Anionic IP reagents: sulphonates vs. sulphates

[Rob Burgess]

Is there any valid reason to use one type in preference to another. The HPLC method development "bible" doesn't seem to suggest any.

It has come to my attention that high purity equivalent sulphates (> 99% purity) are considerably cheaper than specifically sulphonates labelled for ion-pair applications. Is there any reason for this from the chemical manufactureres I wonder?

[tom jupille]

Both have been used, and I'm not aware of any a priori reason to prefer one of the other. I wouldn't be surprised to see selectivity differences, however (i.e., it's probably not a "plug in" substitution).

I suspect that the predominance of the sulfonates arises from the fact that they were used early on and popularized with the Waters PIC reagents.