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Deep eutectic solvents (DESs) as a new-generation of solvents are receiving increasing attention as environmentally friendly solvents in various analytical techniques. These solvents are new generation solvents, and based upon what they are derived from, they can be the safest, cheapest, and most effective extraction methods available. With DES, the extraction efficiency and metal ion recycling are significantly improved. In this work, the potential application of these solvents for the extraction of Pb(II) ions was investigated. For that purpose, hydrophobic DESs (HDESs), based on L-menthol as H-acceptor and decanoic acid as H-donor, were prepared at molar ratios of acceptor to donor of 1:1 and 1:2. In the optimized extraction procedure, the Pb(II) ions were extracted into the organic phase with the efficiency of 94.3% and 97.3% for 1:1Men:DecA and 1:2 Men: Dec A, respectively. The results also showed that unlike of classical liquid-liquid extraction methods, in the original solutions, counterions are not required to transfer the analyte to the hydrophobic phase. Furthermore, no ligands were required to transfer the analyte ions to the HDES phase: the results show that the extraction efficiency of 1:1 HDES decreased to 88.65% in the presence of 18C6, and to 96.5% for 1:2 HDES. Comparable results for HDES (1:1 Men: DecA) extraction efficiency in the proposed method with the efficiency of 1,2- dichloroethane and chloroform in classical methods (96.7% and 92%, respectively), without counterions and without the requirement for ligands as carriers, make this HDES-based extraction method simpler, less expensive, and most importantly, more environmentally friendly. [ABSTRACT FROM AUTHOR]

Cherry (Prunus cerasus var. Oblačinska) is one of the most common varieties in Bosnia and Herzegovina and the region. Owing to the excellent sensory and physico-chemical characteristics and the very high concentration of biologically active ingredients, it is a very good potential for obtaining value added products or products with high content of bioactive, nutritionally and biologically valuable ingredients. The processing techniques of fresh fruit have a large infuence on the content of bioactive components. The aim of this study was to analyse the efects of processing technologies of sour cherries on the content of bioactive compounds (total phenols, total favonoids and anthocyanins) and the antioxidant capacity. Products that were analysed were juice, concentrate, extra jam and lyophilisate. The content of bioactive components and antioxidant capacity of these products was compared with fresh cherries. The results showed that the greatest infuence on the content of bioactive ingredients has process where vacuum concentration is applied. More sophisticated technology such as lyophilization would contribute to the retention of bioactive components and could increase product competitiveness at the market. [ABSTRACT FROM AUTHOR]

Methods for determination of heavy metal content in natural resources (water, soil, air) and also in industrial raw materials and products are increasingly occupying the attention of researchers. Recently used methods for determination of metal cations are generally based on the principle of „molecular recognition“ and include complexation of metal cations with suitable ligands, followed by their removal in the form of coordination compounds. Efficiency of complexation expressed through the stability of formed complexes is determined by compatibility between cations and ligands. The parameters that define the ligand nature are: the number and type of electron-donor atoms, the structure of molecules (macrocyclic or open-chained), polarity, hydrophilic-lipophilic balance, etc. Useful technique for successful separation and preconcentration of metal cations is the transport through liquid organic membranes. The process involves extraction, diffusion and re-extraction of metal ions. Efficiency of this process depends on the choice of: ligands, organic solvents-liquid membranes, counter-ions and stripping agents. In this paper, the influence of ligand structure on the efficiency of Pb and Cd ions transport through liquid organic membranes, was investigated. Two type of ligands: macrocyclic (18-crown-6 and dibenzo-18-crown-6), and acyclic (nonionic surfactant Triton X-100) were used. Organic solvents: dichloromethane and 1,2-dichloroethane were used as the liquid membranes. Experiments included application of homemade "transport cell" which enables transport of metal ions from source aqueous phase through organic membrane layer to receiving aqueous phase. Concentrations of transported Pb and Cd ions were determined by atomic absorption spectrometry. Gained results showed higher transport efficiency in experiments with macrocyclic ligands compared to acyclic. It was also showed that substituents in macrocyclic structure decrease the efficiency of transport in both type of organic solvents. [ABSTRACT FROM AUTHOR]

Solvents prepared from natural terpenes (menthol and thymol), as H-bond acceptors, and a series of organic acids (chain lengths of 8, 10, and 14 C atoms), as H-bond donors, were characterized and tested as reaction media for liquid-liquid extraction purposes. Due to their high hydrophobicity, they seem to be promising alternatives to conventional (nonpolar and toxic) solvents, since they possess relatively less toxic, less volatile, and consequently, more environmentally friendly characteristics. Assuming that the equilibrium is established between solvent and analyte during a ligandless procedure, it can be concluded that those nonpolar solvents can efficiently extract nonpolar analytes from the aqueous environment. Previous investigations showed a wide range of applications, including their use as solvents in extractions of metal cations, small molecules, and bioactive compounds for food and pharmaceutical applications. In this work, hydrophobic solvents based on natural terpenes, which showed chemical stability and desirable physicochemical and thermal properties, were chosen as potential reaction media in the liquid-liquid extraction (LLE) procedure for Pb(II) removal from aqueous solutions. Low viscosities and high hydrophobicities of prepared solvents were confirmed as desirable properties for their application. Extraction parameters were optimized, and chosen solvents were applied. The results showed satisfactory extraction efficiencies in simple and fast procedures, followed by low solvent consumption. The best results (98%) were obtained by the thymol-based solvent, thymol-decanoic acid (Thy-DecA) 1:1, followed by L-menthol-based solvents: menthol-octanoic acid (Men-OctA) 1:1 with 97% and menthol-decanoic acid (Men-DecA) 1:1 with 94.3% efficiency.

The research presented in this paper is focused on blackberry leaf extract (BLE) as a environmentally friendly corrosion inhibitor for copper in 0.5 M NaCl. The caffeic acid, quercetin-3-O-glucoside and kaempferol-3-O-glucoside were identified in BLE by using high-performance liquid chromatography (HPLC-DAD). The BLE functional groups were identified (ATR-FTIR). The electrochemical methods (potentiodynamic polarization, electrochemical frequency modulation and electrochemical impedance spectroscopy) show that BLE acts as a mixed type of inhibitor (max. IE is 97.19 %). The corrosion process is controlled by diffusion (BLE lower than 15 g/L) and charge transfer (15 g/L BLE)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)