Trace metallic elements of Cr, Ni, Mn, and Cu in the atmospheric samples were determined by atomic absorption spectroscopy. Organic membranes coupled with a low volume air sampler were utilized to collect air samples since conventional glass fiber filters were found to be unsuitable for this purpose. A new sample preparation technique and flame conditions were discussed to improve the accuracy of the analysis.
Jae Y. Hwang and Fredric J. Feldman, "Determination of Atmospheric Trace Elements By Atomic Absorption Spectroscopy," Appl. Spectrosc. 24, 371-374 (1970)