Determination of Concentration of Heavy Metals in Wood Ash

Abstract

Heavy Metals such as lead, chromium, and arsenic are thought to be present in wood ashes. As many people use wood ash in gardens, we decided to test how easily these metals can be extracted from wood ash. Metals were extracted from 10-gram samples of ash by mixing with 100 ml of 2.0% trace metal nitric acid, gravity filtering, and final filtering with a 0.22 um. nylon syringe. Absorption data for the extracted samples was compared to a calibration curve of absorption versus concentration constructed from data obtained with a Shimadzu AA7000. Initial results indicate that the concentration of the metals are below the lower limit of detection for Cr, As, and Pb which are 0.2 ppm, 2.0 ppm, and 0.5 ppm respectively. However, the laboratory-fortified matrix sample for each metal failed, thus we will need to perform standard addition tests to certify these results.

This work was supported by NASA WV Space Grant Consortium training grant number 80NSSC20M0055.