R. Djingova

On the microwave digestion of soils and sediments for determination of lanthanides and some toxic and essential elements by inductively coupled plasma source mass spectrometry

Four digestion procedures for microwave dissolution of soils and sediments are investigated. Accurate results (accuracy better than 10%) for lanthanides, Be, Bi, Te, Th, U and Y are obtained only after an overnight stay with a mixture of 2 ml 48% HF and 2 ml 65% HNO(3) and afterwards stepwise microwave digestion with 1 ml 48% HF and 10 ml 5% H(3)BO(3). Only As is not be to be determined by this procedure due to significant interferences from Eu, Nd and Sm. For all other elements, accurate results are obtained by all four procedures.

Chemical fingerprinting of plants

The chemical fingerprinting of a plant demands the determination of a large number of elements at background level but also in polluted regions and in relation to other species. The most important stages of the development of plant fingerprints are mentioned in this paper and a short survey of the state of the art is presented. Examples on fingerprinting of lichens, mosses, Taraxacum officinale and Populus nigra‘Italica’ are presented.

Bromine, copper, manganese and lead content of the leaves of Taraxacum officinale (dandelion)

Neutron activation analysis and atomic absorption spectrometry have been used to determine the Br, Cu, Mn and Pb content of leaves of Taraxacum officinale (dandelion). The elemental content of the leaves correlated with the extent of anthropogenic pollution of the region where the plant developed. The dependence of the element concentrations on the distance from the source has been evaluated. A positive linear correlation was observed between the Cu and Pb, Cu and Sb, Pb and Cd, and Pb and Zn content of the leaves.

Determination of rare earth elements in soils and sediments by inductively coupled plasma atomic emission spectrometry after cation-exchange separation.

The influence of matrix elements such as Ba, Ca, Fe, K, Na and Ti, on the inductively coupled plasma atomic emission spectrometry determination of the rare earth elements in soils and sediments is investigated and analytical lines with minimal interferences are chosen. The analysis of certified reference materials by two calibration methods (pure rare earth solutions and IAEA-Soil 5) and after cation-exchange proved that calibrations with IAEA-Soil 5 increase the number of accurately determined rare earth elements (REE), permitting the instrumental determination of Ce, Eu, La, Nd, Tb, Yb and Y in soils and some sediments. The cation-exchange procedure permits the determination of 12 REE with very good accuracy (below 10%) and detection limits varying between 0.05 (Eu, Tb, Yb) and 0.5 (Er) mg kg(-1).

INAA and flame AAS of various vegetable reference materials

SummaryINAA and flame AAS have been used for the analysis of a large number of vegetable reference materials. Out of all determined elements (28 by INAA and 11 by AAS) nine are common for both methods (Ca, Cd, Co, Cu, Fe, Mg, Mn, Na, Zn) and for these the possibilities of the two methods have been compared.

Comparison of the ability of several vascular plants to reflect environmental pollution

Abstract The response of Taraxacum officinale, Populus nigra, Trifolium repens, Rumex acetosella, Lolium multiflorum, and Poa annua to heavy metal pollution has been comparatively investigated. The enrichment factor is proposed to be used for quantitative assessment of the accumulation in biomonitors.

Possibilities of ED-XRF with radionuclide sources for analysis of plants

A comparative evaluation of the applicability of different radionuclide sources for the determination of toxic elements in plants by ED-XRF is presented.238Pu or109Cd are suggested as most suitable single excitation sources in ED-XRF for monitoring investigations. More elements are determined with a combination of55F/109Cd(238Pu)/241Am. The results obtained by radionuclide ED-XRF analysis of different plants show that the method permits the reliable determination of Br, Ca, Fe, K, Mn, Rb, Sr and Zn in plant bioindicators. For toxic elements like As, Cd, Cu Cr, Hg, Ni, Se and Pb the detection limits of the method are not low enough.

Comparative evaluation of the possibilities of INAA, ED-XRF, ICP-AES and AAS in the analysis of plants

The usefulness of INAA, radionuclide ED-XRF, ICP-AES and AAS are comparatively evaluated for the determination of nutrients, essential and trace elements in various plant matrices. The comparison is performed by analysis of the following reference materials: NIST-SRM-1573, NIST-SRM-1575, NIES-1, NIES-3, NIES-6, IAEA-V-10 and Bowens kale. The detection limits, accuracy and precision of the methods are discussed and a combination of INAA and GFAAS is recommended for analysis of plants for monitoring purposes.

On the possibilities of inductively coupled plasma mass spectrometry for analysis of archaeological bones for reconstruction of paleodiet.

The possibilities of inductively coupled plasma atomic mass spectrometry for determination of elemental composition of archaeological bones for reconstruction of paleodiet are discussed. The interferences of different polyatomic ions on the determination of Fe, Cu, Mg, Mn, Zn, and Zr are investigated and evaluated. Thus, a method for the determination of Al, As, Ba, Mg, Pb, Sr, V, Zn, and Zr is proposed and is validated by analysis of IAEA-SRM-H-5 (animal bone). The applicability of the proposed procedure is demonstrated analyzing real archaeological bone samples dated to 4th century b.c. and the results are compared with the data obtained by inductively coupled plasma atomic emission spectrometry.

Distribution of lanthanoids, Be, Bi, Ga, Te, Tl, Th and U on the territory of Bulgaria using Populus nigra ‘Italica’ as an indicator

The concentrations of lanthanoids, Be, Bi,Ga, Te, Tl, Th and U have been determined using ICP-MS for 100 standardized samples of poplar leaves collected from the territory of Bulgaria. The investigated elements are log-normally distributed on the territory. Using cluster analysis of the analytical data the samples were grouped according soil type on which the plants are growing.