Decontamination procedure for trace elements determination in coral skeleton samples

Abstract

The three most used decontamination procedures for coral samples were evaluated in order to subsidize the development of a simpler, faster and more efficient cleaning procedure for decontaminating coral skeleton for trace element determinations using ICP OES. The procedures tested involved a sequence of ultrasonic cleaning with deionized water, 0.2 mol.L− 1 HNO3 and/or an oxidizing mixture of 30% H2O2 and 0.2 mol.L− 1 NaOH in an ultrasonic bath to remove particles and residues from saw blades used during the collection and pretreatment of coral samples. The main contaminants identified were Fe, Cu and Zn. The three decontamination procedures tested were efficient, but indicated that the decontamination steps with deionized water are unnecessary. The procedure proposed in this study proved to be more efficient, as only one extracting agent was used, the number of steps required to decontaminate the coral samples was reduced, consequently saving time and increasing analytical frequency.