Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:8270d:p1
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 8270D (pt 1/2)
Character Range: 816408–819622

8270D   GC/MS

    10.2.7     Total recoverable hydrocarbons
The term total recoverable hydrocarbons (TRH) is equivalent to the previously used total petroleum hydrocarbons (TPH), and represents extracted biogenic (biological) and petrogenic (petroleum) hydrocarbons by selected solvents. The term has been chosen to avoid confusion with past practices. Where significant levels of non-petroleum hydrocarbon interferences are suspected, a silica gel clean-up is recommended, in which case the analytical report should include a clear statement about this and any relevant interpretation of the chromatogram; the analysis should be referred to as 'TRHsilica'. See Section 11.2.8.1.

When soil contains high levels of non-petroleum-based hydrocarbons (e.g. from heavy manure, compost additions or polymeric materials), inspection of the TRHsilica chromatogram may reveal that the silica gel clean-up was not sufficient to remove the non-petroleum-based hydrocarbons from the sample and resolve interferences. This can result in false positive results for petroleum-based hydrocarbon determination. In these cases it is recommended that GCMS—or other appropriate analytical method, e.g. nuclear magnetic resonance (NMR)—is applied to the extract or a silica gel cleaned sample to improve accuracy.

The analyst should discuss any unusual profiles—and the possibility of interferences from high biogenic hydrocarbon—with the site assessor, before issuing the report.

Where it can be determined that compounds in the sample are of non-petroleum origin, the results should be adjusted as far as practicable to finalise the level of petroleum-based hydrocarbon in the sample.

TRH fractions are based on those used to derive the Health Screening Levels (HSLs) for petroleum hydrocarbon compounds (See Schedule B1).

The TRH method is applicable but not limited to the analysis of hydrocarbons that may be constituents or residues present in or from materials such as the following:
    kerosene
    diesel
    aviation fuel
    lubricating oil
    heating oil/marine fuel
    dry cleaning liquids
    tars
    gasworks wastes
    industrial solvents
    paints, thinners and strippers.

    10.2.8     Total recoverable hydrocarbons by solvent extraction

10.2.8.1     Scope
This method is for the determination of semi-volatile TRH in soil by gas chromatography applicable to hydrocarbons eluting between >nC10 and nC40. The method extracts major hydrocarbons such as aliphatic linear, branched and cyclic hydrocarbons, PAHs, and other compounds in the boiling point range up to nC40. If PAHs are suspected of being present in a sample, target analysis techniques are preferred for risk assessments.

Hydrocarbons with boiling points less than nC10 (volatiles) or greater than nC40 (heavy petroleum compounds) will not be quantitatively determined using this method.

TRH can be defined as those compounds that are extractable into the solvent and elute from a GC column under the conditions specified in the test method. Hydrocarbon interferences such as vegetable and animal oils and greases, organic acids, chlorinated hydrocarbons, phenols and phthalate esters will also be measured. The presence of petroleum