A new technological approach to the analysis and forensic interpretation of TPHCWG in soils and waters using 2D gas chromatography method (GCxGC)

The objective was to develop an analytical methodology for TPHCWG. Raw data from this method is then to be evaluated for forensic interpretation and risk assessment modelling. The development of methods for forensic tracing... [ view full abstract ]

The objective was to develop an analytical methodology for TPHCWG. Raw data from this method is then to be evaluated for forensic interpretation and risk assessment modelling. The development of methods for forensic tracing contaminant sources, transport modelling, human health risk modelling and detailed quantitative risk assessment.

Validation was through a designated systematic experimental protocol and challenged with spikes of known concentration of parameters such as recoveries, precision, bias and linearity. The method was verified by testing a CRM which was used as a proficiency testing for numerous laboratories.

Quantification of compounds were key to developing this method. It was required to individually map out where each compound falls chromatographically in the 2D. This was done through comparing carbon equivalent numbers to the n-alkane carbons. This proved e.g. 2-methylnaphthalene has 11 carbons in its structure; its carbon equivalent is 12.84 , the result of which falls within the band of Aromatic eC12-eC16 as opposed to expected eC10-eC12. This was carried out for all 16 PAH (polyaromatic hydrocarbons) and BTEX.

This method will be used in conjunction with the panel of expert analysis through Bonn Agreement with their OSINet group to which includes CLS. With the use of various statistics differences within numerous fuels and can be used as comparison and identifying tool.

This method has proven itself to be a robust method and benefit the industry for contaminated land and water. It will help identify contaminants and assist consultants, regulators, clients and scientists valuable information not seen in 1D.