Aerosol source (biomass,traffic and coal emission) apportionment in Lithuania using stable carbon and radiocarbon analysis*

In the present study, a combination of the stable carbon isotope ratio (¹³C/¹²C) with radiocarbon data (¹⁴C) allowed us to perform the aerosol source apportionment. Filter samples of PM₁ were collected during the warm and cold periods in rural and urban sites in Lithuania. The ¹⁴C/¹²C ratio of total carbon (TC) was measured using the single stage accelerator mass spectrometer quantifying of fossil and non-fossil derived aerosol emissions. The δ¹³C value was measured using an elemental analyser interfaced with an isotope ratio mass spectrometer. We have found that the highest fraction of contemporary carbon (f_c?=?0.82) was measured during a warm period in a rural location. A higher fraction of fossil fuel-derived carbon was observed for air masses transported from highly industrialized Western European regions during both seasons. Isotope mass balance calculations revealed that the traffic emissions composed 15 and 25?% in rural and urban sites, respectively, and did not change during either season. Input from coal-derived aerosol particles was estimated to be 15?% at an urban site during the cold period. The combination of the stable carbon isotope ratio with the radiocarbon data allowed us to distinguish coal, liquid fossil fuel combustion, and non-fossil derived aerosol particle emissions.     

Stable isotope mass balances versus concentration differences of dissolved inorganic carbon – implications for tracing carbon turnover in reservoirs

The aim of this study was to identify sources of carbon turnover using stable isotope mass balances. For this purpose, two pre-reservoirs in the Harz Mountains (Germany) were investigated for their dissolved and particulate carbon contents (dissolved inorganic carbon (DIC), dissolved organic carbon, particulate organic carbon) together with their stable carbon isotope ratios. DIC concentration depth profiles from March 2012 had an average of 0.33 mmol L^–1. Increases in DIC concentrations later on in the year often corresponded with decreases in its carbon isotope composition (δ¹³C_DIC) with the most negative value of –18.4?‰ in September. This led to a carbon isotope mass balance with carbon isotope inputs of ?28.5?‰ from DOC and ?23.4, ?31.8 and ?30.7?‰ from algae, terrestrial and sedimentary matter, respectively. Best matches between calculated and measured DIC gains were achieved when using the isotope composition of algae. This shows that this type of organic material is most likely responsible for carbon additions to the DIC pool when its concentrations and δ¹³C_DIC values correlate negatively. The presented isotope mass balance is transferable to other surface water and groundwater systems for quantification of organic matter turnover.     

Non-linear dynamics of stable carbon and hydrogen isotope signatures based on a biological kinetic model of aerobic enzymatic methane oxidation

The non-linear dynamics of stable carbon and hydrogen isotope signatures during methane oxidation by the methanotrophic bacteria Methylosinus sporium strain 5 (NCIMB 11126) and Methylocaldum gracile strain 14 L (NCIMB 11912) under copper-rich (8.9 µM Cu²⁺), copper-limited (0.3 µM Cu²⁺) or copper-regular (1.1 µM Cu²⁺) conditions has been described mathematically. The model was calibrated by experimental data of methane quantities and carbon and hydrogen isotope signatures of methane measured previously in laboratory microcosms reported by Feisthauer et al. [1 Feisthauer S, Vogt C, Modrzynski J, Szlenkier M, Krüger M, Siegert M, Richnow HH. Different types of methane monooxygenases produce similar carbon and hydrogen isotope fractionation patterns during methane oxidation. Geochim Cosmochim Acta. 2011;75:1173–1184. doi: 10.1016/j.gca.2010.12.006[Crossref], [Web of Science ®] , [Google Scholar]] M. gracile initially oxidizes methane by a particulate methane monooxygenase and assimilates formaldehyde via the ribulose monophosphate pathway, whereas M. sporium expresses a soluble methane monooxygenase under copper-limited conditions and uses the serine pathway for carbon assimilation. The model shows that during methane solubilization dominant carbon and hydrogen isotope fractionation occurs. An increase of biomass due to growth of methanotrophs causes an increase of particulate or soluble monooxygenase that, in turn, decreases soluble methane concentration intensifying methane solubilization. The specific maximum rate of methane oxidation υ_m was proved to be equal to 4.0 and 1.3 mM mM^?1 h^?1 for M. sporium under copper-rich and copper-limited conditions, respectively, and 0.5 mM mM^?1 h^?1 for M. gracile. The model shows that methane oxidation cannot be described by traditional first-order kinetics. The kinetic isotope fractionation ceases when methane concentrations decrease close to the threshold value. Applicability of the non-linear model was confirmed by dynamics of carbon isotope signature for carbon dioxide that was depleted and later enriched in ¹³C. Contrasting to the common Rayleigh linear graph, the dynamic curves allow identifying inappropriate isotope data due to inaccurate substrate concentration analyses. The non-linear model pretty adequately described experimental data presented in the two-dimensional plot of hydrogen versus carbon stable isotope signatures.     

Stable isotope ratio method for the characterisation of the poultry house environment

Stable isotope analysis was applied to describe the poultry house environment. The poultry house indoor environment was selected for this study due to the relevant health problems in animals and their caretakers. Air quality parameters including temperature, relative humidity, airflow rate, NH₃, CO₂ and total suspended particles, as well as mean levels of total airborne bacteria and fungi count, were measured. Carbon isotope ratios (¹³C/¹²C) were obtained in size-segregated aerosol particles. The carbon (¹³C/¹²C) and nitrogen (¹⁵N/¹⁴N) isotope ratios were measured in feed, litter, scrapings from the ventilation system, feathers and eggs. Additionally, the distribution of δ¹³C and δ¹⁵N values in different tissues of the chicken was examined. The airborne bacteria and fungi extracted from the air filters collected from poultry farms were grown in the laboratory in media with known isotope values and measured for stable isotope ratios. Analysis of isotope fractionation between microorganisms and their media indicated the applicability of stable isotope analysis in bulk samples for the identification of source material. The analysed examples imply that stable isotope analysis can be used to examine the indoor environment along with its biology and ecology, and serve as an informative bioanalytical tool.     

Stable isotope determination of ester and ether methyl moieties in plant methoxyl groups

Plant methoxyl groups of lignin and pectin have both distinct stable hydrogen isotope (δ²H) and carbon isotope (δ¹³C) values that can be used for studying environmental processes and for investigating the origin and authenticity of biomaterials. Up to now, the reported methods have been applied only to determine isotope values of the bulk plant methoxyl pool. In this work, we have applied several methods to distinguish between stable isotope ratios of methoxyl groups of pectin and the bulk plant methoxyl pool. Our results demonstrate that by applying alkaline hydrolysis to specifically cleave off the ester methyl moiety (pectin-like), we can distinguish δ²H and δ¹³C values of the pectin methoxyl pool from the bulk methoxyl pool. No measureable isotope discrimination was observed either during sample preparation or during analytical measurement. Furthermore, using this method, no major isotope difference in either the hydrogen or carbon isotope signature of the methoxyl groups of plant pectin and bulk matter from plant species such as leaves from trees, apples, carrots and potatoes was noted. We show the methanol released during alkaline hydrolysis of plant material and subsequently treated with hydriodic acid to be an excellent procedure to measure specifically and precisely the δ¹³C and δ²H isotope values of plant pectin-like methoxyl groups. This method is particularly advantageous when plant matter with a low methoxyl content has to be analysed.     

Der [15N]Methacetin-Test als Parameter zur Differentialdiagnose des Cholestasesyndroms im Säuglingsalter

The effect of the number of carbon and chlorine atoms on carbon isotope fractionation during dechlorination of chlorinated alkanes by Xanthobacter autotrophicus GJ10 was studied using pure culture and cell-free extract experiments. The magnitude of carbon isotope fractionation decreased with increasing carbon number. The decrease can be explained by an increasing probability that the heavy isotope is located at a non-reacting position for increasing molecule size. The isotope data were corrected for the number of carbons as well as the number of reactive sites to obtain reacting-site-specific values denoted as apparent kinetic isotope effect (AKIE). Even after the correction, the obtained AKIE values varied (on average 1.0608, 1.0477, 1.0616, and 1.0555 for 1,2-dichloroethane, chloropentane, 1,3-dichloropentane and chlorobutane, respectively). Cell-free extract experiments were carried out to evaluate the effect of transport across the cell membrane on the observed variability in the AKIE values, which revealed that variability still persisted. The study demonstrates that even after differences related to the carbon number and structure of the molecule are taken into account, there still remain differences in AKIE values even for compounds that are degraded by the same pure culture and an identical reaction mechanism.     

Fractionation of Oxygen and Hydrogen Isotopes at the Hydrate Gas forming in the Sea Sediments

The paper gives data on isotope composition of interstitial and near-bottom waters sampled in a region of gas-hydrate formation in the Sea of Okhotsk. The studies shows that heavy isotope of oxygen and hydrogen is used in gas-hydrate formation, with the result that isotope composition of its constitution water constitutes δ¹⁸O = +1.99‰, δD = +23‰ relatively to SMOW. Formation of autogenic carbonates leads to isotope exchange with interstitial water wich, in turn, changes its primary isotope composition in the direction of increasing of O-18 content. The near-bottom waters are isotope-light relatively to the SMOW standard and to the mean isotope composition of interstitial water in the studied region of gas-hydrate spreading.     

142—146,148,150Nd+同位素位移的共线快离子束激光光谱学实验研究

原子光谱中,同位素位移是少数几个能够将原子物理学和原子核物理学这两个不同的物理学分支联系起来的课题之一.本文利用共线快离子束激光光谱学方法,测量了正一价钕离子所有7个稳定同位素(A=142—146,148,150)之间的能量位移.与已有的结果比较,测量精度提高了一个数量级 关键词： 同位素位移 快离子束激光光谱学     

87Sr/86Sr-Untersuchungen an Grundwässern des Berliner Urstromtales

From a sector within an extended Tertiary basin 21 groundwater samples as well as 3 rock samples of a Zechslein diapir were analysed for ⁸⁷Sr/⁸⁶Sr-ralio. As a tendency the isotope ratio of the dissolved strontium is decreasing with increasing depth and strontium content. Furthermore, strontium content and salinity are correlated. With two exceptions the isotope data are in the range between about 0.7080 and 0.7100. Significant differences in the strontium isotope composition were found between the Zechstein salts and the typical groundwaters. This shows, that the Zechstein diapir can not be the source of the higher salinity in parts of the groundwater system. The results are discussed.     

Isotope effect of the phonons mean free path in graphene by micro-Raman measurement

The isotope labeled graphene was synthesized in the concentration of ¹³C carbon atom in 1%, 25%, 50%, 75% and 99%. The isotope effect on the phonon behavior in graphene was investigated based on the micro-Raman analysis of ¹³C isotope labeled graphene samples. We found that the phonon scattering is affected by the isotopic carbon atom as a point defect. Based on the experiment results, the Klemens-Callaway model and uncertainty principle were used to obtain the mean free path of the G and D phonons. The results agree with the thermal conductivity measurement by non-contact optical method and with other theoretical calculations.     

Anthropogenic and solar forcing in δ13C time pattern of coralline sponges

We present the results of a re-analysis of a previously published carbon isotope data-set related to coralline sponges in the Caribbean Sea. The original interpretation led to the discrimination between a pre-industrial period, with a signal controlled by solar-induced climatic variations, followed by the industrial era, characterized by a progressive δ¹³C negative shift due to the massive anthropogenic carbon emissions. Our re-analysis allowed to extract from the raw isotopic data evidence of a solar forcing still visible during the industrial era, with a particular reference to the 88-year Gleissberg periods. These signals are related to slope changes in both the δ¹³C versus time and the δ¹³C versus carbon emission curves.     

Petrographic characterization and provenance determination of the white marbles used in the Roman sculptures of Forum Sempronii (Fossombrone,Marche, Italy)

The Roman municipium of Forum Sempronii (Fossombrone, Marche) was located along the ‘Via Consolare Flaminia’, in the stretch of road where it ran along the final sector of the valley of the River Metauro (Mataurus). The ancient colony of Forum Sempronii, which is cited by Strabo, Pliny, and Ptolemy, was found in the second century BC, probably on the site of an earlier community and its activity continued until the end of the fifth century AD. During ancient and more recent archaeological excavations, many fragments of coloured stones and marbles, and some white marble sculptures have been unearthed. In this paper, we report the results of the provenance identification of the white marbles used for the sculptures found in the archaeological site of Forum Sempronii and now displayed at the local archaeological museum. The determination of the source origin of the white marbles used for the sculptures has been established by mineralogical-petrographic and geochemical analyses. Microscopic study of thin sections together with carbon and oxygen stable isotope ratios indicate that more than one type of white marbles was used: Pentelikon, Lunense, and Thasian.     

Isotope Anomalies of Carbon,Hydrogen and Nitrogen in Peat from the Area of the Tunguska Cosmic Body Explosion (1908)

Abstract

Peat profiles from the area of the Tunguska explosion epicentre indicate significant carbon and hydrogen isotopic effects which are clearly associated with the zone of the 1908 “catastrophe”, and which cannot be attributed to any known terrestrial processes. We explain them with the presence of extraterrestrial matter similar to carbonaceous chondrites or, more probably, to cometary matter. Initial data on nitrogen content and its isotope composition are consistent with the assumption of acid rainfall following the passage and explosion of the Tunguska cosmic body, as is known to have occurred during the Cretaceous-Tertiary boundary.     

Chemical and Isotope Investigations in Dissolved Gases of a Meromictic Residual Lake

Abstract

Lake Hufeisen near Halle/Saale has been formed in an old mining pit. Its deepest part is trench shaped and filled with water of sodium chloride content. Due to the density difference strong mixing processes in this part of the water body are prevented all over the year (meromictic lake). Therefore anoxic conditions have been established and the organic matter of the lake sediments is converted to carbon dioxide and methane. Over a period of more than one year gas samples were collected from different water depths. The investigations of the chemical composition (mainly nitrogen, carbon dioxide and methane) and the carbon isotope ratios show different relationships for individual species. The results are discussed with respect to the behaviour of the gases in the water column and to the stability of the density stratification in the saline bottom water.     

应用气-质联机和同位素双标记技术对土壤微生物吸收有机氮的研究

土壤微生物对小分子有机氮的直接吸收和利用是目前微生物氮素营养研究的新方向。本研究通过气相色谱-质谱(GC-MS)对双标记氨基酸(13C,15N)的测定技术探讨土壤微生物对有机氮分子的直接吸收和利用。结果表明：加入土壤中的甘氨酸被微生物迅速利用,半衰期为2.9 h。培养4 h后在微生物体内检测到最大量的双标记甘氨酸(相当于甘氨酸加入量的10%),说明甘氨酸可以被微生物以完整分子形式所吸收。通过此手段也可检测到土壤溶液和微生物体内的单标记ａ-酮酸(双标记甘氨酸分解后的产物),但含量极少,说明加入的甘氨酸主要向微生物提供C源供其生命活动。本研究证明专性化合物同位素双标记手段结合氯仿熏蒸技术是检测微生物吸收小分子有机氮的有效手段。     

~(142—146,148,150)Nd~ 同位素位移的共线快离子束激光光谱学实验研究

原子光谱中 ,同位素位移是少数几个能够将原子物理学和原子核物理学这两个不同的物理学分支联系起来的课题之一 .本文利用共线快离子束 激光光谱学方法 ,测量了正一价钕离子所有 7个稳定同位素 (A =142— 146 ,148,15 0 )之间的能量位移 .与已有的结果比较 ,测量精度提高了一个数量级     

Evaluation of the performance of high temperature conversion reactors for compound-specific oxygen stable isotope analysis

In this study conversion conditions for oxygen gas chromatography high temperature conversion (HTC) isotope ratio mass spectrometry (IRMS) are characterised using qualitative mass spectrometry (IonTrap). It is shown that physical and chemical properties of a given reactor design impact HTC and thus the ability to accurately measure oxygen isotope ratios. Commercially available and custom-built tube-in-tube reactors were used to elucidate (i) by-product formation (carbon dioxide, water, small organic molecules), (ii) 2nd sources of oxygen (leakage, metal oxides, ceramic material), and (iii) required reactor conditions (conditioning, reduction, stability). The suitability of the available HTC approach for compound-specific isotope analysis of oxygen in volatile organic molecules like methyl tert-butyl ether is assessed. Main problems impeding accurate analysis are non-quantitative HTC and significant carbon dioxide by-product formation. An evaluation strategy combining mass spectrometric analysis of HTC products and IRMS ¹⁸O/¹⁶O monitoring for future method development is proposed.     

Microcombustion of ng Amounts of Carbon in Non-Volatile Materials for isotope Ratio Evaluation

Abstract

A novel microcombustion technique for carbon isotopic analysis of nanogram amounts of carbon in non-volatile materials based on isotope ratio monitoring (irm) mass spectrometry is described. Liquid or solid samples placed in a quartz sleeve are combusted at 1000°C in a continuous stream of helium and oxygen. CO₂ removed from the carrier gas stream by cryogenic trapping is transferred onto a GC column. Following GC separation, the CO₂ is transferred via an open split to the ion source of a gas isotope ratio mass spectrometer. Reproducibility for samples >25 nmol carbon is <1‰. Problems associated with blanks from various sources and with reproducible deposition of small sample amounts led to variable accuracy, which was dependent on the compound class being analysed. Minimum sample size was in the range from 5 to 10 nmol carbon. Measurements of dissolved organic carbon (DOC) of groundwater from Germany yielded consistent values of δ¹³C = -28.8‰.     

The isotope effect coefficient dependence on nonstoichiometry for single CuO layer superconductors

Considering that the variation of the critical temperature can be explained if the impurity potential acts only by the non-spin-flip part, in the presence of either a pure d-wave or anisotropic s-wave gap symmetry, and inserting the pair-breaking time dependence on temperature, we obtain a quantitative expression for the isotope effect coefficient as a function of measured critical temperature T_c maximal critical temperature T and degree of anisotropy of the energy gap. Our result predicts the achievement of a large range of values in for different ratios T/T_c. Introducing the dependence of the critical temperature and pair-breaking time on dopant content for a single Cu---O layer superconductors, we can describe the variation of the isotope effect coefficient with nonstoichiometry for these materials. The result for the case of anisotropic s-wave gap symmetry is in good agreement with the experimental data.     

低阶煤热解结构演化及与烷烃气碳同位素相关性的红外光谱

为了阐释煤热解过程中结构演化与烷烃气碳同位素的关系,进行了低阶煤在高压釜密闭体系下热解实验,分析热解烷烃气碳同位素组成;借助傅里叶红外光谱(FTIR)精细剖析了煤结构演化规律,构建了烷烃气碳同位素组成与结构演化的关系模型,揭示了热解烷烃气碳同位素变化的原因。结果显示在R_{o, max}＜1.3%之前的阶段,煤中脂链轻碳同位素被分馏出去而重碳同位素被留在长链中;当1.3%＜R_{o, max}＜2.0%时, 具有相对较重碳同位素组成脂链再进一步的断裂分解仍主导了烷烃气碳同位素变化,也即是R_{o, max}在2.0%之前的阶段,煤中脂链倾向性的裂解方式是烷烃气碳同位素变化的主要因素;此后(R_{o, max}＞2.0%)由于芳环缩聚和解体进程的加剧使得环内重碳物质得以释放进入烷烃气中,而导致其碳同位素组成迅速变重。热解烷烃气中甲烷和乙烷碳同位素组成与煤脂链结构演化呈现同步性特征,δ13C_CH4和δ13C_C2H6值可以作为煤脂链结构演化的敏感性指标。R_{o, max}=1.3%和2.0%是煤热解结构演化与烷烃气碳同位素组成关联性的重要节点。研究成果对探索煤生烃与结构演化的耦合关系及二次生烃机理有理论意义。