Optimization of two-phase synthesis of Fe-hydrochar for arsenic removal from drinking water: Effect of temperature and Fe concentration.

Arsenic-contaminated water is a global concern that demands the development of cost-effective treatments to ensure a safe drinking water supply for people worldwide. In this paper, we report the optimization of a two-phase synthesis for producing a hydrochar core from olive pomace to serve as support for the deposition of Fe-hydroxide, which is the active component in As(V) removal. The operating conditions considered were the initial concentration of Fe in solution in the hydrothermal treatment (phase I) and the temperature of Fe precipitation (phase II). The obtained samples were characterized for their elemental composition, solid yield, mineral content (Fe and K), phenol release, As(V) sorption capacity, and sorbent stability. Correlation analysis revealed that higher Fe concentrations (26.8 g/L) ensured better carbonization during hydrothermal treatment, increased arsenic removal, reduced concentrations of phenols in the final liquid, and improved stability of the sorbent composite. On the other hand, the temperature during Fe precipitation (phase II) can be maintained at lower levels (25-80 °C) since higher temperatures yielded lower adsorption capacity. Regression analysis demonstrated the significance of the main effects of the parameters on sorption capacity and provided a model for selecting operating conditions (Fe concentration and phase II temperature) to obtain composite sorbents with tailored sorption properties.

Advances in Analytical Strategies to Study Cultural Heritage Samples.

The advancements of civilization are based on our ability to pass on the events and knowledge of the past so that the next generations can start from an ever-higher level of expertise [...].

Two-phase synthesis of Fe-loaded hydrochar for As removal: The distinct effects of initial pH, reaction time and Fe/hydrochar ratio.

Hydrothermal carbonization (HTC) is a promising technology for producing char material (hydrochar) from waste biomass. In the present work, a two-stage process was applied and optimized to obtain a composite Fe-loaded hydrochar effective in removing arsenic from water. The first stage of carbonization of the biomass in acid conditions was followed by loading Fe3O4 in the second stage into the hydrochar by alkaline co-precipitation. The effect on the kinetics and on the final yield of HTC induced by a variation of the initial acid pH (5.6, 2.0, and 0.5) was tested. Biomass hydrolysis initially decreased the hydrochar yield and released soluble organic species, responsible for the observed pH variation. This effect was more remarkable at the lower initial pH tested. Soluble organic compounds eventually underwent polymerization, with secondary char formation, an inversion of the pH trend and an increase of hydrochar yield and C%. The final pH attained was linearly related to the hydrochar C%, O/C ratio, and initial pH. Better carbonization performances were achieved at pH = 0.5, 200 °C, and 30 min reaction time, which resulted in 53% mass yield and 72 C%. This value is larger than those previously reported for processes conducted at higher temperatures, and it shows how the addition of acid allows working at lower operative temperatures. Fe loading gave better yields at lower hydrochar concentrations, producing an adsorbent with up to 74% Fe3O4, which adsorbed 2.67 mg/g arsenic. Its adsorption capacity was remarkably affected by the stirring method used, indicating that particle-to-particle interactions considerably influence the process. This effect should be better studied for improved applications in fixed-bed columns.

Visual and Physical Degradation of the Black and White Mosaic of a Roman Domus under Palazzo Valentini in Rome: A Preliminary Study.

Palazzo Valentini, the institutional head office of Città Metropolitana di Roma Capitale, stands in in a crucial position in the Roman archaeological and urban contexts, exactly between the Fora valley, Quirinal Hill slopes, and Campus Martius. It stands on a second-century A.D. complex to which belong, between other archeological remains, two richly decorated aristocratic domus. One of these buildings, the domus A, presents an outward porticoed room with a fourth-century AD central impluvium (open air part of the atrium designed to carry away rainwater) with a black/white tiled mosaic pavement, the preservation status of which is compromised by an incoherent degradation product that has caused gradual detachment of the mosaic tiles. To identify the product and determine the causes of degradation, samples of the product were taken and subjected to SEM-EDS, XRF, NMR, FT-IR and GC-MS analyses. The findings reported in this study can help restorers, archaeologists and conservation scientists in order to improve knowledge about the Roman mosaic, its construction phases, conservation problems and proper solutions.

An Analytical Method for the Biomonitoring of Mercury in Bees and Beehive Products by Cold Vapor Atomic Fluorescence Spectrometry.

Bees and their products are useful bioindicators of anthropogenic activities and could overcome the deficiencies of air quality networks. Among the environmental contaminants, mercury (Hg) is a toxic metal that can accumulate in living organisms. The first aim of this study was to develop a simple analytical method to determine Hg in small mass samples of bees and beehive products by cold vapor atomic fluorescence spectrometry. The proposed method was optimized for about 0.02 g bee, pollen, propolis, and royal jelly, 0.05 g beeswax and honey, or 0.1 g honeydew with 0.5 mL HCl, 0.2 mL HNO3, and 0.1 mL H2O2 in a water bath (95 °C, 30 min); samples were made up to a final volume of 5 mL deionized water. The method limits sample manipulation and the reagent mixture volume used. Detection limits were lower than 3 µg kg-1 for a sample mass of 0.02 g, and recoveries and precision were within 20% of the expected value and less than 10%, respectively, for many matrices. The second aim of the present study was to evaluate the proposed method's performances on real samples collected in six areas of the Lazio region in Italy.

Production of an iron-coated adsorbent for arsenic removal by hydrothermal carbonization of olive pomace: Effect of the feedwater pH.

The removal of arsenic from water by adsorption is currently hindered by the elevated cost of conventional adsorbent materials. To overcome this limit, an innovative iron-coated adsorbent was produced by hydrothermal carbonization (170 °C, 30 min) of olive pomace, an inexpensive byproduct of the olive oil production. Hydrothermal carbonization experiments were performed starting from olive pomace dispersions in solutions with acidic, neutral and alkaline pH, in presence and absence of FeCl3. Acidic conditions improved the carbonization, ensuring reduced H/C and O/C ratios, and increased the adsorbent stability. However, acidic pH yielded unsatisfactory iron coating, with only 32% of the iron dissolved in the initial solution transferred to the produced hydrochar. Under alkaline pH, 96% of the iron in the feedwater was, in contrast, stably dispersed over the hydrochar surface, giving the highest maximum arsenic adsorption capacity (4.1 mg/g). However, alkaline pH promoted biomass hydrolysis, causing the loss of 60% and 87% of the total C and N, respectively, and reducing the stability of the produced hydrochar. A two-stage process was tested to overcome these issues, including hydrothermal carbonization under acidic pH with FeCl3, followed by the addition of NaOH. This process prevented biomass hydrolysis yielding a stable hydrochar. However, as compared to the one-stage alkaline synthesis, the two-stage process produced an hydrochar with reduced arsenic adsorption capacity (1.4 mg/g), indicating that biomass hydrolysis could positively influence hydrochar adsorption characteristics, possibly by increasing the specific surface area. Indications are then provided on how to optimize the two-stage process in order to produce a hydrochar with both satisfactory stability and arsenic adsorption capacity.

Effectiveness of Different Sample Treatments for the Elemental Characterization of Bees and Beehive Products.

Bee health and beehive products' quality are compromised by complex interactions between multiple stressors, among which toxic elements play an important role. The aim of this study is to optimize and validate sensible and reliable analytical methods for biomonitoring studies and the quality control of beehive products. Four digestion procedures, including two systems (microwave oven and water bath) and different mixture reagents, were evaluated for the determination of the total content of 40 elements in bees and five beehive products (beeswax, honey, pollen, propolis and royal jelly) by using inductively coupled plasma mass and optical emission spectrometry. Method validation was performed by measuring a standard reference material and the recoveries for each selected matrix. The water bath-assisted digestion of bees and beehive products is proposed as a fast alternative to microwave-assisted digestion for all elements in biomonitoring studies. The present study highlights the possible drawbacks that may be encountered during the elemental analysis of these biological matrices and aims to be a valuable aid for the analytical chemist. Total elemental concentrations, determined in commercially available beehive products, are presented.

Tetra-2,3-pyrazinoporphyrazines with Peripherally Appended Pyridine Rings. 19. Pentanuclear Octa(2-pyridyl)tetrapyrazinoporphyrazines Carrying Externally Carboranthiolate Groups: Physicochemical Properties and Potentialities as Anticancer Drugs.

New pentanuclear porphyrazine complexes of formula [{Pd(CBT)2}4LM]· xH2O (L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion, CBT = m-carborane-1-thiolate, and M = MgII(H2O), ZnII, PdII) were prepared in good yield as dark green hydrated amorphous solids by reaction of the respective pentanuclear species [(PdCl2)4LM] with m-carboran-1-thiol in CH3CN. Physicochemical characterization of the new species was carried out by elemental and thermogravimetric analysis along with IR and 1H/13C NMR measurements. UV-vis spectral characterization performed in DMSO, DMF, and pyridine solution provided information about the stability of the new homo/heteropentanuclear species and their tendency to undergo detachment of the peripheral Pd(CBT)2 groups. The data from NMR, UV-vis, and electrochemical experiments indicate that external coordination of the Pd(CBT)2 units to the mononuclear [LM] species affects only slightly the π electron distribution within the internal macrocyclic choromophore. The Pd(CBT)2 units are released in pyridine solution and in the case of the ZnII complex [{Pd(CBT)2}4LZn] give rise to a finely crystalline light-yellow solid identified by single-crystal X-ray work as the trans isomer of the bispyridine adduct [py2(CBT)2Pd]. The new pentanuclear macrocyclic complexes behave in DMF solution as active photosensitizers for singlet oxygen production, 1O2, the cytotoxic agent in anticancer photodynamic therapy, and have larger quantum yield values (ΦΔ = 0.6-0.7) than those found on average for the related tetrapyrazinoporphyrazine analogs (ΦΔ = 0.4-0.6). The presence of the CBT groups in the currently investigated complexes opens up the possibility for their use in boron neutron capture therapy, leading potentially to new bimodal anticancer curative drugs.

Dissolution of glass wool, rock wool and alkaline earth silicate wool: morphological and chemical changes in fibers.

The behavior of alkaline earth silicate (AES) wool and of other biosoluble wools in saline solution simulating physiological fluids was compared with that of a traditional wool belonging to synthetic vitreous fibers. Morphological and size changes of fibers were studied by scanning electron microscopy (SEM). The elements extracted from fibers were analyzed by inductively coupled plasma atomic emission spectrometry. SEM analysis showed a larger reduction of length-weighted geometric mean fiber diameter at 4.5 pH than at 7.4 pH. At the 7.4 pH, AES wool showed a higher dissolution rate and a dissolution time less than a few days. Their dissolution was highly non-congruent with rapid leaching of calcium. Unlike rock wool, glass wool dissolved more rapidly at physiological pH than at acid pH. Dissolution of AES and biosoluble rock wool is accompanied by a noticeable change in morphology while by no change for glass wool. Biosoluble rock wool developed a leached surface with porous honeycomb structure. SEM analysis showed the dissolution for glass wool is mainly due to breakage transverse of fiber at pH 7.4. AES dissolution constant (Kdis) was the highest at pH 7.4, while at pH 4.5 only biosoluble rockwool 1 showed a higher Kdis.

Investigation on solvent-free esterification of oleic acid by hemp tea waste-immobilized Candida rugosa lipase.

This study aimed at Candida rugosa lipase immobilization on a low-cost and readily available support. Among agro-industrial crops, hemp tea waste was chosen as the carrier because it provides higher immobilization performance than hemp flower and leaf wastes. Support characterization by ATR-FTIR, SEM and elemental analysis and the optimization of the adsorption immobilization process were performed. The lipase adsorption immobilization was obtained by soaking the support with hexane under mild agitation for 2 h and a successively incubating the enzyme for 1 h at room temperature without removing the solvent. The esterification of oleic acid with n-decanol was tested in a solvent-free system by studying some parameters that influence the reaction, such as the substrates molar ratio, the lipase activity/oleic acid ratio, reaction temperature and the presence/absence of molecular sieves. The biocatalyst showed the ability to bring the esterification reaction to equilibrium under 60 min and good reusability (maintaining 60 % of its original activity after three successive esterification reactions) but low conversion (21 %) at the optimized conditions (40 °C, 1:2 substrates molar ratio, 0.56 lipase/oleic acid ratio, without sieves). Comparing the results with those obtained by free lipase form at the same activity (1 U) and experimental conditions, slightly higher conversion (%) appeared for the free lipase. All this highlighted that probably the source of lipase for its carbohydrate-binding pocket and lid structure affected the esterification of oleic acid but certainly, the immobilization didn't induce any lipase conformational change also allowing the reuse of the catalytic material.

Sphagnum moss and peat comparative study: Metal release, binding properties and antioxidant activity.

Peat is the main constituent of cultivation substrates and a precious non-renewable fossil material. Peatlands provide important ecosystem services and allow the absorption and storage of carbon. Protecting peatlands helps tackle climate change and contributes to biodiversity conservation. Due to its importance, it is necessary to implement strategies to reduce the use of peat, such as replacing it with biomass-based alternative growing media constituents, such as Sphagnum moss. In this study, we compared the metal release and binding properties at two different pH, antioxidant activity, and total phenolic content of peat and Sphagnum moss from the Tierra del Fuego (TdF) region of southern Patagonia. Levels of the elements were determined by inductively coupled plasma mass spectrometry (ICP-MS), while the types and amounts of functional groups were characterized and compared using Fourier transform infrared (FTIR) spectroscopy. The total phenol level and antioxidant capacity were assessed using the Folin-Ciocalteu method and 2,2-diphenyl-1-picrylhydrazyl test. There are generally higher concentrations of leachable elements in peat than in Sphagnum moss at pH = 2, except Cs, Rb, Ti, and Zr. In contrast, at pH = 5, levels of all leached elements are highest in Sphagnum moss. Sphagnum moss shows a higher metal adsorption capacity than peat, except for Be, Mn, Tl, and Zn. Finally, the results showed that both matrices contained similar total phenolic contents: 0.018 ± 0.011 mg gallic acid equivalent (GAE) per gram dry sample for peat and 0.020 ± 0.007 mg GAE g-1 for Sphagnum moss. Instead, Sphagnum moss extracts showed a significantly higher antioxidant activity [0.026 ± 0.028 mmol Trolox equivalents (TE) g-1] than that estimated in peat (0.009 ± 0.005 mmol TE g-1). Humic acids, carboxylic acids, and phenolic and lignin groups were identified as the functional groups that mainly determined the antioxidant activity of the Sphagnum moss compared to peat. The present study resulted in an advancement of knowledge of these materials for more thoughtful future use and possible replacements.

Landfill fire impact on bee health: beneficial effect of dietary supplementation with medicinal plants and probiotics in reducing oxidative stress and metal accumulation.

The honey bee is an important pollinator insect susceptible to environmental contaminants. We investigated the effects of a waste fire event on elemental content, oxidative stress, and metabolic response in bees fed different nutrients (probiotics, Quassia amara, and placebo). The level of the elements was also investigated in honey and beeswax. Our data show a general increase in elemental concentrations in all bee groups after the event; however, the administration of probiotics and Quassia amara help fight oxidative stress in bees. Significantly lower concentrations of Ni, S, and U for honey in the probiotic group and a general and significant decrease in elemental concentrations for beeswax in the probiotic group and Li in the Quassia amara group were observed after the fire waste event. The comparison of the metabolic profiles through pre- and post-event PCA analyses showed that bees treated with different feeds react differently to the environmental event. The greatest differences in metabolic profiles are observed between the placebo-fed bees compared to the others. This study can help to understand how some stress factors can affect the health of bees and to take measures to protect these precious insects.

A multi-analytical approach to studying the chemical composition of typical carbon sink samples.

Peatlands in southern South America (Tierra del Fuego region, TdF) play a key role in the ecological dynamics of Patagonia. It is, therefore, necessary to increase our knowledge and awareness of their scientific and ecological value to ensure their conservation. This study aimed to assess the differences in the distribution and accumulation of elements in peat deposits and Sphagnum moss from the TdF. Chemical and morphological characterization of the samples was carried out using various analytical techniques, and total levels of 53 elements were determined. Furthermore, a chemometric differentiation based on the elemental content of peat and moss samples was performed. Some elements (Cs, Hf, K, Li, Mn, Na, Pb, Rb, Si, Sn, Ti and Zn) showed significantly higher contents in moss samples than in peat samples. In contrast, only Mo, S and Zr were significantly higher in peat samples than in moss samples. The results obtained highlight the ability of moss to accumulate elements and to act as a means to facilitate the entry of elements into peat samples. The valuable data obtained in this multi-methodological baseline survey can be used for more effective conservation of biodiversity and preservation of the ecosystem services of the TdF.

Innovative experimental approach for spatial mapping of source-specific risk contributions of potentially toxic trace elements in PM10.

Exposure to potentially toxic trace elements (PTTEs) in inhalable particulate matter (PM10) is associated with an increased risk of developing cardiorespiratory diseases. Therefore, in multi-source polluted urban contexts, a spatially-resolved evaluation of health risks associated with exposure to PTTEs in PM is essential to identify critical risk areas. In this study, a very-low volume device for high spatial resolution sampling and analysis of PM10 was employed in Terni (Central Italy) in a wide and dense network (23 sampling sites, about 1 km between each other) during a 15-month monitoring campaign. The soluble and insoluble fraction of 33 elements in PM10 was analysed through a chemical fractionation procedure that increased the selectivity of the elements as source tracers. Total carcinogenic risk (CR) and non-carcinogenic risk (NCR) for adults and children due to concentrations of PTTEs in PM10 were calculated and quantitative source-specific risk apportionment was carried out by applying Positive Matrix Factorization (PMF) to the spatially-resolved concentrations of the chemically fractionated elements. PMF analysis identified 5 factors: steel plant, biomass burning, brake dust, soil dust and road dust. Steel plant showed the greatest risk contribution. Total CR and NCR, and source-specific risk contributions at the 23 sites were interpolated using the ordinary kriging (OK) method and mapped to geo-reference the health risks of the identified sources in the whole study area. This also allowed risk estimation in areas not directly measured and the assessment of the risk contribution of individual sources at each point of the study area. This innovative experimental approach is an effective tool to localize the health risks of spatially disaggregated sources of PTTEs and it may allow for better planning of control strategies and mitigation measures to reduce airborne pollutant concentrations in urban settings polluted by multiple sources.

Impairment of the Zn/Cd detoxification systems affects the ability of Salmonella to colonize Arabidopsis thaliana.

Salmonella capacity to colonize different environments depends on its ability to respond efficiently to fluctuations in micronutrient availability. Among micronutrients, Zn, besides playing an essential role in bacterial physiology, is a key element whose concentration can influence bacterial survival in a particular niche. Plant colonization by Salmonella enterica was described for several years, and some molecular determinants involved in this host-pathogen interaction have started to be characterized. However, it is still unclear if Zn plays a role in the outcome of this interaction, as well established for animal hosts that employ nutritional immunity strategies to counteract pathogens infections. In this study, we have investigated the involvement of Salmonella Typhimurium main effectors of zinc homeostasis in plant colonization, using Arabidopsis thaliana as a model host. The results show that to colonize plant tissues, Salmonella takes advantage of its ability to export excess metal through the efflux pumps ZntA and ZitB. In fact, the deletion of these Zn/Cd detoxification systems can affect bacterial persistence in the shoots, depending on metal availability in the plant tissues. The importance of Salmonella ability to export excess metal was enhanced in the colonization of plants grown in high Zn conditions. On the contrary, the bacterial disadvantage related to Zn detoxification impairment can be abrogated if the plant cannot efficiently translocate Zn to the shoots. Overall, our work highlights the role of Zn in Salmonella-plant interaction and suggests that modulation of plant metal content through biofortification may be an efficient strategy to control pathogen colonization.

Probiotics as a promising prophylactic tool to reduce levels of toxic or potentially toxic elements in bees.

Bees are precious living beings for our planet. Thanks to their essential service of pollination, these insects allow the maintenance of biodiversity and the variety and amount of food available. Unfortunately, we are observing an increasingly devastating reduction of bee families and other pollinating insects for factors related to human activities, environmental pollution, diseases and parasites, compromise of natural habitats, and climate change. We show that probiotics can protect bees from element pollution. We collected bees, beeswax, honey, pollen, and propolis directly from hives in a rural area of central Italy to investigate the content of 41 elements in control (not supplemented with probiotics) and experimental (supplemented with probiotics) groups. Our data show a significantly lower concentration of some elements (Ba, Be, Cd, Ce, Co, Cu, Pb, Sn, Tl, and U) in experimental bees than in control groups, indicating a possible beneficial effect of probiotics in reducing the absorption of chemicals. This study presents the first data on element levels after probiotics have been fed to bees and provides the basis for future research in several activities relating to the environment, agriculture, economy, territory, and medicine.

Biomonitoring of element contamination in bees and beehive products in the Rome province (Italy).

In this study, we determined the levels of elements (i.e. As, Be, Cd, Cr, Hg, Ni, Pb, U, and Zn) in bees and edible beehive products (honey, wax, pollen, and propolis) sampled from five selected sites in the Rome province (Italy). RATIONALE: to increase the information variety endowment, the monitoring breakdown structure (MBS) conceptual model was used (nine elements, 429 samples, and approximately thirteen thousand determinations over a 1-year survey). Thus, we employed Johnson's probabilistic method to build the control charts. Then, we measured the element concentration overlap ranges and the overlap bioaccumulation index (OBI). Subsequently, we evaluated the estimated daily intake (EDI) of the analysed elements and matched them with acceptable reference doses. The human health risk caused by the intake of individual elements found in edible beehive products and their risk summation were evaluated through the target hazard quotient (THQ) and hazard index (HI) methods. FINDINGS: excluding honey, this study confirms the capacity of wax, pollen, propolis, and bees to accumulate high levels of toxic and potentially toxic elements from the surrounding environment (with high OBI-U, i.e. OBI-Upper values, i.e. the common upper concentration limit of the overlap concentration range). Bees and pollen showed a high bioaccumulation Cd surplus (OBI-U = 44.0 and 22.3, respectively). On the contrary, honey had high OBI-L values (i.e. honey concentrates metals several times less than the common lower concentration limit of the overlap concentration range). This finding implies that honey is useless as an environmental indicator compared with the other biomonitor/indicators. The EDI values for the edible beehive products were lower than the health and safety reference doses for all the considered elements. Our data show that honey, wax, propolis, and pollen are safe for consumption by both adults and children (THQ < 1; HI < 1), even considering the sporadic possibility of consuming them simultaneously. ORIGINALITY: This study has been conducted for the first time in the Rome province and demonstrates that edible indicators are safe for consumption for the considered elements in bees and edible beehive products. Depending on the ecosystem/pollutants studied, the OBI consents to make a correct choice for environmental biomonitoring studies and to focus the attention on the most sensitive biomonitors/indicators when required at the project level.

Biomonitoring of Exposure to Urban Pollutants and Oxidative Stress during the COVID-19 Lockdown in Rome Residents.

BACKGROUND: The objective of this study is to evaluate the effects of traffic on human health comparing biomonitoring data measured during the COVID-19 lockdown, when restrictions led to a 40% reduction in airborne benzene in Rome and a 36% reduction in road traffic, to the same parameters measured in 2021. METHODS: Biomonitoring was performed on 49 volunteers, determining the urinary metabolites of the most abundant traffic pollutants, such as benzene and PAHs, and oxidative stress biomarkers by HPLC/MS-MS, 28 elements by ICP/MS and metabolic phenotypes by NMR. RESULTS: Means of s-phenylmercaputric acid (SPMA), metabolites of naphthalene and nitropyrene in 2020 are 20% lower than in 2021, while 1-OH-pyrene was 30% lower. A reduction of 40% for 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodGuo) and 60% for 8-oxo-7,8-dihydroguanine (8-oxoGua) were found in 2020 compared to 2021. The concentrations of B, Co, Cu and Sb in 2021 are significantly higher than in the 2020. NMR untargeted metabolomic analysis identified 35 urinary metabolites. Results show in 2021 a decrease in succinic acid, a product of the Krebs cycle promoting inflammation. CONCLUSIONS: Urban pollution due to traffic is partly responsible for oxidative stress of nucleic acids, but other factors also have a role, enhancing the importance of communication about a healthy lifestyle in the prevention of cancer diseases.

An optimized method for sample preparation and elemental analysis of extra-virgin olive oil by inductively coupled plasma mass spectrometry.

The accurate determination of trace elements in vegetable edible oils is still an analytical challenge, owing to their low concentration levels and the complex matrix of the vegetable oils. The aim of this study was to develop a fast and simple analytical method to quantify 45 elements in small mass samples (0.5 g) of extra virgin olive oils by inductively coupled plasma mass spectrometry. To evaluate the best and fastest sample preparation procedure, ultrasonic extraction and wet digestion methods were compared using oil certified reference material with different reagent mixtures, reagent volumes, and times for sample extraction or digestion. The use of 5 mL reagent mixture F [10% (v/v) HNO3 and H2O2, 2:1 (v/v)] for sample digestion in a water bath (95 °C, 40 min) was found to produce satisfactory results in all cases as validated from sample recovery experiments over three different extra virgin olive oil samples.

Exposure Profile to Traffic Related Pollution in Pediatric Age: A Biomonitoring Study.

The aim of this study was to trace an exposure profile to traffic-derived pollution during pediatric age. For this purpose, two biomonitoring campaigns for the determination of urinary (u-) methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and diisopropyl ether (DIPE) were carried out in two different periods of the year (summer 2017 and winter 2018), among a large sample of healthy children (n = 736; 5-11 years old) living in rural and urban areas in central Italy. The quantification of u-MTBE, u-ETBE, u-TAME, and u-DIPE was performed by HS-SPME-GC/MS technique and information on participants was collected by a questionnaire. u-DIPE concentrations resulted always under the LOQ. u-TAME mean levels were similar in both seasons (18.7 ng L-1 in summer vs. 18.9 ng L-1 in winter), while u-MTBE and u-ETBE levels were, respectively, 69.9 and 423.5 ng L-1 (summer) and 53.3 and 66.2 ng L-1 (winter). Main predictors of urinary excretion resulted the time spent in motor vehicles, being male and younger.