engleski

Determination of selected metals in freshwater sponge (Eunapius Subterraneus) by atomic spectrometry methods

The Ogulin cave sponge (Eunapius Subterraneus) belongs to a multitude of over 300 endemic species of underground fauna in Croatia. Metal content in sponge, water and in sediment, is very important marker of pollution for this ecosystem. We determined metal concentrations for some toxic and essential metals (Fe, Mn, Cu, Zn, Ca, Mg, Ba, Sr, Ni, Cd and Pb) in sponge tissue, water and sediment using atomic spectrometry methods. These techniques require total digestion of solid samples by using strong acids such as HCl, HNO3, H2SO4, and dilution with water. Results obtained for sponge and water samples of different locations show variations in metal content. The Dinaric karstic area is acknowledged as the richest reserve of the subterranean water fauna, where the Ogulin region in Central Croatia is one of the hot spots of biodiversity with high number of endemic species. The Ogulin cave sponge (Eunapius Subterraneus) belongs to a multitude of over 300 endemic species of underground fauna in Croatia. It dwells exclusively in the karst subterranean waters of Ogulin region.1 Karst underground streams have poor natural purification ability against all kinds of pollution. Therefore, metal content in sponge, water it lives in and sediment, is very important marker of pollution for this ecosystem. We determined metal concentrations for some toxic and essential metals (Fe, Mn, Cu, Zn, Ca, Mg, Ba, Sr, Ni, Cd and Pb) in sponge tissue, water and sediment.2, 3 Samples were collected during February 2004. Samples of water were taken from caves: Medvedica, Zala, Gojak and Tounjčica, samples of sponges were taken from caves: Gojak and Tounjčica where help of speleodivers was needed, as for the sample of sediment, it was taken from cave Medvedica. The samples were stored immediately in a cool box and then transferred to a refrigerator, where they were stored at 4 º C until beginning of the analysis. The common procedures for chemical analysis of biological tissue, natural water and sediment are atomic spectrometry methods, ICP-AES (inductively coupled plasma atomic emission spectrometry) and FAAS (flame atomic absorption spectrometry). These techniques require total digestion of solid samples by using strong reactants of high purity such as HCl, HNO3, H2SO4 and H2O2. Obviously, sample preparation is the crucial first step in the analysis of this kind of samples. By preparing of blank solution analytical procedure was better controlled. Water samples were preconcentrated before measurement. All prepared samples were diluted using high-purity water (Milli-Q type). Elements Ba, Sr, Al, Fe and Mn were determined using ICP-AES, and Pb, Cu, Zn, Cd and Ni by FAAS. Metal concentration observed for preconcentrated water samples differ due to a location of sampling. Measured content did not excide maximum acceptable concentration limits (MAC) given with Croatian laws for water quality. There is also noted the difference in metal content for sponge samples for different location of sampling as expected. By comparing results from different location of sampling, it is obvious that there are some variations in metal concentrations for sponge and water samples. Higher toxic metal content is probably result of anthropogenic pollution and might originate from a nearby energetic plant. General conclusions about influences of metal content variation in such sensitive environmental system could only be drawn after long term monitoring studies.

freshwater sponge; metal content; ICP-AES; FAAS

nije evidentirano