Polar and non-polar volatile organic compounds (VOCs) in urban Algiers andsaharian sites of Algeria

For the first time, polar and non-polar organic compounds From C-4 to C-20 have been identified and quantified in one urban and two saharan sites loca ted in Algeria. They were collected on adsorption traps filled with graphit ic carbons and analyzed by high-resolution gas chromatography-mass spectrom etry after thermal desorption. More than 190 compounds released by man-made and biogenic sources or formed in air by degradation of photochemical smog precursors were identified in the city center of Algiers. Some of them wer e never reported before. During our determinations, high levels of pollutio n characterized the city. Transport of anthropogenic pollutants together wi th some biogenic emission from date palm trees was mainly responsible for t he levels of VOCs measured in Melika oasis located at the entrance of the S ahara desert. Background tropospheric levels of VOCs were instead detected in Bouchene sandy site of the Sahara desert where no biogenic sources were present. (C) 2001 Elsevier Science Ltd. All rights reserved.