TIME DEPENDENT CHARACTERIZATION of OMBROTROPHIC PEAT CORES from POLAND and AUSTRIA for STUDYING ATMOSPHERIC DEPOSITION of METALS

Ombrotrophic peat bogs form an independent ecosystem fed entirely by atmospheric deposition. Ombrothropic peat preserves the record of deposition of metals of crustal origin and anthropogenic origin that is, caused by industrial, agricultural and other human activities. Two cores each of 40 cm length were taken f?om the peat bogs in southern Poland and the alpine region in Austria. The cores were cut in to 2 cm sections and dated using the natural radionuclide 210Pb with a half life of 22.3 years. Pollen analyses were performed in order to corroborate the 210Pb dating. Several elements and ash content were determined in all the sections. The Energy Dispersive X-ray Fluorescence (EDXRF) method with usining pellets and Total Reflection X-ray Fluorescence Analysis (TXRF) were applied in this work for the determination of 16 elements. The values of detection limit (LOD) are in the range of few pg/g for low atomic number Z elements and fractions of ug/g for medium and high Z elements. The precision (rel. stand. deviation) of the method for the determination of low Z elements is within l-3%; for TXRF the values of precision are within 1.3% 13% depending on the concentration. The accuracy of the method was tested using various standard reference materials. Concentration depth profiles for the determined elements and ash content were constructed, and show strong time dependent variations. The majority of the elements were significantly lower in the Austrian core from the mountain bog (1360 m above sea level) than in the Polish one (656 m above sea level), which can be attributed to different climatological conditions. The concentrations of Pb and Zn in all cores could indicate their anthropogenic origin. INTRODUCTION Ombrotrophic peat bog is fed only by atmospheric fallout. It has long been considered to preserve the record of atmospheric deposition of metal pollutants [l]. The history of atmospherically derived pollution specifically by Pb of this ecosystem is nowadays of great interest to many scientists [2,3,4]. Other elements of both crustal and anthropogenic origin are also worth studying [5]. There have been some studies on the determination of the concentrations of Zn, Cu, U, V and other elements in the top 40 cm of peat cores from Czech Republic [6], Scotland [7], Canada, Sweden and New Zealand [8,9], which suggested the accumulation of these elements in peat. In this paper we present the results of the study of two peat cores from ombrotrophic bogs, one from southern Poland, the other t?om the alpine region in Austria. The methods of sampling of the cores, sample preparation, dating by means of 210Pb, and pollen analysis have been described in detail elsewhere [5]. In this paper the analytical procedures will be more widely discussed. Copyright(c)JCPDS-International Centre for Diffraction Data 2000,Advances in X-ray Analysis,Vol.43 553