Evaluation of thiosemicarbazone derivative as chelating agent for the simultaneous removal and trace determination of Cd(II) and Pb(II) in food and water samples

Insights into manganese ferrite anchored graphene oxide to remove Cd(II) and U(VI) via batch and semi-batch columns and its potential antibacterial applications

The bioaccumulation, non-biodegradability, and high toxicity of Cd(II) and U(VI) in water is a serious concerns. Manganese ferrite/graphene oxide (GMF) nanocomposites were synthesized, characterized, and used to efficiently remove Cd(II) and U(VI) from an aqueous solution in this study. X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS) analyses, respectively, confirmed the formation of GMF and the adsorptive removal mechanism. The XRD results revealed an amorphous structure when MnFe₂O₄ was loaded onto the GO surface. XPS results suggest that C = C, C-OorOH, and metal oxides are responsible for the removal of Cd(II) and U(VI) via electrostatic and chemical interaction. According to the Brunauer Emmett and Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) characterization analysis, GMF has a high surface area (117.78 m²/g) and a spherical shape with even distribution. The kinetics data were successfully reproduced by a pseudo-second-order non-linear model indicating the complexity of the sorption mechanism was rate-limiting. The maximum Langmuir uptake ability of GMF for Cd(II) and U(VI) was calculated to be 232.56 mg/g and 201.65 mg/g, respectively. Using external magnetic power, the prepared GMF can easily separate from the aqueous solution and can keep both metal ions under Environmental protection agency standards in water for up to six cycles of re-use of GMF. Finally, the GMF nanocomposite demonstrated significant promise as an adsorbent for removing Cd(II) and U(VI) from actual contaminated water samples. The antibacterial test was expanded to include gram-negative E. coli and gram-positive S. aureus to better understand GMF's bacterial inhibition efficacy.

Chemical Composition, Antioxidant and Antimicrobial Activity of Some Types of Honey from Banat Region, Romania

Honey is a natural product with multiple health benefits. The paper presents the chemical characterization and the antioxidant and antimicrobial potential of ten types of honey (knotweed, linden, wild cherry, acacia, honeydew, oilseed rape, sunflower, phacelia, plain polyflora and hill polyflora) from the Banat region, Romania. We studied the water content, dry matter, impurities, acidity and pH of honey. We also determined the content of reducing sugar, minerals and flavonoids and the total phenolic content. All honey samples analysed showed good nutritional characteristics according to the standard codex for honey. From the analysis of the mineral content of the honey samples, we observed a variability in the macro and microminerals, influenced by the botanical origin, ranging between 0.25% (wild cherry honey) and 0.54% (honeydew). The toxic metals’ (Cd and Pb) levels met the standard for almost all samples analysed except for knotweed. The flavonoid content of the samples ranged from 9.29 mg QE/100 g for wild cherry honey to 263.86 mg QE/100 g for linden honey, and for polyphenols between 177.6 mgGAE/100 g for acacia honey and 1159.3 mgGAE/100 g for honeydew. The best antioxidant capacity was registered in the case of linden honey (79.89%) and honeydew (79.20%) and the weakest in acacia (41.88%) and wild cherries (50.4%). All studied honey samples showed antimicrobial activity, depending on the type of honey, concentration and strain analysed. The novelty of this study is given by the complex approach of the study of honey quality, both from the perspective of chemical attributes and the evaluation of the antimicrobial potential on specific strains in correlation with the botanical and geographical origin of the analyzed area.

A novel model for prediction of stability constants of the thiosemicarbazone ligands with different types of toxic heavy metal ions using structural parameters and multivariate linear regression method

A novel model is presented for reliable estimation of the stability constants of the thiosemicarbazone ligands with different types of toxic heavy metal ions (log β₁₁) in an aqueous solution, which has wide usage in environmental safety and ecotoxicology applications. The biggest reported data of log β₁₁ for 120 metalthiosemicarbazone complexes are used for deriving and testing the novel model. In contrast to available methods where they need the two-dimensional (2D) and three-dimensional (3D) complex molecular descriptors as well as expert users and computer codes, the novel correlation uses four additive and two non-additive structural parameters of thiosemicarbazone ligands. The calculated results of the novel correlation are compared with the outputs of the genetic algorithm with multivariate linear regression method (GA-MLR) as one of the best existing methods, which requires seven complex descriptors. The estimated results for 78 of training as well as 42 of two different test sets were established by external and internal validations. The values of statistical parameters comprising average deviation, average absolute deviation, average absolute relative deviation, absolute maximum deviation, and the coefficient of determination for 73 data of training set of New model/GA-MLR are 0.04/ - 0.25, 1.06/1.31, 14.4/18.7, 3.18/7.92, and 0.830/0.652, respectively. Thus, the predicted results of the new model are worthy as compared to the complex GA-MLR model. Moreover, assessments of various statistical parameters confirm that the new model provides great reliability, goodness-of-fit, accuracy, and precision.

The concentration of potentially toxic elements (PTEs) in the onion and tomato irrigated by wastewater: A systematic review; meta-analysis and health risk assessment

Nowadays, vegetable irrigation with wastewater in developing countries has become a serious issue. In this regard, the current investigation was performed to collect the related data regarding the concentration of potentially toxic elements (PTEs) including Fe, Zn, Cu, Cr, Pb, Ni, and Cd in onion and tomato samples irrigated with wastewater by the aid of a systematic review among the Scopus, Medline and Embase databases between 1/January/1983 to 31/January/2019. Also, the health risk assessment for consumers due to PTEs ingestion via the consumption of onion and tomato was estimated by using target hazard quotient (THQ). In this context, 35 articles with 64 studies out of 779 retrieved citations were included in the meta-analysis. The ranking of different parts of tomato based on Pb, Cd, and Cu concentration was shoot > root > leave > edible part; Fe, leave > shoot > root > edible part; Cr, root > leave > shoot > edible part; Zn, shoot > leave > root > edible part; and Ni, leave > edible part > root > shoot. Moreover, the ratio concentration of Pb, Cd, Cu, Fe, Cr, Zn and Ni in the edible part to leave of onion was 2.92, 6.01, 1.29, 4.17, 0.84, and 3.55, 10.10, respectively. According to findings, the rank order of PTEs in the onion was Fe (43.09 mg/kg-dry weight) > Zn (34.3 mg/ kg-dry weight) > Pb (18.54 mg/ kg-dry weight) > Cu (14.9 mg/ kg-dry weight) > Ni (11.92 mg/ kg-dry weight) > Cr (7.24 mg/ kg-dry weight) > Cd (0.23 mg/ kg-dry weight) and tomato; Fe (139.12 mg/ kg-dry weight) > Zn (29.81 mg/ kg-dry weight) > Cu (25.04 mg/ kg-dry weight) > Cr (14.28 mg/ kg-dry weight) > Pb (9.58 mg/ kg-dry weight) > Ni (9.23 mg/ kg-dry weight) > Cd (4.64 mg/kg-dry weight). However, the concentration of PTEs investigated in the edible part of onion was higher than leaves; their concentrations in the edible part of the tomato were lower than other parts. The health risk assessment indicated that consumers groups are at significant non-carcinogenic risk due to the ingestion of PTEs via consumption of the onion and tomato vegetable wastewater irrigated (THQ > 1). Therefore, the irrigation of vegetables with wastewater should be monitored and controlled by some prevention plans.

An integrated system for field analysis of Cd(ii) and Pb(ii) via preconcentration using nano-TiO2/cellulose paper composite and subsequent detection with a portable X-ray fluorescence spectrometer

An integrative field analytical system was developed for the determination of Pb(ii) and Cd(ii).

Simultaneous spectrophotometric determination of copper, cobalt, nickel and iron in foodstuffs and vegetables with a new bis thiosemicarbazone ligand using chemometric approaches

A newly synthesized bis thiosemicarbazone ligand, (2Z,2'Z)-2,2'-((4S,5R)-4,5,6-trihydroxyhexane-1,2-diylidene)bis(N-phenylhydrazinecarbothioamide), was used to make a complex with Cu(2+), Ni(2+), Co(2+) and Fe(3+) for their simultaneous spectrophotometric determination using chemometric methods. By Job's method, the ratio of metal to ligand in Ni(2+) was found to be 1:2, whereas it was 1:4 for the others. The effect of pH on the sensitivity and selectivity of the formed complexes was studied according to the net analyte signal (NAS). Under optimum conditions, the calibration graphs were linear in the ranges of 0.10-3.83, 0.20-3.83, 0.23-5.23 and 0.32-8.12 mg L(-1) with the detection limits of 2, 3, 4 and 10 μg L(-1) for Cu(2+), Co(2+), Ni(2+) and Fe(3+) respectively. The OSC-PLS1 for Cu(2+) and Ni(2+), the PLS1 for Co(2+) and the PC-FFANN for Fe(3+) were selected as the best models. The selected models were successfully applied for the simultaneous determination of elements in some foodstuffs and vegetables.