Monitoring and Method development of Hg in Istanbul Airborne Particulates by Solid Sampling Continuum Source-High Resolution Electrothermal Atomic Absorption Spectromerty

Istanbul Technical University, Faculty of Science and Letters Department of Chemistry, 34469, Maslak, Istanbul

Abstract

In this work, a method has been developed and monitoring for the determination of mercury in PM2.5 airborne particulates by solid sampling high-resolution continuum source electrothermal atomic absorption spectrometry. The PM2.5 airborne particulates were collected on quartz filters using high volume samplers (500 L/min) in Istanbul (Turkey) for 96 hours every month in one year. At first, experimental conditions as well as the validation tests were optimized using collected filter. For this purpose, the effects of atomization temperature, amount of sample intoduced in to the furnace, addition of acids and/or KMnO₄ on the sample, covering of graphite tube and platform or using of Ag nanoparticulates, Au nanoparticulates, and Pd solutions on the accuracy and precision were investigated. After optimization of the experimental conditions, the mercury concentrations were determined in the collected filter. The filters with PM2.5 airborne particulates were dried, divided into small fine particles and then Hg concentrations were determined directly. In order to eliminate any error due to the sensitivity difference between aqueous standards and solid samples, the quantification was performed using solid calibrants. The limit of detection, based on three times the standard deviations for ten atomizations of an unused filter, was 30 ng/g. The Hg content was dependent on the sampling site, season etc, ranging from <LOD to 450±64 ng/g in Istanbul. In addition that direct determination of the Hg content in the samples, addition of AuNPs, AgNPs and Pd solution for amalgamation effects on the recoveries were investigated. The results were compared using statistical tests.