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Amperometric or Coulometric EC?

Posted: Mon Jul 30, 2007 7:43 pm
by foren
Hi all,
I will try to adapt an HPLC-EC method for SAM (s-adenosylmethionine) and SAH (s-adenosylhomocystein). Virtually all of the literature data are based on colometric detection. I will only have access to a Recipe EC3000 with EC4000 cell (model sputnik). I don't have the manual yet.
I may handle the sample prep and separation but I don't have much experience with EC.
Are there great differences between amperometric and coulometric cells?
Can I run an amperometric cell and have a response comparable to coulometric cell?
Best regards,
Foren

Posted: Wed Aug 15, 2007 7:21 am
by Markus Laeubli, Metrohm
Back from my job in instrument development I have the experience that there is almost no difference between amperometric and coulometric detection. In amperometric detection usually approx. 10 % of the component is converted (coulometric detection 100%). The lower signal of the amperometry is usually compensated by the higher background/noise of the coulometric detection.