Chromatography Forum

Hello, I am trying to develop the method for PCB analysis in transformer oil by GC ECD; I am adapting the EPA 8081 methodoly; but i have serious problems with the sample treatment; I would like to test with SFE fro extraction and may be a SPE diferent than Florisil.

Any advice is wellcome.

Thanks in Advance.

Oscar.

Oscar,

The dioxin sample system sold by my company Supelco has a normal phase column followed by a dual carbon layer column which will pass the oil but retain the PCBs and dioxins for reverse elution with toluene.

Glassware and connections are available to do custom research.

Recoveries are quite good with this dual layer carbon column from a great many matrices.

I would suggest that you call Supelco technical service

800-359-3041 or techservice@sial.com

and ask for a bulletin or check out the web site for information:

www.sial.com

See the Supelco 2007/8 catalog p197-199

best wishes,

Rod

Thanks Rob for your replay:

I need to ask you sometinhg.
With this system I do not have to do extraction before clean up?
I just take the oil sample and pass it trought the column?

This sounds very good, I will follow your advice!!

Addtional to this I am still interested to know a about SFE, because i will need to do anothers kind of analysis like, pesticides in sediments, and solid wates.
If some one else can giveme an oppiniom abou it, it will be good.

Regards
Oscar.

Try out 8082 instead of the pesticide method, 8081.
http://www.epa.gov/epaoswer/hazwaste/test/pdfs/8082.pdf

The normal prep method for oils is dilution in hexane or similar solvent. Then the cleanup starts. The more oil you can remove the better your chromatography and the less your signal suppression. Clean up columns can be nice or essential depending on your requirements and how low of concentration you need to see. Acid treatment and silica gel or Florisil is a minimum. The carbon columns can be a big help. Some time and money invested in the cleanup pays big dividends in the analysis.

OscarBal,

I would recommend the hexane dilution followed by sulfuric acid/florisil cleanup if you have to do lots of oil samples. I have used this method extensivly and have had very good luck in almost all cases.

Best regards.