Methodology for the Collection and Analysis of Trace Metals in Atmospheric Precipitation

摘要

The procedures used for the collection of rain water for trace metal analysis are described. Due to the low concentrations of many trace metals, measures were taken to avoid sample contamination. A clean room was built and acid washing of labware and rain collectors was begun. Graphite furnace atomic absorption spectroscopy (GFAAS) is used to determine trace metal concentrations. Detection limits for the GFAAS system are 0.002 ng Cd/ml, 0.04 ng Cu/ml, 0.02 ng Fe/ml, 0.008 ng Mn/ml, 0.04 ng Pb/ml and 0.02 ng Zn/ml. Findings on trace metal concentration in monthly atmospheric precipitation samples from two sites in southern Sweden indicate that the acid washing of labware and collectors is necessary. Contamination of samples is random and samples are more susceptible to contamination for some metals than for others.