Articles & Tech Notes

Introduction Polycyclic Aromatic Hydrocarbons (PAHs) are large class of compounds comprising two or more fused aromatic rings. PAHs are naturally occurring in fossil fuels and their derived products and can be formed during incomplete combustion of carbon based fuels. As such they are a by-product of many industrial processes. PAHs vary greatly in size, nature and hazard to human health, some are not classified as toxic, where as others are known carcinogens. The IARC specified 16 as being of particular interest, others have subsequently added this list. In all, over 100 PAHs have been described. Given the risks and potential risks to human health presented by PAHs, many high risk organisations, such as Foundries, Bitumen Works & Smoke Houses routinely monitor workers and their environment for PAH levels. Typically PAHs are trapped using filters (particulate forms) or resins such as XAD2 (gaseous forms) through which work place environmental air is drawn. Filters may be situated in a small device attached to the workers overalls, or from larger units measuring the air in a wider area. Potential problems exist when recovering the PAHs from the filters and preparing the samples for analysis, principally, losses due to PAH volatility are reported for bi- and tri-cyclic PAHs (ISO11338-2:2003). Therefore, ITGA undertook a study to improve sample recovery and therefore PAH determination when working with low and very low levels of analytes.