Have any of you had success with HPLC analysis of peptides that require basic pH to keep in solution and are very hydrophobic?

Hi,

For a simple separation at a basic pH you could try a column with a polymeric (PSDV) packing. If you need higher plate counts you could try some of the newer silica column that are more base stable. I have had good column lifetimes with the Develosil columns with pH in the 8-9 range. If you need a pH greater than this you could try the new Zorbax bi-dentate column (I think its brand name is Extend). I tried a prototype of this column on a basic small molecule and had stable column performance out to 5000 column volumes of pH 10.6 mobile phase. Water's also has a new base stable hybrid column, I haven't tried it yet.
If this isn't what you were looking for provide a little more information and someone will try to help. Good luck.

ZirChrom's PBD-coated zirconia columns work well under basic conditions.

Thanks for the help. We are currently using a Waters Xterra, 4.6 x 150mm, C8 (dp 3.5µm) column at pH 10.7 and it appears to be working well. I've seen ads for the other columns that are useful at high pH but haven't had time to try them. We use a binary gradient of mobile phases containing water/ACN/20mM NH4OH. We're using NH4OH because we have to work at 215nm.