Oil in wastewater analysis by GC

[Iain C]

I work for a waste management company and we are currently looking for a method of analysing oil concentration in wastewaters, specifically garage forecourt-type interceptors. Any visible oil layer would be physically separated off by decanting, and it would be the remaining aqueous phase which we are trying to test. We have explored various IR and UV absorbance instruments but none have proved satisfactory, so this leaves us with the GC route. Has anyone any experience of this type of analysis and if so can they offer any advice?

[bhuvfe]

Solvent extraction with CHCl3 after addition of 20-30 % NaCl to your sample (using GC-MS or GC-FID as detectors)?

[GasMan]

You should try to get a copy of the ISO 9377 method. This method is for looking at oil in surface water and uses a GC with an FID.

Gasman