Abdelmnim M. Altwaiq

This study presents a quantitative determination of titanium dioxide (TiO2, E171) in food products frequently consumed by children. An optimized acid digestion method using concentrated sulfuric acid, nitric acid, and hydrogen peroxide at 200 °C for 45 minutes was developed to efficiently extract TiO2 from food matrices. The recovered TiO2 was quantified using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and UV–Visible spectrophotometry. Both methods were successfully applied to twentyfive food products from the Jordanian market, including chewing gums, candies, and powdered juices. Structural and morphological characterization of the extracted TiO2 was carried out using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Dynamic Light Scattering (DLS). XRD confirmed the presence of both anatase and rutile crystalline phases, while SEM revealed irregular particle morphology. FTIR spectra showed characteristic Ti–O vibrations, and DLS analysis indicated that the particle sizes were in the micrometer range, with no evidence of engineered nanoparticles. The proposed approach enables accurate monitoring of TiO2 content in foods and supports regulatory efforts to evaluate consumer exposure to E171, particularly in products marketed to children.

Galena is a natural mineral enriched with lead sulfide (PbS). It typically forms in hydrothermal veins associated with igneous rocks and can also occur as a gangue mineral in other ore deposits. PbS is of special importance for scientific research applications due to the possibility of tuning its semiconductor energy gap using nanotechnology in conjunction with powder metallurgy as an easy, controllable production route. In this paper, almost pure PbS was successfully produced starting from a high ratio of PbS phase galena ore. As-received galena lumps were roughly pulverized and milled to produce four particle size ranges of 38, 63, 125, and 250 µm prior to compaction and sintering in a vacuum (pre-flushed with argon gas). SEM coupled with the EDAX analysis unit was employed to investigate the microstructure and chemical composition of the as-received galena and the subsequent products after sintering. The chemical analysis confirmed the high ratio of PbS compound in the as-received galena and sintered products with approximately 85% Pb and 13% S mass ratio. The sintering process of the galena powder was carried out at different values of temperature, time, and compaction pressure. Additionally, the effect of length to diameter ratio of compacted and sintered samples was investigated. XRD analysis confirmed the existence of the PbS phase in the as-received and sintered samples at 700 °C with approximately 98 wt.%, as well as a new phase that is formed at 800 °C with a lower percentage. The micro-hardness of the as-received and sintered samples was measured and compared with the as-received galena ore. The results showed a significant reduction in the hardness of sintered galena powder compared with the bulk as-received galena by 52%. Furthermore, a relative sintered density of 99.3% for the as-received galena density signifies a novel result using powder metallurgy techniques.

Monosodium glutamate is a food additive that gives sweetness, sourness, bitterness, and saltiness tastes together. In the present study, a simple and accurate high-performance liquid chromatography with ultraviolet spectrophotometer detector method was developed for the determination of monosodium glutamate in both dried and moist food samples. This method was carried out on different eleven food samples including potato chips, soups, and vegetable concentrates from the local market in Jordan. The approach was based on the derivatization step of MSG with 1-fluoro-2,4-dinitrobenzene. A good chromatographic separation is obtained by using a 5-micro meter particle size octadecyl column and one-to-one methanol: water mixture as mobile phase. The results in the calibration curve were linear with a correlation coefficient R2 was 0.9533. The tested food samples contained various MSG contents (the highest content was in the Mexicana chips sample 353 ± 7 ppm). The contents of monosodium glutamate in most investigated food samples were between 170 and 350 ppm. These contents are allowed according to the general standards of the codex Alimentarius Commission for food additives.

The aim of this research is to study the anticorrosive behavior of a coating consisting of modified montmorillonite nanoclay as an inorganic green inhibitor. The anticorrosion protection for mild steel in 1.0 M HCl solution is studied via weight loss, electrochemical methods, SEM, and XRD. The results proved that montmorillonite nanoclay acts as a good inhibitor with a mixed-type character for steel in an acidic solution. Both anodic and cathodic processes on the metal surface are slowed down. There is a clear direct correlation between the added amount of montmorillonite nanoclay and the inhibition efficiency, reaching a value of 75%. The inhibition mechanism involves the adsorption of the montmorillonite nanoclay onto the metal surface. Weight loss experiments are carried out with steel samples in 1.0 M HCl solution at room temperature, and the same trend of inhibition is produced. SEM was used to image the surface at the different stages of the corrosion inhibition process, and also to examine the starting nanoclay and steel. XRD was used to characterize the nanoparticle structure of the coating. Montmorillonite nanoclay is an environmentally friendly material that improved the corrosion resistance of mild steel in an acidic medium.

Humans are increasingly required to harvest green solar energy in order to reduce energy bills and save the environment from the excessive use of fossil resources. In this article, the microstructures of both commercial non-colored anodized Al and commercial blackened anodized Al were studied using optical and scanning electron microscopy in order to interpret the results of their use as solar absorbing surfaces. Microscopic examination showed that the thickness of the anodization layers of the non-colored anodized Al and the blackened anodized Al were approximately 11 µm and 14 µm, respectively, and they were perfectly adhered to the mother Al. The corrosion rate of all studied Al surfaces was investigated using the potentiodynamic polarization technique in 3.5% NaCl as the corrosive medium. The blackened anodized Al surface exhibited the highest corrosion resistance, which made it the best surface for solar heating systems. Moreover, raw Al, matte black painted Al, and blackened anodized Al were tested as selective surfaces for solar radiation in different weather conditions. Our results demonstrated the superiority of the blackened anodized Al in terms of the ability to absorb solar radiation, in addition to its higher corrosion resistance properties. In experimental testing, temperature values higher than 90 °C were reached several times. A gain of an extra 5 °C was achieved when using a double-glazed cover in comparison with a single-glazed setup. In conclusion, we highly recommend using a commercial blackened anodized Al surface to manufacture solar absorbing heaters, owing to its similarity in solar radiation absorptivity with the commercial matte black painted Al, excellent corrosion resistance, superior endurance upon long-term exposure to solar radiation, light weight, low price, and availability. Additionally, the light reflectance % test demonstrated the characteristics of the used solar selective surfaces.

The adsorption of sodium dodecyl sulfate (SDS) and N,N-dimethyldodecan-1-amine oxide (DDAO) and their mixtures from their solutions, onto Jordanian Natural Clay (JNC) was investigated at room temperature. The clay was firstly analyzed with X-ray fluorescence technique. The surface tension of the single and mixed surfactant solutions was then measured as a function of the total surfactant concentration and the critical micelle concentration (CMC) values of these solutions were determined. The interaction between SDS and DDAO as indicated by their interaction parameter was calculated according to the regular solution model. Adsorption of single surfactants onto 3 % wt/vol Jordanian Natural Clay, using the depletion method, was ultimately investigated. Although no absorbed SDS molecules were found onto the Jordanian Clay, but a pronounced adsorption tendency for DDAO and mixed SDS/DDAO molecules was obtained. The amounts of surfactant adsorbed onto 3 wt/vol% JNC follow the trend: SDS/DDAO > DDAO > SDS indicating the importance of synergistic interaction of surfactants on their adsorption behavior.