What role does Sodium Dedecyl Sulfate play in Mobile Phase

[Charissa]

What role does Sodium Dedecyl Sulfate (SDS) play in Mobile Phase? I have a test method where SDS is added to acidified Methanol: Water (2:1). I would like to understand if SDS affects the retention time of HPLC Analysis using the above mentioned mobile phase? If it does, how?

Thanks in advance for any comments.

[tom jupille]

SDS acts as an ion-pair reagent.

Do a search of the Forum using "ion pair" as the keywords and you will get a tremendous amount of information about the topic. Chris Pohl had a very informative post a few weeks ago (maybe a bit advanced for your question, though):
http://www.sepsci.com/chromforum/viewto ... t=ion+pair

[Charissa]

Hi Tom,

Thanks for the tips. I will certainly do a search using your suggestion.

Charissa