Various studies have established that feedstock choice, pyrolysis temperature, and pyrolysis type influence final biochar physicochemical characteristics. However, overarching analyses of pre-biochar ...creation choices and correlations to biochar characteristics are severely lacking. Thus, the objective of this work was to help researchers, biochar-stakeholders, and practitioners make more well-informed choices in terms of how these three major parameters influence the final biochar product. Utilizing approximately 5400 peer-reviewed journal articles and over 50,800 individual data points, herein we elucidate the selections that influence final biochar physical and chemical properties, total nutrient content, and perhaps more importantly tools one can use to predict biochar’s nutrient availability. Based on the large dataset collected, it appears that pyrolysis type (fast or slow) plays a minor role in biochar physico- (inorganic) chemical characteristics; few differences were evident between production styles. Pyrolysis temperature, however, affects biochar’s longevity, with pyrolysis temperatures > 500 °C generally leading to longer-term (i.e., > 1000 years) half-lives. Greater pyrolysis temperatures also led to biochars containing greater overall C and specific surface area (SSA), which could promote soil physico-chemical improvements. However, based on the collected data, it appears that feedstock selection has the largest influence on biochar properties. Specific surface area is greatest in wood-based biochars, which in combination with pyrolysis temperature could likely promote greater changes in soil physical characteristics over other feedstock-based biochars. Crop- and other grass-based biochars appear to have cation exchange capacities greater than other biochars, which in combination with pyrolysis temperature could potentially lead to longer-term changes in soil nutrient retention. The collected data also suggest that one can reasonably predict the availability of various biochar nutrients (e.g., N, P, K, Ca, Mg, Fe, and Cu) based on feedstock choice and total nutrient content. Results can be used to create designer biochars to help solve environmental issues and supply a variety of plant-available nutrients for crop growth.
•Wine traceability by multi-elemental, isotopes and chemometric analysis is proposed.•219 samples of seven PDOs from the Veneto region were analysed.•As, Ca, Cs, δ11B and 87Sr/86Sr were variables ...that differentiate the PDOs.•Cluster analysis, PCA and seven classification methods were applied.•A successful traceability tool for four Venetian PDOs wines was reached.
The traceability and authentication of PDOs wines are important issues for safeguarding their production and distribution systems. This paper evaluated seven Venetian PDO wines, i.e., Amarone, Bardolino, Custoza, Pinot Grigio, Recioto, Soave and Valpolicella. For this purpose, 219 wine samples from the Veneto region were characterised by determining 63 elements and six isotope ratios by HR-ICP-MS and MC-ICP-MS. Chemometric tools highlighted As, Ca, Cs, δ11B and 87Sr/86Sr as the most informative variables to differentiate the PDOs. Seven classification methods, such as Linear Discriminant Analysis, Quadratic Discriminant Analysis, k-Nearest Neighbours, Naïve Bayes, Random Forest, Artificial Neural Networking, and Support Vector Machine were tested and perform a correct classification for Amarone, Bardolino, Pinot Grigio and Recioto PDOs. This paper successfully proposes for the first time advanced traceability tools of seven Venetian PDO by the use of an integrated approach of multi-elemental and isotopes followed by chemometrics analysis.
Reports indicate that silver nanoparticles (nAg) are toxic to vegetation, but little is known about their effects in crop plants. This study examines the impacts of nAg on the physiology and ...nutritional quality of radish (Raphanus sativus) sprouts. Seeds were germinated and grown for 5 days in nAg suspensions at 0, 125, 250, and 500 mg/L. Seed germination and seedling growth were evaluated with traditional methodologies; the uptake of Ag and nutrients was quantified by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and changes in macromolecules were analyzed by infrared (IR) spectroscopy. None of the nAg concentrations reduced seed germination. However, the water content (% of the total weight) was reduced by 1.62, 1.65, and 2.54% with exposure to 125, 250, and 500 mg/L, respectively, compared with the control. At 500 mg/L, the root and shoot lengths were reduced by 47.7 and 40%, with respect to the control. The seedlings exposed to 500 mg/L had 901 ± 150 mg Ag/kg dry wt and significantly less Ca, Mg, B, Cu, Mn, and Zn, compared with the control. The infrared spectroscopy analysis showed changes in the bands corresponding to lipids (3000-2800 cm(-1)), proteins (1550-1530 cm(-1)), and structural components of plant cells such as lignin, pectin, and cellulose. These results suggest that nAg could significantly affect the growth, nutrient content and macromolecule conformation in radish sprouts, with unknown consequences for human health.
•Radioactivity content and elemental composition have been determined in different grain sizes of beach sands.•238U and 232Th was found to be the highest in lower grain size (250–125 µm).•The ...fourteen elements have been identified viz O, Si, Al, Fe, Ca, Mn, Mg, K, Ti, V, Cr, Co, ni and zn.
Measurement of natural radioactivity content as well as elemental composition in three different grain sizes (600–425 μm, 425–250 μm and 250–125 μm) of Mamallapuram beach sand, obtained from three sites, have been undertaken using gamma ray spectroscopy and SEM-EDX respectively. 238 U and 232Th activities are higher at the lowest grain size sands (250–125 μm); 40 K activity is seen, only in those samples, where 238 U and 232Th activities are comparatively lesser. In SEM-EDX analysis of the beach sand samples, fourteen elements have been identified. Besides Oxygen (39.06 %) and Silicon (24.59 %), other elements identified, which are more than 1 % are, Iron (13.46 %), Titanium (10.75 %), aluminum (5.22 %), calcium (1.46 %), magnesium (1.28 %) and Potassium (1.28 %). Six elements in trace levels have also been observed viz., Mn (0.68 %), Ni (0.38 %), V (0.36 %), Cr (0.35 %), Zn (0.35 %) and Co (0.32%).
Matrix effects caused by Na and Al in the nitrogen Microwave-sustained, Inductively Coupled, Atmospheric-pressure Plasma (MICAP) were investigated. Easily ionizable elements, such as Na, can suppress ...or enhance the analyte signal; Al is shown here to produce a similar effect. The influence of these matrices was examined for 18 emission lines of 8 analyte atoms and ions having a wide range of excitation and ionization energies. The plasma operating conditions were fixed during all experiments at a total nitrogen flow of 19.4Lmin−1 and a microwave power of 1.5kW. An Fe solution was used to determine the excitation temperature of the plasma by the Boltzmann plot method at selected matrix concentrations. In addition, vertical emission profiles of the plasma were measured. The matrix effect becomes worse at higher concentrations of an easily ionizable element. The effect is caused not only by a shift in ionization equilibrium but also by a possible change in plasma ionization temperature. Correction methods to reduce the matrix effects were tested and are discussed.
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•The spatial behavior of elemental emission from the MICAP is a function of concomitant elements present in a sample solution.•Unlike in the argon ICP, a concomitant does not produce a shift in the vertical distribution of emission intensity.•Rather, the result of adding an easily ionized matrix element to a sample solution is to lower emission intensity of ion lines and to boost emission from neutral-atom lines.•Overall, the effect appears to be due mainly to a shift in ion-atom equilibrium induced by electrons added to the discharge.•A secondary effect seems to be a modification of the ionization temperature of the MICAP.
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•Detailed analysis of asphaltenes originated from light, medium and heavy oils is provided.•Asphaltenes are compared with least, intermediately and most soluble medium asphaltenes ...subfractions.•Heavy oil asphaltenes and most soluble subfractions displayed least aromaticity and longest alkyl side chains.•Precipitation/destabilization is majorly driven by π-π interactions and low steric hindrance.•The effect of asphaltenes structures on their stability behavior is discussed.
Asphaltenes, and their related issues, have been the focus of many literature investigations. However, in-depth analysis of asphaltenes structure and its relation to asphaltenes stability has been considered by fewer studies. In this research, extensive analysis of the structure of asphaltenes extracted from light, medium, and heavy oils is provided, together with analysis of three subfractions of the medium oil asphaltene having the least, intermediate, and highest solubilities. To this end, elemental analysis, EDX, mass spectroscopy, FTIR, NMR, XRD, and SEM results were collected. Higher hydrogen content and hydrogen/carbon atomic ratio, lower aromatic nature and olefinic entities were observed in heavy oil asphaltenes as well as the most soluble subfraction. Moreover, the molecular structure of heavy oil asphaltenes and the most soluble subfraction displayed broader mass to charge (m/z) distribution range, longer alkyl side chains as well as higher number of stacked aromatic sheets within their nanoclusters. Asphaltenes hydrogens in α position followed similar trend as their heteroatom content, which was higher for the less soluble subfraction and medium oil asphaltenes. Generally, heavy oil asphaltenes possessed a molecular structure that was closer to the most soluble asphaltenes subfraction, whereas light oil asphaltenes possessed a molecular structure similar to the least soluble subfraction. Asphaltenes precipitation/destabilization was attributed to primarily higher attractive π-π interactions coupled with lower steric hindrance.
A method for simultaneous determination of nitrogen content and 15N isotope abundance in plants was established by Elemental analysis-gas isotope ratio mass spectrometry. Taking poplar leaves and ...l-glutamic acid as standards, nitrogen content was determined using the standard curve established by weighted least squares regression between the mass of nitrogen element and the total peak height intensity at m/z 28 and 29. Then the 15N isotope abundance was calculated with the peak height intensity at m/z 28 and 29. Through the comparison of several sets of experiments, the impact of mass discrimination effect, tin capsule consumables, isotope memory effect, and the quality of nitrogen on the results were assessed. The results showed that with a weight of 1/x2, the standard curve has a coefficient of determination (R2) of 0.9996. Compared to the traditional Kjeldahl method, the measured nitrogen content deviated less than 0.2 %, and the standard deviation (SD) was less than 0.2 %. Compared to the sodium hypobromite method, the 15N isotopic abundances differed less than 0.2 atom%15N, and the SD was less than 0.2 atom% 15N. The established method offers the advantages of being fast, simple, accurate, and high throughput, providing a novel approach for the simultaneous determination of nitrogen content and 15N isotope abundance in plant samples.
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•Plant nitrogen content and 15N isotope abundance with mass spectrometry.•Plant nitrogen content analysis with weighted least squares regression.•Determination of nitrogen content and 15N abundance using peaks at m/z 28 and 29.•Simultaneous acquisition of two key parameters in a single sampling process.•Accurate and precise nitrogen content and 15N isotope abundance analysis method.
The study of the provenance of dolomitic marble artefacts has become relevant since it was discovered that quarries of this marble other than that of Cape-Vathy located on the island of Thasos have ...been exploited since Antiquity. To improve our knowledge about the provenance of materials and the extent of their dispersion, multiple archaeometric studies were performed in the past including isotope analyses, petrography, cathodoluminescence, and elemental analyses. In the present work, solid-state nuclear magnetic resonance (NMR) spectroscopy has been added to this panel of techniques. NMR allows the characterization of the material at a molecular level by looking at different nuclei: carbon, magnesium, and calcium. Statistical analysis of the data collected on both quarry samples and archaeologic items was also implemented and clearly demonstrates the efficiency of a holistic approach for provenance elucidation. Finally, the first sup.25Mg NMR tests have shown the potential of this technique to discriminate between dolomitic marbles of different provenance. The results are discussed in terms of their historical meaning and illustrate the exploitation of sources of dolomitic marbles other than the Greek Thasos source.
This article presents a review involving the application of slurry sampling as a sample treatment for the determination of metals and metalloids by spectroanalytical techniques. The fundamentals of ...this approach are presented and discussed with its characteristics, advantages, and limitations. The main parameters (particle size, diluent type, stabilizer, sample mass/liquid phase volume ratio, and homogenization technique) needed to optimize a procedure based on slurry sampling are also critically discussed. The analytical techniques most used in the determination of metals in the sample slurries and their particularities in this task are discussed to highlight their characteristics. Finally, new approaches and trends related to slurry sampling, such as dispersive solid phase extraction with the direct introduction of the adsorbent into the equipment, the use of pre-digestion, coupling to flow injection analysis, the use of slurries in TXRF, and gas phase molecular absorption spectrophotometry and the performance of speciation analysis, are also discussed.
Methods involving slurry sampling are revised and critically discussed.
The key characteristics of this preparation technique are addressed.
Analytical characteristics, and the advantages and disadvantages of the methods, among other aspects are compared.
New approaches and trends about this preparation method are also presented.
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