System's uncoated solid-source material and higher temperature filaments reduce typical performance problems in the analysis of polynuclear aromatic hydrocarbons
Agilent Technologies says that its inert gas chromatograph/mass selective detector (GC/MSD) system improves the analysis of polynuclear aromatic hydrocarbons (PAHs), a class of pollutants found throughout the environment.
This system provides scientists in the food safety and environmental industries with a reliable and robust means of monitoring these widespread compounds.
PAHs are formed by the incomplete combustion of organic substances such as coal, oil, gas, garbage, tobacco and meat.
Exposure to PAHs usually occurs by breathing polluted air or consuming contaminated water or food.
Laboratory tests indicate that PAHs are carcinogenic and may also harm the reproductive and immune systems.
The US Environmental Protection Agency lists 16 PAHs as 'priority pollutants', and the US Department of Health and Human Services includes PAHs in its registry of toxic substances.
The analysis of PAHs can be problematic because of the tendency of these compounds, particularly ones with high molecular weights, to adhere to the surfaces of the analytical system.
Typical PAH analyses, therefore, show decreasing response and sensitivity with increasing molecular weight.
This trend results in nonlinear calibrations and the need to use selected ion monitoring (SIM) for low-level analyses.
The Agilent 6890/5973 inert GC/MSD system has features that enable more accurate PAH analysis.
These include an uncoated solid-source material and higher temperature filaments for improved response and peak shape.
The system also features a direct-connect inlet liner to allow the complete transfer of analytes onto the column, eliminating the problem of inlet discrimination and further increasing sensitivity.
Although full-scan data are preferable to SIM data for compound confirmation, low-level PAH analyses have historically required the use of SIM mode because of instrument sensitivity considerations and the loss of PAHs at lower concentrations.
With this system, users can now analyse PAHs at low levels in full scan mode while maintaining linearity across a wide calibration range.
Results show that this system can analyse PAHs using full scan data acquisition over a calibration range of 0.1 to 10 parts per million with performance similar to SIM methods.
Further information is available by requesting Agilent application note 'Full-scan low-level polynuclear aromatic hydrocarbon analysis using the Agilent Technologies 6890/5973 inert gas chromatograph/mass selective detector', publication 5989-0264EN.
This note is available without charge from any Agilent sales office or its website.
