INFLUENCE OF WASHING AS PRETREATMENT OF BEACH SEDIMENT SAMPLES FOR TRACE ELEMENTS DETERMINATION BY ICP OES

The State of Espirito Santo has a coastline with great touristic potential, with its beaches widely frequented by local residents and tourists. Due to the use and occupation of the coastal region, this environment is exposed to contamination of chemical and biological origins, bringing risks to the population and the environment.
In the universe of contaminants, it is possible to highlight the trace elements that even found in small proportions, represent a risk to the environment and human health. Heavy metals occur naturally in sediments, however, in the last decades, anthropogenic activities have substantially increased the concentration of some of these elements in several ecosystems.
Therefore, this project used the technique of inductively coupled plasma optical emission spectrometry (ICP OES), one of the main techniques used to environmental samples analysis, to determine trace elements in beach sediments. Because it is a sensitive technique with low detection limits, the samples analyzed by ICP OES undergo pretreatment in order to eliminate any interferences that might impair the quantification of the analytes and obtain also samples in an appropriated form to be introduced in ICP OES.
The sediment samples with or without water washing were digested in ultrapure nitric acid using microwave radiation, following the method US EPA 3051a, for the extraction of the pseudo-total fraction of the analytes. The results obtained in the analysis did not show significant differences in the concentrations of the studied metals for the washed and unwashed samples.