Slavica Ražić

Trace elements analysis of Echinacea purpurea—herbal medicinal

Elemental composition of Echinacea purpurea (Asteracae), grown in Serbia under strongly controlled conditions, has been studied. To distinguish elemental patterns of different parts of the plant, the content of Zn, Fe, Cu, Mn, Ca, Mg, Sr, Ni, and Li in root versus upper plant parts were determined, by flame atomic absorption and flame atomic emission spectrometry. Analyses of the mentioned elements in soil and in an ethanolic extract of E. purpurea were made, too. The trace element data were evaluated by multivariate methods, i.e. principal component analysis and hierarchical cluster analysis. This revealed two groups of elements (I: Fe, Cu, Mn, Li; II: Ca, Mg, Zn, Ni), while trace element profiles of root, stem, leaves, and flowers of this plant differed significantly. However, no significant difference in the trace element patterns between the summer and the autumn harvest samples was found.

Determination of chromium in Mentha piperita L. and soil by graphite furnace atomic absorption spectrometry after sequential extraction and microwave-assisted acid digestion to assess potential bioavailability

Analysis of chromium in Mentha piperita and the soil where it is cultivated was done. The capacity of soil for chromium immobilization and the capacity of M. piperita L., to control its uptake were analyzed by spiking the soil with standard solutions of Cr(III). For each concentration three acidity levels: natural, one unit below and one above its natural acidity (pH(2)=6, pH(1)=5 and pH(3)=7) were tested. Three-stage sequential extraction was performed (I stage: 1M ammonium-acetate, II stage: 0.1M hydroxylamine-chlorohydrate and III stage: 0.2/0.2M oxalic acid/ammonium-oxalate mixture). The chromium content in the extracts was obtained after the measurements by GFAAS. The results (expressed in mgL(-1)), at pH(1), pH(2) and pH(3), respectively, were as follows: I stage: 4.64-10.93, 0.79-5.78 and 0.26-5.26; II stage: 1.14-15.99, 0.76-20.31 and 0.67-20.64; III stage: 0.67-20.64, 19.17-100.76 and 19.17-116.05. A high potential of the soil for chromium immobilization was observed. In parallel, soil and plant samples were prepared by microwave-assisted acid digestion for total chromium determination. By analysis of SRMs (NIST SRM 2711 - Montana II Soil, NIST SRM 8433 - Corn Bran and NIST SRM 1547 - Peach Leaves) good recoveries (72.7-115.3%) were obtained. Additionally, iron and manganese oxides and hydroxides were recognized as matrix components of special importance for mobility of chromium species within a soil structures so, the determination of Mn and Fe was done too.

Trace elements in aerial parts and rhizosphere of Thymus pannonicus All.

This paper brings out the results of the study on the levels of selected trace elements (Cu, Fe, Mn, Zn and Cr) in aerial parts of Thymus pannonicus All. (Lamiaceae) and rhizosphere soil from twelve locations in Serbia. Prior to assays by flame and flameless atomic absorption spectrometry, samples were subjected to microwave-assisted acid digestion. Real and potential acidity of soil samples were also measured. Obtained results for soil samples, although slightly higher for some elements (Cu: 12.38–45.18 mg/kg; Fe: 22102–46193 mg/kg; Mn: 776.95–4901.27 mg/kg; Zn: 62.27–214.02 mg/kg; Cr: 48.86–69.13 mg/kg), were found to fit into biogeochemical background. Element contents in plant samples differed depending on collecting site (Cu: 5.26–14.07 mg/kg; Fe: 25.92–1454.07 mg/kg; Mn: 89.29–278.25 mg/kg; Zn: 1.81–10.64 mg/kg; Cr: 1.11–3.51 mg/kg), which can be partly explainable by different nutrient availability influenced by soil acidity. Zinc levels in T. pannonicus were below expected and seem to be strongly influenced by plant physiological properties.

A chemometrics as a powerful tool in the elucidation of the role of metals in the biosynthesis of volatile organic compounds in Hungarian thyme samples.

The volatile fraction of the leaves of Thymus pannonicus All. (Lamiaceae) was analyzed by headspace extraction followed by GC-FID and GC-MS analysis. The different headspace profiles were recognized, with citral and with monoterpene hydrocarbons as dominant compounds. In addition, the determination of Cr, Co, Ni, Mo, Cu, Zn, Mn, Fe, Mg, Ca, K and Na was conducted by spectroscopic techniques (FAAS, GFAAS and ICP-OES). In order to evaluate the relationship between volatile organic compounds and metals, a chemometrics approach was applied. The data obtained by analysis of the headspace and elemental content were subjected to correlation analysis, factor analysis, principal component analysis and cluster analysis. A number of significant correlations of metals with plant volatiles were found. Correlation of Zn with citral, Mn with oxygenated monoterpenes and Mg with β-bourbonene, could be explained by involvement of metals in the biosynthesis of volatile organic compounds.

Accumulation of heavy metals from soil in medicinal plants

Abstract Medicinal plants accumulate heavy metals from contaminated soil, and their consumption can cause poisoning. Our objective was to determine the levels of Pb, Cd, Zn, Cu, Fe, and Mn in four medicinal plant species (Achillea millefolium, Hypericum perforatum, Plantago lanceolata, and Urtica dioica) and their native soil, all sampled at a former smelter. The highest soil Cd, Pb, and Zn levels surpassed the maximum allowed limit 75-fold, 48-fold, and 14-fold, respectively. Their soil levels correlated with those in the plants, but this was not the case with Cu, Fe, and Mn. Heavy metal accumulation seems to depend on the plant species, yet even so, medicinal herbs should be cultivated and gathered only from controlled (uncontaminated) areas. Polluted areas should be monitored on a regular basis, while further research should investigate the connection between the heavy metal levels in the soil, their levels available for plants, and the levels extractable from plants.

Euroanalysis XVI—challenges in modern analytical chemistry

In the International Year of Chemistry, Belgrade was the meeting place for almost 600 participants of Euroanalysis XVI, from 57 countries from all over Europe and overseas. As a broad-spectrum conference on analytical chemistry, held biennially with its venue rotating between European countries, Euroanalysis has established itself as a regular forum of the national societies represented in the Division of Analytical Chemistry of the European Association for Chemical and Molecular Sciences (EuCheMS). The 16th European Conference on Analytical Chemistry, held in September 2011, was hosted by the Division of Analytical Chemistry of the Serbian Chemical Society (SCS), and fully supported by the SCS and its president Ivanka Popovic. The Congress Centre SAVA in Belgrade, located in one of the modern quarters of New Belgrade but still very close to the old historic and charming city centre, provided an excellent venue for the conference, enabling networking at its best on both the scientific and social level. An attractive scientific program was presented under the motto “Challenges in Modern Analytical Chemistry” and there was much to be learnt about the trends and perspectives in the different areas of the analytical sciences. Ten plenary lectures built the framework of the conference. How far can one go with all the available analytical tools? “Diving Deep into the Chemistry of the Human Brain”, the lecture of Jonas Berquist from Uppsala University (Sweden), was a good example of the use of novel techniques for analysis of complex samples, the isolation and enrichment of the non-soluble portion of the proteome membrane-bound proteins from brain tissue. The techniques applied (CPE, 1D gel electrophoresis, in-gel digestion with RP-nanoLC, ESI and high-resolution MS–MS, or direct digestion with RP-nanoLC, MALDITOF/TOF-MS or high-resolution IEF with ESI-nanoLC– MS–MS) are very promising in the study of tissues from the human central nervous system or animal models of neurological diseases. His presentation was awarded the Robert Kellner Lecture prize, established by the Division of EuCheMS in memory of the efforts and contributions of the late Robert Kellner, from Vienna University of Technology, and traditionally sponsored by Springer, Heidelberg. In his lecture “The Role of Accurate Mass Measurement in Chemical, Analytical and Medical Mass Spectrometry” G. Brenton outlined how high-resolution mass spectrometry