Determination of volatile organic compounds in coal, fly ash and slag samples by direct thermal desorption/GC/ms

This work proposes a method for quantifying volatile organic compounds (VOCs) in coal, fly ash and slag, coming from coal-fired power stations, using direct thermal desorption coupled with gas chromatography (GC) and mass spectrometry (MS) detection. The described method requires practically no sample handling and is precise and sensitive. Aromatic and aliphat ic hydrocarbons (benzene, toluene, alkylbenzes, heptane and octane) are the most abundant compounds in these solid samples, coal samples presenting higher levels than fly ash and slag. Other compounds (acids, ketones, aldehydes, limonene, etc.) were identi- fied by mass spectrometry.