Carbon Isotope Ratio Analysis Research Articles

Revealing lost secrets about Yingpan Man and the Silk Road

Yingpan Man, is one of the most exquisitely preserved mummies found in the Xinjiang Uyghur Autonomous Region of China. Here links between Yingpan Man and the Silk Road are explored through a detailed isotopic and bioarchaeological investigation of his life history. Analytical techniques of carbon, nitrogen, and sulfur stable isotope ratio analysis on hair, teeth, muscle and bones as well as associated animal and plant remains, radiocarbon dating and starch grain analysis of dental calculus are presented to visualize never before seen aspects of Yingpan Man’s life, including: environment, breastfeeding and weaning practices, adolescent and adult diet, disease and nutritional status as well as season of death. Furthermore, in combination with a detailed review of his associated grave goods, this research examines the social status and identity of Yingpan Man, and demonstrates the profound impact and cultural fusion that the Silk Road had upon the peoples of Xinjiang and Eurasia.

Development and Validation of Gas Chromatography – Tandem Mass Spectrometry and Gas Chromatography – Isotope Ratio Mass Spectrometry Methods for Determining Volatile Organic Compounds and Isotope Ratio Analysis of Carbon and Hydrogen in Lavender Essential Oil

Development and Validation of Gas Chromatography – Tandem Mass Spectrometry and Gas Chromatography – Isotope Ratio Mass Spectrometry Methods for Determining Volatile Organic Compounds and Isotope Ratio Analysis of Carbon and Hydrogen in Lavender Essential Oil

Stable isotope ratio analysis of carbon to distinguish sialic acid from freshly stewed bird's nest products.

Freshly stewed bird's nest products are easily adulterated with exogenous synthetic sialic acid to enhance the grade of the products and sell at high prices. This paper identifies the carbon stable isotope characteristics of sialic acid from natural and commercially synthetic sources using stable isotope ratio mass spectrometry (IRMS). Specifically, an off-line pretreatment technique combined with on-line LC-IRMS was developed to accurately determine δ13C values of sialic acid in a freshly stewed bird's nest. This method has no obvious isotope fractionation and good reproducibility. EA-IRMS was used to determine the δ13C values of commercial sialic acid. The results showed that the δ13C values of sialic acid from natural and synthetic sources were -29.90% ± 0.42% and -16.26% ± 3.91%, respectively, with distinct carbon stable isotope distribution characteristics. By defining a δ13C threshold value of -28.54% for natural SA, additional commercial SA from a minimum of 10% can be identified. Therefore, δ13C was proposed as a suitable tool for verifying the authenticity of fresh stewed bird's nests on the market.

Analysis of Carbon and Hydrogen Stable Isotope Ratios of Phenolic Compounds: Method Development and Biodegradation Applications

Phenolic compounds are priority water pollutants of both natural and anthropogenic origins. Distinguishing the sources and degradation pathways of phenolic compounds in the environment is essential for sustainable water management. In this study, we have developed and validated methods based on gas chromatography–isotope ratio mass spectrometry for analysis of hydrogen and carbon isotope ratios of phenol and cresols. For carbon stable isotope analysis, solid-phase extraction was applied, whereas liquid–liquid extraction, followed by derivatization with trifluoroacetic anhydride, was used for hydrogen stable isotope analysis. The methods were verified in biodegradation experiments using p-cresol and phenol as substrates. Methyl group oxidation of p-cresol by Pseudomonas pseudoalcaligenes and Aromatoleum aromaticum resulted in the strong hydrogen (−76 ± 2 and −103 ± 2 mUr, respectively) and varying carbon isotopic fractionation (−2.1 ± 0.1 and −1.0 ± 0.1 mUr, respectively), leading to distinguishable two-dimensional plots for hydrogen versus carbon isotope ratios, indicating slightly different enzymatic reactions. For anaerobic phenol degradation by Desulfosarcina cetonica, the absence of hydrogen isotopic fractionation indicates adenosine triphosphate-dependent carboxylation as the initial step of the biodegradation pathway. The methods developed in this study are useful to detect biological degradation of phenolic compounds in highly contaminated aqueous environmental systems.

Multi-isotope evidence of population aggregation in the Natufian and scant migration during the early Neolithic of the Southern Levant

Human mobility and migration are thought to have played essential roles in the consolidation and expansion of sedentary villages, long-distance exchanges and transmission of ideas and practices during the Neolithic transition of the Near East. Few isotopic studies of human remains dating to this early complex transition offer direct evidence of mobility and migration. The aim of this study is to identify first-generation non-local individuals from Natufian to Pre-Pottery Neolithic C periods to explore the scope of human mobility and migration during the Neolithic transition in the Southern Levant, an area that is central to this historical process. The study adopted a multi-approach resorting to strontium (87Sr/86Sr), oxygen (δ18OVSMOW) and carbon (δ13C) isotope ratio analyses of tooth enamel of 67 human individuals from five sites in Jordan, Syria, and Israel. The isotope ratios point both to a significant level of human migration and/or mobility in the Final Natufian which is compatible with early sedentarism and seasonal mobility and with population aggregation in early sedentary hamlets. The current findings, in turn, offer evidence that most individuals dating to the Pre-Pottery Neolithic were local to their respective settlements despite certain evidence of non-locals. Interestingly, isotopic data suggest that two possible non-local individuals benefitted from particular burial practices. The results underscore a decrease in human mobility and migration as farming became increasingly dominant among the subsistence strategies throughout the Neolithic transition of the Southern Levant.

Detection of Adulterated Natural Sweeteners by Carbon Isotopic Ratio Analysis

Detection of Adulterated Natural Sweeteners by Carbon Isotopic Ratio Analysis

Compound specific isotope analysis (CSIA) of phthalates and non-targeted isotope analysis (NTIA) of SPE-extractable organic carbon in dilute aquatic environments

Isotope ratio analysis of total organic carbon (TOC) is well-established for the study of rivers, lakes, and oceans. Similarly, these aquatic systems are routinely surveyed to quantify natural and anthropogenic organic compounds and pollutants, including such things as pharmaceuticals, illicit drugs, and phthalates. We merged these two approaches to demonstrate compound specific isotope analysis (CSIA) on four phthalate esters and non-targeted isotope analysis (NTIA) on a gas chromatography isotope ratio mass spectrometry (GC-IRMS) platform. Water from the Rivers Foss and Trent and a waste-water treatment plant (WWTP) effluent was sampled, followed by solid phase extraction (SPE) and GC-IRMS. Di–ethyl hexyl phthalate (DEHP) concentration in the effluent was 0.20 µg/L while it was 0.22 µg/L and 0.14 µg/L in the Trent and Foss Rivers, respectively. CSIA δ 13C values for selected phthalates measured in river and effluent samples ranged from −24.3‰ to −28.8‰. NTIA returned over 100 compounds which in aggregate aligned well with published values for isotope analysis of TOC. NTIA demonstrated that the volatile SPE-extractable fraction of TOC has high heterogeneity with δ 13C from −26.8‰ to −44.3‰ for matched compounds in both rivers. GC-IRMS can be applied to dilute environmental systems using both compound specific and non-targeted strategies.

Stable carbon isotope ratio analysis of Philippine honeys for the determination of adulteration with C4 sugars

The Internal Standard Stable Carbon Isotope Ratio Analysis (ISCIRA) or AOAC 998.12 is a method for detecting honey adulteration using C4 sugars, such as cane and corn syrup. This method was developed and used mainly on European honeybees (Apis mellifera) and may not necessarily be applicable to honey produced by other bee species. In this study, the applicability of the ISCIRA method was validated for honeys produced by bees common to the Philippines, namely the native giant honeybees Apis breviligula, the stingless bee Tetragonula biroi, as well as Apis mellifera. Results show that authentic honeys from all three bee species collected across the Philippines (n = 14 for A. breviligula, 13 for T. biroi, and 11 for A. mellifera) displayed ISCIRA indices greater than − 1.0, validating the applicability of the ISCIRA method. Furthermore, removing suspended insoluble pollen from honey via centrifugation and filtration is not recommended as this additional step tends to shift the honey protein δ13C to a more positive value, potentially adding more leeway for C4 sugar adulteration. When the ISCIRA method was used for assessing adulteration in honey products available in the Philippine market, it was found that 12 of 16 (75%) local store-bought, 0 of 41 (0%) imported store-bought, and 64 of 74 (86.5%) local online-bought honey brands were adulterated with C4 sugars. Among the 76 adulterated honeys, 71 (93.4%) contain more than 78% apparent C4 sugar. These results demonstrate the need for stricter honey quality regulations and policies to protect the Philippines’ bee industry and its consumers.

Soil apparent electrical conductivity and must carbon isotope ratio provide indication of plant water status in wine grape vineyards

Proximal sensing is being integrated into vineyard management as it provides rapid assessments of spatial variability of soils’ and plants’ features. The electromagnetic induction (EMI) technology is used to measure soil apparent electrical conductivity (ECa) with proximal sensing and enables to appraise soil characteristics and their possible effects on plant physiological responses. This study was conducted in a micro irrigated Cabernet Sauvignon (Vitis vinifera L.) vineyard to investigate the technical feasibility of appraising plant water status and its spatial variability using soil ECa and must carbon isotope ratio analysis (δ13C). Soil temperature and soil water content were monitored in-situ using time domain reflectometry (TDR) sensors. Soil ECa was measured with EMI at two depths [0–1.5 m (deep ECa) and 0–0.75 m (shallow ECa)] over the course of the crop season to capture the temporal dynamics and changes. At the study site, the main physical and chemical soil characteristics, i.e. soil texture, gravel, pore water electrical conductivity (ECe), organic carbon, and soil water content at field capacity, were determined from samples collected auguring the soil at equidistant points that were identified using a regular grid. Midday stem water potential (Ψstem) and leaf gas exchange, including stomatal conductance (gs), net carbon assimilation (An), and intrinsic water use efficiency (WUEi) were measured periodically in the vineyard. The δ13C of produced musts was measured at harvest. The results indicated that soil water content (relative importance = 24%) and texture (silt: relative importance = 22.4% and clay: relative importance = 18.2%) were contributing the most towards soil ECa. Deep soil ECa was directly related to Ψstem (r2 = 0.7214) and gs (r2 = 0.5007). Likewise, δ13C of must was directly related to Ψstem (r2 = 0.9127), gs (r2 = 0.6985), and An (r2 = 0.5693). Results from this work provided relevant information on the possibility of using spatial soil ECa sensing and δ13C analysis to infer plant water status and leaf gas exchange in micro irrigated vineyards.

Simultaneous Analysis of the Stable Carbon Isotope Ratios of Acetoin and Acetic Acid by GC-C-IRMS for Adulteration Detection in Brewed Rice Vinegar Products.

In this study, we developed a method to simultaneously measure the stable carbon isotope ratio for acetic acid (δ 13Caceticacid) and acetoin (δ13Cacetoin) in rice vinegar by gas chromatography-combustion-isotope ratio mass spectrometry. The method showed good precision and accuracy. With this method, data from 16 brewed rice vinegars and 10 acetic acid samples were used to evaluate the feasibility of adulteration detection. On the basis that all δ13Cacetoin values of brewed rice vinegars are nearly constant, a characteristic pattern of the stable carbon isotope in rice vinegar was built with the 95% confidence intervals for δ13Caceticacid (-26.97 to -25.38‰), δ13Cacetoin (-28.14 to -27.09‰), and Δδ13C (0.61 to 2.27‰). An adulteration detection curve of Δδ13C was proposed based on the results of vinegar and acetic acid samples and confirmed by vinegar spiked with different amounts of acetic acid. This method could be useful in estimating the blending ratio of adulterated rice vinegar products. Products containing more than 10% of synthetic acetic acid could be possibly identified.

Natural abundance carbon isotope ratio analysis and its application in the study of diet and metabolism.

Due to differences in carbon assimilation pathways between plants, there are subtle but distinct variations in the carbon isotope ratios of foods and animal products throughout the food supply. Although it is well understood that the carbon isotope ratio composition of the diet influences that of the consumers' tissues, the application of natural abundance carbon isotope ratio analysis in nutrition has long been underappreciated. Over the past decade, however, several studies have investigated the utility of carbon isotope ratio analysis for evaluation of nutritional biomarker status, primarily focusing on its application as an objective indicator of sugar and animal protein intake. More recently, research investigating the application of natural abundance measurements has been extended to study fatty acid metabolism and has yielded encouraging results. Collectively, data from large-scale observational studies and experimental animal studies highlight the potential for carbon isotope ratio analysis as an additional and effective tool to study diet and metabolism. The purpose of this review is to provide an overview of natural abundance carbon isotope ratio analysis, its application to studying nutrition, and an update of the research in the field.

Effects of Aphid Density and Plant Taxa on Predatory Ladybeetle Abundance at Field and Landscape Scales.

Simple SummaryIn agroecosystems, predatory ladybeetles play an important role in suppressing aphid populations. How ladybeetles make use of host plant diversity in multicropping landscapes has rarely been documented in China. In this study, we examined the relationship between aphid densities and ladybeetle densities at both the local field and landscape scales. Overall, we found that there was a positive correlation between aphid densities and ladybeetle densities. However, plant taxa had no significant influence on predatory ladybeetle abundance at the local field scale. In addition, the effect of aphids on ladybeetles abundance was influenced by the crop type and growing season at the regional landscape scale. There was a significant positive correlation between aphid and ladybeetle populations on cotton only in July and August, whereas the correlation was significant for maize throughout the whole growing season. The δ13C value indicated that most prey aphids for ladybeetles originated from crops where aphids are abundant (cotton in June and July; both maize and cotton in August). These findings improved our understanding of the migration and dispersal of ladybeetles among different habitats and plant species and provided insight into the promotion of regional conservation and pest control of natural enemies in Northern China.In agroecosystems, predatory ladybeetles play an important role in restraining aphid population growth and suppressing aphid populations. They can adapt to various habitats and make use of various aphid species associated with multiple host plants during their life cycle. Agricultural landscapes in China are composed of a mosaic of small fields with a diverse range of crops, and how ladybeetles make use of host plant diversity in such landscapes has rarely been documented. In this study, we examined the relationship between aphid densities and ladybeetle densities in two different settings: (i) on the majority of plant species (including crops, trees, and weeds) at a local field scale in 2013 and 2014, and (ii) in paired cotton and maize crop fields at a regional landscape scale in 2013. Overall, we found that aphid abundance determined predatory ladybeetle abundance at both the local field and landscape scales, and there was a positive correlation between aphid densities and ladybeetle densities. However, plant taxa had no significant influence on the predatory ladybeetle abundance at the local field scale. In addition, the effect of aphids on ladybeetles abundance was influenced by the crop type and growing season at the regional landscape scale. There was a significant positive correlation between aphids and ladybeetles populations on cotton only in July and August, whereas the correlation was significant for maize throughout the whole growing season. We also conducted an analysis of the stable carbon isotope ratios of the adult ladybeetles caught in cotton and maize fields (C3 and C4 crops, respectively) in a regional landscape-scale survey in 2013. The δ13Cvalue indicated that most prey aphids for ladybeetles originated from crops where aphids are abundant (cotton in June and July; both maize and cotton in August).These findings improved our understanding of the migration and dispersal of ladybeetles among different habitats and plant species and provided insight into the promotion of the regional conservation and pest control of natural enemies in northern China.

Stable isotope profile (C, N, O, S) of Irish raw milk: Baseline data for authentication

Grass-based milk production is a major contributor to Irish agricultural output. The study characterized the Irish milk pool using stable isotope ratio analysis of carbon, nitrogen, oxygen and sulphur. Authentic raw milk samples were collected from 50 farms on five occasions over 13 months. Mean values of −27.11, 6.79, −3.27 and 6.16‰ were obtained for δ13C, δ15N, δ18O and δ34S, respectively. δ13C values reflected a high level of grass input and values increased with increasing cereal concentrate feed input (P < 0.001). δ18O values were most negative in spring. There was a significant interaction between feed and season for δ13C and δ15N values (P < 0.05), with the impact of concentrate feeding most evident in spring. δ34S values were lowest at the highest level of concentrate input (P < 0.05). The isotopic values reported here describe the Irish milk pool and may offer the potential to discriminate Irish milk and dairy products from similar commodities from other countries.

Archives of human-dog relationships: Genetic and stable isotope analysis of Arctic fur clothing

Among Indigenous populations of the Arctic, domestic dogs (Canislupus familiaris) were social actors aiding in traction and subsistence activities. Less commonly, dogs fulfilled a fur-bearing role in both the North American and Siberian Arctic. Examples of garments featuring dog skins were collected during the 19th-20th centuries and are now curated by the National Museum of Denmark. We sequenced the mitochondrial genomes of macroscopically identified dog skin garments. We conducted stable carbon and nitrogen isotope ratio analysis of the dog furs and of fur samples from contemporaneous pelts of Arctic (C. lupus arctos) and grey (C. lupus) wolves. Despite the presence of biocides used to protect the fur clothing during storage, we extracted well-preserved DNA using a minimally-invasive sampling protocol. Unexpectedly, the mtDNA genomes of one-third of the samples were consistent with wild taxa, rather than domestic dogs. The strong marine component in the diets of North American dogs distinguished them from Greenland and Canadian wolves, but Siberian dogs consumed diets that were isotopically similar to wild species. We found that dog provisioning practices were variable across the Siberian and North American Arctic, but in all cases, involved considerable human labor.

Using 13C/12C isotopic ratio analysis to differentiate between rice spirits made from rice and cane molasses

In this paper, we used automated 15N 13C analysis MS (ANCA-MS) and stable carbon isotope ratio analysis to analyze samples of rice- and cane molasses-based spirits and their constituent principal ingredients. This methodology was developed to distinguish, in a scientifically accurate manner, rice spirits made of rice from that made of cane molasses. Spirits with different mixed ratios of rice and cane molasses were also prepared for a detection capability test. Series dilution for spirit samples was performed to assess operational consistency. Test results demonstrated that 13C/12C values, as measured by ANCA-MS, can be used as reliable benchmark to distinguish between the two types of rice spirits. It is recommended that test samples should be distillated or diluted to an equivalent level of ethanol prior to measuring 13C/12C values. Data established in this paper can provide criteria necessary to monitor rice spirits sold in the marketplace.

Diversity in Labrador Inuit sled dog diets: Insights from δ13C and δ15N analysis of dog bone and dentine collagen

Sled dogs were an integral part of Labrador Inuit life from the initial expansion and settlement of northeastern Canada to the present day. Tasked with pulling sleds and assisting people with other subsistence activities in the winter, dogs required regular provisioning with protein and fat. In this paper, we conduct stable carbon and nitrogen isotope ratio analysis of the skeletal remains of dogs (n = 35) and wild fauna (n = 68) from sites located on the north and south coasts of Labrador to characterize dog provisioning between the 15th to early 19th centuries. In addition, we analyse bone (n = 20) and dentine (n = 4) collagen from dogs from Double Mer Point, a communal house site in Hamilton Inlet to investigate how dog diets intersected with Inuit subsistence and trade activities at a local level. We find that dog diets were largely composed of marine mammal protein, but that dogs on the north coast consumed more caribou and fish relative to dogs from the central and south coast sites. The diets of dogs from Double Mer Point were the most heterogenous of any site, suggesting long-distance movement of people and/or animals along the coast.

Identification of wintertime carbonaceous fine particulate matter (PM2.5) sources in Kaunas, Lithuania using polycyclic aromatic hydrocarbons and stable carbon isotope analysis

Abstract The study aimed at demonstrating the application of PAHs and δ13C indoor and outdoor measurements towards resolving airborne carbonaceous particle sources in wintertime. Concurrent outdoor and indoor measurements of PM2.5 and size-resolved (PM0.056-2.5) particulate matter were conducted at 6 one-family houses in Kaunas, Lithuania during January–March 2013. PM2.5 and size-resolved filter samples were analyzed for total carbon (TC) and stable carbon isotopic composition by elemental analyzer connected to isotope ratio mass spectrometer. Moreover, the indoor-outdoor concentrations of 10 selected polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were quantified. The simultaneous stable carbon isotope ratio and PAHs diagnostic ratio analysis enabled to identify main anthropogenic sources (traffic, biomass burning, and coal combustion) of PM2.5. Our study indicated that during winter period outdoor PM2.5 in Kaunas were mainly derived from biomass burning (solid fuel stoves) and vehicular emissions. Whereas indoor particulate matter had different stable carbon isotope composition of TC indicating the existence of pollution sources which was likely cooking emissions. The differences of indoor/outdoor stable carbon isotope composition in PM2.5 and size-resolved aerosol particles supported the existence of distinct TC sources and suggested that cooking emissions inside the house could strongly affect δ13C values.

THE TEMPLE OF QUETZALCOATL, TEOTIHUACAN: NEW DATA ON THE ORIGINS OF THE SACRIFICIAL VICTIMS

AbstractContinuing isotopic investigation of the sacrificial burials and trophies beneath the Feathered Serpent Pyramid (Temple of Quetzalcoatl) in ancient Teotihuacan, Mexico, has produced new results. Isotopic proveniencing using bioapatite strontium and structural carbonate oxygen isotopes in tooth enamel was applied to 39 samples, 24 from the sacrificial victims and 15 from the trophy jaws. Both the strontium and oxygen isotope ratios suggest that most or all of the sacrificial victims came from the central highlands of Mexico, which includes the area of Teotihuacan. In this sense, we find somewhat less multiethnicity represented among the military at Teotihuacan than previously thought. Analysis of carbon isotope ratios in enamel structural carbonate indicated a childhood diet dominated by maize, relatively homogeneous among the victims at the pyramid, and typical for much of pre-Hispanic Mesoamerica.

Effect of tannic acid combined with fluoride and lignosulfonic acid on anaerobic digestion in the agricultural waste management chain

Livestock waste is stored and used as soil fertilizer or directly as substrate for biogas production. Methane emissions from manure storages and ammonia inhibition of anaerobic digesters fed with manure, are well-known problems related to manure management. This study examines the effect of adding tannic acid with fluoride (TA-NaF) and lignosulfonic acid (LS) on methanogenic activity in batch reactors with ammonia inhibited maize silage digestate and in batch reactors with manure. Lignosulfonic acid counteracted urea induced ammonia inhibition of methanogenesis, whereas TA-NaF inhibited methanogenesis itself. Stable carbon isotope ratio analysis and methanogen community analysis suggested that TA-NaF affected acetoclastic methanogens the most. The combined findings suggest that TA-NaF could be used to reduce methane emissions from stored manure. Conversely, LS could be used as supplement in anaerobic digesters prone to urea induced ammonia inhibition.

Bulk and compound-specific stable isotope ratio analysis for authenticity testing of organically grown tomatoes

Until now, there has been a lack of analytical methods that can reliably verify the authenticity of organically grown plants and derived organic food products. In this study, stable isotope ratio analysis of hydrogen (H, δ2H), carbon (C, δ13C), nitrogen (N, δ15N), oxygen (O, δ18O) and sulfur (S, δ34S) was conducted along the tomato passata production process using organic and conventionally grown tomatoes from two Italian regions over two years. A gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) based method was developed and applied for analysis of C and N isotope ratios in amino acids derived from tomatoes. Of the bulk isotope ratios, δ15N was the most significant parameter for discriminating organic from conventional products. The classification power was improved significantly by compound-specific isotope analysis regardless of the production years and regions. We conclude that isotope analysis of amino acids is a novel analytical tool for complementing existing certification and control procedures in the organic tomato sector.