Formic acid solubilization of marine biological tissues for multi-element determination by ETAAS and ICP–AES

A simple, fast method is described for the determination of Ag, As, Cd, Cu, Cr, Fe, Ni, and Se in marine biological tissues by electrothermal atomic-absorption spectrometry (ETAAS) and Na, Ca, K, Mg, Fe, Cu, and Mn by inductively coupled plasma–atomic emission spectrometry (ICP–AES). Solubilization of the biological tissue was achieved by using formic acid with vortex mixing followed by heating to 50°C in an ultrasonic bath. Once solubilized, the tissues were diluted to an appropriate volume with water for analysis. Aliquots were sampled into a graphite furnace and ICP–AES using a conventional autosampler. The method was validated by use of biological certified reference materials from NRC, DORM-2, DOLT-2, DOLT-3, LUTS-1, TORT-2, and NIST SRMs 1566b and 2976. Simplicity and reduced sample-preparation time prove to be the major advantages to the technique.