A new modified ion-selective electrode with membranes of LaF₃ single crystals with different internal contacts (solid steel or electrolyte) and with Fe_xO_y nanoparticles as loading was developed. The best response characteristic with linear potential change was found in the fluoride concentration range from 10⁻¹ to 3.98 × 10⁻⁷ M. The detection limit for the electrolyte contact was determined at 7.41 × 10⁻⁸ M with a regression coefficient of 0.9932, while the regression coefficient for the solid contact was 0.9969. The potential change per concentration decade ranged from 50.3 to 62.4 mV, depending on whether the contact was solid or electrolytic. The prepared modified electrode has a long lifetime, as well as the possibility of application in different positions (solid contact), and it can also be used for the determination of iron ions. The electrode characterization was performed with scanning electron microscopy and elemental analysis with the technique of electron-dispersive X-ray spectroscopy.

Samples of white and red wines produced in two different wine-growing regions, coastal (Dalmatia) and continental (Hrvatsko zagorje) of Croatia, were analysed for biogenic amines content. Biogenic amines content was determined, and its concentration levels were associated with the geographical origin of the wine. Due to its high sensitivity, HPLC method with ultraviolet detector was used, including the derivatisation step with dansyl chloride. The method was applied to detect and quantify 11 biogenic amines in 48 red and white wines. It was found that both Dalmatian red and white wines are characterised by tryptamine (0.23–1.22 mg L⁻¹), putrescine (0.41–7.5 mg L⁻¹) and ethanolamine (2.87–24.32 mg L⁻¹). White wines from the Hrvatsko zagorje region are characterised by content of isopentylamine (0.31–1.47 mg L⁻¹), putrescine (0.27–1.49 mg L⁻¹) and ethanolamine (3.80–17.96 mg L⁻¹). In contrast to white wines from the Hrvatsko zagorje region, in the red wines, all biogenic amines except ethylamine, were found and equally presented.

Plant extracts are increasingly being examined in the corrosion inhibition of metal and alloys in various environments due to their potent antioxidant properties. The use of Artemisia annua L. aqueous extract (AAE) as an aluminium alloy 5083 (ALA) corrosion inhibitor in artificial seawater (ASW) was investigated using electrochemical tests and spectroscopy tools, while the active biocompounds found in AAE were analyzed using high-performance liquid chromatography (HPLC). Electrochemical results showed that AAE acts as an anodic inhibitor through the physisorption (ΔG ≈ –16.33 kJ mol⁻¹) of extract molecules on the ALA surface, thus reducing the active sites for the dissolution of the alloy in ASW. Fourier-transform infrared spectra confirmed that phenolic acids found in AAE formed the surface layer that protects ALA against the corrosive marine environment, while HPLC analysis confirmed that the main phytoconstituents of AAE were chlorogenic acid and caffeic acid. The inhibition action of phenolic acids and their derivatives found in the AAE was based on the physisorption of caffeic acid on the ALA surface, which improved physicochemical properties of the barrier film and/or conversion of Al³⁺ to elemental aluminium by phenolic acids as reducens, which slowed down the diffusion rate of Al³⁺ to or from the ALA surfaces. The protective effect of the surface layer formed in the presence of AAE against ASW was also confirmed by inductively coupled plasma–optical emission spectrometry (ICP-OES) whereby the measured concentration of Al ions after 1 h of immersion of ALA in the pure ASW was 15.30 μg L⁻¹ cm⁻², while after the addition of 1 g L⁻¹ AAE, the concentration was 3.09 μg L⁻¹ cm⁻².

The advantages of microwave technology over conventionally conducted experiments are numerous. Some of them are reduction in reaction time, a higher degree of process control, repeatability, and work safety. Microwave synthesis routes require a complete description of the experimental details, instrumentation, and design program of a microwave oven used in the experiments. In this work, microwave-assisted hydrothermal synthesis of hematite (α-Fe₂O₃) particles from 0.1 M FeCl₃ solution in highly alkaline media with heating in a microwave oven at continuous microwave emission of 800 W at 150 °C, 200 °C, and 250 °C for 20 min are presented. Also, the influence of the percentage of the addition of a cationic surfactant, cetyltrimethylammonium bromide (CTAB) on the composition, size, and shape of the final product was investigated. The samples precipitated at 150 °C formed a final product consisting of goethite (α-FeOOH) and hematite particles in contrast to the those precipitated at 200 °C and 250 °C where pure hematite phase was obtained. In these synthesis routes, the CTAB caused to slow down the rate of the goethite-to-hematite transformation process at temperatures at 200 °C but did not affect the transformation at 250 °C.