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Grape molasses (GM), produced from grapes, is a traditional Iranian food and is widely consumed in Iran. However, GM adulteration is among the most widespread illegitimate procedures involving contamination of food with foreign materials, such as adding sugar–water solution, date syrup, sugar beet syrup, and grape sauce. This study used stable carbon 13C/12C isotope ratio analysis method to detect adulteration of GM samples with glucose syrups (GS), fructose syrups (FS), and beet sugar syrups (BS) at the ratio of 0%, 10%, 30%, and 50% (by weight). Physicochemical properties of GM including °Brix, conductivity, specific gravity, pH, moisture content, ash content, hydroxymethyl furfural, sugar content, and rheological properties of samples were investigated. The δ13C isotope ratio of the GM was determined as −26.61%, that of the GS as −13.23%, that of the FS as −13.42%, and that of the BS as −16.58%. The δ13C isotope ratio increased by the addition of adulterant syrups to GM. The addition of each adulterant syrup had a different effect on the physicochemical parameters; however, the °Brix and specific gravity had a positive correlation with the δ13C isotope ratio results. The magnitudes of G' and G" increase with an increase in frequency representing the viscoelastic behavior of samples. The obtained results of this study suggest the use of δ13C isotope ratio method as a fast and accurate method to investigate the adulteration of grape molasses. [ABSTRACT FROM AUTHOR]

Mobile proximal gamma-ray spectrometry (GS) is an emerging approach to estimate soil texture directly in the field. It relies on gamma radiation emitted during the natural decay of potassium-40 (K-40) and other isotopes. The K-40 counts are correlated with total K content, mineralogical soil composition and therefore with soil texture. Yet, it is not clear if K fertilisation impacts the ratio of K-40 to total K which would necessitate to take the fertilisation history into account for soil sensing applications. To elucidate this question, a well-documented long-term experiment was selected. The soils of the Rengen grassland experiment (55 plots) were investigated for total K (XRF-K) and for K-40 via mobile proximal GS. No significant differences in XRF-K and K-40 were found between the treatments with and without K fertilisation, although formely published results point to negative and positive K balances, respectively. Fertiliser analysis revealed a ratio of K-40 to total K that was almost identical to the natural abundance of 0.0117%. It was concluded that it is not necessary to take K fertilisation history into account when predicting soil texture from mobile proximal GS on agricultural land for, e.g., precision farming purposes. [ABSTRACT FROM AUTHOR]

Particulate matter (PM) in the air has significant implications for human health and the environment, particularly in urban areas with high concentrations. This study focuses on the isotopic (δ13C and δ15N), elemental (CNS) as well as the total carbon to total nitrogen ratio (TC/TN) characterization of PM in Trombay, Mumbai. Monthly atmospheric dust samples were collected from 2016 to 2020 during the premonsoon and postmonsoon seasons. The average elemental concentrations for premonsoon samples were N (1.73% ± 0.25%), C (7.38% ± 0.72%), S (0.84% ± 0.13%), and TC/TN ratio (4.38 ± 0.86). For postmonsoon samples, the average elemental concentrations were N (1.47% ± 0.185%), C (6.95% ± 1.04%), S (0.84% ± 0.13%), and TC/TN ratio (4.80 ± 0.94). The average δ13C values for premonsoon and postmonsoon seasons were −24.31 ± 1.15‰ and −24.56 ± 1.20‰, respectively. The average δ15N values for premonsoon and postmonsoon seasons were 5.22 ± 1.92‰ and 4.57 ± 1.32‰, respectively. The resultsshowed variationsin elemental concentrations between the seasons, with higher values observed in premonsoon samples which can be attributed to increased dust generation from land and sea. Overall, this study provides insights into the local sources and characteristics of PM in the Trombay area and highlights the importance of long-term monitoring to understand the seasonal variations in PM composition. [ABSTRACT FROM AUTHOR]

The intensity ratio (αI) and area ratio (αA) obtained using Raman spectroscopy are used widely to characterize the physical properties of gases, fluids, and solids, but the underlying parameters which affect their precision (σαI and σαA) have not been elucidated. We use simulations, experiments, and theoretical analyses to investigate the effects of instrumental performance, analytical conditions, and sample size on σαI and σαA. We identified the parameters which strongly influence σαI: (1) the weaker peak intensity Iw; (2) the ratio of the bandwidth to pixel resolution of the weaker peak Γw/Δxw; (3) the degree of detector saturation; (4) σD2+σR2/σS2 with readout noise σR, dark noise σD, and shot noise σS; (5) drift; and (6) sample size. Theoretical and simulation results show that, when Γw/Δxw ≪ (Γs/Δxs)/αI, increasing Iw or Γw/Δxw by n times can improve σαI by a factor of n. Results showed that σD2+σR2/σS2 is a measure of how much the achievable σαI in the experiment differs from that under ideal analytical conditions (i.e., σD2+σR2≪σS2). When σD2+σR2≪σS2 is not the case (i.e., when Iw is low), reducing σD or σR by decreasing the readout speed, setting a lower charge coupled device (CCD) sensitivity, reducing number of readouts, or narrowing vertical binning width can improve σαI. We demonstrated that evaluations of σαI or σαA based on small sample sizes can engender physically unattainable precision. When the sample size is n = 5, 10, or 20, the average uncertainties of σαI and σαA correspond, respectively, to approximately 30%, 20%, and 15%. Giving an accurate and comparable assessment for σαI and σαA necessitates the reporting of intensity (in units of electrons), bandwidth, Δx, and the sample size. [ABSTRACT FROM AUTHOR]

Carbon and nitrogen composition and isotopic ratios (δ15N, δ13C, and δ13C-DIC) as well as physicochemical parameters were measured in hazardous waste leachate connected to an environmental pollution crime. A forensic metrology approach was employed by estimating the measurement uncertainty, including that from the sampling process, using range statistics. The physicochemical parameters demonstrated differences in the leachate from some of the different ponds and this was supported by carbon and nitrogen elemental and isotopic analyses. The isotopic signature of δ15N and δ13C-DIC was highly enriched in the heavy isotope demonstrating that those analyses are a substantial tool for leachate pollution tracking. The uncertainty of the measurements was below or slightly above 20% for most parameters which can be considered fit-for-purpose for a great deal of environmental surveys and was remarkably lower in the isotopic analyses. The uncertainty of measurement including the primary sampling is a relevant information in environmental investigations, especially forensic ones. This knowledge is crucial for a consistent interpretation of environmental samples analyses results, specially from polluted sites and pollution source characterization and tracking, where there is often substantial heterogeneity in environmental samples. [ABSTRACT FROM AUTHOR]

Aims: Forests with various mixed patterns often show large differences in water use strategies. However, mixed planting may enhance the drought resistance of the whole forest community. We evaluated whether mixed planting could enhance the drought resistance of Robinia pseudoacacia and Quercus acutissima under different seasons in the warm temperate zone of North China. Methods: Shallow-rooted R. pseudoacacia and deep-rooted Q. acutissima were studied to determine plant water use strategies under different seasons and planting methods. We measured hydrogen and oxygen isotope ratios of two species grown under pure and mixed planting methods, as well as those of the environment, including rainwater, soil water, and groundwater in spring, summer, and autumn. Results: Hydrogen and oxygen isotopic contents of soil water were significantly less than groundwater and significantly more than rainwater irrespective of the season. However, season was the key factor influencing the plant water use strategies. In spring and autumn, Q. acutissima used more groundwater while R. pseudoacacia used more soil water; in summer, both of the two species took more use of rainwater and soil water. Mixed planting significantly increased the proportion of groundwater use and the diversity of plant water use strategies of two species. Conclusion: Diversity of plant water use strategies facilitate the coexistence of two species with the same ecosystem irrespective of the changes in water availability in their respective root zones. Besides, mixed planting can enhance the drought resistance of the whole forest community via reducing competition for the seasonal changes in water resources. [ABSTRACT FROM AUTHOR]

The determination of isotope ratios in individual uranium particles is very important for nuclear safeguards. In this work, accelerator mass spectrometry (AMS), thermal ionization mass spectrometry (TIMS), and secondary ion mass spectrometry (SIMS) were applied to isotope ratio analysis of individual uranium particles and compared in terms of background, measurement accuracy, and efficiency. Several individual uranium particles (1–7 μm) from certified reference materials were used as samples. The results show that the average values of blank counting rate of 235U for AMS, FT‐TIMS (FT: fission track), SEM‐TIMS (SEM: scanning electron microscope), and SIMS were 7.3, 7.8, 2.7 and 2.2 cps, respectively. The relative error of 234U/235U and 234U/236U isotope ratios of the particles from U200 for AMS were within 10% and 20%, whereas the results of FT‐TIMS and SIMS were within 5% and 10%, respectively. The relative error and external precision of 234U/238U and 235U/238U of the particles from U850 for the method of AMS, SEM‐TIMS, and SIMS were within 10% and 5%, respectively. For 236U/238U, the average values of the relative error and external precision measured by AMS were within 5%, which measured by SEM‐TIMS and SIMS were all within 10%. AMS has advantages in measuring 236U/238U. The measurement time of AMS and SEM‐TIMS was shorter than that of FT‐TIMS and longer than that of SIMS. It is considered that AMS and SEM‐TIMS have a certain development prospect, and it is necessary to research deeply. [ABSTRACT FROM AUTHOR]

Stable hydrogen, carbon, nitrogen, oxygen and sulfur (HCNOS) isotope compositions expressed as isotope-delta values are typically reported relative to international standards such as Vienna Standard Mean Ocean Water (VSMOW), Vienna Peedee belemnite (VPDB) or Vienna Cañon Diablo Troilite (VCDT). These international standards are chosen by convention and the calibration methods used to realise them in practice undergo occasional changes. To ensure longevity and reusability of published data, a comprehensive description of (1) analytical procedure, (2) traceability, (3) data processing, and (4) uncertainty evaluation is required. Following earlier International Union of Pure and Applied Chemistry documents on terminology and notations, this paper proposes minimum requirements for publishing HCNOS stable-isotope delta results. Each of the requirements are presented with illustrative examples. [ABSTRACT FROM AUTHOR]

Serving as a medium between source water and cellulose, leaf water contributes to the isotope ratios (δ18O, δ2H) of plant organic matter, which can be used for paleoclimate reconstruction. This study is the first to examine the diurnal variations in the δ18O and δ2H of leaf water on the southern Tibetan Plateau. The δ18O and δ2H of leaf water were relatively low when precipitation events occurred. In particular, 18O and 2H of leaf water became extremely depleted 5 h after the precipitation event. Our findings demonstrate that precipitation can modify the isotope ratios of leaf water from external and internal causes. First, precipitation events affect meteorological elements, lead to decreases in leaf transpiration, and immediately weaken the isotope enrichment of leaf water ('rapid effect' of precipitation). Second, precipitation events affect the internal plant–soil water cycle process, causing the plant to preferentially use deeper soil water, and the corresponding isotope ratios of leaf water exhibit extremely low values 5 h after precipitation events ('delay effect' of precipitation). This study suggests that researchers need to be cautious in separating the signals of precipitation and hydrological processes when interpreting isotope records preserved in tree-ring cellulose archives from the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

This paper details the different steps for the isotopic determination of UAmO2 discs from analytical irradiation. MARIOS and DIAMINO irradiations were performed in materials testing reactors to study the behaviour of americium bearing blanket samples in regard of heterogeneous recycling in sodium-cooled fast reactor. Six irradiated discs were dissolved in hot cells and were analyzed to determine isotope ratios of uranium, plutonium, americium and neodymium. The ratios were measured combining chemical separations and TIMS analyses. Using the double isotope dilution methodology helps measuring 238Pu/238U, 241Am/238U and 148Nd/238U ratios with uncertainty about a few per mil (k = 2). [ABSTRACT FROM AUTHOR]

The most challenging problems in the field of chemico- and bioanalytical measurements are described. These problems are being solved, in particular, by participating in new international comparisons organized by the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology of the International Committee of Weights and Measures (CCQM CIPM). Solutions of these challenging problems are presented. The objectives and tasks of developing key comparisons in the following areas are described: isotopic measurements; determination of the purity of substances; organic analysis; bioanalytical measurements; measurements of aerosol particle parameters; measurements in the field of gas analysis and electrochemistry. It is shown that participation in international key comparisons allows obtaining valid and reliable results of measurements of the composition and properties of gas and liquid media, as well as solid substances and materials. [ABSTRACT FROM AUTHOR]

BACKGROUND: The use of PDO (protected designation of origin) and PGI (protected geographical indication) labels allows to protect and promote agricultural products characterized by unique features related to the place of origin and traditional know‐how. However, the presence of non‐authentic products in the market represents a fraud that can be tackled applying analytical techniques combined with chemometric analysis. In this study, we applied multi‐element and multi‐isotope analysis to characterize PDO and PGI apples cultivated in northern Italy, comparing them with Italian apples without labels of geographical indications. RESULTS: The multi‐element and multi‐isotope approach allowed to characterize the apples cultivated in northern Italy. Despite a significant effect of the sampling sites on the apple composition, the comparison of the multi‐chemical fingerprint of the apples significantly varied among cultivation areas. Results of this characterization were used to classify samples according to their cultivation area applying a linear discriminant analysis (LDA). Outputs of the LDA showed that correct sample classification can be successfully achieved (balanced accuracy > 96%). Moreover, using a selection of variables, it was possible to correctly classify samples also at regional level. CONCLUSION: The presented evidences indicate that the multi‐element and multi‐isotope fingerprint can be successfully applied to traceability studies. The combination of this characterization with chemometric tools allows the classification of Italian apples based on their origin both on a national and regional scale. This approach represents an interesting tool to enhance and protect PDO and PGI Italian products. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Field studies in post-mining sites on epigeic invertebrate groups are scarce despite their importance in pedogenesis and ecosystem multifunctionality. This research investigated the diversity, abundance and succession of aboveground invertebrates in a rehabilitated Pb/Zn tailings chronosequence of 5, 20 and 35 years. The study also explored the trophic relationship of selected arthropods and characterized the nitrogen (N) cycle using stable isotope measurements. The abundance and species richness in most investigated groups and the dominance index Berger–Parker (BP) of aboveground invertebrates increased with rehabilitation age from 0.17 BP in early to 0.31 BP in late stage. Elemental and stable isotope ratio analysis showed that N and C soil content increased and the C/N ratio decreased with age, yet despite this increased N availability in the system, the maturing N-cycle used N efficiently. The lack of large N losses from the system despite substantial atmospheric deposition inputs was indicated by the fact that N isotope ratios (δ15N) in plants and animals became significantly more negative with rehabilitation age, −6.0 δ15N for plants, −5.0 δ15N for herbivores and 3.0 δ15N for carnivores. The length of the invertebrate food chain expanded by more than half a trophic level (2.7‰ δ15N) for top predator Coleoptera from early to late stage, probably reflecting more complex food webs including intra-guild predation in older communities. In conclusion, δ15N measurements in plants and animals provided novel insights into the N-cycle, accumulative N flows and the trophic position in post-mining sites. It is proposed that isotope ratio measurements could be used as easy-to-measure, integrating indicators of nutrient cycling and the soil food web complexity of rehabilitated mine tailings and similar soil ecosystems. [ABSTRACT FROM AUTHOR]

This study presents a method for calibrating the isotope ratios of the total carbon, nitrogen, and sulfur in particulate matter (PM) collected from the Seoul metro using an elemental analyzer-isotope ratio mass spectrometer (EA-IRMS). Mixtures of isotope reference materials (MRMs) from the U.S. Geological Survey (USGS) and International Atomic Energy Agency (IAEA) reference materials formed an input dataset for generalized least squares (GLS) regression to yield calibration lines. The analytical method proposed in this study enabled the measurement of stable isotope ratios of total carbon, nitrogen, and sulfur simultaneously. Results showed good linearity and repeatability for carbon and nitrogen isotopes, but poor results for sulfur isotopes due to peak broadening. Reference values with uncertainties for the isotope ratios of total carbon, nitrogen, and sulfur were determined for the collected PM, demonstrating twice as much uncertainty as that of the USGS and IAEA reference materials. Homogeneity was the biggest uncertainty source for the calibrated values. Isotope ratios in PM's C/N/S were simultaneously calibrated with mixtures of IAEA and USGS reference materials using EA-IRMS. Calibration uncertainty was assessed using the generalized least squares. Homogeneity was also assessed. Parametric uncertainty evaluation was cross-validated by Monte Carlo simulation. [Display omitted] • Analytical method for isotope ratios of total C/N/S in the particulate matter were optimized for simultaneous measurement using EA-IRMS. • Isotope ratio values of the total C/N/S of the PM sampled in the Seoul metro were calibrated by mixtures of USGS and IAEA reference materials. • Calibration uncertainty were evaluted with those of measurement, regression, reference materials, and homegeneity. [ABSTRACT FROM AUTHOR]

When measuring the isotope ratio of plutonium by thermal ionization mass spectrometry with conventional method, the plutonium isotope standard material is usually needed to calibrate the bias caused by the isotope fractionation which is the main factor that influences the accuracy of results. Recent years, the total evaporation technique has become a good choice because of its inherent characteristics that can obtain results with no significant bias without calibrate by external standard. In this work, the main factors were investigated that influence the total evaporation measurement of thermalionization mass spectrometry, including the amplifier current gain calibration, sample amount, and the isobaric interference 238 U and 241 Am. 241 Am was separated from the aged plutonium by UTEVA resin, it was shown that isotopic analysis of plutonium should be completed within a reasonable time period after separation from Americium to minimize interference of 241 Am in-growth from decaying 241 Pu, and the interval limiting between sample purification and isotopic analysis was about 20 days to make sure the accuracy and precision, the re would be about 2% bias after 30 days of separation. The sample lost between integration due to the necessary to adjust the filament current and the residual sample after measuring was eliminated as less than 0. 3%. Measured with total evaporation technique utilizing Faraday cups only, IRMM-086 with different sample loadings were studied respectively, the results showed that sample loading between 50 and 100 ng were likely enough for good accuracy and precision, but there were also slightly biases in the 238 Pu/ 239 Pu and 242 Pu/239 Pu due to the low signal of 238 P u and 242 Pu influenced by the noise of Faraday cups. The results of IRMM-086 using total evaporation and conventional techniques were compared, and showed that the total evaporation technique could obtain better accuracies than t he conventional method while sample loading for total evaporation and conventional were 50 ng and ZOO ng respectively. There was no significant bias between measured and certified value when isotope ratio was more than 10-4 For IRMM-086, the relative standard deviations of 240 Pu/ 239 Pu, 241 P u/ 239 Pu, 242 Pu/239Pu measured by total evaporation were 0. 006 8%, 0. 50% and 0. 83%, respectively. Giving high precision and accuracy results without calibration, the total evaporation technique will be more widely used when we have a lower noise amplifier for Faraday collectors. In the field of spent fuel reprocessing analysis, plutonium isotope composition varies greatly due to different b urn-up. Total evaporation measurement technology has a very good application prospect in the field of plutonium isotope composition measurement. [ABSTRACT FROM AUTHOR]

This article explores the impact of an arginine phosphate-containing fertilizer on nitrogen uptake, carbon content, and elemental concentrations in pine needles in different forest types in Latvia. The study used isotope ratio mass spectrometry and inductively coupled plasma mass spectrometry to analyze pine needle samples. The findings reveal diverse patterns in nitrogen uptake and isotope ratio changes among the forest types, indicating the importance of considering forest type and environmental conditions when assessing fertilizer efficacy. This research contributes to our understanding of nutrient dynamics in forest ecosystems and guides sustainable forest management practices. [Extracted from the article]

An analytical technique was developed to determine the age of uranium particles. After the chemical separation of uranium and thorium, the 230Th/234U ratio was measured using single-collector inductively coupled plasma mass spectrometry and a 233U-based reference material comprising a certain amount of 229Th as a progeny nuclide of 233U. The results allowed us to determine the purification age of two certified materials, i.e., U-850 and U-100, which was in good agreement with the reference purification age (61 y). Moreover, the age of a single U-850 particle was determined with a difference of − 28 to 2 years from the reference date. [ABSTRACT FROM AUTHOR]

The half-life of 243Am has been measured by an absolute and a relative method, i.e. by determining the specific activity of 243Am and the specific activity ratio with 241Am. A mixed 241,243Am reference material was produced and certified for its americium mass content and its isotope amount ratios. The characterisation of the mass content of 243Am was established by isotope dilution mass spectrometry using an 241Am spike, produced from highly enriched 241Pu material. The isotope amount ratios n(241Am)/n(243Am) and n(242mAm)/n(243Am) were measured by thermal ionisation mass spectrometry. Activity measurements were performed by alpha-particle counting at a defined solid angle, as well as high-resolution alpha-particle spectrometry. From the 243Am/241Am activity and isotopic amount ratios, a value of 16.988 (24) was derived for the 243Am/241Am half-life ratio. Using a value of 432.6 (6) a for the 241Am half-life, the corresponding 243Am half-life value, 7349 (15) a, is in good agreement with the result obtained from the absolute method, 7342 (14) a. The mean value, 7345 (14) a, agrees well with data from literature and lowers the relative standard uncertainty to 0.2%. [ABSTRACT FROM AUTHOR]

This study presents the development of an innovative experiment using a surrogate, for monitoring the depletion kinetics of plutonium dissolution residues in an irradiated fuel dissolution solution containing a high plutonium concentration. The surrogate, a (U,Pu)O2 compound, was synthesized from a plutonium having an isotopic composition different from the dissolution solution. This helps monitoring the plutonium residue depletion by TIMS measurements of the 240Pu/239Pu isotope ratio. Repeatability better than 83 ppm was achieved for the 240Pu/239Pu ratios in each aliquot of the dissolution profiles allowing qualitative and quantitative interpretation of the kinetic evolution that could not be reached by a conventional direct concentration determination. [ABSTRACT FROM AUTHOR]

In this study, we report the first independent measurements of lutetium isotopic composition using multi-collector ICPMS in four commercial lutetium materials, including a new NRC candidate lutetium isotopic reference material, LUIS-1. The regression model was used to correct for the instrumental isotopic fractionation (mass bias) using NIST SRM 989 isotopic rhenium as the primary calibrator. The regression model is based on a short 15-min measurement sessions at varying ICP plasma power. Isotope ratio of R176/175 = 0.026553(11)k = 1, corresponding isotopic abundances of x176 = 0.025866(11)k = 1, x175 = 0.974134(11)k = 1, and an atomic weight of Ar(Lu) = 174.966693(13)k = 1 were obtained for lutetium in LUIS-1. Uncertainty estimation was performed using a mixture of modeling approaches in accordance with the JCGM 100:2008 "Guide to the Expression of Uncertainty in Measurement" and its Supplement 1. The relative contribution of the rhenium primary standard to the combined uncertainty of 176Lu/175Lu isotope ratio was 15%. [ABSTRACT FROM AUTHOR]

BACKGROUND Apples have a leading role in the Italian fruit sector, and high‐quality apples, including the Golden Delicious variety, are cultivated mainly in the Northern mountain districts. In the present study, Golden Delicious apples from PDO (Protected Designation of Origin) and PGI (Protected Geographical Indication) cultivation districts were characterized according to their Sr isotope composition and compared with apples from other Northern Italian districts. RESULTS: Apples collected in two consecutive years (2017 and 2018) confirmed the low annual variability of the 87Sr/86Sr ratio. The isotope ratio of apples was highly correlated with that of the soil extracts of the respective orchards. Statistical differences were highlighted between cultivation districts. However, because similar geological features characterized some areas, their ratios overlapped and a complete separation of the districts was not possible. CONCLUSION: The 87Sr/86Sr ratio is an excellent marker for studies of food traceability because it retains the information about the place of origin. However, its strength is limited when comparing products from cultivation areas sharing similar geological features. In the perspective of geographical traceability, a multichemical characterization can overcome the limits of single‐parameter approach. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the hydration of fat-free mass (FFM) in athletes and non-athletes.Methods: We analyzed the data of 128 healthy young adults (athletes: 61 men, 36 women; non-athletes: 19 men, 12 women) using the two-component (2C), 3C and 4C models. Under-water weighing or air-displacement plethysmography and deuterium dilution methods were used for estimating body density and total body water, respectively. The bone mineral content (BMC) was determined using whole-body scans by dual-energy X-ray absorptiometry.Results: There was no significant difference in FFM hydration between the athletes (men, 72.3 ± 1.3%; women, 71.8 ± 1.3%) and non-athletes (men, 72.1 ± 1.2%; women, 72.2% ± 1.0%) in the 3C model. The total mean FFM hydration (72.1% ± 1.3%) was similar to the corresponding value in the literature (~ 73%). The estimation error of the percentage fat by the 2C vs the 4C model was significantly and highly correlated with hydration (r = 0.96), BMC (r = - 0.70), and total body protein (r = - 0.86) in the 4C model FFM.Conclusion: Although FFM hydration was similar in athletes and non-athletes, it would be underestimated or overestimated when the 2C model is used for evaluation, and the biological FFM hydration value deviates from the 73% value inter-individually. Despite that this inter-individual variation in FFM hydration is low in terms of between-individual standard deviation (1.3%), the BMC and total body protein differ greatly in athletes, and when it affects FFM hydration, it may also affect the percentage fat measurement in the 2C model. Thus, FFM hydration would not be affected by FFM, percent body fat, or the athletic status. [ABSTRACT FROM AUTHOR]

Resonance ionization mass spectroscopy has proven to be a very efficient and selective method for the spatially resolved ultratrace determination of actinide contaminations, and the analysis of specific element and isotopic distributions on surfaces and environment particles. We report on the identification of highly element-selective optical excitation schemes identified for this purpose, with a particular focus on the precise determination of the isobaric ratios of 235U to 239Pu as well as 243Am to 241Pu. The chosen two-step ionization schemes were characterized with respect to their element selectivity on synthetic multi-element actinide mixtures, with an element ratio Pu : Am : U of 1 : 10 : 104, a composition which is typical, e.g., for spent nuclear reactor fuels. [ABSTRACT FROM AUTHOR]

BACKGROUND: Quantitative determination with site‐specific natural isotope fractionation nuclear magnetic resonance (SNIF‐NMR) has been exploited widely in detecting adulteration and for the classification of natural products by their geographical origin. RESULTS: We compared isotopic parameters such as deuterium / hydrogen (D/H) site specific ratios and the R parameter for alcoholic beverages, obtained using (i) a 500 MHz spectrometer equipped with a dedicated probe for isotopic measurements, and (ii) a 700 MHz spectrometer equipped with a standard probe. The factors affecting the accuracy and precision of quantitative NMR with the second instrument have been explored. CONCLUSIONS: It has been demonstrated that, in laboratories with a spectrometer that is not equipped with a specific deuterium probe, the selection of the appropriate experimental parameters enables measurements with a similar precision and accuracy as in the case of the official method adopted by the International Organisation of Vine and Wine. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Resonance ionization mass spectrometry is an ultra-sensitive and highly element selective tool for spectroscopy, ionization and detection of atoms and thus enables rare isotope determination. In combination with spatially resolved sputtering of neutrals by an initial ion beam, e.g. within a commercial secondary ion mass spectrometer, an isotope and isobar selective analysis technique with resolution on the micrometer scale for particles and surfaces is realized. Detection of minuscule amounts of specific actinides, e.g. of plutonium, in environmental and technical samples by this ultra-trace analysis technique requires detailed knowledge about the atomic physics of the element. Identification and characterization of the specific resonance ionization scheme applied within the particular geometry of the apparatus in use is needed. An analysis of the dependence of the specifications, specifically regarding the influence of the relative laser beam polarizations is presented here as an aspect, that could have a severe impact on isotope ratio precision and overall efficiency in the resulting ion signal. [ABSTRACT FROM AUTHOR]

Mixotrophic microorganisms are able to use organic carbon as well as inorganic carbon sources and thus, play an essential role in the biogeochemical carbon cycle. In aquatic ecosystems, the alteration of carbon dioxide (CO2) fixation by toxic metals such as cadmium – classified as a priority pollutant – could contribute to the unbalance of the carbon cycle. In consequence, the investigation of cadmium impact on carbon assimilation in mixotrophic microorganisms is of high interest. We exposed the mixotrophic microalga Chlamydomonas reinhardtii to cadmium in a growth medium containing both CO2 and labelled 13C‐[1,2] acetate as carbon sources. We showed that the accumulation of cadmium in the pyrenoid, where it was predominantly bound to sulphur ligands, impaired CO2 fixation to the benefit of acetate assimilation. Transmission electron microscopy (TEM)/X‐ray energy dispersive spectroscopy (X‐EDS) and micro X‐ray fluorescence (μXRF)/micro X‐ray absorption near‐edge structure (μXANES) at Cd LIII‐edge indicated the localization and the speciation of cadmium in the cellular structure. In addition, nanoscale secondary ion mass spectrometry (NanoSIMS) analysis of the 13C/12C ratio in pyrenoid and starch granules revealed the origin of carbon sources. The fraction of carbon in starch originating from CO2 decreased from 73 to 39% during cadmium stress. For the first time, the complementary use of high‐resolution elemental and isotopic imaging techniques allowed relating the impact of cadmium at the subcellular level with carbon assimilation in a mixotrophic microalga. Cadmium clearly impairs carbon assimilation in Chlamydomonas reinhardtii grown in mixotrophic conditions. Due to the pyrenoidal sequestration of cadmium, carbon dioxide fixation is limited during cadmium exposure, whereas acetate assimilation is favoured; thus, the alteration of carbon dioxide (CO2) fixation in microalgae by toxic metals could contribute to the unbalance of the biogeochemical carbon cycle. [ABSTRACT FROM AUTHOR]

The processes of planetary accretion or formation of the Earth and other celestial objects can be studied by using the 182Hf-182W chronometer which requires precise measurements of tungsten isotope ratios. Many comparative measurements for the isotopic composition of tungsten have been performed using either thermal ionization mass spectrometry (TIMS) or multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Yet, calibrated measurements of tungsten isotope ratios, and, in turn, isotopic abundances and atomic weight, are still lacking. In this study, we report the first independent measurements of all tungsten isotope ratios in five commercial tungsten reagents, including the new NRC candidate isotopic reference material WOLF-1 by MC-ICP-MS with use of the-state-of-the-art optimized regression mass bias correction model and NIST SRM 989 isotopic rhenium as calibrator. Image 1 • First calibrated measurements for the isotopic composition of tungsten. • Results of isotopic composition of tungsten are traceable to the SI. • Mass-independent isotopic fractionation was observed for tungsten isotopes of 180W, 182W and 183W in MC-ICP-MS. • Instrumental isotope fractionation law must be validated for each isotope system prior to its use in MC-ICP-MS. [ABSTRACT FROM AUTHOR]

Total evaporation thermal ionization mass spectrometry (TE-TIMS) has gradually gained recognition and application in the fields of nuclear industry, environment, geology and metrology due to its advantages including small sample dosage, good reproducibility, high accuracy and theoretically mass bias free nature. Due to the low thermal ionization efficiency and imperfect ion transmission, the establishment of TE-TIMS needs four prerequisites. Firstly, the ionization efficiency should be constant throughout the TE process. Secondly, the ion transmission efficiency should be constant throughout the TE process. Thirdly, the detection probability should be consistent for different isotopes. Fourthly, the ion loss before TE analysis should be negligible compared with the total signal. However, in practical, these prerequisites are difficultly satisfied completely, resulting in measurement uncertainty. In order to obtain more accurate TE-TIMS results, several improvements have been made during the last two decades, including introducing regular interruptions during TE process for ion-beam re-focusing, peak centering and peak tailing correction, combining with other mature methods, improving detector sensitivity, and establishing perfect uncertainty evaluation procedure, etc. In this review, the principle and the technical characteristics of TE-TIMS were introduced. Then, the methodology developments of TE-TIMS and its applications in nuclear industry, environment, geology and metrology were summarized. Finally, the development tendency of TE-TIMS was prospected. [ABSTRACT FROM AUTHOR]

Determination of the ratios of natural stable isotopes (13C/12C and 15N/14N) in unfed Ixodes ricinus nymphs and adults, which, in their previous stage, fed on captive wild rodents (Apodemus sylvaticus and Myodes glareolus), wild birds (Parus major and Cyanistes caeruleus) or domestic ruminants (Ovis aries and Bos taurus), demonstrated that it is possible to identify each host category with confidence. First, the tick–blood spacing, which is the difference between values obtained from ticks and the blood of hosts that they had fed on in the previous stage, was consistent (152 spacings investigated from 15 host individuals in total). Second, potential confounding factors (tick age and sex) did not affect the discriminatory power of the isotope patterns, nor did different rearing conditions (room temperature vs. 4 °C) or the duration of development (maximum of 430 days). The findings that the tick–blood isotope spacings, across a diverse range of hosts, were similar and predictable, and that confounders had little or no effect on this, strongly support the usage of the isotope approach. Because each of the host categories has a different role in the population dynamics of I. ricinus and in tick‐borne pathogen ecology, the method described here has great potential for the clarification of tick and tick‐borne pathogen ecology in the field. [ABSTRACT FROM AUTHOR]

The goal of this research was to assess the potential of Sr and Pb composition and also isotopic signature of lead (207Pb/206Pb, 208Pb/206Pb and 204Pb/206Pb), strontium (87Sr/86Sr) of wines from Bujoru, Smuli and Oancea wine-growing centers from Dealu Bujorului vineyard. In this study 162 wine samples were investigated. The wine samples were obtained from micro-wine production under conditions of 2014-2016 from Dealu Bujorului vineyard. For all tested wine samples, the toxic metals contents were found in quantities below the limits established by legislation. The highest values were registered to wine obtained from Feteasca Neagra(2016) variety (0.74275±0.00261) from Smul?i wine-growing center, the lowest value of 87Sr/86Sr isotope ratio was recorded to wine obtained from Muscat Ottonel (2014) variety (0.70165±0.00058) Oancea wine-growing center. A possible explanation for the higher mean of 87Sr/86Sr isotopic ration for wine can be the mineral consistency of the vineyard soil and its different eco-climatic conditions. Regarding 206Pb/207Pb isotopic ratios, we can say that the analyzed wine samples show shows traces of pollution comes from cars (automobile emissions) (if 206Pb/207Pb=1.1000-1.1400 [automobile emissions]). The Pb isotope ratio from wines varies in range between 1.12305-1.18597 (206Pb/207Pb), 2.09404-2.14190 (208Pb/206Pb) and 17.21089-17.70857 (206Pb/204Pb) with average 1.15202 (206Pb/207Pb), 2.10878 (208Pb/206Pb) and 17.42240 (206Pb/204Pb). Heat map was discovered a separation of wine varieties for white of this red depending on elemental contents and 206Pb/207Pb, 208Pb/206Pb, 206Pb/204Pb, 87Sr/86Sr isotope ratios. [ABSTRACT FROM AUTHOR]

Abstract A two-parameter modeling formula is proposed for quadrupole ICP-MS (ICP-QMS) data, which corrects for nonlinearity with a "dead-time" function and makes subsequent weighted mass-bias corrections to normalize isotope ratio data to pertinent isotopic reference materials. The methodology improves the short-term and long-term precision as well as accuracy of the measurements. Applying the model to isotopes spanning a wide mass range revealed that values for the parameters describing nonlinearity and mass bias do not conform to expectations based on conventional interpretation. Within a single analysis run for a specific element, nonlinearity and mass-bias corrections can be evaluated to very tight tolerances and the model fits the data to within a few parts per thousand. However, in a different run or with a different element, the values of the parameters might change. A comprehensive strategy for conducting measurements of isotope ratios or trace-element concentrations is described, which takes advantage of the model's strengths and accommodates the observed run-to-run variations. Supporting data is presented to demonstrate improved precision and accuracy with the widely available ICP-QMS system. Graphical abstract Unlabelled Image Highlights • Mass bias was shown to not be a smooth function of isotope ratio reference mass. • Nonlinearity was shown to vary between analyses. • Run-by-run nonlinearity and mass bias corrections can result in substantial improvements to precision. [ABSTRACT FROM AUTHOR]

BACKGROUND The production of 'Polish Vodka' is restricted by law to the ethyl alcohol of agricultural origins obtained from rye, wheat, barley, oat, triticale and potatoes grown on the territory of the Republic of Poland. The current labeling system should guarantee that the spirit is authentic and of good quality but not all producers are honest. Unfortunately, authentic 'Polish Vodka' is the most often counterfeited by the addition of cheaper and more accessible maize spirits. These illegal practices significantly reduce costs of the spirit production. Therefore, determination of the botanical origin of alcohol in Poland is highly relevant. RESULTS: Quantitative 2H nuclear magnetic resonance and isotope ratio mass spectrometry were used to investigate the authenticity of 30 samples of Polish spirits. Several isotopic parameters were used to determine the botanical origin of 10 unknown samples. Both approaches led to the same conclusions regarding the percentage of maize‐derived ethanol addition. CONCLUSIONS: Applied techniques are a valuable tool in the fight against counterfeiting of products. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Contamination of vineyard soils with heavy metals has been a worldwide problem, determination of these metals it is important for the wine industry. The aim of this research was to determine the concentration of different heavy metals (Cd, U, Hg, As, Co, Cu, Ni, Cr, Mn, Pb and Sr) isotopic signature of lead (207Pb/206Pb, 208Pb/206Pb and 204Pb/206Pb) and strontium (87Sr/86Sr) from Bujoru, Smulti and Oancea wine-growing centers from Dealu Bujorului vineyard and to assess their ability to discriminate between geographical origin of wines. In this study 180 soils samples from Dealu Bujorului vineyard were investigated. The determination of metals from soil samples was performed on mass spectrometer with inductively coupled plasma, (ICP-MS) iCAP Q Thermo scientific model. In case of Cd (1 mg/kg), Pb (20 mg/kg), Hg (0.1 mg/kg), As (5 mg/L), Co (15 mg/kg), Ni (20 mg/kg) and Cr (30 mg/kg) metals in analysed in soil samples were under Maximum Permissible Limits (MPL). Cu concentration in the soil exceeds the maximum admissible limit (20 mg/kg) having the average value of 415.40 mg/kg, this value is a common one for vineyards soils. Our results confirm that the 207Pb/206Pb, 208Pb/206Pb, 204Pb/206Pb and 87Sr/86Sr isotope ratio can be used to track the geographical origin of wine. [ABSTRACT FROM AUTHOR]

Information on the Cu speciation in blood serum can be valuable for a better understanding of the metabolism of this essential transition metal, but Cu speciation analysis and, to an even larger extent, compound-specific high-precision Cu isotopic analysis are challenging. In this work, quantification and isotopic analysis of Cu were carried out in bulk serum and in both its exchangeable + ultrafiltrable (EXCH + UF) Cu fraction and its non-exchangeable + non-ultrafiltrable (NEXCH + NUF) fraction using quadrupole and multi-collector ICP-mass spectrometry, respectively. The EXCH + UF serum Cu represents the labile Cu pool, i.e. Cu loosely bound to proteins, such as albumin, alpha-2 macroglobulin and other low molecular weight compounds, while the NEXCH + NUF serum Cu contains the Cu firmly bound to ceruloplasmin (Cp). The method was evaluated using human, goat and fetal bovine serum and applied to serum samples from assumed healthy subjects and from patients with alcoholic liver cirrhosis (AC). The healthy subjects showed an isotopic composition of EXCH + UF serum Cu heavier (by on average + 0.4‰) than that of their total serum Cu. In general, patients with AC showed higher EXCH + UF serum Cu concentrations and significantly lower δ 65 Cu EXCH+UF and δ 65 Cu serum values than did healthy subjects. Within the AC population, δ 65 Cu EXCH+UF values were comparable to or lower than the corresponding δ 65 Cu serum values, potentially reflecting the extent of labile Cu deregulation. As to be expected, the NEXCH + NUF serum Cu isotopic composition was similar to that of the total serum Cu, as most of the serum Cu is firmly bound to Cp. [ABSTRACT FROM AUTHOR]

The capabilities of Cu isotope ratio measurements are often restricted by the small volumes of sample available and/or their low Cu concentration. In this work, an analytical approach was developed for performing Cu isotopic analysis via multi-collector ICP-mass spectrometry (MC-ICP-MS) at ultra-trace level using Ga as an internal standard for mass bias correction. The minimum concentration of Cu required for accurate and precise isotope ratio measurements was established to be 20 μg L −1 with wet plasma conditions and 5 μg L −1 with dry plasma conditions. The use of Ga as an internal standard for mass bias correction provided several advantages compared to Ni, i.e. improved internal precision on δ 65 Cu values and lower blank levels. Ga can also be used at a 4-fold lower concentration level than Ni. However, in wet plasma conditions, the signals of 36 Ar 16 O 2 1 H + and 40 Ar 15 N 16 O + interfered with the signals of 69 Ga + and 71 Ga + , respectively, while in dry plasma conditions, realized by the use of a desolvation unit, 69 Ga + suffered from spectral interference from 40 Ar 14 N 2 1 H + . These interferences were resolved by using medium mass resolution. For validation purposes, the approach was applied to commercially available blood and serum samples. The δ 65 Cu values for the samples measured at a concentration level of 5 μg L −1 Cu and 5 μg L −1 Ga using dry plasma conditions were in good agreement with those obtained for isotope ratio measurements at the “standard” concentration level of 200 μg L −1 Cu and 200 μg L −1 Ni using wet plasma conditions. In addition, the δ 65 Cu values obtained for micro-samples of serum/blood (volume of 100 µL) were in good agreement with the corresponding ones obtained using the “standard” volume for isotopic analysis (500 μL). [ABSTRACT FROM AUTHOR]

In this paper, a simple analytical procedure was developed to measure americium isotope ratios and concentration with high accuracy. The method was tested during the participation in a round robin test organized by the Analytical Methods Committee of the French Atomic Energy Commission. The measurements were performed by Thermal Ionization Mass Spectrometry using the total evaporation method, which is a reference technique for determining actinide isotopic compositions. Expanded uncertainties were estimated at 0.1% and 0.8% for the 241 Am/ 243 Am isotope ratio and the Am concentration, respectively. Compared to the assigned value, biases below 0.0001% and 0.02% were calculated for the 241 Am/ 243 Am isotope ratio and the Am concentration, respectively. [ABSTRACT FROM AUTHOR]

NMR is a primary method of measurement that provides quantitative traceable results without the need for a standard of the same measurand. Despite the advantages of the 1 H nucleus, such as high sensitivity, short relaxation times and widespread distribution in organic compounds, some molecules present only labile H atoms, or the 1 H peaks of a sample may overlap with impurities. With the CHORAD scheme – a combination of the pulse sequence CHORUS and adiabatic modulation for 1 H decoupling – this study has shown that 13 C NMR can be used for quantitative analyses with a bias smaller than 2% and expanded uncertainty of 0.7% (for a confidence level of 95%). Since 13 C is found with significant non-statistic isotope fractionation, all the peaks of the sample and internal standard should be integrated and their bulk 13 C abundances obtained by isotope ratio mass spectrometry (IRMS) must be considered to meet quantitative requirements. Future experimental work may be performed to test this procedure for complex matrix samples. This approach also proved to be suitable for studies of site-specific 13 C distribution and led to better heteronuclear decoupling when compared with the use of adiabatic decoupling with ordinary hard 90° pulses, a combination extensively reported in the literature over the last decade. An examination of the molecules studied in this work and others from the literature revealed an overall trend in the 13 C intramolecular profile – hydrogen-containing positions are often 13 C-depleted. A potential contribution of 1 J CH coupling to these results is discussed. [ABSTRACT FROM AUTHOR]

Mercury forms potent toxic compounds, which cause irreversible damage to the central nervous system, while selenium, if present in an adequate concentration, is an essential micronutrient needed for the regulation of metabolic processes. The interactions between mercury and selenium have been rigorously scrutinized particularly due to observed protective effects of selenium against mercury toxicity, however very few proposed mechanisms are supported by empirical data. With mercury concentrations steadily rising in the environment, this matter is of urgency, and pushes for the development of new sample preparation protocols and analytical techniques. Softer extraction methods should preserve the true chemical species, while a combination of chromatographic and direct analytical techniques enable identification and quantitation. This review summarizes the state of the art of current analytical techniques, which focus on the interactions between mercury and selenium in biological matrices and outlines the future trends that might fill major gaps in our analytical capabilities. [ABSTRACT FROM AUTHOR]

Conditions of chemical separation of Al macroamounts and U microamounts, followed by atomic emission spectroscopic determination of the isotope composition and gravimetric content of U, were studied. An algorithm was developed for constructing calibration plots to determine the 235U/238U isotope ratio in various samples from nuclear fuel reprocessing. Optimum conditions of the spectral analysis for the U content were found by mathematical design of the experiment: NaCl content 2%, current 18 А, and exposure time 40 s. With the use of these conditions and of a specially developed form of carbon electrode, the uranium detection limit was decreased from 10-3 to 10-5%. [ABSTRACT FROM AUTHOR]

Molecular diffusion is a key transport process for noble gases in water. Such diffusive transport is often thought to cause a mass-dependent fractionation of noble gas isotopes that is inversely proportional to the square root of the ratio of their atomic mass, referred to as the square root relation. Previous studies, challenged the commonly held assumption that the square root relation adequately describes the behaviour of noble gas isotopes diffusing through water. However, the effect of diffusion on noble gas isotopes has only been determined experimentally for He, Ne and Ar to date, whereas the extent of fractionation of Kr and Xe has not been measured. In the present study the fractionation of Kr and Xe isotopes diffusing through water immobilised by adding agar was quantified through measuring the respective isotope ratio after diffusing through the immobilised water. No fractionation of Kr and Xe isotopes was observed, even using high-precision noble gas analytics. These results complement our current understanding on isotopic fractionation of noble gases diffusing through water. Therefore this complete data set builds a robust basis to describe molecular diffusion of noble gases in water in a physical sound manner which is fundamental to assess the physical aspects of gas dynamics in aquatic systems. [ABSTRACT FROM AUTHOR]

Abstract: The evaluation of intramolecular 2H or 13C isotopic composition of vanillin by liquid‐state nuclear magnetic resonance (NMR) is an illustrative example of the analytical challenges associated with molecular authenticity/traceability investigations in food products, and the determination/understanding of metabolic/synthetic pathways. Although isotopic ratio monitoring by 13C NMR (irm‐13C NMR) provides a valuable new source of isotopic information, the analysis of position‐specific (2H/1H) isotopic fractionation of vanillin remains incomplete because of the overlap of two aromatic 2H resonances, and the impossibility of separating these fortuitous isochronous nuclei by isotropic NMR. Exploiting the analytical potential of 2H 2D‐NMR in media containing polypeptide‐based liquid crystals, we show that all aromatic monodeuterated isotopomers can be spectrally discriminated on the basis of 2H residual quadrupolar couplings, ΔνQ(2H), thus enabling the determination of their relative proportions for the first time. After discussing the multiple relevant cofactors leading to the best discrimination and optimization of experimental conditions for reliable quantitative measurements by anisotropic 2D‐NMR, a comparative analysis of six vanillin samples from diverse origins is reported. How the 2H distribution might relate to the biosynthesis of vanillin is discussed. [ABSTRACT FROM AUTHOR]

Isotope ratio analysis has been shown to discriminate samples of forensic interest and to link many synthesized and natural materials to their precursors when traditional chemical and physical analyses cannot. Successful application of stable isotope analysis to chemicals of interest requires a background of likely variations in stable isotope ratios; often, this background population can be generated from analysis of possible precursors and the relationships of stable isotopes of precursor(s) to product(s), which may depend on synthesis techniques. Here we measured the carbon ( 13 C/ 12 C) and hydrogen ( 2 H/ 1 H) isotope ratios of the oft-illicitly manufactured explosive triacetone triperoxide, TATP, and one of its precursors, acetone. As acetone is the sole source of carbon and hydrogen to TATP, a survey of acetone from 12 countries was conducted to explore the breadth of 13 C/ 12 C and 2 H/ 1 H variation in the precursor, and therefore, its product. Carbon and hydrogen isotope ratios were measured using continuous flow isotope ratio mass spectrometry (IRMS) techniques. We observed greater ranges in both C and H isotope ratios of acetone than previously published; we also found that country-of-purchase was a large contributing factor to the observed variation, larger than acetone grade and brand. Following clandestine production methods, we observed that the stable isotope ratios of TATP retained the stable isotope signatures of acetone used in synthesis. We confirmed the robustness of TATP carbon isotope ratios to both recrystallization and time-dependent sublimation, important considerations when faced with the task of practical sampling of potential unexploded TATP from a crime scene. [ABSTRACT FROM AUTHOR]

A number of innovative methodologies are currently employed to analyse soil organic matter (SOM). In this review we outline three such methods; (1) Elemental analysis coupled to Isotope ratio mass spectrometry (EA-IRMS), which provides representative data for the elemental composition and isotopic signature of a sample; (2) Pyrolysis − gas chromatography coupled to mass spectrometry (Py-GCMS), a method in which the sample is heated to decomposition to produce smaller molecules which are separated and detected; (3) Nuclear magnetic resonance spectroscopy (NMR), a technique for atomic and molecular level structure elucidation. We also present some of the most recent works employing these techniques and discuss the suitability of the methods. [ABSTRACT FROM AUTHOR]

A new dual-beam atomic absorption technique is applied to laser-induced plasmas. The technique uses an optical parametric oscillator pseudocontinuum, producing emission that is both wider than the absorption line profile, but narrow enough to allow the use of an echelle spectrograph without order sorting. The dual-beam-in space implementation makes the technique immune to nonspecific attenuation of the probe beam and the structure of the pseudocontinuum. The potential for plasma diagnostics is demonstrated with spatially and temporally resolved measurements of magnesium metastable and lithium ground state optical depths in a laser-induced plasma under reduced pressure conditions. The lithium measurements further demonstrate the technique's potential for isotope ratio measurements. [ABSTRACT FROM AUTHOR]

Geographical wine traceability is an important topic in the context of wine authentification. Therefore, many researchers have addressed this subject by developing different methodologies based on multivariate analysis of organic and inorganic parameters and also by isotopic signature. The goal of this research was to assess the potential of elemental composition and isotopic signature of lead (207Pb/206Pb, 208Pb/206Pb, 204Pb/206Pb) and strontium (87Sr/86Sr) of wines from three Romanian vineyards, in order to highlight reliable markers for wine geographical origin. The ICP-MS method was used for the concentration determination for 30 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, In, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Tl, V, U, Zn, Hg). In this study 10 wines (2 red and 8 white) obtained from 'Merlot', 'Fetească neagră', 'Fetească albă', 'Fetească regală', 'Băbească gri', 'Şarba', 'Aligoté', 'Sauvignon blanc', 'Muscat Ottonel', 'Italian Riesling' cultivars were investigated. The wine samples were obtained from micro-wine production under conditions of 2014, 2015, 2016 from Dealu Bujorului, Murfatlar and Ştefăneşti-Argeş vineyards. The high level of K (148.66±5.41-633.74±4.13 mg/L), Mg (88.23±0.84-131.66±3.42 mg/L), Ca (49.84±1.22-89.18±2.34) and Fe were observed in the wine samples analysed. Heavy metals like Hg, Pb, As and Cd (10.2-315 μg/L) were found below acceptable limits. Concentration of Na (1 mg/L), Cu (1 mg/L), As (0.2 mg/L), Cd (0.01 mg/L), Zn (5 mg/L) and Pb (0.15 mg/L) metals in analysed wine samples were under Maximum Permissible Limits (MPL), respectively as published by the Organization of Vine and Wine. The variation of the 207Pb/206Pb, 208Pb/206Pb, 204Pb/206Pb and 87Sr/86Sr ratio and K/Rb, Ca/Sr of the investigated wine clearly demonstrated that these variables are suitable traces for wine geographical origin determination. The proposed methodology allowed a 100% successful classification of wines according to the region of provenance. [ABSTRACT FROM AUTHOR]

The ion source of a thermal ionization mass spectrometer (TIMS) has been designed to enhance the source sensitivity by modifying the geometry of extraction lens. Computer simulation studies on different combinations of the electro-static lens components and experimental validations were carried out. This also involved designing a robust triple filament assembly in a home-built TIMS. A good agreement between the simulated and experimental results, led to overall improvements in terms of the consistency of the source performance, a higher through put and an overall sensitivity enhancement by a factor of two. [ABSTRACT FROM AUTHOR]

In this study, stable isotope signatures (δ13C, δ15N, and δD) of both tea leaves and tea infusions were investigated to identify the geographical origin of Turkish domestic and imported tea samples. Sixteen domestic tea samples collected from different locations in the Black Sea Region, which produces almost 100% of tea in Turkey, and 11 imported tea samples (Kenya, India, Sri Lanka, Indonesia, and China) purchased from importers were studied. δ13C, δ15N, and δD in the samples were determined using isotope ratio mass spectrometry (IR-MS). δ13C in the samples ranged from −29.18 ± 0.01 to −25.7 ± 0.2, while δ15N ranged between 1.1 ± 0.2 and 5.2 ± 0.8. However, δD in the samples were found to be in the range from 56.5 ± 0.3 to 72 ± 1. The classifications of the tea samples into domestic and imported tea samples were achieved with 100% accuracy using multivariate statistical analyses (principal component analysis, PCA, and hierarchical cluster analysis, HCA). In conclusion, the domestic tea samples had a distinctive isotopic fingerprint and the isotopic ratios used in the study can be significant predictors in determination of the geographical source of Turkish tea. [ABSTRACT FROM AUTHOR]

Several technologies are being developed to examine the intramolecular isotopic structures of molecules (i.e., site-specific and multiple substitution), but limitations in sample size and type or (for mass spectrometry) resolution have so far prevented the creation of a general technique. We have now demonstrated the capacity for precise and accurate study of molecular isotopic contents and structures by Fourier transform mass spectrometry, using instruments containing a Thermo Scientific™ Orbitrap™ mass analyzer, here the Thermo Scientific Q Exactive GC™ and Q Exactive HF™ instruments. Orbitrap mass analyzers achieve mass resolutions in the range ∼250,000–1 M (FWHM) in the mass range of greatest interest to studies of molecular isotopic structure, 50–200 amu. This allows for resolution of many nearly isobaric interferences for compounds containing H, C, N, O and/or S. In this paper we show that internal and external experimental reproducibilities of isotope ratio analyses using the Orbitrap analysis can conform to shot-noise limits down to levels of tenths of per mil (1SE), with similar accuracy when standardized to reference materials. Precision reaches ±0.015‰ for exceptionally long integrations. Such measurements do not call for modifications to the ion optics of the Q Exactive instruments, but do require specially designed sample introduction devices to permit sample/standard comparison and long integration times. The sensitivity of the Q Exactive instruments permit analysis of sub-nanomolar samples and quantification of multiply-substituted species. Site-specific capabilities arise from the fact that mass spectra of molecular analytes commonly contain diverse fragment ion species, each of which samples a specific sub-set of molecular sites. [ABSTRACT FROM AUTHOR]

Heroin manufacturing and distribution by criminal and terrorist organizations produce illicit economic benefits from the opium and heroin trade and result in devastating societal problems. Heroin chemical signatures provide important information to law enforcement and the intelligence community in order to combat the national and international heroin epidemic. Authentic (known origin) heroin samples from Southeast Asia (SEA), Southwest Asia (SWA), South America (SA) and SA-like heroin manufactured in Mexico (MEX-SA), were prepared for chemical analysis by microwave-assisted acid digestion. Strontium concentration data were acquired using inductively-coupled plasma mass spectrometry (ICP-MS). The samples having sufficient [ 88 Sr] (1.25 µg/g in the solid sample) were purified by ion exchange resin and strontium isotope ratio ( 87 Sr/ 86 Sr) values were measured using multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS). South American and MEX-SA heroin samples are presently the most challenging regions to differentiate by analysis of their organic compositions. The SA and MEX-SA heroin samples were correctly classified 82% and 77% of the time, respectively, when the 87 Sr/ 86 Sr values of individual authentic samples were compared to the overall mean values from the four regions. This is the first reporting on the use of 87 Sr/ 86 Sr analysis of heroin for the profiling of samples from specific geographic regions. In addition, a value of 87 Sr/ 86 Sr for the National Institute of Standards and Testing’s standard reference material NIST SRM 1570a (spinach leaves) of 0.70905 ± 0.00002 (95% confidence interval, n = 3) is also reported for the first time. [ABSTRACT FROM AUTHOR]

Establishing the geographical origin of wines is an issue of major concern for countries around the world, in order to protect quality of wine in case of false statements regarding their geographical origin. The goal of this research was to assess the potential of elemental composition and isotopic signature of lead (207Pb/206Pb, 208Pb/206Pb and 204Pb/206Pb) and strontium (87Sr/86Sr) of wines from three Romanian vineyards, in order to highlight the reliable markers for Italian Riesling geographical origin of wines. In this study 33 white wines obtained from Italian Riesling cultivars were investigated. The wine samples were obtained from micro-wine production under conditions of 2006-2016 from Dealu Bujorului vineyard. The high concentration of K (176.09±3.09-514.03±0.72 mg/L), Mg (82.42±1.20-122.14±2.47 mg/L), Ca (30.39±1.50-77.45±1.97) and Fe were observed in the wine samples analysed. Heavy metals like Hg (16 μg/L), Pb (42.53 μg/L), As (13.02 μg/L) and Cd (0.08 μg/L) were found below acceptable limits. Concentration of Na (1 mg/L), Cu (1 mg/L), As (0.2 mg/L), Cd (0.01 mg/L), Zn (5 mg/L) and Pb (0.15 mg/L) metals in analysed wine samples were under Maximum Permissible Limits (MPL), respectively as published by the Organization of Vine and Wine. The variation of the 207Pb/206Pb, 208Pb/206Pb, 204Pb/206Pb and 87Sr/86Sr isotopic ratio of the investigated wine clearly demonstrated that these variables are suitable traces for wine geographical origin determination. [ABSTRACT FROM AUTHOR]