Possible transformation of zinc dissolved in mediterranean coastal sea water

Abstract

In current studies on the behaviour of trace elements in seawater, special attention has been directed to the chemical speciation of trace elements and dynamic equilibria between different chemical species in situ. The evidence to date for the association of various trace elements with organic molecules has been critically reviewed (FUKAI, 1970), and the conclusions deduced indicate that the occurrence of organically bound trace elements in seawater can now be regarded as an established fact, though contradictory evidence was obtained in some cases as to the chemical nature of organic compounds involved. Very little is known, however, about equilibria between different chemical species of any trace element in seawater as well as the possibility of transformation of one chemical species into another. Determinations of different chemical forms of in the seawater around Monaco were carried out over a period of 16 months during 1970-1971 in order to obtain some insight into an understanding of the processes involved in chemical speciation in situ. Sea water samples were periodically taken from the surface at a station situated i km south of Monaco, brought to the laboratory immediately after sampling, filtered through Millipore filters of 0.45/zm pore size and analyzed for and total as soon as possible thereafter. All possible precautions against sample contamination were taken. The extractable zinc was determined by direct extraction of with dithizone at pH 7+0.5, removal of copper at pI-I around 2 and successive spectrophotometry; similar