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Selenium (Se) is considered to be an essential trace element needed for all living organisms. The importance, deficiency, and toxic effects of Se mainly depend on its quantity and chemical nature. It has been observed that the inorganic versions of Se are more hazardous than the organic versions. This review is mainly focused on the application of different extraction methods used for Se extraction and determination such as microextraction, solid-phase extraction (SPE), and their modified modes in the last 12 years. The use of different dispersive medium (magnetic field, ultrasonic radiation, and vortex agitator) to enhance Se separation is also part of this review. The usage of environmentally friendly solvents such as supramolecular solvents, hydrophobic deep eutectic solvents (DESs), and ionic liquids (ILs) are also the focus of attention in this review. This review is also emphasized the application of advanced microextraction methods, particularly liquid-phase microextraction (LPME). The most recent advances in LPME extraction techniques for Se in various environmental samples, as well as their prospects, are reviewed. Additionally, a summary of cheap, simple, and accurate techniques that have not yet been used to determine small amounts of Se has been provided. [ABSTRACT FROM AUTHOR]

Rifampicin nanoparticles (RF NPs) was sunthesized by lyophilization method and characterized by using scanning electron spectroscopy (SEM) and atomic force spectroscopy (AFM). It is found that the dimension of the RF NPs was 85.74 nm. An electrochemical measurement approach has been used to examine the effects of various temperature degrees for a range of 30-70 °C on the redox current peaks of RF NPs in the KCl solution as an electrolyte. The results of the electrochemical analysis of RF NPs in KCl solution were obtained by the cyclic voltammetric method to find two oxidation peaks (I,II) at +900 and +225 mV, also two reduction peaks appeared at -680 and -300 mV. They were studied at different temperatures to identify the values of the activation energies (Ea *) of these peaks by Arrhenius equation as well as their thermodynamic values using the Eyring equation to determine the values of Gibbs activation energy (ΔG*), activation enthalpy (ΔH*), and activation entropy (ΔS*). RF NPs were analyzed through the effect of different temperatures on both the oxidation and reduction peaks, which showed that the high temperature leads to a catalytic state as an electrochemicalcatalyst. [ABSTRACT FROM AUTHOR]

For the first time, air-assisted cloud point extraction (AA-CPE) procedure was applied to determine selenium in black tea samples at room temperature. The Air agitation is powered by a small fish tank generator to improve the dispersion phase and reduce the critical temperature for surfactants. The ligand and surfactant were 1-(2-hydroxy-5-ptolylazo-phenyl)-ethan-one (HPAPEO) and TritonX-100, respectively. Afterward, the extracted selenium complexes were injected into a hydride generation atomic absorption spectrometer (HGAAS). At the optimal conditions of experimentation, linearity from 0.3 to 1000 µg l-1 was constructed with an enhancement factor, preconcentration factor, detection limit, and extraction recovery of 150, 100, 0.02 µg l-1, and 99.1-102%, respectively. The AA-CPE technique's accuracy has been proven using certified reference materials. Ultimately, the Red-Green-Blue (RGB12), Analytical Greenness Metric Approach (AGREE), and Complementary Green Analytical Procedure Index (ComplexGAPI) scales have been applied to assess the whiteness and greenness of this method. An accurate evaluation of the criteria has been performed to ensure this procedure is eco-friendly for the environment. [ABSTRACT FROM AUTHOR]

The cloud point extraction technique has become increasingly popular in recent years for trace metal separation and preconcentration. When heated to a specific temperature, cloud point extraction utilizes the property of nonionic surfactants in aqueous solutions to generate micelles and become turbid (so-called cloud point temperature). For analytical chemists, developing a simple and selective technology for the separation and determination of metals and medicinal drugs is a critical concern. Therefore, a sensitive, accurate, and green cloud point extraction (CPE) procedure was developed for the micro-determination of metal cations like zinc (II) and cadmium (II) in food samples. Triton X–114 and 1-(4-(Phenyldiazenyl) phenyl) azo naphthalene-2-ol (Sudan III) were used as extractants. Sudan III forms an ionpair association complex with metal ions when the pH is 9. In the presence of 5 ppm zinc (II) or 4 ppm cadmium (II) in an aqueous solution, the maximum extraction efficiency should be achieved. In order to create Cloud Point Temperature (CPT) quantitatively, the extraction applications in this approach required heating at 85°C for 20 minutes. In this work, the impacts of different surfactants, pH, stoichiometry, and various organic reagents on interferences as well as spectrophotometric determination were explored. The linearity ranges of zinc (II) and cadmium (II) were 0.25-700 and 0.25-400 ppm, respectively. The results show low detection limits of 0.035 and 0.042 ppm for zinc (II) and cadmium (II), respectively. Also, the quantification limits for zinc (II) and cadmium (II) are 0.116 and 0.140 ppm, respectively. [ABSTRACT FROM AUTHOR]

For the enrichment of iron(III) prior to spectrophotometric determination, displacement cloud point extraction (D-CPE) technique was applied depending on the difference in stability constant of metal complexes. Zinc(II) as gallic acid complex was first separated into a Triton X-100 surfactant. Then, once the aqueous phase has been removed, the sample containing Fe(III) is added, and another CPE process is performed. Because Fe-GA has a higher stability than Zn-GA, Fe(III) can displace Zn(II) from the pre-extracted Zn-GA, allowing for Fe(III) separation from the complex sample matrix and its spontaneous spectrophotometric determination at 560 nm. The effects of pH, ligand, and surfactant quantities, temperature and heating time, centrifuge processes, and interferences were all studied. At the optimal conditions, the calibration graph was linear from 0.5 to 500 µg L-1 with enrichment factor of 75.0. The LOD was 0.15 µg L-1 and the RSD was 1.3% for 60 µg L-1 of Fe(III), n = 10. Accuracy was also evaluated using the standard reference substance (SRS) and flame atomic absorption spectroscopy (FAAS) approaches. This procedure was used for separation and micro-determination of Fe(III) in water and fruit tests (banana, strawberry, lemon, orange, and peaches) with recoveries ranged from 96.5 to 105%. [ABSTRACT FROM AUTHOR]

Green nanomaterial synthesis is the process of producing various metallic nanoparticles (MNPs) utilizing bioactive reagents. It attempts to reduce waste and promote environmental sustainability by employing mild reaction conditions and safe materials. Researchers have demonstrated a strong interest in using natural biomolecules extracted from plants to synthesize MNPs. The individual biomolecules in this plant extract function as reducing, capping, and stabilizing substances in the green production of stable MNPs using their related metal ion precursor solution. The advantages of this method are that it is environmentally friendly, does not require energy, and is cheap and quick. Recently, MNPs have been developed in the field of cancer due to various qualities, including their increased reactive surfaces and small specified volume, which make them suited for traditional small pharmaceuticals and pharmaceutical compounds. MNPs, such as gold (AuNPs), silver (AgNPs) and copper (CuNPs), are increasingly being used as anticancer agents. This review describes the synthesis of three MNPs: AuNPs, AgNPs and CuNPs nanoparticles from plant extracts. AgNPs are the most often used synthetic NPs, accounting for more than 25% of all consumer items. AgNPs are generally employed for antibacterial, antifungal and antiviral purposes. Also, the anti-cancer activities of the MNPs were explained. The challenges and predicted developments for future studies are addressed, which are critical for real-world applications. In the future, new types of NPs will be generated employing modern technology, with a wide range of uses in numerous industries. [ABSTRACT FROM AUTHOR]

AbstractThe current work is devoted to a comparative analysis of enhanced co-factors in solidified floating organic drop microextraction methods (SFODME) and an environmental assessment. Also, the description of SFODME, with a focus on its applications in the determination of metals in different matrices, was explained. The impact of several parameters, developments, and greenness evaluations was introduced. Especially, the review provides a concise overview of the multiple approaches to SFODME, with an emphasis on environmentally friendly, supported co-factors. These mods include ultrasound, vortex, and air-assisted SFODME procedures. The selectivity and sensitivity increase when co-factors are added to SFODME. Lastly, the analysis also aims to select tools (Analytic GREEnness Metric Approach (AGREE), Red-Green-Blue (RGB12), and Blue Applicability Grade Index (BAGI)) that have been described as environmentally friendly. Additionally provide an explanation of the data collected, compare, and emphasize the advantages of certain characteristics in each tool. Furthermore, case studies and comparisons for three tools were shown. [ABSTRACT FROM AUTHOR]