The cathodically pretreated boron-doped diamond electrode as an environmentally friendly electrochemical tool for the detection and monitoring of mesotrione in food samples.

Excessive pesticide use can harm human health, making it essential to develop new techniques to monitor hazardous pesticides in food. Our study focuses on detecting mesotrione (MST) using an unmodified boron-doped diamond (BDD) electrode. This was the first application of cathodically pretreated BDD electrode for the detection of MST, based on its oxidation at a high potential value of +1.4 V. We theoretically examined the oxidation mechanism of MST trough the utilization of density functional theory (DFT) methodology. The utilized DPV method achieved a detection limit of 0.45 µM and showed satisfactory selectivity. The practical application of this method was demonstrated by examining corn-based food products. To ensure practical application of the method, MST was deliberately added to the samples to evaluate the accuracy of the proposed method. The effectiveness of the method was confirmed by using HPLC method. This environmentally-friendly approach can establish a solid foundation for future use in food analysis.

Triangle-Shaped Cerium Tungstate Nanoparticles Used to Modify Carbon Paste Electrode for Sensitive Hydroquinone Detection in Water Samples.

In this study, we propose an eco-friendly method for synthesizing cerium tungstate nanoparticles using hydrothermal techniques. We used scanning, transmission electron microscopy, and X-ray diffraction to analyze the morphology of the synthesized nanoparticles. The results showed that the synthesized nanoparticles were uniform and highly crystalline, with a particle size of about 50 nm. The electrocatalytic properties of the nanoparticles were then investigated using cyclic voltammetry and electrochemical impedance spectroscopy. We further used the synthesized nanoparticles to develop an electrochemical sensor based on a carbon paste electrode that can detect hydroquinone. By optimizing the differential pulse voltammetric method, a wide linearity range of 0.4 to 45 µM and a low detection limit of 0.06 µM were obtained. The developed sensor also expressed excellent repeatability (RSD up to 3.8%) and reproducibility (RSD below 5%). Interferences had an insignificant impact on the determination of analytes, making it possible to use this method for monitoring hydroquinone concentrations in tap water. This study introduces a new approach to the chemistry of materials and the environment and demonstrates that a careful selection of components can lead to new horizons in analytical chemistry.

Antioxidative enzymes, alkaline phosphatases and Hsp70 expression in larvae of Lymantria dispar (Lepidoptera: Erebidae) from unpolluted and polluted forests after chronic cadmium treatment.

Long-term exposure of populations to pollution may result in enhanced ability to cope with environmental stress. To compare the responses of two Lymantria dispar populations living in unpolluted and polluted forests (UP and PP, respectively), we chronically exposed larvae to cadmium at concentrations of 50 and 100 µg Cd/g dry food (Cd1 and Cd2, respectively). We examined cadmium accumulation in the midgut and hemolymph, activities of superoxide dismutase (SOD), catalase (CAT), and alkaline phosphatases (ALP) in the midgut, as well as Hsp70 protein expression in the midgut, hemolymph, and brain and evaluated these parameters as biomarkers of cadmium contamination. Larvae from PP, fed a control diet, showed higher activity of SOD and increased Hsp70 expression compared with larvae from UP. Excessive amounts of Cd were accumulated in the midgut of all Cd-fed larvae, whereas Cd content in the hemolymph was elevated only in larvae from PP after Cd2 treatment. In larvae from UP, Cd2 treatment decreased the activity of CAT and induced the expression of Hsp70 in the midgut and hemolymph. In larvae from PP, exposure to both Cd concentrations strongly attenuated SOD and CAT activities, while Hsp70 expression was not induced in any organ/tissue. Cd did not affect ALP activity in either population. Midgut Cd content proved to be a suitable indicator of Cd contamination for both polluted and unpolluted habitats.

Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance.

Efficient cathodes for the hydrogen evolution reaction (HER) in acidic water electrolysis rely on the use of expensive platinum group metals (PGMs). However, to achieve economically viable operation, both the content of PGMs must be reduced and their intrinsically strong H adsorption mitigated. Herein, we show that the surface effects of hydrogenated TiO2 nanotube (TNT) arrays can make osmium, a so far less-explored PGM, a highly active HER electrocatalyst. These defect-rich TiO2 nanostructures provide an interactive scaffold for the galvanic deposition of Os particles with modulated adsorption properties. Through systematic investigations, we identify the synthesis conditions (OsCl3 concentration/temperature/reaction time) that yield a progressive improvement in Os deposition rate and mass loading, thereby decreasing the HER overpotential. At the same time, the Os particles deposited by this procedure remain mainly sub-nanometric and entirely cover the inner tube walls. An optimally balanced Os@TNT composite prepared at 3 mM/55 °C/30 min exhibits a record low overpotential (η) of 61 mV at a current density of 100 mA cm-2, a high mass activity of 20.8 A mgOs-1 at 80 mV, and a stable performance in an acidic medium. Density functional theory calculations indicate the existence of strong interactions between the hydrogenated TiO2 surface and small Os clusters, which may weaken the Os-H* binding strength and thus boost the intrinsic HER activity of Os centers. The results presented in this study offer new directions for the fabrication of cost-effective PGM-based catalysts and a better understanding of the synergistic electronic interactions at the PGM|TiO2 interface.

Eu2O3@Cr2O3 Nanoparticles-Modified Carbon Paste Electrode for Efficient Electrochemical Sensing of Neurotransmitters Precursor L-DOPA.

There are ten million people in the world who have Parkinson's disease. The most potent medicine for Parkinson's disease is levodopa (L-DOPA). However, long-term consumption of L-DOPA leads to the appearance of side effects, as a result of which the control and monitoring of its concentrations are of great importance. In this work, we have designed a new electrochemical sensor for detecting L-DOPA using a carbon paste electrode (CPE) modified with Eu2O3@Cr2O3 composite nanoparticles. Rare earth elements, including Eu, are increasingly used to design new electrode nanocomposites with enhanced electrocatalytic properties. Europium has been considered a significant lanthanide element with greater redox reaction behavior. We conducted a hydrothermal synthesis of Eu2O3@Cr2O3 and, for the first time, the acquired nanoparticles were used to modify CPE. The proposed Eu2O3@Cr2O3/CPE electrode was investigated in terms of its electrocatalytic properties and then used to develop an analytical method for detecting and quantifying L-DOPA. The proposed sensor offers a wide linear range (1-100 µM), high sensitivity (1.38 µA µM-1 cm-2) and a low detection limit (0.72 µM). The practical application of the proposed sensor was investigated by analyzing commercially available pharmaceutical tablets of L-DOPA. The corresponding results indicate the excellent potential of the Eu2O3@Cr2O3/CPE sensor for application in real-time L-DOPA detection.

Orally Administrated Lactiplantibacillus plantarum BGAN8-Derived EPS-AN8 Ameliorates Cd Hazards in Rats.

Cadmium (Cd) is a highly toxic metal that is distributed worldwide. Exposure to it is correlated with a vast number of diseases and organism malfunctions. Exopolysaccharides (EPS) derived from Lactiplantibacillus plantarum BGAN8, EPS-AN8, previously showed great potential for the in vitro protection of intestinal cells from this metal. Here, we investigated the potential of food supplemented with EPS-AN8 to protect rats from the hazardous effects of Cd exposure. After thirty days of exposure to lower (5 ppm) and higher (50 ppm)-Cd doses, the administration of EPS-AN8 led to decreased Cd content in the kidneys, liver, and blood compared to only Cd-treated groups, whereas the fecal Cd content was strongly enriched. In addition, EPS-AN8 reversed Cd-provoked effects on the most significant parameters of oxidative stress (MDA, CAT, GST, and GSH) and inflammation (IL-1ß, TNF-α, and IFN-γ) in the duodenum. Moreover, micrographs of the duodenum were in line with these findings. As the gut microbiota has an important role in maintaining homeostasis, we used 16S rRNA amplicon sequencing and investigated the effects of Cd and EPS-AN8 on one part of the microbiota presented in the duodenum. Although Cd decreased the growth of lactobacilli and mostly favored the blooming of opportunistic pathogen bacteria, parallel intake of EPS-AN8 reversed those changes. Therefore, our results imply that EPS-AN8 might be extremely noteworthy in combatting this toxic environmental pollutant.

Voltammetric immunoassay based on MWCNTs@Nd(OH)3-BSA-antibody platform for sensitive BSA detection.

An electrochemical approach is presented based on multiwall carbon nanotubes (MWCNTs) and neodymium(III) hydroxide (Nd(OH)3) nanoflakes for detection of bovine serum albumin (BSA). The materials were characterized morphologically (XRPD, SEM, and HR-TEM) and electrochemically (DPV, EIS). The MWCNTs@Nd(OH)3 composite was used as support for bovine serum albumin polyclonal antibody (anti-BSA). After the antibody immobilization on the electrochemical platform and antigen/antibody binding time (optimum 60 min), the proposed approach shows a linear voltammetric response toward BSA concentration in the range 0.066 to 6.010 ng mL-1 at maximum peak potential of 0.13 V (vs. Ag/AgCl). Limit of detection (LOD) and limit of quantification (LOQ) were 18 pg mL-1 and 61 pg mL-1, respectively. The precision of the method calculated as relative standard deviation (RSD) of five independent measurements was better 3%. The selectivity of the optimized method regarding structurally similar proteins (human serum albumin and human hemoglobin), ions (Na+, K+, Ca2+, and NO2-), or compounds (glucose, ascorbic acid, dopamine, uric acid, paracetamol, and glycine) was found to be satisfactory, with the current changes of less than 5% in the presence of up to 1 × 105 times higher concentrations (depending on the compound) of the listed potential interfering compounds. Practical applicability of immunosensor for BSA determination in cow whey sample, with recovery values in the range 97 to 103%, shows that the developed method has high potential for precise and accurate detection of BSA, as well as exceptional miniaturization possibilities for on-site and equipment-free sensing.

Elemental profiling of human semen with confirmed normozoospermia: Baseline levels for 44 elements.

BACKGROUND: As a consequence of the progressive decline in human semen quality in recent decades, modern epidemiological investigations have identified several trace elements that could be responsible for this phenomenon. However, their levels in semen have not been clearly elucidated, particularly for elements present in ultra-trace levels. METHODS: We aimed to determine the levels of 39 (ultra)trace elements and 5 macroelements in human semen samples with confirmed normozoospermia using ICP-based techniques. The research was amplified by analyzing blood samples from the same participants. RESULTS: Among the analyzed (ultra)trace elements in semen samples, Zn is the most and Tm is the least prominent. Zn levels in semen are so high that Zn should be considered as a macroelement in this matrix. The levels of Zn, Rh, Sm, Re, Ir, Tl, Na, and Ca were significantly higher in semen, while the levels of Cu, As, Rb, Gd, Sb, Tb, Tm, Lu, K, and Fe were significantly higher in blood. Correlation analysis of the levels of 44 individual elements in paired semen and blood samples revealed positive correlations between 43 of the elements, particularly for Tl and Pt. An exception was the negative correlation for Cu, which showed that its high level in semen is associated with a low level in blood and contrariwise. CONCLUSION: The reported data can be used as baseline levels/reference values for 44 elements in human semen. Furthermore, the findings of this study could be relevant for further consideration of male infertility.

Examination of Trace Metals and Their Potential Transplacental Transfer in Pregnancy.

With the ever-growing concern for human health and wellbeing, the prenatal period of development requires special attention since fetuses can be exposed to various metals through the mother. Therefore, this study explored the status of selected toxic (Pb, Cd, Ni, As, Pt, Ce, Rb, Sr, U) and essential trace metals (Mn, Co, Cu, Zn, Se) in the umbilical cord (UC) sera, maternal sera, and placental tissue samples of 92 healthy women with normal pregnancies. A further aim focuses on the potential transplacental transfer of these trace metals. Based on the obtained levels of investigated elements in clinical samples, it was observed that all of the trace metals cross the placental barrier and reach the fetus. Furthermore, statistical analysis revealed significant differences in levels of toxic Ni, As, Cd, U, Sr, Rb, and essential Mn, Cu, and Zn between all three types of analyzed clinical samples. Correlation analysis highlighted As to be an element with levels that differed significantly between all tested samples. Principal component analysis (PCA) was used to enhance these findings. PCA demonstrated that Cd, Mn, Zn, Rb, Ce, U, and Sr were the most influential trace metals in distinguishing placenta from maternal and UC serum samples. As, Co, and Cu were responsible for the clustering of maternal serum samples, and PCA demonstrated that the Pt level in UC sera was responsible for the clustering of these samples. Overall, the findings of this study could contribute to a better understanding of transplacental transfer of these trace metals, and shed a light on overall levels of metal exposure in the population of healthy pregnant women and their fetuses.

Protective Effect of an Exopolysaccharide Produced by Lactiplantibacillus plantarum BGAN8 Against Cadmium-Induced Toxicity in Caco-2 Cells.

Cadmium (Cd) ranks seventh on the list of most significant potential threats to human health based on its suspected toxicity and the possibility of exposure to it. It has been reported that some bacterial exopolysaccharides (EPSs) have the ability to bind heavy metal ions. We therefore investigated the capacity of eight EPS-producing lactobacilli to adsorb Cd in the present study, and Lactiplantibacillus plantarum BGAN8 was chosen as the best candidate. In addition, we demonstrate that an EPS derived from BGAN8 (EPS-AN8) exhibits a high Cd-binding capacity and prevents Cd-mediated toxicity in intestinal epithelial Caco-2 cells. Simultaneous use of EPS-AN8 with Cd treatment prevents inflammation, disruption of tight-junction proteins, and oxidative stress. Our results indicate that the EPS in question has a strong potential to be used as a postbiotic in combatting the adverse effects of Cd. Moreover, we show that higher concentrations of EPS-AN8 can alleviate Cd-induced cell damage.

Is a Lead Isotope Ratios in Wine Good Marker for Origin Assessment?

Lead isotope ratio pattern (206Pb/207Pb, 208Pb/206Pb, 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb) was analyzed in 59 samples of Serbian wine, from four geographical regions. By utilization of powerful inductively coupled plasma mass spectrometry (ICP-QMS), lead isotope ratios were used as unique "fingerprint", when combined with multivariate methods of analysis (Principal Component Analysis), provided information on the geographical origin of wine. In validation of ICP- QMS method and quantitative analysis, the certified reference material NIST SRM 981 was employed to test the mass-bias correction and thallium isotopes 203Tl and 205Tl (NIST SRM 997) as an internal standard. The obtained results were discussed in correlation with the corresponding values of LIRs of different European and Australian wines. In addition, the impact of anthropogenic Pb from different sources on the total Pb isotopic composition in Serbian wines was analyzed too. On the other side, the obtained values of Pb content were compared with the applicable health safety standards, according to the International Code of Oenological Practices.

Lead isotope ratios as tool for elucidation of chemical environment in a system of Macrolepiota procera (Scop.) Singer - soil.

The analysis of isotope ratios of lead in the mushrooms and soil, where they were grown, assisted with a principal component analysis, offered a new perspective for understanding possible chemical environment in a real setup of those compartments. The content of lead and its isotope compositions were determined in soil samples and mushroom Macrolepiota procera from unpolluted area of Mountain Goc, Serbia. Sequential extraction procedure based on the Commission of the European Community Bureau of Reference (BCR) was applied on soil samples in order to determine the distribution of lead in the labile and un-labile fractions of the soil. Caps and stipes of mushrooms were subjected to microwave acid-assisted digestion prior to measurements by inductively coupled plasma quadrupole mass spectrometer for determination of lead content and lead isotope ratios. Information about the chemical fractionation of Pb in soil, Pb isotopic data from soil fractions and fruiting bodies allowed a more detailed insight on the uptake mechanisms. Lead was predominantly associated with reducible fraction (~ 60%). Only its small portion (∼ 1%) was present in the exchangeable and acid-extractable fractions suggesting the low mobility of Pb. Lead isotope analysis revealed the presence of anthropogenic lead in the surface soil. Significant lower 206Pb/207Pb compared with other fractions was found in exchangeable and acid-soluble fraction (1.331 ± 0.010), which corresponds to the isotope ratio of European gasoline. The highest 206Pb/207Pb ratio was observed in reducible fraction (1.162 ± 0.007), while in oxidizable and residual fraction, those values were similar (1.159 ± 0.006 and 1.159 ± 0.004, respectively). Distinction of exchangeable and acid-extractable fractions from others was also confirmed, for the first time, by principal component analysis. The analysis of four isotope ratios (206Pb/207Pb, 208Pb/206Pb, 206Pb/204Pb, and 207Pb/204Pb) indicated that the analyzed M. procera accumulates lead from the first two fractions of topsoil layers.

Two aspects of honeydew honey authenticity: Application of advance analytical methods and chemometrics.

Taking into account a growing market and small number of articles related to honeydew honey, a metabolomic approach associated with multivariate analysis and modelling was proposed to discriminate five varieties of honey. Advanced analytical techniques were used for determination of 20 elements, 14 carbohydrates and stable carbon isotope ratio. No chemical marker has been found within sugar compounds, but several elements (Ba, Ca, Mg, Sr, Mn, Al, Co, Ni, Se) were marked as characteristic of honey type and allow classification of three botanical origins (Abies alba, Quercus frainetto, Quercus ilex). Sugars turanose, trehalose, arabinose and raffinose, elements Ba, Sr, P, Cd and Se, and δ13C values of honey, have different concentrations in honeys of the same botanical origin but harvested in different season. In addition to a confirmation of authenticity in terms of production, the values of δ13C of protein could be a good indicator of botanical origin.

Accumulation of U, Th, Pb, V, Rb, and Ag in wild mushrooms Macrolepiota procera (Scop.) Singer from Goc, Serbia.

In this study, the content of U, Th, Pb, V, Rb, and Ag in 19 soil samples from unpolluted Goc Mountain area (Serbia) was determined. The same elements were determined in 19 Macrolepiota procera samples, separately for caps and stipes. Soil samples were subjected to the BCR sequential extraction procedure. Element contents were determined by inductively coupled plasma mass spectrometry (ICP-MS). Obtained soil values for U were in the range from 0.30 to 0.86 mg/kg and for Th from 1.7 to 13.2 mg/kg. These values are the first for background levels at unpolluted Goc area, and they are lower than the corresponding values for European unpolluted soil. The mean values in soil for Pb, V, Rb, and Ag were 27.6, 57.4, 15.8, and 0.76 mg/kg, respectively. PCA was applied to establish criteria for translocation of the analyzed elements between two parts of the mushroom. Efficient translocation for all elements except Ag as the main amount of the elements was found in caps. The mean content in the caps for U and Th was 4.3 and 63 µg/kg, respectively. Bioconcentration factors were much higher than 1 only for Rb and Ag. M. procera only weakly accumulates U and Th from soil in unpolluted areas. These findings indicate limited role of M. procera in the mycoremediation of the mentioned actinides.

Scandium, yttrium, and lanthanide contents in soil from Serbia and their accumulation in the mushroom Macrolepiota procera (Scop.) Singer.

The mobility (fractionation) of rare earth elements (REEs) and their possible impacts on ecosystems are still relatively unknown. Soil samples were collected from two sites in central Serbia, an unpolluted mountain region (site 1) and a forest near a city (site 2). In order to investigate REE fractions (acid-soluble/exchangeable, reducible, oxidizable, and residual) in soils, BCR sequential extraction was performed. Additionally, the content of REEs was also determined in stipes and caps of the mushroom Macrolepiota procera, growing in the observed sites. Sc, Y, and lanthanide contents were determined by inductively coupled plasma mass spectrometry (ICP-MS), and results were subjected to multivariate data analysis. Application of pattern recognition technique revealed the existence of two distinguished clusters belonging to different geographical sites and determined by greater levels of Sc, Y, and lanthanides in Goc soil compared to Trstenik soil. Additionally, PCA analysis showed that REEs in soil were concentrated in two groups: the first consisted of elements belonging to light REEs and the second contained heavy REEs. These results suggest that the distribution of REEs in soils could indicate the geographical origin and type of soil. The bioconcentration factors and translocation factors for each REE were also calculated. This study provides baseline data on the rare earth element levels in the wild edible mushroom M. procera, growing in Serbia. In terms of bioconcentration and bioexclusion concept, Sc, Y, and REEs were bioexcluded in M. procera for both studied sites.

Urban honey - the aspects of its safety.

To contribute to the development of urban beekeeping, we designed this study to obtain more information about the contamination of urban bee products with toxic metals, polycyclic aromatic hydrocarbons (PAHs), and pesticides. The samples of honey (N=23), pollen (N=13), and floral nectar (N=6) were collected from the experimental stationary apiary of the Belgrade University Faculty of Agriculture located in centre of Zemun (a municipality of the Belgrade metropolitan area) in 2015 and 2016. Metals (Pb, Cd, As, Cu, Zn, Fe, Mn, Ni, Cr, and Hg) were determined with inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Polycyclic aromatic hydrocarbons (PAHs) were analysed with high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Pesticides were analysed with gas chromatography - mass spectrometry (GC-MS). The honey samples were generally within the European and Serbian regulatory limits. The levels of all the 123 analysed pesticides were below the limit of quantification (LOQ). Regarding PAH levels in honey, the highest content was found for naphthalene. The elevated levels of Hg and Cr and of PAHs in the pollen samples indicated air pollution. Pesticide residues in pollen, however, were below the LOQ. In nectar, metal levels were relatively similar to those in honey. Our results suggest that the investigated urban honey meets the regulatory requirements for metals, PAHs, and pesticides and is therefore safe for consumption.

Characterization of Croatian Rape (Brassica sp.) Honey by Pollen Spectrum, Physicochemical Characteristics, and Multielement analysis by ICP-OES.

Rape (Brassica sp.) unifloral honey from Croatia was characterized by certain physicochemical parameters, micro- and macroelement content, and pollen spectrum, as determined in 21 honey samples. The Brassica sp. pollen type was predominant in the analyzed samples and ranged between 60 and 98%, with Trifolium spp., Robinia pseudoacacia, Rosaceae, Helianthus annuus, Salix spp., and Taraxacum officinale as the main accompanying pollen types. The electrical conductivity mean value was 0.22 ± 0.05 mS/cm and the glucose/fructose ratio mean value was 1.1 ± 0.07, whereas sucrose was absent in the samples. The most abundant macroelement was potassium (K) (268.49 mg/kg), followed by phosphorus (P) (60.23 mg/kg), calcium (Ca) (54.02 mg/kg), sodium (Na) (22.52 mg/kg), sulfur (S) (15.79 mg/kg), and magnesium (Mg) (12.58 mg/kg). Toxic elements were mainly bellow the LODs; only arsenic (As) concentration was detectable in higher amount (0.233 mg/kg), which may be related to the high arsenic concentration in the soil and groundwater of eastern Croatia. The differences between the two harvesting seasons observed in a large number of elements could be related to climatic and soil conditions and different nectar yields originating from the associated plant species.

Influence of dietary cadmium exposure on fitness traits and its accumulation (with an overview on trace elements) in Lymantria dispar larvae.

Bioaccumulation and excretion of heavy metals in insects is only partially clarified. We have investigated cadmium accumulation in the feces, head and integument of Lymantria dispar (Lepidoptera: Lymantriidae) larvae exposed to chronic dietary intake of cadmium. The aim of the experiment was to establish modalities of metal accumulation, primarily cadmium, as well as changes in fitness traits in two insect populations receiving 50 or 100µgCd/g dry food. The egg-masses originated from two localities: a protected nature reserve (unpolluted population) and an area near a busy highway (polluted population) in Serbia. At both added dietary levels cadmium concentration was highest in feces. Small alterations in metal concentrations after both cadmium treatments were detected in the integument. It was established that irrespective of population origin, the modality of decline of larval mass and relative growth rate (RGR) was similar. Concentrations of Cu and Zn in the integument were approximately the same regardless of dietary cadmium intake. However, cadmium accumulation in the examined tissues, as well as variability of fitness traits depended on population origin and cadmium concentration. In larvae from both populations not given contaminated food the head was the organ with the greatest accumulation of trace elements. Our results reveal how invasive phytophagous insects cope with high metal concentrations in their food by body mass (RGR) reduction and energy allocation towards processes that enable accumulation of cadmium and other trace elements in different tissues.