheless, further studies on adsorbing and removing various heavy metals using these novel beads in column systems can be planned.