Chromatography Forum

Dear all,


I am trying to run pentachlorophenol method on GCMS. As there is installed one column RTX-1301 that is of mid polarity. I tried to get that pentachlorphenol method on the same column (just avoid changing columns for different methods). But I couldn't see peaks of PCP and IS Tribromphenol (both in acetate forms). I could see peaks of hexane, acetic anhydride (derivatisation agent) and other, but no needen peaks. I lifted temperature upt o 260 (max temp for that phase) and tried with quite high linear velocity of helium.


so maybe it's imposible to have PCP and TBP acetates out from column with that kind of stationary phase?? What you think??

Or it could be that derivatization with acetic anhydride wasn't succesfull??

I am working according EN normative where extraction is with methanol, derivatization with acetic anhydride in presence of potassium carbonate. then liquid liquid extraction with hexane and GC analysis.


So maybe somebody alreday had some exprience with that. Maybe some advises


kindly thanks in advance

First thing I would do is to confirm that my analyte is getting through to the detector by injecting a known standard at a known concentration.

Once that is confirmed, then I would spike a sample preparation with the analyte and confirm that my matrix is not effecting the elution of the analyte, the analyte is stable in the matrix and under my injection conditions.

After that I would evaluate my derivitization reaction and determine if my reagents were effective.

One step at a time. You will find your answers.

best wishes,

Rod

I have not used this method and I cannot improve on the advice of Chromatographer1, but can you tell us what is the number of the European Standard you are working to?

For example if it was CEN report TR 14823:2003 that was produced by working group 26 of CEN committee TC38
http://www.cen.eu/CENORM/BusinessDomain ... EN%2FTC+38

Assuming this is the correct standard and if you still can't get this method working you could address technical questions through the Lithuanian Standards body to reach the convenor of CEN TC38/WG26. Or Google will tell you who the WG26 convenor is. He is Swedish but I am not going to name him here. WG26 are the best people to know the problems with their own method.