Evaluation of wet deposition of heavy metals in Washington, DC using graphite furnace atomic absorption spectrometry

ANYL 56

S. Melaku, samuelmelaku@yahoo.com1, Charles M. Hosten, chosten@howard.edu1, D. Raghavan, draghavan@howard.edu2, and Vernon Morris, vmorris@howard.edu1. (1) Department of Chemistry, Howard University, 525 College Street, NW, Washington, DC 20059, (2) Polymer Program, Department of Chemistry, Howard University, Washington, DC 20059
Atmospheric wet deposition samples were collected on the campus of Howard University, Washington, DC, beginning in January 2006. The aim of this study is to determine the seasonal variation of the atmospheric wet deposition of three heavy metals (As, Cd, and Pb) to the Washington, DC watershed. The analytical procedure was validated using Graphite Furnace Atomic Absorption Spectrometry (GF-AAS) by the analysis of standard reference materials of Urban Dust origin, SRM 1649a. A recovery of 62-98% was obtained. The limits of detection of the instrument were found to be 0.015, 0.057 and 0.059 µg/l for As, Cd, and Pb, respectively. A number of wet deposition samples were analyzed. We observe a slightly increasing trend in the concentration of lead whereas for arsenic and cadmium their concentrations remain relatively constant from winter to spring.
 

General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006