Chromium in marine sediment samples from the Ria de Arousa (Galicia, NW of Spain): analysis of the total content in slurries by ETAAS

The study attempts to measure the total chromium content in sediments of all the Ria de Arousa (Galicia, NW Spain). The method was developed by analysing slurries by electrothermal atomic absorption spectromety. The metal determination was carried out optimising the electrothermal programme and the concentration of magnesium nitrate as a chemical modifier. What was aimed to be achieved is a general explanation of the chromium content along the estuary because there could be a chromium sink in this marine environment. Results obtained were between 43.4(plus-minus)1.7 (mu)g g^-1 and 184.6(plus-minus)26.9 (mu)g g^-1 from the end of the Ulla river to the Atlantic Ocean, most of them higher than the background reference levels.