Multielemental analysis of macroalgae from the Baltic Sea by ICP-OES to monitor environmental pollution and assess their potential uses

Abstract

The aim of this article was to discuss the mineral composition of marine edible macroalga Enteromorpha spp. sampled from the coast of the Gulf of Gdańsk and from the open Baltic Sea, with the consideration of its use both as biomonitor and also as a future feed additive for animals and food for humans. The mineral content of Baltic seaweed was determined by the multielemental analysis by ICP-OES Vista-MPX instrument from Varian (Australia). The results indicated geographical and seasonal differences between concentrations of elements. The content of microelements in all examined macroalgae was at a rather steady level. Significant fluctuations were observed in the content of macroelements – generally, Enteromorpha spp. from the southern Baltic contained more alkali (Na, K) and alkaline earth metals (Ba, Mg, Ca) than macroalga from the Gulf of Gdańsk. In order to determine the degree of accumulation of each element by the green alga, concentration factors (CFs) with respect to seawater were calculated. This factor for Fe, Al, Cu, Mn and Ti in algae was much higher, than for K, Ca, Mg and Na. The composition of Enteromorpha spp. was also compared with grains (corn, spring wheat, spring triticale, spring barley, oat, rye), which are commonly used as feed material. Macroalgae contained on average 56 times more Na(I), 11 times more Mg(II), 8 times more Ca(II), 5 times more K(I) and 3 times more Cu(II) than the grains mentioned previously. The content of Mn(II) was 20% higher.