Heptanesulfonic sodium salt as Buffer

[mobunvar]

Can I any one tell me about Heptanesulfonic sodium salt as Buffer in HPLC ? I tried to search about its information but i am unable to get it ? I want its UV cut-off and its reaction on C18 column and also along with other organic solvents especially ACN ?

Will it harm column ? or is it better than Potassium buffer when i want to use pH of 2.3 ?

[alemaggot]

You find some information about it in the end of this post:

viewtopic.php?f=1&t=19081

Bye!

[bisnettrj2]

Heptanesulfonic acid is used as an ion-pairing agent, not a buffer. If you have very basic compounds you're trying to analyze, or you have some very polar compounds you need to retain on a C18, ion-pairing chromatography is useful, but there are caveats about its use, one of which usually is that you should dedicate that column to ion-pairing only.

If you want a pH buffer only at pH 2.3, phosphate is the choice for you, depending on your method of detection. UV and phosphate are good, phosphate has a low UV-cutoff. MS and phosphate are bad, phosphate isn't volatile.

Here are some buffer recipe calculators - the ZirChrom one has good info about buffer properties and prep, the second one accounts for pH as a function of temperature (important when prep temp is much different than use temp - like in HPLC).

http://www.zirchrom.com/buffer.asp

http://www.liv.ac.uk/buffers/buffercalc.html