Peter Kump

Comparison of essential and non-essential element distribution in leaves of the Cd/Zn hyperaccumulator Thlaspi praecox as revealed by micro-PIXE

A detailed localization of elements in leaf tissues of the field-collected Cd/Zn hyperaccumulator Thlaspi praecox (Brassicaceae) growing at a highly metal-polluted site was determined by micro-proton-induced X-ray emission (micro-PIXE) in order to reveal and compare nutrient and non-essential element accumulation patterns in the case of multiple metal accumulation within particular leaf tissues, including the detailed distribution between apoplast and symplast regions. On the larger scans, the highest concentrations of metals were observed in the epidermis, S and Ca in the palisade mesophyll, Cl in the spongy mesophyll and vascular bundles, and P and K in the vascular bundles. On the more detailed scans, the highest Cd, Pb, Cl and K concentrations were observed in vascular bundle collenchyma. The relative element distribution (%) was calculated based on concentrations of elements in particular leaf tissues and their relative weight portions, indicating that most of the accumulated Zn was located in epidermises, while the majority of Cd and Pb was distributed within the mesophyll. Detailed scans of epidermal/mesophyll tissues revealed that Zn was mainly accumulated and detoxified in the symplast of large vacuolated epidermal cells, Cd in the mesophyll symplast, and Pb in the mesophyll symplast and apoplast.

Carbon and nitrogen natural stable isotopes in Slovene honey: adulteration and botanical and geographical aspects.

Isotope parameters (δ(13)C(honey), δ(13)C(protein), δ(15)N) were determined for 271 honey samples of 7 types (black locust, multifloral, lime, chestnut, forest, spruce, and fir honeys) from 4 natural geographical regions of Slovenia. Carbon and nitrogen stable isotope ratios were measured to elucidate the applicability of this method in the identification of the botanical and geographical origin of honey and in honey adulteration. Only 2.2% of the samples were adulterated according to the internal standard carbon isotope ratio analysis method. Botanical origin did not have any major influence on the honey isotope profiles; only black locust honey showed higher δ(13)C values. Some differences were seen across different production years, indicating that the influence of season should be further tested. Statistical and multivariate analyses demonstrated differences among honeys of various geographical origins. Those from the Alpine region had low δ(13)C (-26.0‰) and δ(15)N values (1.1‰); those from the Mediterranean region, high δ(13)C (-24.6‰) and medium δ(15)N values (2.2‰); those from the Pannonian region, medium δ(13)C (-25.6‰) and high δ(15)N value (3.0‰); and those from the Dinaric region, medium δ(13)C (-25.7‰) and low δ(15)N values (1.4‰).

Determination of sulfur and chlorine in fodder by X-ray fluorescence spectral analysis and comparison with other analytical methods

Abstract Sulfur and chlorine are essential elements in the metabolic processes of ruminants, and correct planning strategy of ruminant nutrition should provide a sufficient content of S and Cl in the animals body. S and Cl can be found in various types of animal fodder in the form of organic compounds and minerals. In this work, the Cl and S content in forage was determined by X-ray fluorescence spectrometry (XRF), and its performance was then compared in parallel analyses by instrumental neutron activation analysis (INAA), inductively coupled plasma atomic emission spectrometry (ICP-AES) and potentiometric methods. The results were compared and critically evaluated in order to assess the performance and capability of the XRF technique in analysis of animal fodder.

ROOTS OF METAL HYPERACCUMULATING POPULATION OF THLASPI PRAECOX (BRASSICACEAE) HARBOUR ARBUSCULAR MYCORRHIZAL AND OTHER FUNGI UNDER EXPERIMENTAL CONDITIONS

Thlaspi praecox (Brassicaceae) is a recently discovered metal hyperaccumulating plant species colonized by arbuscular mycorrhizal fungi (AMF). The identity and diversity of the AMF colonizing its roots have not been determined so far. Therefore, T. praecox was inoculated with an indigenous fungal mixture from a metal polluted site and grown in original polluted soil/ commercial substrate mixtures (i.e., 100%, 50%, and 25%). Low to moderate mycorrhizal frequencies (F = 33–68%) and only rare arbuscules were observed. Densities of vesicles and microsclerotia, typical structures of dark septate endophytes (DSE), were greater in pots with 100% original polluted soil. In contrast, the highest diversity of fungal genotypes was observed in the roots from 25% polluted soil/ commercial substrate mixture, with the lowest soil concentrations of Cd, Zn, and Pb. The sequences obtained corresponded to Glomus species (Glomeromycota), to putative DSE Phialophora verrucosa and Rhizoctonia sp. and to some other fungi from Asco- and Basidiomycota, that are known to associate with plants, namely Capnobotryella sp., Penicillium brevicompactum, Rodotorula aurantiaca and Rodotorula slooffiae. This is the first report of DSE occurrence in roots of hyperaccumulating T. praecox, a promising candidate for phytoextraction.

Multielement Analysis of Rubber Samples by X-Ray Fluorescence

Destructive elemental analysis of rubber samples for major and trace element constituents is a rather demanding task, mainly because of the need for sophisticated and time-consuming sample preparation procedures. X-ray analysis has so far been used in the rubber industry primarily as a rapid tool for qualitative analysis, but a more realistic estimate of the accuracy of this, in many aspects, advantageous technique indicates that it could qualify as a quantitative method. In this work rubber samples were analyzed by the X-ray fluorescence analysis (XRFA) technique, utilizing Cd-109 and Fe-55 for excitation radioactive sources. The quantification procedure used employed a minimum number of calibration steps, utilizing only single-element-thick standards and stable compounds, or standard reference materials. Matrix correction calculations employed known fundamental constants and absorption measurements on a particular sample. In order to validate the results, and to establish the accuracy of analysis, some samples were also analyzed by neutron activation analysis (NAA). For the same purpose, the analysis of some standard reference materials of biological and inorganic matrices were performed. The accuracy of 5 to 6% achieved by XRFA means that it should be considered in the rubber industry as a rapid, simple, and cheap alternative to the analytical methods usually adopted.

Inventory of regulations and analysis techniques for trace elements in some water supply companies in Eastern and Western Europe

With the ultimate objective in contributing to the improvement of the quality control of drinking water and to facilitate the checking of its compliance with the respective regulations, an inventory of analytical techniques used in water supply companies in Eastern and Western European countries is presented. The existing regulations for drinking water and bottled mineral water quality with respect to trace elements in these countries are compared to regulations of the World Health Organisation. The data obtained can be useful for further harmonisation of the respective regulations in Europe.

Leaf optical properties are affected by the location and type of deposited biominerals

This study aimed to relate the properties of incrusted plant tissues and structures as well as biomineral concentrations and localization with leaf reflectance and transmittance spectra from 280nm to 880nm in the grasses Phragmites australis, Phalaris arundinacea, Molinia caerulea and Deschampsia cespitosa, and the sedge Carex elata. Redundancy analysis revealed that prickle-hair length on adaxial surface and thickness of lower epidermis exerted significant effects in P. australis; prickle-hair density at abaxial leaf surface and thickness of epidermis on adaxial leaf surface in P. arundinacea; thickness of epidermis on adaxial leaf in D. cespitosa; prickle-hair density on adaxial leaf surface and thickness of cuticle in M. caerulea; and prickle-hair density on adaxial leaf surface and cuticle thickness of the lower side in C. elata. Micro-PIXE and LEXRF elemental localization analysis show that all of these structures and tissues are encrusted by Si and/or by Ca. Reflectance spectra were significantly affected by the Ca concentrations, while Si and Mg concentrations and the Ca concentrations significantly affected transmittance spectra. High concentrations of Mg were detected in epidermal vacuoles of P. arundinacea, M. caerulea and D. cespitosa. Al co-localises with Si in the cuticle, epidermis and/or prickle hairs.

Performance and characteristics of two total-reflection X-ray fluorescence and a particle induced X-ray emission setup for aerosol analysis

Abstract Two X-ray emission techniques, total-reflection X-ray fluorescence (TXRF) and proton induced X-ray emission (PIXE), were applied to atmospheric trace element determinations and compared with respect to detection properties, speed of analysis, precision and sampling strategy. The advantage of the commercial TXRF system over all the other techniques evaluated was clearly demonstrated. The lowest detection limits were found to be at a level of 0.01 ng m −3 . The use of an economical TXRF module exhibited reasonably satisfactory results in this atmospheric research study; the detection limits were about one order of magnitude less favourable than those of the commercial unit. For TXRF, aerosols were collected directly on quartz glass or Plexiglas® carriers in a single-orifice impactor during 3–5 h; the measuring time was some minutes. For PIXE, aerosols were deposited on Nuclepore® filters during 48 h. PIXE was performed under less than optimal conditions using 1.4 MeV protons, and therefore the PIXE detection limits were also recalculated for an optimised setup using 2.5 MeV protons.

Isotopic and elemental characterisation of Slovenian apple juice according to geographical origin: Preliminary results

This study examined the applicability of stable isotope and multi-element data for determining the geographical origin of fresh apple juices. Samples included three apple cultivars (Idared, Golden Delicious and Topaz) harvested in 2011 and 2012 from five different geographical regions of Slovenia. Regional discrimination of the juice samples was most successful when using linear discriminant analysis (LDA) and taking into account the following parameters: δ(2)H and δ(18)O content of juice water; δ(15)N and δ(13)C content of the pulp, (D/H)I and (D/H)II in ethanol and the concentration of S, Cl, Fe, Cu, Zn and Sr. Overall prediction ability was 83.9%. The factors that best distinguished the different types of cultivar were the δ(2)H and δ(18)O content of fruit juice water; the δ(13)C and (D/H)I content of ethanol; and the concentration of S, Mg, K, Cu, and Ti. Prediction ability, taking into account all ten parameters, was 75.8%.

Protein quality of leguminous plants determined by proton-induced radiation analysis

Abstract Analysis of total sulphur and nitrogen in samples of leguminous plants and cereals using PIXE and the nuclear reaction 15N(p, αγ)12C is presented.