Determination of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn in red wine samples by inductively coupled plasma optical emission spectroscopy: Evaluation of preliminary sample treatments

A comparative study of sample treatment for removing the organic matter (mainly alcohol) to analyse red wine samples for metal content (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn) from ICP-OES has been carried out. Thus, three procedures have been assayed before metal analysis: Dry ashing (DA), wet ashing (WA) and the removal of alcohol by evaporation (AR). The obtained results showed that the three methods lead to unbiased recoveries close to 100%. However, the uncertainty of AR method was about twice of the remainder ones. From practical considerations, the DA procedure was considered more suitable for determining metal elements in wine samples by ICP-OES.