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The study presents for the first time the figures of merit of a completely miniaturized instrumentation based on a capacitively coupled plasma microtorch as the core element interfaced with a small-sized electrothermal vaporization device and a low-resolution microspectrometer for the simultaneous determination of Cd, Pb, Cu and Zn by optical emission spectrometry in soil as total and labile fractions after diffusive gradients in thin-film (DGT) accumulation. The coupling of the low-power and low-argon consumption plasma (15 W; 150 mL min−1) with the DGT passive accumulation technique, although requiring a too-long time for sample preparation, allowed a considerable improvement of the detection limits and avoidance of the non-spectral matrix effects, otherwise a recognized process in low power microplasmas, when a complex matrix is analysed, like environmental samples. The detection limits for the total content in soil were (mg kg−1), 0.10(Cd), 0.40(Pb), 0.15(Cu), and 0.03(Zn), one order of magnitude better than in the procedure without DGT accumulation and 10–3300-times lower than the guide values in soil. In the DGT-based labile fraction exhibiting the highest bioavailability the detection limits were (μg kg−1) 0.01(Cd, Cu, and Zn) and 0.03(Pb), which allowed the determination of Cd, Pb, Cu and Zn in the concentration range (μg kg−1) of 0.3–2.0, 0.8–18.4, 2.4–56.3 and 9.4–60.6, respectively. Validation through the analysis of certified reference materials (CRMs) showed a recovery of 85–123% with a relative expanded uncertainty of 19–35% (k = 2) for the total content of analytes. The analysis of the certified reference materials highlighted that the DGT accumulation was not affected by the multielemental matrix, since the experimental diffusion coefficients of the analytes were similar in the four analyzed CRMs and to those provided by the manufacturer, respectively. Precision for the measurements of the total content and DGT-labile fraction in real samples evaluated from the combined uncertainty was 10–19% and 10–15%, respectively. The Bland–Altman plot applied to the results of real samples indicated the lack of statistical differences versus line-source graphite furnace atomic absorption spectrometry for both the total content and DGT-based labile fraction. [ABSTRACT FROM AUTHOR]

Increased concentrations of heavy metals in the environment are of public health concern, their removal from waters receiving considerable interest. The aim of this paper was to study the simultaneous adsorption of heavy metals (Cu, Cd, Cr, Ni, Zn and Pb) from aqueous solutions using the zeolitic volcanic tuffs as adsorbents. The effect of thermal treatment temperature, particle size and initial metal concentrations on the metal ions sorption was investigated. The selectivity of used zeolite for the adsorption of studied heavy metals followed the order: Pb > Cr > Cu > Zn > Cd > Ni. The removal efficiency of the heavy metals was strongly influenced by the particle sizes, the samples with smaller particle size (0–0.05 mm) being more efficient in heavy metals removal than those with larger particle size (1–3 mm). Generally, no relevant changes were observed in heavy metals removal efficiency for the treatment temperatures of 200 °C and 350 °C. Moreover, at a higher temperature (550 °C), a decrease in the removal efficiencies was observed. The Cd, Zn, Cu, Cr, Zn and Ni sorption was best described by Langmuir model according to the high values of correlation coefficient. The pseudo-first-order kinetic model presented the best correlation of the experimental data. [ABSTRACT FROM AUTHOR]

In the present work, the capability of the volcanic tuff from Macicasu (Romania) to remove ammonia (NH3) from air with different contamination levels during 24 h of adsorption experiments was investigated. The natural zeolitic volcanic tuff was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), the Brunauer–Emmett–Teller (BET) method, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis (TGA). The adsorption capacities varied between 0.022 mg NH3 g−1 zeolite and 0.282 mg NH3 g−1 zeolite, depending on the NH3 concentrations in the air and at the contact time. The nonlinear forms of the Langmuir and Freundlich isotherm models were used to fit the experimental data. Additionally, the adsorption of NH3 was studied using nonlinear pseudo-first-order (PFO), pseudo-second-order (PSO), and Elovich kinetic model. Based on the total volume of pores of used volcanic tuff, the NH3 was removed from the air both due to the physical adsorption of NH3 gas and the ion exchange of NH4+ (resulted from a reaction between NH3 and H2O adsorbed by the zeolite). Depending on the initial NH3 concentration and the amount of volcanic tuff, the NH3 concentrations can be reduced below the threshold of this contaminant in the air. The adsorption capacity of NH3 per unit of zeolite (1 g) varied in the range of 0.022–0.282 mg NH3 g−1 depending on the NH3 concentration in the air. [ABSTRACT FROM AUTHOR]

This study aimed to determine the chemical composition of three species of wild edible mushrooms growing in the Apuseni Mountains near a copper mine. The mushrooms' proximate composition, fatty acid profile, and element contents were assessed. The content of total fatty acids increased in the following order: Cantharellus cibarius < Boletus edulis < Amanita rubescens. The average content of elements in mushrooms decreased in the following order: K (16780), P (5630), S (1940), Na (1790), Ca (624), Mg (425), Zn (89), Fe (81), Cu (32), B (14), Mn (5.1), Sr (2.4), Cr (2.3), Hg (1.1), Ni (0.85), Pb (0.23), Li (0.20), Cd (0.18) (mg kg−1 dw). The analyzed toxic elements in the soil were below the maximum allowable limits, although the amount of Cu was higher than the normal value. Bioconcentration factors > 1 were obtained for P, S, K, Na, B and Hg. Adults can be susceptible to non-carcinogenic risks related to Hg through ingestion of Boletus edulis and Amanita rubescens , while children are vulnerable to the consumption of all studied mushroom species due to the high content of Cu and Hg. The estimation of the carcinogenic risk assessment indicated that the ingestion of all studied mushroom species could pose cancer risks for children. • The composition of selected mushrooms growing in the Apuseni Mountains was determined • Bioconcentration factors (BCFs) exceeding 1 were calculated for P, S, K, Na, B and Hg • Among mushroom species, a significantly high BCF of Hg in Boletus edulis was found • Non-carcinogenic risk due to Hg and Cu through mushroom consumption was observed • Carcinogenic risk for children, due to the presence of toxic elements in mushrooms, exists. [ABSTRACT FROM AUTHOR]

[Display omitted] • DGT sampling was used for Fe, Mn, Cu, Pb and Zn fractionation analysis in beer; • Total and DGT-labile fractions of metals were measured in beer; • DGT can reliably assess the labile fraction of metals in beer; • Average DGT fractions of Fe, Cu, Pb, Zn and Mn were: 7, 15, 12, 31, 29 %, respectively. Fractionation analysis of Fe, Mn, Cu, Zn and Pb in beer is of high interest since their labile forms affect its stability and have implications for toxicity. In this study, we used the Diffusive Gradient in Thin-film (DGT) technique for the first time as a tool for passive sampling of labile species of Fe, Mn, Cu, Zn and Pb from beer. The validity of methodologies for total, total-dissolved and DGT-labile concentrations of Fe, Cu, Mn, Zn and Pb in beer was checked and then were applied to measure metals concentrations in two beer sorts: filtered and unfiltered (craft) beer. Commercial beer spiked with target analytes was used to check the linear accumulation of metals by DGT for 72 h DGT deployment period. The obtained determination coefficients were in the range of 0.986–0.998. The total concentrations of metals in beers determined by GFAAS were in the range of 60.4–957 µg/L (Fe), 58.0–206 µg/L (Mn), 45.6–314 µg/L (Cu), 70.0–313 µg/L (Zn) and 0.75–4.22 µg/L (Pb). Of these, the DGT-labile fractions of Fe, Cu, Mn, Zn and Pb were 5.0 – 7.8 µg/L Fe, 4.5 – 15.0 µg/L Cu, 23.1 – 37.0 µg/L Mn, 17.7 – 41.5 µg/L Zn and 0.15 – 0.35 µg/L Pb. This study provides a simple and reliable methodology for the fractionation of metals in beer. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lycium barbarum L. has received considerable attention due to nutritional value of berries and its cultivation in Europe has attracted growing interest. OBJECTIVE: The aim of the study was characterization of Lycium barbarum L. berry cultivated in North Macedonia in terms of nutritional and functional properties and comparison with Lycium chinense M. variety. METHODS: Minerals, total proteins, sugars, antioxidant activity, fatty acids, carotenoids and polyphenols were determined and lipid indices were evaluated. Principal Component Analysis was used to describe variability of composition, while heat map to recognize the parameters significantly different for varieties. RESULTS: Lycium barbarum L. cultivated in North Macedonia represents a rich source of K, Cu, Mn, P, Zn, Mg, Fe and antioxidant compounds. Polyunsaturated fatty acids (mainly linolenic acid) were dominant in oil resulting in very low atherogenic and thrombogenic indices. A variability of 35.1% was ascribed to minerals, carbohydrates and proteins, 22.3% to ω-6 fatty acids and lipid indices of oil, 19.4% to nutrients with antioxidant activity and 13.4% to ω-3 fatty acids (n-3 and n-3/n-6 ratio). CONCLUSIONS: Chemometric analysis highlighted significant differences in terms of inorganic nutrients, antioxidant capacity, proteins, sugar profile and lipid indices in Lycium barbarum L. compared to Lycium chinense M. [ABSTRACT FROM AUTHOR]

This study presents for the first time the coupling between in-situ Diffusive Gradient in Thin-film (DGT) passive sampling technique and ex-situ small-sized instrumentation based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry (SSETV-μCCP-OES) for the simultaneous determination of Cd, Pb, Cu, Zn and Hg in surface water. Unique features of the DGT-SSETV-μCCP-OES are low power and low Ar consumption for plasma generation (15 W, 150 mL min−1) and significant improvement of the detection limits following DGT passive sampling. The new method was validated in terms of river water analysis in comparison with graphite furnace atomic absorption spectrometry and thermal decomposition atomic absorption spectrometry. Combining the abilities of preconcentration by in-situ Chelex-DGT passive sampling with plasma microtorch equipped with a low resolution microspectrometer provided multielemental simultaneous determination with detection limits of (μg L−1) 0.01 (Cd, Zn and Hg), 0.02 (Cu) and 0.07 (Pb) in water, at least one order of magnitude better than using grab sampling without preconcentration. It was possible the quantification of labile fraction of priority hazardous metals (Cd, Pb) in river water below the instrumental limits of detection (μg L−1) of 0.12 and 0.80 obtained in SSETV-μCCP-OES without DGT sampling. The precision of the method was in the range 15.3–22.4% (combined uncertainty), while the accuracy was 95–103% and trueness of 27–33% (expanded uncertainty, k = 2). The DGT-SSETV-μCCP-OES coupling proved to be an ideal and powerful tool for surface water analysis in compliance with green and white analytical chemistry concepts. The application of the RGB-12 algorithm provided very good red/green (AGREEprep)/blue/white scores (%) of 100/80/98/93, determined primarily by in-situ DGT passive sampling, very good detection limits and cost-effective SSETV-μCCP-OES instrumentation. [Display omitted] • In-situ DGT sampling was coupled with a cost-effective ex-situ microplasma set-up. • The applicability was checked by determining Cd, Pb, Hg, Zn, Cu in river water. • DGT passive sampling allowed the removal of As–Cd spectral interference. • The LODs have been improved 10 times by the new DGT-SSETV-μCCP-OES coupling. • The new DGT-SSETV-μCCP-OES method exhibits 93/80% whiteness/greenness score. [ABSTRACT FROM AUTHOR]

A highly sensitive method based on UV photochemical vapor generation capacitively coupled plasma microtorch optical emission using a low resolution microspectrometer was developed for total mercury determination in food and water. The method fulfils most of the eco-scale criteria in terms of derivatization and cost-effective miniaturized instrumentation, which are major benefits compared to cold vapor atomic fluorescence spectrometry and inductively coupled plasma optical emission spectrometry. Formic acid was the single reagent used for the extraction of Hg species from solid samples and as a reaction medium for the UV photo-induced cold vapor generation. A 200 mg lyophilized sample was subjected to ultrasonic assisted extraction in 10 mL of HCOOH 98–100% at 50 °C for 3 h, and then on-line derivatization to cold vapor was performed in 0.6 mol L−1 HCOOH. Water and food with low Hg content adjusted in HCOOH 0.6 mol L−1 underwent on-line preconcentration of Hg vapor on a gold filament microcollector. Total Hg was quantified against external standards containing Hg2+ by recording emission at 253.652 nm in a low power/Ar consumption (15 W/100 mL min−1) plasma source with a Maya2000 Pro (Ocean Optics) microspectrometer. The proposed method was compared with common laboratory approaches based on derivatization with SnCl2 and detection by inductively coupled plasma optical emission spectrometry/atomic fluorescence spectrometry, and thermal decomposition atomic absorption spectrometry. The limits of detection obtained without/with preconcentration were 3.5/0.1 ng L−1 in solution and 9/0.25 μg kg−1 in the solid, much better than those in the reference methods. The proposed method was found to be free from interference coming from multimineral matrices and organic matter, and suitable for sample analysis with various matrices as it provided a recovery of Hg without/with preconcentration of 101 ± 7%/101 ± 12% in food and 97 ± 12% in water. [ABSTRACT FROM AUTHOR]

A non-chromatographic method was developed for Hg speciation as CH 3 Hg + and Hg 2+ using simple instrumentation based on optical emission spectrometry in a low power and low Ar consumption capacitively coupled plasma microtorch and detection with a low resolution microspectrometer. The method is based on (i) determination of total Hg after sample digestion in nitric acid-hydrogen peroxide mixture, derivatization to cold vapor with 20% SnCl 2 in 15% HCl medium; (ii) determination of CH 3 Hg + separated by double liquid-liquid extraction as recommended in JRC Technical Report of European Commission, followed by photochemical vapor generation in 0.6 mol l −1 formic acid and (iii) calculation of the inorganic (Hg 2+ ) species as difference. The calibration curve was generated with external Hg 2+ standards in 5% (v/v) HCl for total Hg determination and 0.6 mol l −1 HCOOH medium for CH 3 Hg + , respectively. The method was validated against certified reference materials and successfully applied for Hg speciation in most consumed fish species. The limits of detection of the method were 2 and 3 μg kg −1 CH 3 Hg + and total Hg respectively, which made possible quantification of 6/9 μg kg −1 organic/total Hg. The method proved to be accurate with recovery of 101 ± 10% (total Hg), 100 ± 8% (CH 3 Hg + ) and 102 ± 13% (Hg 2+ ), and precision in the range 2.4–7.8% (total Hg), 2.4–11.9% (CH 3 Hg + ) and 3.8–14.0% (Hg 2+ ). The speciation method allowed accurate and precise determination of CH 3 Hg + and Hg 2+ even when the organic species represented more than 98% of total Hg. Total Hg in fish depended on variety but in all cases it was below the maximum admitted level (0.5 mg kg −1 ). Methylmercury represented 22.3–93.3% of total Hg, with higher weights in salmon, carp, mackerel and hake and lower in cod, trout and pangasius irrespective of total Hg. Evaluation of risk exposure to CH 3 Hg + from occasional fish consumption based on Provisional Tolerable Weekly Intake seems to be much more informative than the concentration of total or organic Hg species. It has been concluded from our study that there is no health risk from exposure to methylmercury for 300–1000/60-200 g weekly fish consumption by adult/child when fish comes from reliable sources. [ABSTRACT FROM AUTHOR]

Mobilization of As from geological materials into ground and drinking water sources may represent an important threat to human health. The objective of this study was to assess the As concentration and availability in underground water used as drinking water sources. Water samples were collected from public and private wells in Timis-Bega area of Pannonian Basin, West Romania. Total-dissolved As measured after “classical” filtration of water samples was in the range of 0.10–168 μg L−1, thus exceeding the guideline value in majority of the samples. The aim of this study was also to assess the “truly dissolved” concentrations of As considered as available concentrations, in well waters, after passive sampling by Diffusive Gradients in Thin-films (DGT). The results showed that over 70% of total-dissolved As is in available forms. The obtained data were used to evaluate the risks of using the wells as drinking water source. Hazard quotients for ingestion and dermal pathways and hazard index (HI) for exposure to As were calculated. The HI values > 1 found that majority of samples indicated a health risk for local residents. [ABSTRACT FROM AUTHOR]

A non-chromatographic method based on double liquid-liquid extraction and measurements by UV photochemical vapor generation capacitively coupled plasma microtorch optical emission spectrometry was developed and characterized for methylmercury determination in seafood. Samples were prepared following the procedure recommended in JRC Technical Report of European Commission formerly proposed for the determination of methylmercury in seafood by thermal decomposition atomic absorption spectrometry, namely confinement of Hg species in 47% HBr solution, extraction of CH 3 Hg + in toluene and back-extraction in 1% l -cysteine aqueous solution. Mercury cold vapor was generated by flow injection UV photo-reduction from CH 3 Hg + in 0.6 mol L −1 HCOOH, while quantification was performed against external Hg 2+ aqueous standards and measuring Hg 253.652 nm emission using a low power/Ar consumption plasma microtorch (15 W, 100 mL min −1 ) and a low resolution microspectrometer (Ocean Optics). The figures of merit and analytical capability were assessed by analyzing certified reference materials and test samples of fish fillet and discussed in relation with requirements for Hg determination in seafood in European legislation (Decisions 2007/333/EC and 2002/657/EC) as well as compared to performances achieved in thermal decomposition atomic absorption spectrometry. The limit of detection and quantification of 2 µg kg −1 and 6 µg kg −1 respectively, precision of 2.7–9.4% and accuracy of 99±8% of the proposed method for the determination of CH 3 Hg + fulfill the demands of European legislation for Hg quantification. The limit of detection and quantification were better than those in the used reference method or other non-/chromatographic methods taken for comparison. The analysis of certified reference materials and the Bland and Altman test performed on 12 test samples confirmed trueness of the proposed method and its reliability for the determination of traces of CH 3 Hg + with 95% confidence level. The proposed method fulfills several demands of the eco-scale concept, is sensitive, simple and safe related to sample preparation through elimination of classical, harmful reductants and attractive by using economical miniaturized instrumentation incorporating a low power and low Ar consumption plasma. [ABSTRACT FROM AUTHOR]

Precious metals such as palladium (Pd) have many applications, ranging from automotive catalysts to fine chemistry. Platinum group metals are, thus, in massive demand for industrial applications, even though they are relatively rare and belong to the list of critical materials for many countries. The result is an explosion of their price. The recovery of Pd from spent catalysts and, more generally, the development of a circular economy process around Pd, becomes essential for both economic and environmental reasons. To this aim, we propose a sustainable process based on the use of supercritical CO2 (i.e., a green solvent) operated in mild conditions of pressure and temperature (p = 25 MPa, T = 313 K). Note that the range of CO2 pressures commonly used for extraction is going from 15 to 100 MPa, while temperatures typically vary from 308 to 423 K. A pressure of 25 MPa and a temperature of 313 K can, therefore, be viewed as mild conditions. CO2-soluble copolymers bearing complexing groups, such as pyridine, triphenylphosphine, or acetylacetate, were added to the supercritical fluid to extract the Pd from the catalyst. Two supported catalysts were tested: a pristine aluminosilicate-supported catalyst (Cat D) and a spent alumina supported-catalyst (Cat A). An extraction conversion of up to more than 70% was achieved in the presence of the pyridine-containing copolymer. The recovery of the Pd from the polymer was possible after extraction, and the technological and economical assessment of the process was considered. [ABSTRACT FROM AUTHOR]

The study proposes a combined model based on diagrams (Gibbs, Piper, Stuyfzand Hydrogeochemical Classification System) and unsupervised statistical approaches (Cluster Analysis, Principal Component Analysis, Fuzzy Principal Component Analysis, Fuzzy Hierarchical Cross-Clustering) to describe natural enrichment of inorganic arsenic and co-occurring species in groundwater in the Banat Plain, southwestern Romania. Speciation of inorganic As (arsenite, arsenate), ion concentrations (Na + , K + , Ca 2+ , Mg 2+ , HCO 3 − , Cl − , F − , SO 4 2− , PO 4 3− , NO 3 − ), pH, redox potential, conductivity and total dissolved substances were performed. Classical diagrams provided the hydrochemical characterization, while statistical approaches were helpful to establish (i) the mechanism of naturally occurring of As and F − species and the anthropogenic one for NO 3 − , SO 4 2− , PO 4 3− and K + and (ii) classification of groundwater based on content of arsenic species. The HCO 3 − type of local groundwater and alkaline pH (8.31–8.49) were found to be responsible for the enrichment of arsenic species and occurrence of F − but by different paths. The PO 4 3- –AsO 4 3- ion exchange, water-rock interaction (silicates hydrolysis and desorption from clay) were associated to arsenate enrichment in the oxidizing aquifer. Fuzzy Hierarchical Cross-Clustering was the strongest tool for the rapid simultaneous classification of groundwaters as a function of arsenic content and hydrogeochemical characteristics. The approach indicated the Na + –F - –pH cluster as marker for groundwater with naturally elevated As and highlighted which parameters need to be monitored. A chemical conceptual model illustrating the natural and anthropogenic paths and enrichment of As and co-occurring species in the local groundwater supported by mineralogical analysis of rocks was established. [ABSTRACT FROM AUTHOR]

The paper presents the metals content and bioavailability in waters of Aries River catchment, Romania. Concentration of labile dissolved metal species measured by diffusive gradients in thin films technique (DGT), metals in colloidal and in particulate phases, and also general physical-chemical indicators of water were determined. Very high total metal concentrations were found in the tributaries that drain the mining areas. However, the influence of the polluted tributaries on the Aries River water quality was moderate, as a consequence of the tributaries low flow rate compared with that of the Aries River. Using the DGT technique the bioavailable metals fractions expressed as % of total dissolved metals concentrations were found to be 28–88% for Cu, 43–72% for Zn, 73–85% for Fe, and 33–70% for Mn. Depending on the used method for dissolved metals determination the classification of waters according to quality classes may differ. Excluding the colloidal metal fractions, DGT measures only truly dissolved metal concentrations. In cases with very high metal contamination the differences between total dissolved and DGT-labile concentrations are unimportant for waters classification. However, where the metals concentration is near the thresholds values the determination method is very important. [ABSTRACT FROM AUTHOR]

Background: The metals bioavailability in soils is commonly assessed by chemical extractions; however a generally accepted method is not yet established. In this study, the effectiveness of Diffusive Gradients in Thin-films (DGT) technique and single extractions in the assessment of metals bioaccumulation in vegetables, and the influence of soil parameters on phytoavailability were evaluated using multivariate statistics. Soil and plants grown in vegetable gardens from mining-affected rural areas, NW Romania, were collected and analysed. Results: Pseudo-total metal content of Cu, Zn and Cd in soil ranged between 17.3-146 mg kg-1, 141-833 mg kg-1 and 0.15-2.05 mg kg-1, respectively, showing enriched contents of these elements. High degrees of metals extractability in 1M HCl and even in 1M NH4Cl were observed. Despite the relatively high total metal concentrations in soil, those found in vegetables were comparable to values typically reported for agricultural crops, probably due to the low concentrations of metals in soil solution (Csoln) and low effective concentrations (CE), assessed by DGT technique. Among the analysed vegetables, the highest metal concentrations were found in carrots roots. By applying multivariate statistics, it was found that CE, Csoln and extraction in 1M NH4Cl, were better predictors for metals bioavailability than the acid extractions applied in this study. Copper transfer to vegetables was strongly influenced by soil organic carbon (OC) and cation exchange capacity (CEC), while pH had a higher influence on Cd transfer from soil to plants. Conclusions: The results showed that DGT can be used for general evaluation of the risks associated to soil contamination with Cu, Zn and Cd in field conditions. Although quantitative information on metals transfer from soil to vegetables was not observed. [ABSTRACT FROM AUTHOR]

The ability of natural zeolite amendment to reduce the uptake of potentially toxic elements (PTEs) by lettuce, spinach and parsley was evaluated using pot experiments. PTE concentrations in roots and shoots, as well as the pseudo total (PT), water soluble (WS) and bioavailable (BA) PTE fractions in the amended soils, were assessed. Although the PT PTE concentration was high, the WS fraction was very low (<0.4%), while the BA fraction varied widely (<5% for Cr, Mn and Co, <15% for Ni, Pb and Zn, >20% for Cd and Cu). PTE concentration decreased in both roots and shoots of all leafy vegetables grown on zeolite amended soils, especially at high amendment dose (10%). The uptake of PTEs mainly depended on plant species, PTE type and amendment dose. With the exception of Zn in spinach, the bioaccumulation factor for roots was higher than for shoots. Generally, lettuce displayed the highest PTE bioaccumulation capacity, followed by spinach and parsley. Except for Zn in spinach, the transfer factors were below 1 for all PTEs, all plant species and all amendment doses. Our results showed that the natural zeolites are promising candidates in the reclamation of contaminated soils due to their ability to immobilize PTEs. [ABSTRACT FROM AUTHOR]

Palladium (Pd) and platinum (Pt) are extensively used as catalysts in the petrochemical and automotive industries, and due to high demand for them on the market, their recycling from spent supported catalysts is clearly needed. To assess the content of Pd and Pt in catalysts in order to establish their commercial value or to evaluate the recovery efficiency of technologies used for recycling, reliable analytical methods for determination of these elements are required. Spectrometric methods, such as inductively coupled plasma optical emission spectrometry (ICP-OES) and graphite furnace atomic absorption spectrometry (GFAAS) are powerful tools that can be employed for the determination of Pd and Pt in various sample matrices. However, these methods allow only the injection of liquid samples. In this regard, the digestion of solid sample by microwave-assisted acid extraction procedures at high pressures and temperatures is often used. In this study, a microwave acid digestion method was optimized for the extraction of Pd and Pt from spent catalysts, using a four-step program, at a maximum 200 °C. The resulting solutions were analyzed using ICP-OES, at two different wavelengths for each metal (Pd at 340.458 and 363.470 nm, and Pt at 265.945 and 214.423 nm, respectively) and using GFAAS (Pd at 247.64 nm, Pt at 265.94 nm). Five types of spent catalyst were analyzed and the standard deviations of repeatability for five parallel samples were less than predicted relative standard deviations (PRSD%) calculated using Horvitz's equation for all the analyzed samples. [ABSTRACT FROM AUTHOR]

An analytical method based on microwave-assisted acid digestion and atomic absorption spectrometry with graphite furnace as atomization source was developed and validated for determining trace elements (Cd and Pb) in zeolites used as dietary supplements, for their characterization and safety evaluation. The method was checked for the main performance parameters according to the legislation requirements in the field of dietary supplements. In all cases, the obtained performance parameters were satisfactory. The selectivity study showed no significant non-spectral matrix effect. The linearity study was conducted for the calibration curves in the range of 0–10 ng mL−1 for Cd and 0–30 ng mL−1 for Pb. The obtained limits of detection (LoDs) and the limits of quantification (LoQs) were sufficiently low in order to allow Pb and Cd determination in dietary supplements. For the internal quality control, certified reference materials were analysed and good recoveries were obtained. The precision study was performed in terms of repeatability and reproducibility, considering the requirements imposed by the Commission Decision (2007/333/EC) and the method fulfilled these performance parameters. Expanded measurement uncertainties were estimated to 11% for Cd and 10% for Pb. Cd and Pb content were measured in real zeolite samples and, using these data, a safety evaluation was carried out. [ABSTRACT FROM AUTHOR]

This study presents the effect of thermal treatment (450, 500, 600, 750, and 800 °C) on a Romanian clinoptilolite-rich natural zeolite, along with the interaction of raw and thermally treated zeolites with simulated gastric fluid (SGF, pH = 1.20) at different zeolite to SGF ratios and exposure times. The zeolites were characterized using gravimetric analysis, X-ray fluorescence, powder X-ray diffraction (pXRD), and Fourier transform infrared (FT-IR) spectroscopy. The chemical composition of the zeolite subjected to thermal treatment did not change significantly with the increase of temperature. Structural changes were not detectable by pXRD and FT-IR analyses in the zeolites thermally treated up to 500 °C, while above 600 °C a gradual structural breakdown of zeolite was noticed. At high temperatures, the broad, low-intensity peaks in pXRD patterns indicated the partial amorphization of the crystalline structure. The pXRD and FT-IR analyses showed that the crystalline structure of zeolites remains unaffected after their exposure to SGF. The results revealed that the amounts of Fe, Na, Mg, K, Ca, Al, and Si released depends mainly on the zeolite to SGF ratio, and to a lower extent on the thermal treatment temperature, while the exposure time of 1 to 7 days does not have a significant impact on the elements released in SGF. [ABSTRACT FROM AUTHOR]

Natural zeolites are hydrated aluminosilicate minerals that, due to their remarkable physical-chemical properties of being molecular sieves and cation exchangers, have applications in different areas such as environmental protection, catalysis, animal feed, and dietary supplements. Since natural zeolites may contain traces of undesirable compounds such as toxic metals, the accurate quantification of these elements is necessary. In this study, a direct method for Hg determination in zeolite samples based on the thermal desorption atomic absorption spectrometry (TD-AAS) technique is fully validated, taking into account the legislative requirements in the field. The chosen quantification limit was 0.9 µg kg−1, which is satisfactory for intended use. Trueness was evaluated by recovery rate using certified reference materials containing mercury, with satisfactory results. Other figures of merit, such as repeatability and measurement uncertainty, also fulfill the legislative requirements related to the analysis of dietary supplements. This paper presents, for the first time, a fully validated method for mercury determination in zeolite samples, and the obtained results reveal that the method can be applied successfully for the intended purpose. [ABSTRACT FROM AUTHOR]

Caves are complex systems characterized by high variability in trace element signatures that simple geochemical analysis cannot detect since useful information hidden in the dataset may be lost. Sufficiently robust unsupervised statistical approaches may provide these significant signatures for cave hydro/geochemical profiling. The present study focused primarily on quantifying the relevant contributions of elements and their relationships to the variability of the hydro/geochemical profiles of speleothems, sediments and drip water within a cave using Principal Component Analysis (PCA) after Varimax rotation and two-way joining analysis as a clustering method. This prospective study was conducted on the Urșilor (Bears') show cave (Romania). The contents of Ca, Mg, Sr, Al, P, S, Fe and Zn in the mineral deposits were determined via X-ray fluorescence, while the content of these elements in drip water was determined via inductively coupled plasma–optical emission/mass spectrometry. The contents of HCO 3 −, Cl−, F−, NO 3 −, and SO 4 2−; pH; electrical conductivity; and organic and inorganic carbon fractions were also determined. In the case of speleothems, the determinations were performed on randomly selected spots, reflecting the composition at various growth times. The PCA revealed that the geochemical profile of speleothems can be described by four principal components (PCs), represented by 71% for stalactites and 82/92% by three PCs for stalagmites/sediments. The strong signatures of Ca, Mg/Ca, K, and detrital elements (Al, Si, P, S) in stalagmites/sediments in proportions of 41/46%; K, Fe and Zn 30/32%; and Sr and Sr/Ca 11/15% were retained by PCA. The geochemical profile of the stalactites was described by Mg (35%), P, Zn, and Sr (21%); Al and Si (15%); and S, Ca and Mg/Ca (10%). Reducing the dimensionality of the data matrix to alkaline earth elements, two PCs described 95% of the mineral deposits, including the strong signatures of Mg/Ca and Sr/Ca, exceeding 50% of the variability in the first PC. Stalactites and stalagmites were primarily grouped based on their geochemical profile and less so on location, yielding two clusters/four subclusters of stalagmites. The PCA plot did not show a separation between stalactites and stalagmites, as their geochemical profiles differ significantly only in terms of Fe concentration. The hydrochemical profile of drip water was described by 4 PCs at a percentage of 95%: (i) alkaline elements, alkaline earth elements, anions and organic carbon and (ii) trace elements and DOC. The profile of Ca2+–HCO 3 − imprint drip water was described by two PCs at proportions of 66% (Ca, Mg, Na, K, Mg/Ca, Sr/Ca, Ba/Ca ratios, HCO 3 − and organic carbon) and 74% by trace elements (Co, Ni, Ti, Fe, Mn, V and Si). The transition trace elements have very complex chemical behaviour and appear in drip water as Ca-/Si-rich inorganic/organic colloids and simple ions. Although complementary to the PCA, the two-way joining analysis in a heatmap did not offer relevant information in the description of the hydro/geochemical profile of the karst system compared to PCA. A study of a farmed calcite sample highlighted its difference in composition compared with stalagmites in terms of Mg, Si, K, Zn, Sr and Sr/ Ca. Future development could include the application of PCA to seasonally collected farmed calcite and drip water samples to obtain hydro/geochemical profiles of stalagmites in the making to determine the seasonal leaching of metals from bedrock/soil by drip water, inclusion in stalagmites, and seasonal growth. The practical significance of this paper for trace element research is of great concern because it allows these recorded indicators to be connected to the ancient climate and environment of stalagmites. • Element signatures in the hydro/geochemical profile of a cave highlighted by PCA. • Geochemical pattern of the mineral deposits was described as a proportion of 80–90%. • The Ca2+-HCO 3 − imprint drip water profile is described as a proportion of 95%. • The speleothems were primarily grouped by geochemical profile and then by location. • Stalactites and stalagmites differed significantly only in terms of Fe content. [ABSTRACT FROM AUTHOR]

L-poly(lactic acid), poly(3-hydroxybutyrate), and poly-hydroxybutyrate-co-hydroxyvalerate are biodegradable polymers that can be obtained from renewable biomass sources. The aim of this study was to develop three types of environmentally friendly film biocomposites of altered microstructure by combining each of the above-mentioned polymers with cellulose nanocrystal fillers and further processing the resulting materials via space-confined solvent vapor annealing. Cellulose was previously obtained from renewable biomass and further converted to cellulose nanocrystals by hydrolysis with the lactic acid. The solutions of biodegradable polymers were spin-coated onto solid substrates before and after the addition of cellulose nanocrystals. The obtained thin film composites were further processed via space-confined solvent vapor annealing to eventually favor their crystallization and, thus, to alter the final microstructure. Indeed, atomic force microscopy studies have revealed that the presence of cellulose nanocrystals within a biodegradable polymer matrix promoted the formation of large crystalline structures exhibiting fractal-, spherulitic- or needle-like morphologies. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the production of poly(3-hydroxybutyrate) (PHB) from lignocellulosic biomass through a series of steps, including microwave irradiation, ammonia delignification, enzymatic hydrolysis, and fermentation, using the Bacillus megaterium ATCC 14581 strain. The lignocellulosic biomass was first pretreated using microwave irradiation at different temperatures (180, 200, and 220 °C) for 10, 20, and 30 min. The optimal pretreatment conditions were determined using the central composite design (CCD) and the response surface methodology (RSM). In the second step, the pretreated biomass was subjected to ammonia delignification, followed by enzymatic hydrolysis. The yield obtained for the pretreated and enzymatically hydrolyzed biomass was lower (70.2%) compared to the pretreated, delignified, and enzymatically hydrolyzed biomass (91.4%). These hydrolysates were used as carbon substrates for the synthesis of PHB using Bacillus megaterium ATCC 14581 in batch cultures. Various analytical methods were employed, namely nuclear magnetic resonance (1H-NMR and13C-NMR), electrospray ionization mass spectrometry (EI-MS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA), to identify and characterize the extracted PHB. The XRD analysis confirmed the partially crystalline nature of PHB. [ABSTRACT FROM AUTHOR]

An eco-scale method based on UV–Vis photochemical vapor generation and detection in a capacitively coupled plasma microtorch by optical emission measurement with a low resolution microspectrometer was developed for Hg speciation as Hg 2+ and CH 3 Hg + in seafood. Our proposal provides a simpler, greener analytical method in terms of sample preparation and derivatization, and use of small-scale instrumentation. Coupling of UV–Vis photo-reactor with plasma microtorch is a very promising approach to develop eco-scale methods for Hg speciation in seafood with major advantages to classical methods. The most distinctive characteristic of the method is the use of a single reagent, formic acid, for the extraction of Hg species from solid sample and as medium for the photo-induced cold vapor generation. An amount of 0.2 g lyophilized sample was subjected to ultrasound assisted extraction in 10 ml HCOOH 98–100% at 50 °C for 3 h then on line UV–Vis photo-induced derivatization in 0.6 mol l −1 HCOOH was achieved. Total Hg and Hg 2+ species were quantified against Hg 2+ external standard solutions by measuring emission at 253.652 nm in a low power/low Ar consumption (15 W/100 ml min −1 ) plasma source with Maya2000 Pro (Ocean Optics) microspectrometer. Under UV exposure both Hg 2+ and CH 3 Hg + species were converted with same efficiency to cold vapor, while natural room light (Vis) achieved selectively derivatization of Hg 2+ . Concentration of CH 3 Hg + was obtained by subtracting Hg 2+ amount from total. The proposed method was compared with Thermal Decomposition Atomic Absorption Spectrometry eco-scale method developed for the determination of total Hg from solid sample and CH 3 Hg + according to the procedure recommended by the European Commission. The limits of detection/quantification provided by the proposed method were 9/27 μg kg −1 total Hg and 4.8/14.4 μg kg −1 Hg 2+ . Study of accuracy against certified reference materials gave recovery of 99 ± 6% total Hg, 99 ± 9% Hg 2+ and 99 ± 10% CH 3 Hg + , while precisions assessed from measurements on real sample were 2.6–10.2%, 2.0–13.4% and 5.3–14.5% respectively, similar to those in the reference method. [ABSTRACT FROM AUTHOR]

The photosynthetic pigments, protein, macro and microelements concentrations, and fatty acids composition of Salvinia natans, a free-floating aquatic plant, were analyzed after exposure to Hoagland nutrient solution containing 1, 3, and 5 mg/L Li. The Li content of Salvinia natans grew exponentially with the Li concentration in the Hoagland nutrient solution. The exposure to Li did not induce significant changes in Na, Mg, K, Cu, and Zn content but enhanced the Ba, Cr, Mn, Ni and Mo absorption in Salvinia natans. The most abundant fatty acids determined in oils extracted from Salvinia natans were C16:0, C18:3(n6), C18:2(n6), and C18:3(n3). The photosynthetic pigments did not change significantly after exposure to Li. In contrast, chlorophyll and protein content decreased, whilst monounsaturated and polyunsaturated fatty acids content increased after the exposure to 1 mg/L Li. The results indicated that Salvinia natans exposed to low Li concentrations may be a good source of minerals, omega 6 and omega 3. [ABSTRACT FROM AUTHOR]

L-polylactic acid (PLA), a semi–crystalline aliphatic polyester, is one of the most manufactured biodegradable plastics worldwide. The objective of the study was to obtain L-polylactic acid (PLA) from lignocellulosic plum biomass. Initially, the biomass was processed via pressurized hot water pretreatment at a temperature of 180 °C for 30 min at 10 MPa for carbohydrate separation. Cellulase and the beta-glucosidase enzymes were then added, and the mixture was fermented with Lacticaseibacillus rhamnosus ATCC 7469. The resulting lactic acid was concentrated and purified after ammonium sulphate and n-butanol extraction. The productivity of L-lactic acid was 2.04 ± 0.18 g/L/h. Then, the PLA was synthesized in two stages. Firstly, lactic acid was subjected to azeotropic dehydration at 140 °C for 24 h in the presence of xylene, using SnCl2 (0.4 wt.%) as a catalyst, resulting in lactide (CPLA). Secondly, microwave-assisted polymerization was carried out at 140 °C for 30 min with 0.4 wt.% SnCl2. The resulting powder was purified with methanol to produce PLA with 92.1% yield. The obtained PLA was confirmed using electrospray ionization mass spectrometry, nuclear magnetic resonance, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. Overall, the resulting PLA can successfully replace the traditional synthetic polymers used in the packaging industry. [ABSTRACT FROM AUTHOR]

The clarity of the beer is essential to its marketability and good consumer approval. Moreover, the beer filtration aims to remove the unwanted constituents that cause beer haze formation. Natural zeolite, an inexpensive and widespread material, was tested as a substitute filter media for diatomaceous earth in removing the haze constituents in beer. The zeolitic tuff samples were collected from two quarries in Northern Romania: Chilioara, in which the zeolitic tuff has a clinoptilolite content of about 65%, and the Valea Pomilor quarry, containing zeolitic tuff with a clinoptilolite content of about 40%. Two-grain sizes, <40 and <100 µm, from each quarry were prepared and thermally treated at 450 °C in order to improve their adsorption properties and remove organic compounds and for physico-chemical characterization. The prepared zeolites were used for beer filtration in different mixtures with commercial filter aids (DIF BO and CBL3) in laboratory-scale experiments, and the filtered beer was characterized in terms of pH, turbidity, color, taste, flavor, and concentrations of the major and trace elements. The results showed that the taste, flavor, and pH of the filtered beer were generally not affected by filtration, while turbidity and color decreased with an increase in the zeolite content used in the filtration. The concentrations of Na and Mg in the beer were not significantly altered by filtration; Ca and K slowly increased, while Cd and Co were below the limits of quantification. Our results show that natural zeolites are promising aids for beer filtration and can be readily substituted for diatomaceous earth without significant changes in brewery industry process equipment and protocols for preparation. [ABSTRACT FROM AUTHOR]

• Waters from protected area are rich in As, Ca and heavy metals (Pb, Al, Mn, Fe, Se). • Generally, the WQI scores indicate excellent, medium, and low quality. • HEI and HPI scores indicate three levels of pollution. • Na, Ca, Mg, Co, Cd are mainly transfer from mud to the alluvial aquifers. • This research is a reference for aquifers protection in a protected area. This study was carried out in a protected area (Ronișoara Forest) in Romania. A combined approach of quality assessment of alluvial aquifers is employed, by determining the chemistry and applying two pollution indices based on heavy metals concentrations (HPI- Heavy metal Pollution Index and HEI- Heavy metal Evaluation Index), a quality assessment index based on specific physico-chemical indicators (WQI- the Water Quality Index) and different plots (Durov, Schoeller and TIS-Total Ion Salinity). The study revealed that waters are rich in manganese, calcium, sodium, sulphate, ammonium, manganese, iron, total dissolved solids, dominated by bicarbonates. The chemicals' sources are related to the water–rock interactions and to mine exploitation activities. Correlations were observed between the electrical conductivity and sulphate, total dissolved solids and sulphate, and total hardness and electrical conductivity. The results based on the levels of heavy metals pollution indicate that the studied water samples are characterized by low, medium and high pollution levels, with values ranging between 0.40 and 234. The WQI scores vary from 8.6 to 54, generally indicating excellent and medium quality, and low quality for two samples. This research, one of the first in the area, can serve as a reference for the protection of natural water resources and for the contamination control of alluvial aquifers in the protected area of Ronișoara Forest. [ABSTRACT FROM AUTHOR]

The present study uses the Taguchi method of experimental design to optimize lipid extraction from Spirulina spp. by ultrasound application and mechanical stirring. A Taguchi L9 orthogonal array was used to optimize various parameters, such as methanol: chloroform (M:C) ratio, biomass: solvent ratio, and extraction time for lipid extraction. The results were analyzed using the signal-to-noise (S/N) ratio and analysis of variance (ANOVA). The biomass: solvent ratio significantly influenced lipid content (p < 0.05) with 92.1% and 92.3% contributions to the lipid and S/N ratio data, respectively. The extraction time presented a contribution value of 5.0%, while the M:C ratio presented the most negligible contribution of 0.4% for S/N data. The optimum extraction conditions were: M:C ratio of 1:1, biomass: solvent ratio of 1:60, and extraction time of 30 min. The predominant fatty acids were palmitic acid (44.5%), linoleic acid (14.9%), and gamma-linolenic acid (13.4%). The confirmation experiments indicated a lipid content of 8.7%, within a 95% confidence interval, proving the Taguchi method's effectiveness in optimizing the process parameters for lipid extraction. [ABSTRACT FROM AUTHOR]

A precise, accurate and sensitive method based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry for Cd determination in various dietary products was developed. The instrumentation is inexpensive as it includes a low power (15 W) and low argon consumption (150 ml min −1 ) microplasma connected to a small-sized Rh electrothermal vaporization device and a low resolution microspectrometer. The sample was subjected to microwave assisted digestion in HNO 3 – H 2 O 2 mixture and Cd was determined in 10 μl sample without preconcentration. The standard addition method was used to compensate for the non-spectral matrix effects. The new method was in-house validated by analyzing certified reference materials and test dietary samples for which the Cd maximum level was established in Commission Regulation 488/2014/EU. The figures of merit of the proposed method and the experimental results were compared to those obtained in graphite furnace atomic absorption spectrometry as standardized method and discussed in relation with the requirements in the Commission Decision 2002/657/EC and Commission Regulations 2011/836/EU and 2007/333/EC. The limit of detection in fresh sample (0.001–0.009 mg kg −1 ), limit of quantification (0.002–0.018 mg kg −1 ), recovery (103 ± 15%), trueness (−3.0)–(+7.3)% and precision (0.8–14.0%) were similar to those found in the reference method and comply with the minimal criteria imposed to a method to be used in official laboratories for Cd determination in food. Precision for Cd determination close to maximum admitted levels or higher was of 0.8–6.0%, while for lower concentration in the range 4.0–14.0%. The Bland and Altman statistical test allowed successful evaluation of the new method as an alternative to the well established graphite-furnace atomic absorption spectrometry. The proposed method has analytical potential and is easy to run, while the full miniaturized instrumentation could be considered as a useful tool for the future as an alternative to the traditional instrumentation. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of a platform of novel functional fluorinated gradient copolymers soluble in liquid and supercritical CO2 is reported. These functional copolymers are bearing different types of complexing units (pyridine, triphenylphosphine, acetylacetate, thioacetate, and thiol) which are well-known ligands for various metals. They have been prepared by reversible addition–fragmentation chain-transfer (RAFT) polymerization in order to obtain well-defined gradient copolymers. The copolymers have been characterized by proton nuclear magnetic resonance (1H-NMR) spectroscopy, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, thermal gravimetric analysis (TGA), dynamical scanning calorimetry (DSC) and cloud point measurements in dense CO2. All the investigated metal-complexing copolymers are soluble in dense CO2 under mild conditions (pressure lower than 30 MPa up to 65 °C), confirming their potential applications in processes such as metal-catalyzed reactions in dense CO2, metal impregnation, (e.g., preparation of supported catalysts) or metal extraction from various substrates (solid or liquid effluents). Particularly, it opens the door to greener and less energy-demanding processes for the recovery of metals from spent catalysts compared to more conventional pyro- and hydro-metallurgical methods. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the use of natural zeolite as support for microbial community formation during wastewater treatment. Scanning electron microscopy (SEM), thermal decomposition and differential thermogravimetric curves (TGA/DGT) techniques were used for the physicochemical and structural characterization of zeolites. The chemical characterization of wastewater was performed before and after treatment, after 30 days of using stationary zeolite as support. The chemical composition of wastewater was evaluated in terms of the products of nitrification/denitrification processes. The greatest ammonium (NH4+) adsorption was obtained for wastewater contaminated with different concentrations of ammonium, nitrate and nitrite. The wastewater quality index (WWQI) was determined to assess the effluent quality and the efficiency of the treatment plant used, showing a maximum of 71% quality improvement, thus suggesting that the treated wastewater could be discharged into aquatic environments. After 30 days, NH4+ demonstrated a high removal efficiency (higher than 98%), while NO3+ and NO2+ had a removal efficiency of 70% and 54%, respectively. The removal efficiency for metals was observed as follows (%): Mn > Cd > Cr > Zn > Fe > Ni > Co > Cu > Ba > Pb > Sr. Analysis of the microbial diversity in the zeolite samples indicated that the bacteria are formed due to the existence of nutrients in wastewater which favor their formation. In addition, the zeolite was characterized by SEM and the results indicated that the zeolite acts as an adsorbent for the pollutants and, moreover, as a support material for microbial community formation under optimal conditions. Comparing the two studied zeolites, NZ1 (particle size 1–3 mm) was found to be more suitable for wastewater treatment. Overall, the natural zeolite demonstrated high potential for pollutant removal and biomass support for bacteria community growth in wastewater treatment. [ABSTRACT FROM AUTHOR]

The study presents the current status of contamination with metals (Cu, Cr, Cd, Pb, Ni, Zn and As) and their anthropogenic or natural origin in the sediments of the Aries River Basin, Romania, affected by mining activities. The results indicated an enrichment of metals in the sediments. Different contamination levels of the Aries River and its tributaries were identified. According to sediment quality guidelines and contamination indices, the sediments from the Aries River were found to be highly contaminated with Cd, Cu and As, considerably with Zn and moderately with Pb and Ni. The right-bank tributaries were found to be more contaminated than the left-bank effluents, where only contamination with As of geogenic origin was identified. Principal Component Analysis enabled the identification of five latent factors (86 % total variability), reflecting the anthropogenic and natural origins of the metals. Arsenic, Cd and partially Pb were found to have a common anthropogenic origin, different from that of Cu. The statistical approach indicated also the geogenic origin of Pb due to its association with Ca, K, Na and Sr. Chromium and Ni were attributed to natural sources through their association with Mn, Fe, Al and Mg. [ABSTRACT FROM AUTHOR]

This study explores the characteristics of a micronized natural zeolitic volcanic tuff (MZ) as ingredient in cosmetic formulations. In particular, the purpose was to prepare and investigate the organoleptic and physicochemical properties of two representative cosmetic formulations containing MZ. The MZ samples were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. pH, cation exchange capacity (CEC), apparent density, chemical composition and particle size distribution of MZ samples were also determined. The micronization treatment applied did not produce significant structural and physicochemical changes with respect to the raw zeolitic volcanic tuff. The prepared formulations containing 5% MZ with different particle sizes (100–125 µm and 125–250 µm) were subjected to preliminary and accelerated stability tests, and the pH and organoleptic properties were also evaluated. The cosmetic formulations presented a pH of 4.3, a pleasant touch, good spreadability, easy application on skin, no color alteration and a good stability after 15, 30 and 60 days of storage at room temperature, low temperature and freezer during the accelerated stability tests. The obtained results endorse the MZ as suitable for the development of formulations exploiting the clinoptilolite properties as a cosmetic ingredient. [ABSTRACT FROM AUTHOR]

Vineyard solid wastes are regarded as an alternative source of renewable raw materials for the production of hemicellulosic sugars and their conversion into furfural. In this work, a liquid hemicellulosic fraction was extracted from vineyard wastes in order to produce a higher furfural yield. A simple ultra-high-performance liquid chromatography with diode array detection (UHPLC-DAD) method was used for determining furfural from vineyard wastes. The UHPLC-DAD method was validated for the determination of furfural from vineyard wastes. The described method shows good linearity with a coefficient of determination higher than 0.998. The limits of detection (LOD) and quantification (LOQ) were 0.3 µg mL−1 and 1.0 µg mL−1, respectively. The recoveries determined by the spiking solutions varied between 95.1 and 100.8%. The relative expanded uncertainty of the method was evaluated based on a bottom-up approach and was 13.5%. [ABSTRACT FROM AUTHOR]

Abstract: A new sensitive method for total mercury determination in digested soils using a miniaturized analytical system based on cold vapor capacitively coupled plasma microtorch optical emission spectrometry was developed and compared with cold vapor atomic fluorescence spectrometry as the standardized method. The soil samples were subjected to microwave digestion in aqua regia, than Hg cold vapor were chemically generated with SnCl2 and introduced via a 150mlmin−1 Ar flow rate in the plasma microtorch operated at 10W power level. The optical emission signal at 253.652nm was measured with a commercially available microspectrometer. The method detection limit was 4.8μgkg−1 Hg, similar to that obtained in the standardized reference method. The precision of Hg determination over the concentration range of 0.27–55mgkg−1 was 0.8–7.7%. Analysis of six CRMs revealed a recovery of 97±7% similar to 97±9% found in the method based on cold vapor atomic fluorescence spectrometry. The Bland and Altman test carried out on 31 test soil samples showed no significant statistical difference between the results obtained by the proposed method and that taken as reference. The investigated analytical system can be prototyped as an alternative for the commercially existing atomic fluorescence spectrometry instrumentation. The benefits of the system are related to small size instrumentation and low analysis cost due to the low power and low Ar consumption for plasma generation. [Copyright &y& Elsevier]

The goal of this study was to investigate the effect of thermal treatment (200, 400, and 600 °C) on the adsorption capacity of a natural clinoptilolite-rich zeolite (NZ) of different particle sizes for methylene blue removal from aqueous solution. The physical properties and chemical composition of the natural zeolites treated at several temperatures were determined. Powder X-ray diffraction, Brunauer–Emmett–Teller, and scanning electron microscopy were used to characterize the thermally treated zeolites. X-ray diffraction showed that the main crystalline phases of the thermally treated zeolites were clinoptilolite-Na, quartz, muscovite, and albite. The equilibrium measurements were analyzed using Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The experimentally fitted Freundlich isotherm was a better fit than the Langmuir model for methylene blue adsorption onto the thermally treated zeolites. The adsorption of methylene blue on the thermally treated natural zeolites was shown to involve chemisorption. [ABSTRACT FROM AUTHOR]

Abstract: A new, low power capacitively coupled plasma microtorch (30W, 13.56MHz, 0.5Lmin−1 Ar) was investigated in conjunction with commercially available microspectrometers for the simultaneous multielemental analysis by atomic emission spectrometry of liquid samples without desolvation. Emission spectrum is simpler than in ICP-AES, the resonance lines are the most intense, so that a microspectrometer with FWHM of at least 1.5nm is satisfactory for the record. The deviation from the Boltzmann distribution for Fe I has demonstrated the departure from the LTE in plasma. The non-spectral matrix effects of Li, Na, K, Ca and Mg on analytes emission are depressive and depend on matrix volatility, ionization potential of the interferent and analyte excitation energy. The detection limits (μgmL−1) are in the range 0.003 (Li) and 1.5 (Mn). The use of the standard additions method allowed the simultaneous determination of elements in environmental certified reference materials with overall recovery of 95±10% and relative standard deviation of 1.7–8.2%. Compared to the traditional ICP, the microtorch has a simple construction, runs at low argon flow and can be integrated in a portable system suitable for in-situ simultaneous determination of elements. [ABSTRACT FROM AUTHOR]

Abstract: The single ring electrode radiofrequency capacitively coupled plasma torch (SRTr.f.CCP) operated at 275W, 27.12MHz and Ar flow rate below 0.7lmin−1 was investigated for the first time as atomization cell in atomic fluorescence spectrometry (AFS) using electrodeless discharge lamps (EDL) as primary radiation source and charged coupled devices as detector. The signal to background ratio (SBR) and limit of detection for Cd determination by EDL-SRTr.f.CCP-AFS were compared to those obtained in atomic emission spectrometry using the same plasma torch. The detection limit in fluorescence was 4.3ngml−1 Cd compared to 65ngml−1 and 40ngml−1 reported in r.f.CCP-atomic emission (AES) equipped with single or double ring electrode. The lower detection limit in EDL-SRTr.f.CCP-AFS is due to a much better SBR in fluorescence. The limit of detection was also compared to those in atomic fluorescence with inductively coupled plasma (0.4ngml−1), microwave plasma torch (0.25ngml−1) and air–acetylene flame (8ngml−1). The influence of light-scattering through the plasma and the secondary reflection of the primary radiation on the wall of the quartz tube on the analytical performance are discussed. The non-spectral matrix effects of Ca, Mg and easily ionized elements are much lower in EDL-SRTr.f.CCP-AFS compared to SRTr.f.CCP-AES. The new technique was applied in the determination of Cd in contaminated soils, industrial hazardous waste (0.4–370mgkg−1) and water (113μgl−1) with repeatability of 4–8% and reproducibility in the range of 5–12%, similar to those in ICP-AES. The results were checked by the analysis of a soil and water CRM with a recovery degree of 97±9% and 98±4%, for a confidence limit of 95%. The present EDL-SRTr.f.CCP-AFS is a promising technique for Cd determination in environmental samples. [Copyright &y& Elsevier]

Rehabilitation of contaminated soils is a complex and time-consuming procedure. One of the most cost-effective and easy-to-use soil remediation approaches is the use of amendments that stabilize the potential toxic elements (PTE) in soil by reducing their mobility and bioavailability. The stabilization of Cu, Pb, Zn, Cd, Co, Cr, Ni in a contaminated soil using 5% and 10% amendment with thermally treated natural zeolite was investigated using a sequential extraction procedure, contamination and environmental risk factors. The results showed that after amendment, the PTE concentration decreased in the exchangeable and reducible fractions and increased in the oxidizable and residual fractions. The highest immobilization effect, consisting in the decrease of exchangeable fractions with 69% was obtained in case of 10% zeolite amendment and 90 days of equilibration time for Pb; also, more than half of the mobile fraction was immobilized in case of Zn, Cu, and Co and about one third in case of Ni, Cr, and Cd. Generally, the immobilization effect of the 5% and 10% amendment is comparable, but a higher equilibration time enhanced the immobilization effect, especially in the case of Cd, Co, Cu, Pb, and Zn. [ABSTRACT FROM AUTHOR]

Precious metals, in particular Pd, have a wide range of applications in industry. Due to their scarcity, precious metals have to be recycled, preferably with green and energy-saving recycling processes. In this article, palladium extraction from an aluminosilicate-supported catalyst, containing about 2 wt% (weight%) of Pd (100% PdO), with supercritical CO2 (scCO2) assisted by complexing polymers is described. Two polymers, p(FDA)SH homopolymer and p(FDA-co-DPPS) copolymer (FDA: 1,1,2,2-tetrahydroperfluorodecyl acrylate; DPPS: 4-(diphenylphosphino)styrene), were tested with regards to their ability to extract palladium. Both polymers showed relatively low extraction conversions of approximately 18% and 30%, respectively. However, the addition of piperidine as activator for p(FDA-co-DPPS) allowed for an increase in the extraction conversion of up to 60%. [ABSTRACT FROM AUTHOR]

The bioremediation of petroleum hydrocarbons (PHCs)-polluted soils was studied by an ex-situ, lab-scale, biopile experiment with different parameters: aeration rate (1 h day−1 and 2 h day−1), soil moisture (44% and 60%), and microorganisms consortia addition (320 and 640 mL). The trial was conducted using eight treatment cells, each having different parameters, and one control cell for 18 weeks on soil containing 7600 ± 400 mg kg−1 total PHCs, taken from a former petroleum product warehouse in Sfantu Gheorghe, Covasna County (Romania). The microorganisms used for bioremediation were isolated from the native microflora of the polluted soil and grown in laboratory on culture media. A bioremediation yield up to 76% was obtained in the test cells, while in the control cell the reduction of PHCs content by 16% was attributed to natural attenuation. The results indicated that by addition of microorganisms the bioremediation is much more effective than natural attenuation. The results also revealed an accentuated decrease in PHC concentrations after 4 weeks of treatment, irrespective of the treatment conditions. [ABSTRACT FROM AUTHOR]