Search Results (54)

A simple and fast analytical method was developed and applied to assess the effect of two forms of zinc fertilization on a pecan tree cultivar in Uruguay: fertigation and foliar application with a specially formulated fertilizer. Zinc content was determined in 36 leaf samples from two crop cycles: 2020–2021 and 2021–2022. Fresh samples were dried, ground, and sieved. Analytical determinations were performed by flame atomic absorption spectrometry (FAAS, considered a standard method) and energy dispersive X-ray spectrometry (EDXRF, the proposed method). In the first case, sample preparation was carried out by microwave-assisted digestion using 4.5 mol L⁻¹ HNO₃. In the second case, pellets (Φ 13 mm, 2–3 mm thick) were prepared by direct mechanical pressing. Figures of merit of both methodologies were adequate for the purpose of zinc monitoring. The results obtained from both methodologies were statistically compared and found to be equivalent (95% confidence level). Based on the principles of Green Analytical Chemistry, both procedures were evaluated using the Analytical Greenness Metric Approach (AGREE and AGREEprep) tools. It was concluded that EDXRF was notably greener than FAAS and can be postulated as an alternative to the standard method. The information emerging from the analyses aided decision-making at the agronomic level. Full article

Honey is increasingly recognized not only as a functional food but also as a potential bioindicator of environmental pollution. This study assessed the concentrations of four potentially toxic elements (PTEs)—lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn)—in 48 multifloral honey samples collected in 2023 from seven locations across a historically polluted agro-industrial region in Romania. Samples were analyzed using Flame Atomic Absorption Spectrometry (FAAS) and Graphite Furnace AAS (GFAAS), with quality control ensured through certified reference materials. Results revealed that Pb (0.72–1.69 mg/kg) and Cd (0.02–0.37 mg/kg) levels consistently exceeded international safety thresholds, while Cu (0.62–2.22 mg/kg) and Zn (0.91–1.93 mg/kg), although essential nutrients, were found in elevated concentrations. Spatial analysis indicated a general trend of higher contamination in sites located closer to former industrial facilities, influenced by factors such as altitude and atmospheric transport. These findings confirm the persistent environmental burden in post-industrial landscapes and support the use of honey as a cost-effective tool for pollution monitoring. The study underscores the need for targeted environmental policies, sustainable apicultural practices, and continued surveillance to protect ecosystem health and food safety. Full article

Beryllium (Be) is one of the most toxic non-radioactive elements on the periodic table, and its presence or intake can negatively impact both the environment and human health. Classified as a carcinogen, Be is dangerous even at trace concentrations, stressing the necessity of developing reliable methods for quantifying it at very low levels. Spectrometric techniques for quantifying Be vary in sensitivity and applicability, with inductively coupled plasma mass spectrometry (ICP-MS) being the most sensitive for ultra-trace analysis. Flame atomic absorption spectrometry (FAAS) is suitable for higher Be concentrations, but preconcentration techniques can significantly lower detection limits. Electrothermal atomic absorption spectrometry (ETAAS) provides enhanced sensitivity for low-level Be quantification, further optimized using pyrolytically coated graphite tubes and chemical modifiers such as Mg(NO₃)₂ or Pd(NO₃)₂. Effective separation and preconcentration techniques are essential for reliable Be quantification in complex matrices. Liquid-liquid extraction (LLE), including single-drop microextraction (SDME) and dispersive liquid-liquid microextraction (DLLME), have evolved to reduce the use of hazardous solvents. When combined with ETAAS, surfactant-assisted DLLME using agents like cetylpyridinium ammonium bromide (CPAB) and dioctyl sodium sulfosuccinate (AOT) achieves preconcentration factors of approximately 25, reducing LOD to 1 ng/L. Vesicle-mediated DLLME coupled with ETAAS further enhances sensitivity, allowing detection limits as low as 0.01 ng/L in seawater. Cloud-point extraction (CPE), often employing Triton X-114, facilitates Be extraction using complexing agents or nanomaterials like graphene oxide. These advancements are critical for accurately quantifying Be at ultra-trace levels in diverse environmental and biological samples, overcoming challenges posed by low analyte concentrations and matrix interferences. Full article

Evaluation of 12 commercially available products of Cannabis sativa L. was performed to find similarities and differences in their composition. The contents of metallic elements determined by flame atomic absorption spectrometry (FAAS) made it possible to order microelements as follows: Fe > Mn > Zn > Cu. As for the contents of macroelements, the pattern was Ca > K > Mg > Na. Analyses of hemp samples were also performed via assays of their phenolic compounds and ascorbic acid by UV/Vis spectrophotometry. The antioxidant activity was determined based on the Ferric-Reducing Antioxidant Power (FRAP), Cupric-Reducing Antioxidant Capacity (CUPRAC), 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), and ABTS Radical-Scavenging Activity. We concluded from the application of cluster analysis (CA) and principal component analysis (PCA) that several hemp samples (for example, the sample from Italy) were well-separated from the others due to their different chemical composition. In conclusion, the results achieved with the statistical methods are helpful in interpreting the results obtained for hemp samples and reveal characteristic tendencies among the investigated samples due to their contents of metals, phenolic compounds, ascorbic acid concentrations, and antioxidant properties. Full article

Lead (Pb) is a persistent and toxic heavy metal that threatens aquatic ecosystems. Wetlands act as natural filters, while beaver dams influence sediment deposition and metal retention. This study investigates Pb fixation in wetland sediments by analyzing its spatial and temporal variations, considering organic matter content and sediment composition. Pb concentrations were determined using flame atomic absorption spectrometry (FAAS), and fixation processes were assessed using concentration coefficients relative to background values (15 µg g⁻¹, Lithuanian Hygiene Standard HN 60:2004). A total of 165 sediment samples were collected during the spring and the autumn of 2022 and 2023 across three study sites. The results indicate that Pb fixation strongly correlates with organic carbon content, while sediment texture influences its mobility. A key finding is that beaver dams contribute to Pb retention by altering hydrodynamic conditions and sedimentation patterns. Despite sediment stability, new Pb inputs continue to enter water bodies, depending on pollution sources. However, Pb concentrations remain within background levels and do not exceed the Maximum Allowable Concentration (MAC). These findings are essential for wetland conservation and contribute to sustainable strategies for mitigating heavy metal contamination in aquatic ecosystems. Full article

This paper evaluates the possibility of analyzing the composition of high-quality copper scrap with X-ray fluorescence spectrometry (XRF) instead of electrogravimetry combined with flame atomic absorption spectroscopy (EG+FAAS) method. The evaluation of the methods was performed on three real copper scraps, the composition of which were estimated in average samples taken after re-melting. Traceability of XRF results was ensured by the use of new certified reference materials (CRMs) dedicated to copper scrap analysis. The copper content results obtained by XRF were characterized by high agreement with the reference results obtained by EG+FAAS method. The estimated expanded uncertainty for Cu of both methods was 0.23%. In addition to significant time savings without compromising accuracy, the XRF method additionally provided information on the content of 12 other elements, such as Sn, Zn, Co, Cd, Sb, Ni, Fe, Pb, Bi, Ag, Al, and P. This may make the XRF method attractive compared to the commonly used EG+FAAS method. Full article

The increasing demand for gold necessitates the development of sustainable and environmentally friendly recovery methods, particularly from mining waste. In this study, trace and ultra-trace levels of gold ions were preconcentrated using solidified floating organic drop microextraction (SFODME) and quantified by flow injection–flame atomic absorption spectrometry (FI-FAAS). Sodium diethyldithiocarbamate was used as the chelating agent. Key parameters, including the pH, buffer volume, complexing agent concentration, salt effect, extraction time, stirring speed, temperature, and final volume, were optimized using univariate analysis, yielding an enhancement factor of 42.6. The method demonstrated linearity between 20 and 450 µg/L, with limits of detection and a quantification of 5.03 µg/L and 16.76 µg/L, respectively. In order to evaluate the applicability and reliability of the developed method, the method was applied to certified reference samples (Rocklabs CRM SE114, OREAS CRM 61 f, OREAS CRM 231, and OREAS CRM 235) and real mining samples (mining waste samples from an open pit gold–silver mine in the Aegean Region and tailing samples from an underground gold–silver mine in the Aegean Region) after the real sample preparation procedure. The method was further evaluated for the environmental impact using the Analytic GREEnness (AGREE) metric, based on the 12 principles of green chemistry. Full article

The mineral composition of wine is affected by numerous factors, including treatments with bentonite to control colloidal hazes. In this study, 10 parallel samples of white wine (Chardonnay, 2021 vintage year) were treated with pre-selected bentonite (activated calcium bentonite) at increasing doses, from 0.3 to 3.0 g/L. Following acid mineralization, the content of some important elements was determined. The elements Al, Ba, Cd, Cu, Cr, Fe, Mg, Mn, P, Pb, and Zn were measured by inductively coupled plasma with optical emission spectrometry (ICP-OES), while flame atomic absorption spectrometry (FAAS) was used for the determination of Ca, K, and Li. Depending on the applied dose, the bentonite changed the concentration of the determined elements in different ways. Results indicated that higher doses of bentonite led to an increase in Al, Ca, and Fe content, while Cu and Zn initially rose with low doses before declining to near-baseline levels with higher doses. Full article

Zinc is a trace element, which plays an important role in many biological processes. The deficiency of zinc will lead to many diseases. Thus, it is of great significance to develop fast and efficient quantitative detection technology for zinc ions. In this study, a novel fluorescence probe FP2 was designed for Zn²⁺ quantification based on pyrano[3,2-c] carbazole. The structure of FP2 was characterized by ¹HNMR, ¹³CNMR, HRMS, and X-ray diffraction. In the HEPES buffer solution, FP2 is responsive to Zn²⁺ and greatly enhanced. The pH value and reaction time were investigated, and the optimum reaction conditions were determined as follows: the pH was 7~9 and the reaction time was longer than 24 min. Under the optimized conditions, the concentration of FP2 and Zn²⁺ showed a good linear relationship in the range of 0~10 μM, and the LOD was 0.0065 μmol/L. In addition, through the ¹H NMR titration experiment, density functional theory calculation, and the job plot of FP2 with Zn²⁺ in the HEPES buffer solution, the binding mode of FP2 and Zn²⁺ was explained. Finally, the method of flame atomic absorption spectrometry (FAAS) and FP2 were used to detect the content of Zn²⁺ in the water extract of tea. The results showed that the FP2 method is more accurate than the FAAS method, which shows that the method described in this work could be used to detect the content of Zn²⁺ in practical samples and verify the practicability of this method. Full article

This study evaluates the concentrations of trace elements (TEs) in soils from the rutile deposit area of Akonolinga, Cameroon, and analyzes the associated health risks. A total of 25 samples were analyzed using flame atomic absorption spectrometry (FAAS). The results show that TE concentrations follow the decreasing order Fe, Ti, Zr, Mn, Cr, V, Ba, Zn, Nb, Ni, Pb, Ga, Cu, Co, Y, Br, and Sn. Pollution indices and the Pearson correlation matrix reveal moderate correlations between Fe and several other TEs, indicating a common origin. Enrichment Factors show significant enrichment in Zr, Nb, and Ti, with notable enrichment in Cr and Co at certain sites. Although the Geo-Accumulation Index indicates no direct contamination and the overall ecological risk is low, the Contamination Factor reveals high levels for Cr, Nb, Ti, and Zr. The carcinogenic risk is moderate, while non-carcinogenic risks are high for children and considerable for adults. These research highlight the potential public health impacts in this mining region and provide essential baseline data for future environmental risk management. Full article

A low-cost laser-induced breakdown spectroscopy (LIBS) instrument equipped with a charge-coupled device (CCD) was tested in the atmospheric environment for the quantification of K, Ca, Mg, and Mn in some organo–mineral fertilizers, mineral P fertilizers, and rock fertilizers of various compositions and origins, using flame atomic absorption spectrometry (FAAS) as the reference technique. The correlation analysis performed between each CCD pixel and the corresponding element concentration measured by FAAS allowed to choose the most appropriate K, Ca, Mg and Mn emission lines for LIBS analysis. The normalization process applied to LIBS spectra to correct physical matrix effects and small fluctuations was able to increase the linear correlation of the calibration curves between LIBS data and FAAS data by an average of 0.15 points of the R-value for all elements of interest. The R values of calibration curves were 0.97, 0.96, 0.86 and 0.84, for K, Ca, Mg and Mn, respectively. The limits of detection (LOD) were 66 mg/kg (K), 35 mg/kg (Ca), 5.4 mg/kg (Mg) and 0.8 mg/kg (Mn) when using LIBS in the quantification model. The cross-validation (leave-one-out) analysis yielded an absolute average error of 12% (K), 21% (Ca), 8% (Mg) and 13% (Mn) when LIBS data were correlated to FAAS ones. These results showed that the calibration models used were close to the optimization limit and satisfactory for K, Ca, Mg, and Mn quantification in the fertilizers and rocks examined. Full article

The study investigated the biological properties of a composite material composed of poly(lactide) (PLA) and iron (Fe) produced by sputtering iron onto melt-blown poly(lactide) nonwoven fabrics. The research aimed to thoroughly understand the structure and properties of these materials and their potential applications in biomedicine. We conducted comprehensive chemical and structural analyses using techniques such as microscopic analysis, flame atomic absorption spectrometry (FAAS), and Brunauer–Emmett–Teller (BET) surface area analysis to precisely determine the properties of PLA-Fe materials. Additionally, we evaluated their impact on blood coagulation processes by measuring activated partial thromboplastin time (aPTT) and prothrombin time (PT). We also performed biological analyses on human peripheral blood mononuclear cells (PBM cells) including cell viability and DNA damage. Our results clearly demonstrate that PLA-Fe materials do not significantly influence blood coagulation mechanisms, as they only slightly prolong aPTT time and have no effect on PT. This suggests their potential in biomedical applications. Our results indicate the absence of cyto- and genotoxic properties of PLA-Fe materials against normal blood cells. In conclusion, the research findings suggest that the novel poly(lactide) and iron-sputtered nonwoven fabrics are promising tools in the field of biomedicine, offering potentially innovative therapeutic solutions for the treatment of wounds and injuries. Full article

Thallium is an accumulative highly toxic metal, that can be present in environmental samples due to industrial pollution and is dangerous for living organisms. Thus, its determination at trace levels is necessary. The lab-in-syringe (LIS) is considered to be a simple, functional, and versatile, technique that combines operational concepts and flow and sequential injection analysis. In this study, a liquid-phase microextraction LIS system was developed as a front-end to flame atomic absorption spectrometry (FAAS) for the determination of thallium in water samples. The proposed approach is based on the formation of Tl(III) ammonium–pyrrolidine–dithiocarbamate complex followed by its extraction using di-isobutyl-ketone. These procedures take place within the syringe barrel of the LIS system. The limit of detection of the developed method was 2.1 µg L⁻¹ with a linear range from 7.0 to 400 µg L⁻¹. The relative standard deviation (RSD) was 3.9% (at 50.0 µg L⁻¹ Tl(I)), demonstrating good precision. Moreover, good method accuracy was obtained since the relative recovery values were within the range of 93.4–101.2%. Finally, reliable method applicability and green merits were demonstrated using the blue applicability grade index and green analytical procedure index, respectively. The proposed method was used for the analysis of environmental water samples. Full article

This article presents the biochemical properties of poly(lactide)-zinc (PLA-Zn) composites obtained by DC magnetron sputtering of zinc onto melt-blown nonwoven fabrics. The biochemical properties were determined by the evaluation of the activated partial thromboplastin time (aPTT) and prothrombin time (PT). The antimicrobial activity of the PLA-Zn samples was additionally tested against representative Gram-positive and Gram-negative bacteria strains. A structural study of the PLA-Zn has been carried out using specific surface area and total pore volume (BET) analysis, as well as atomic absorption spectrometry with flame excitation (FAAS). PLA-Zn composites exhibited an antibacterial effect against the analyzed strains and produced inhibition zones against E. coli and S. aureus. Biochemical investigations revealed that the untreated PLA fibers caused the acceleration of the clotting of human blood plasma in the intrinsic pathway. However, the PLA-Zn composites demonstrated significantly different properties in this regard, the aPTT was prolonged while the PT was not altered. Full article

Despite numerous studies focused on the hydrothermal (HT) synthesis of fly ash zeolites (FAZs), this method still has many limitations, the main of which is the low yield of zeolites. Hydrothermally synthesized zeolites are typically multiphase and exhibit low purity, which limits their applicability. Pure-phase zeolites have been primarily prepared from filtrates after alkaline mineralization of fly ashes, not directly in suspension. In addition, the published methodologies have not been tested in a wider set of samples, and thus their reproducibility is not confirmed. The aim of the study is to propose a reproducible methodology that overcomes the mentioned limitations. The influence of the Si/Al ratio (1.3:1–1:2), the type and concentration of the activator (2/4 M NaOH/KOH/LiOH), the reagent (30% LiCl), the duration (24–168 h), and the temperature (50–180 °C) of the synthesis phases were studied. The sequence of the synthesis phases was also optimized, depending on the type of heat transfer. The fly ashes were analyzed by wavelength-dispersive X-ray fluorescence (WD XRF), flame atomic absorption spectrometry (F-AAS), and X-ray diffraction (XRD). The energy intensity of the synthesis was reduced through the application of unique microwave digestion technology. Both microwave and combined (microwave and convection) syntheses were conducted. FAZs were identified and quantified by XRD analysis. This study presents a three-stage (TS) hydrothermal synthesis of pure-phase sodalite in suspension. Sodalite (>99 wt.%) was prepared from nine fly ashes under the following conditions: I. microwave phase: 120 °C, 150 min, solid-to-liquid ratio (S/L) 1:5, Si/Al ratio 1:1.5, and 4 M NaOH; II. convection phase: 120 °C, 24 h, S/L 1:40, and the addition of 30 mL of 30% LiCl; and III. crystallization: 70 °C for 24 h. The formation of rhombododecahedral sodalite crystals was confirmed by scanning electron microscope (SEM) images. Full article