Elemental Composition Patterns Research Articles

Early-stage growth and elemental composition patterns of Brassica napus L. in response to Cd–Zn contamination

Soil contamination caused by the presence of Cd and the excess amount of Zn is a widespread concern in agricultural areas, posing significant risks to the growth and development of crops. In this paper, the early-stage development and metal (Cd and Zn) accumulation potential of rapeseed (Brassica napus L.) grown under different metal application schemes were assessed by determining radicle and hypocotyl length and the micro- and macro elemental composition of plantlets after 24, 72, and 120 h. The results indicated that the single and co-application of Cd and Zn significantly reduced the radicle and hypocotyl lengths. Accumulation intensity for Cd and Zn was affected by Cd and the combination of Cd and Zn in the solution, respectively. In addition, both metals significantly influenced the tissue Mn and had a minor effect on Cu and Fe concentrations. Both Cd and Zn significantly affected macro element concentrations by decreasing tissue Ca and influencing K and Mg concentrations in a dose- and exposure time-dependent manner. These findings specify the short-term and support the long-term use of rapeseed in remediation processes. However, interactions of metals are crucial in determining the concentration patterns in tissues, which deserves more attention in future investigations.

Formation of reference groups for archaeological pottery using neutron activation and multivariate statistical analyses

AbstractFor the first time in Russia, instrumental neutron activation analysis (INAA) and related analytical techniques were used to determine the distribution patterns of elemental composition in archeological pottery in terms of classification and provenance of medieval pottery. A total of 48 fragments have been discovered in three locations; Bolgar, the Moscow Kremlin (MosKremlin), and Selitrennoe settlement (Selitrennoe). The assemblages were subjected to INAA in order to determine the concentrations of 37 elements in mg/kg. The data were analyzed using geochemical, bivariate, and multivariate statistical techniques. To classify the fragments according to their origin hierarchical clustering (HCA), linear discriminant (LDA), and principal component analyses (PCA) were used. Based on the INAA results, the first attempt was made to apply machine learning methods to the study of artifacts in Russia. The results show that they are reliable and powerful in extracting information about critical elements for identifying ceramic fragments and using them as chemical fingerprints. Chromium was the most useful element and was used in conjunction with other elements as a fingerprint to distinguish sherds. Chemical and statistical analyses help to establish of reference groups for medieval archeological pottery, which will be used in the future to classify and identify various unknown sherds. These reference groups serve as baseline data for determining the fragment's place of manufacture and are considered a reasonable judgment based on experimental data.

Ontogenetic Patterns of Elemental Tracers in the Vertebrae Cartilage of Coastal and Oceanic Sharks

As predators, coastal and oceanic sharks play critical roles in shaping ecosystem structure and function, but most shark species are highly susceptible to population declines. Effective management of vulnerable shark populations requires knowledge of species-specific movement and habitat use patterns. Since sharks are often highly mobile and long-lived, tracking their habitat use patterns over large spatiotemporal scales is challenging. However, the analysis of elemental tracers in vertebral cartilage can describe a continuous record of the life history of an individual from birth to death. This study examined trace elements (Li, Mg, Mn, Zn, Sr, and Ba) along vertebral transects of five shark species with unique life histories. From most freshwater-associated to most oceanic, these species include Bull Sharks (Carcharhinus leucas), Bonnethead Sharks (Sphyrna tiburo), Blacktip Sharks (Carcharhinus limbatus), Spinner Sharks (Carcharhinus brevipinna), and Shortfin Mako Sharks (Isurus oxyrinchus). Element concentrations were compared across life stages (young-of-the-year, early juvenile, late juvenile, and adult) to infer species-specific ontogenetic patterns of habitat use and movement. Many of the observed elemental patterns could be explained by known life history traits: C. leucas exhibited clear ontogenetic changes in elemental composition matching expected changes in their use of freshwater habitats over time. S. tiburo elemental composition did not differ across ontogeny, suggesting residence in estuarine/coastal regions. The patterns of elemental composition were strikingly similar between C. brevipinna and C. limbatus, suggesting they co-occur in similar habitats across ontogeny. I. oxyrinchus elemental composition was stable over time, but some ontogenetic shifts occurred that may be due to changes in migration patterns with maturation. The results presented in this study enhance our understanding of the habitat use and movement patterns of coastal and oceanic sharks, and highlights the applicability of vertebral chemistry as a tool for characterizing shark life history traits.

Grain mineral composition of Argentinean-adapted wheat cultivars: a case study

Improvement of the nutritional quality of wheat (Triticum aestivum L.) has been quite challenging, due, in part, to the limited variation found in modern cultivars and the strong effect exerted by the environment, which hinder the selection process. The aim of this study was to characterise the mineral profile of grains of 35 Argentinean-adapted, mostly spring wheat cultivars in two successive years. Concentrations of most mineral nutrients in grains spanned approximately a two-fold range. Our study revealed a strong effect of the environment, but also that some key differences among genotypes are maintained over years. Correlation and principal component analyses showed the existence of a strong and stable association of variables determining the global elemental profile in grains of the wheat lines under analysis. In this regard, some cultivars displayed, over successive years, opposite global patterns of elemental composition, suggesting the existence of a genotype dependent ionome signature. Important negative correlations were found for the concentration of most, but not all, nutrients with yield, thus indicating a potential compromise among beneficial traits. The genotypic variation characterised in the present study has potential to be used in breeding programs aimed at improving wheat grain quality.

Biogeography of Macrophyte Elemental Composition: Spatiotemporal Modification of Species-Level Traits

The elemental composition of primary producers represents a potentially important pathway for linking ecosystem scale, climate-driven changes in nutrient supply to ecological processes at the population and community scales. However, such cross-scale linkages may also be dampened by conservation of species-specific differences in tissue stoichiometry. We investigated biogeographic patterns of elemental composition (%N, %C, and C:N ratio) of four ecologically dominant and functionally diverse marine intertidal macrophyte species (the brown algae Fucus distichus and Hedophyllum sessile, the red alga Mazzaella splendens, and the surfgrass Phyllospadix scouleri) along 900 km of coastline of the California Current System over a 10-year period. We used a nested hierarchical design to identify the dominant spatial and temporal scales of elemental composition variability and to test the sensitivity of macrophyte stoichiometry to changing ocean conditions in upwelling, the El Nino-Southern Oscillation (ENSO), the North Pacific Gyre Oscillation (NPGO), and the Pacific Decadal Oscillation (PDO). Elemental composition was highly conserved at the species level but was also sensitive to the environment, displaying marked species-dependent responses to spatial and temporal variation in ocean conditions. Moreover, the effects of local and seasonal processes were strong and with conserved species-specific differences, likely limited coherent cross-species sensitivity to climate variability from ENSO, NPGO and PDO. Unanticipated long-term steady increases in %C and bimodal increases in %N in brown algae and similar decreases in elemental composition of the red alga generated trimodal changes in C:N for these species. These changes may reflect responses of macrophyte communities to continuing changes in carbonate chemistry from ocean acidification.

Quantitative analysis of plant leaf elements using the LA-ICP-MS technique

The use of Laser Ablation coupled to Mass Spectrometry is a promising technique for analysis of plant tissue elements because it has advantages over conventional digestion techniques such as reduced levels of contamination and sample preparation time, possibility of spatial distribution analysis of elements, high number of repetitions, among others. This technique still has some limitations, especially with regard to calibration, which may result in inaccurate chemical analyses. The present study aims to compare two types of analyzers (quadrupole and magnetic sector field) regarding precision and accuracy. Certified material was examined, and also plant material analyzed by both solution in inductively coupled plasma optical emission spectrometry (ICP OES) and by laser ablation methods. It was observed that the magnetic sector field analyzer gave better results in relation to precision (relative standard deviation - RSD) and accuracy (recovery). An elemental composition pattern similar to that of the sample to be analyzed is relevant to validate the methodology for the analysis of leaves collected under different environmental conditions. Thus, pulverized Eremanthus erytropappus leaves were suggested as a second type of validation standard to be used in analyzes of plants belonging to the Atlantic and Cerrado Forest biomes.

Ecological mechanisms and phylogeny shape invertebrate stoichiometry: A test using detritus‐based communities across Central and South America

Abstract Stoichiometric differences among organisms can affect trophic interactions and rates of nutrient cycling within ecosystems. However, we still know little about either the underlying causes of these stoichiometric differences or the consistency of these differences across large geographical extents. Here, we analyse elemental (carbon, nitrogen, phosphorus) composition of 872 aquatic macroinvertebrates (71 species) inhabiting tank bromeliads (n = 140) from five distantly located sites across Central and South America to (i) test phylogenetic, trophic and body size scaling explanations for why organisms differ in elemental composition and (ii) determine whether patterns in elemental composition are universal or context dependent. Taxonomy explained most variance in elemental composition, even though phylogenetic signals were weak and limited to regional spatial extents and to the family level. The highest elemental contents and lowest carbon:nutrient ratios were found in organisms at high trophic levels and with smaller body size, regardless of geographical location. Carnivores may have higher nutrient content and lower carbon:nutrient ratios than their prey, as organisms optimize growth by choosing the most nutrient‐rich resources to consume and then preferentially retain nutrients over carbon in their bodies. Smaller organisms grow proportionally faster than large organisms and so are predicted to have higher nutrient requirements to fuel RNA and protein synthesis. Geography influenced the magnitude, more than the direction, of the ecological and/or phylogenetic effects on elemental composition. Overall, our results show that both ecological (i.e. trophic group) and evolutionary drivers explain among‐taxa variation in the elemental content of invertebrates, whereas intraspecific variation is mainly a function of body size. Our findings also demonstrate that restricting analyses of macroinvertebrate stoichiometry solely to either the local scale or species level affects inferences of the patterns in invertebrate elemental content and their underlying mechanisms. A plain language summary is available for this article.

Spatial distribution of polycyclic aromatic hydrocarbon and polychlorinated biphenyl sources in the Nakdong River Estuary, South Korea

ABSTRACTOur research team investigated the elemental composition and the presence of various toxic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), in estuary surface sediments to trace the spatial distribution of the sources of pollution deposited in Nakdong River, Busan, South Korea. The spatial patterns of elemental composition and toxic organic compounds were determined from the measurements of total organic carbon (TOC), total nitrogen, total sulfur, PAHs, and PCBs. The sediments had TOC contents of between 0.02 and 1.80 wt% (avg. 0.34 wt%), depending on the amount of clay-sized particles. The concentrations of PAHs and PCBs (10.8–167.7 ng g−1 dry wt and 197.0–754.0 pg g−1 dry wt, respectively) in surface sediments revealed different spatial patterns for these compounds, suggesting that they partially originated from the combustion of fossil fuels and from the use of commercial PCB products at adjacent industrial complexes. Although these concentrations were far below the Sediment Quality Guideline (SQG) of the National Oceanic and Atmospheric Administration (NOAA), the sediments at one site contained PCBs at concentrations close to the response level (754.0 pg g−1 dry wt), and were dominated by low-molecular-weight PAHs. The PAHs and PCBs in Nakdong River Estuary sediments were likely to have originated from the combustion of fossil fuels and biomass at the adjacent industrial complexes. The primarily analyzed results determined that PAHs originated from the combustion of fossil fuels and biomass, and overall concentrations were related to the contributions of individual PAHs in most sediment samples. Based on the SQG of the NOAA, our results indicate that the anthropogenic activity should be considered on the future-sustainable management of this estuary system.

Evaluation of Sources and Patterns of Elemental Composition of PM2.5 at Three Low-Income Neighborhood Schools and Residences in Quito, Ecuador.

Elemental characterization of fine particulate matter was undertaken at schools and residences in three low income neighborhoods in Quito, Ecuador. The three zones were located in the northern (Cotocollao), south central (El Camal), and south east (Los Chillos) neighborhoods and were classified as zones 1–3, respectively. Forty elements were quantified via ICP-MS analysis. Amongst the geogenic elements, the concentration of Si was the most abundant followed by S, Al, and Ca. Elements with predominantly anthropogenic sources such as Zn, V, and Ni were higher in zone 3 school followed by zone 2 and zone 1 schools. Enrichment factors were calculated to study the role of crustal sources in the elemental concentrations. Geogenic elements, except K, all had values <10 and anthropogenic elements such as Ni, V, Zn, Pb, As, Cr had >10. Principal Component Analysis suggested that Ni and V concentrations were strongly attributable to pet coke and heavy oil combustion. Strong associations between As and Pb could be attributed to traffic and other industrial emissions. Resuspended dust, soil erosion, vehicular emissions (tailpipe, brake and tire wear, and engine abrasion), pet coke, heavy oil combustion, and heavy industrial operations were major contributors to air pollution.

Does the elemental composition of indoor and outdoor PM2.5 accurately represent the elemental composition of personal PM2.5?

The complex mixture of chemical and elemental constituents that comprise particulate matter (PM) is hypothesized to be, in part, responsible for its toxicity. Epidemiologic studies have identified specific components and sources of PM2.5 associated with adverse health outcomes, but the majority of these studies use the mass concentration of elements in outdoor PM2.5 at central monitoring sites as a surrogate for personal exposure. Personal exposure to PM2.5 and its elemental composition, however, may vary from stationary outdoor measurements. Here, we use concurrent indoor, outdoor, and personal sampling of PM2.5 and its elemental constituents along with personal and home characteristics, collected as a part of the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study to characterize the differences in PM2.5 among indoor, outdoor, and personal air samples. We found that personal exposure to PM2.5 and most elements were significantly correlated with, though frequently exceeded, both indoor and outdoor measurements. Principal component scores were used to determine that the mixture of elemental components in PM2.5 varies significantly across indoor, outdoor, and personal sample types. Using model-based clustering, we identified 7 clusters of RIOPA participants whose personal PM2.5 samples had similar patterns of elemental composition. Using this approach, two subsets of RIOPA participants were identified whose personal exposure to PM2.5 and elemental concentrations were significantly increased compared to both their indoor and outdoor levels. Collectively, our results suggest that the elemental composition of PM2.5 obtained at central monitoring stations do not accurately represent the overall elemental composition of personal PM2.5 exposure.

Distinct regional profiles of trace element content in muscle of Japanese eel Anguilla japonica from Japan, Taiwan, and China

Trace element distribution patterns were examined in Japanese eel from five Asian regions for the purpose of identifying the elements and patterns that could be used to determine provenance. Distinctive patterns were found in eels from the Japanese prefectures of Miyazaki, Kagawa, and Shizuoka, and from Taiwan and China. The levels of six trace elements, selenium, mercury, copper, manganese, zinc, and arsenic, in muscle tissue varied among eels of different origins, and factorial analysis of the elemental patterns showed that Factor 1 was attributable to selenium and mercury levels and Factor 2 to zinc and copper levels. Multivariate analysis showed that the patterns of elemental composition in fish muscle were mainly differentiated by these two factors.

Elemental Composition of Littoral Invertebrates from Oligotrophic and Eutrophic Canadian Lakes

The P, N, and C content of littoral macroinvertebrates from 8 lakes located in 3 distinct geographical regions of Canada (central Alberta, northwestern Ontario, and Rocky Mountains near Jasper, Alberta) is described. A wide range of values was found in the body content (all values are % of dry mass) of P (0.4-1.6%), N (5.8-13.7%), and C (32.5-53.5%) in the data set containing inver- tebrates from all 8 lakes. C:P (63-324), N:P (9.6-60), and C:N (4.2-7.6) (all by atom) also varied widely. This variation was partly related to the different mean body content of P, N, and C among taxonomic groups. However, the mean P, N, and C content of macroinvertebrate assemblages varied little among lakes. The patterns of elemental composition in benthic invertebrates shown here are similar to zoo- plankton and terrestrial insects, and indicate that the strength of stoichiometric constraints acting in littoral food webs will depend on the taxa being considered.

Elemental composition of airborne particulate matter in the multi-impacted urban area of Thessaloniki, Greece

Ambient concentrations of PM 10 and their elemental composition in the multi-impacted area of Thessaloniki, N. Greece is presented in this study. High concentrations of PM 10 were observed, with 80% exceedances of the proposed daily limit of 50 μg m −3. The elemental concentrations were similar to the levels observed in moderately polluted urban areas. Spatial and temporal variation of particle mass and elemental concentrations as well as the influence of meteorological conditions were examined. The examined elements were characterised with respect to their origin from natural or anthropogenic emissions on the basis of crustal and marine enrichment factors. Factor analysis of elemental composition pattern and elemental ratios in PM 10 were also used to identify possible pollution source-types.

Observations of systematic temporal evolution in elemental composition during gradual solar energetic particle events

The WIND/EPACT experiment offers a ∼100 fold increase in collecting power over instruments flown in previous solar cycles, thus allowing unprecedented detailed studies of temporal evolution in gradual solar energetic particle (SEP) events. We present hourly WIND/EPACT observations at ∼2–10 MeV/nuc from the 20 April 1998 and 26 August 1998 SEP events. These observations show striking patterns in elemental composition which evolve in a systematic fashion throughout the events' several‐day durations. These data, combined with theoretical modeling in a companion Letter [Ng et al. 1999], suggest that a dynamic Alfvén wave field, generated primarily by streaming energetic protons, is responsible for the complex behavior which is observed.

A secondary ion mass spectroscopic study of the elemental composition pattern in rat incisor dental enamel during different stages of ameloblast differentiation

In most earlier studies on the elemental composition pattern of dental enamel, a picture is presented which describes a limited region. In this study, estimates of the incorporation of some critical elements into enamel were correlated with the differentiation stages of the ameloblasts through out the whole tooth. Elemental analyses of rat incisor dental enamel during the secretory, transitional and maturation phases were performed using two different modes of secondary ion mass spectrometry (SIMS). The results were presented as ion images and three-dimensional spatial resolution graphs. In the elemental images of 23Na, 26CN, 35Cl and 39K, counts were detected during the secretory and maturation phases of amelogenesis. Variations were interpreted as resulting from secretion of elements during the secretory phase and resorption during the maturation phase. In line scans the ion yield from enamel during different stages of differentiation of the ameloblasts was analysed. The elements investigated were 12C, 19F, 23Na, 31P, 39K and 77CaCl. As seen in the images, most elements exhibited a higher ion yield during the earlier stages of secretion, and lower yields during the maturation-phase resorption. Cl, together with P, increased during the phases of maturation. In the most apical portions of the teeth, corresponding to a presecretory phase, an inverse pattern was seen for most of the elements. If the surface yield was high at the onset of the secretory phase, the presecretory yields were lower, and vice versa.

New approaches to the characterization and classification of ceramics on the basis of their elemental composition

This study is a part of a larger investigation related to questions of the systemization of neutron activation analysis results. It considers the analysis of experimental data and focuses on the application of a multivariate statistical technique to the characterization and classification of ceramic artifacts in order to establish and assess their provenance. Central to the statistical methodology reported here is the determination of a specific characterization-classification function. This function provides a method of defining a group of archaeological ceramics on the basis of their elemental composition patterns. Conditional and expected probabilities calculated from the function are then used as a means of classifying unknown observations, indicating outliers, and detecting the existence of another group as yet unidentified. The utility of the function is demonstrated in a specific test case. The possibility of using the characterization-classification function to increase the portability of information and to reduce the need for centralized computer data banks is pointed out.

Neutron activation analysis of bald eagle feathers: analytical precision and sources of sampling variation

Instrumental neutron activation analysis was used to investigate the feather chemistry of wild and captive bald eagles (Haliaeetus leucocephalus). This paper documents variation that may be attributable to method of feather collection, laundering of samples, and precision of the analysis, as well as the variability within and among feathers from different locations on the body of individual birds. For most samples, reliable estimates could be made of the concentrations of bromine, magnesium. manganese, sodium, vanadium, aluminum, chlorine, calcium, and sulphur. Iodine and copper were detected but could not be measured precisely. There were highly significant patterns of variation along the length of a single feather for most chemical elements. The vane and calamus portions of feathers differed in chemical composition and the concentrations of the elements in the two parts were not correlated. Feathers belonging to the same molt but collected several months apart had similar chemical profiles. Variation within an individual feather and among feathers from different parts of the body necessitates rigorous consistency in the method of sampling feathers. Possible explanations for the observed patterns of elemental composition are discussed.

Composition of fine particle regional sulfate component in Shenandoah Valley

Fine fractions of atmospheric particulate samples collected over 3 weeks in July/Aug 1980 in Shenandoah Valley, VA, and previously analyzed by X-ray fluorescence analysis to provide data for many additional elements. Modified factor analysis of the combined data yielded a regional sulfate component containing S, NH/sub 4//sup +/, V, Mn, Zn, Se, As, In, Sb, And Pb. If the component originates mainly from coal combustion, there is modification of the elemental composition pattern during transport from distant mental composition pattern during transport from distant power plants to the receptors, even in the <2.5-..mu..m fraction. The regional sulfate component should be used in receptor-model treatments of areas strongly affected by sulfate from distant sources, as it may account for substantial fractions of several airborne elements, especially Se and Mn. Particulate S/Se mass ratios from this and other work are usually in the vicinity of 3300 in areas not immediately affected by fresh SO/sub 2/ sources, but drop significantly near such sources.