Method development for the determination of Cd, Cu, Ni and Pb in PM2.5 particles sampled in industrial and urban areas of Greater Cairo, Egypt, using high-resolution continuum source graphite furnace atomic absorption spectrometry

Abstract

Energy-dispersive X-ray fluorescence (EDXRF) spectrometry is not adequate for the determination of some potentially hazardous trace elements, such as Cd, Cu, Ni and Pb at low concentration in PM2.5 atmospheric aerosol particles. Therefore, a method has been developed for the determination of these elements in atmospheric aerosol particles using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GF-AAS) without using modifiers. The pyrolysis and atomization temperatures were optimized for this analysis. The samples were collected from industrial and urban areas of Greater Cairo, Egypt. Atmospheric aerosol particles, PM2.5, have been collected on polycarbonate filters loaded by a cyclone sampler. The duration of the collection was 24h at an air flow-rate of 3Lmin−1. Microwave-assisted acid digestion with ultra-pure nitric acid was used to dissolve the polycarbonate filters, including the atmospheric aerosol particles. For the validation of the methods, the results were compared with those obtained by total reflection X-ray fluorescence (TXRF) and inductively coupled plasma mass spectrometry (ICP-MS). Good agreement between the results of the different spectrometric techniques was found. The measured concentrations of Cd, Cu, Ni, and Pb were below the limits defined by international guidelines and national standards of ambient air quality.