Questions about trace metal preservation are resurfacing because the health effect risks associated with certain metals continue to drive the required reporting limits lower. Inductively coupled plasma-mass spectrometry was used in this study to analyze preservation of samples containing trace metals. Metal concentrations in nonacidified drinking waters may decrease if the sample is held for two weeks. Acidification of these drinking water samples resolubilized the metals that had fallen out of solution. The preservation of metal samples within drinking waters by acidification to a pH of <2 effectively stabilized the metal concetration for 180 days. Includes 13 references, tables, figure.