Determination of zinc levels in waters from southeastern Spain by electrothermal atomic absorption spectrometry: relationship with industrial activity

An efficient method for the determination of nanogram levels of zinc in waters (potable, irrigation, waste and sea waters) is described. Acidified water samples were analyzed by an accurately optimized time/temperature program for electrothermal atomic absorption spectrometry. The samples were previously treated with a matrix modifier consisting of 0.1% Mg(NO3)2 in 0.5 M HNO3 and injected through a graphite tube with L’Vov platform. Sample recoveries, repeteability, and analyses of NIST reference material demonstrated the reliability and accuracy of this technique. Zinc concentrations ranged from 2.0 to 73.0 μg l−1. No significant differences among the mean zinc levels determined in the four types of water considered from southeastern Spain were found. Zinc concentrations in waters from the zone were not affected by human and industrial activity.