Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:3630c
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 3630C
Character Range: 821240–821964

3630C  Silica gel clean-up
       Clean-up is necessary if the extract contains interfering quantities of polar non-petroleum compounds evidenced by a GC/FID profile or GC/MS analysis uncharacteristic of petroleum hydrocarbons.

       Clean-up may be achieved after solvent exchange to hexane or other suitable solvent. Clean-up can be either carried out using a silica gel column or by shaking a solvent extract with loose silica gel.

       Silica gel activity may have to be adjusted by water addition for optimum retention of PAHs and TRH in the extract. US EPA Method 3630C gives conditions for silica gel clean-up of PAHs.

10.2.8.4     Extract Analysis
The table below lists the specified US EPA SW-846 methods.