stability diphenyl column ?

[rick1112]

hi

we are finding that there is loss of binding (and R.T variation) in diphenyl columns?
could some one tell the life of these column? do we need to take some extra care for the column?

column details
Pursuit Diphenyl (2.0X150 3 um)
mobile phase
A:-100% water+0.15% TFA
B:-90%ACN in water +0.1%TFA

thanks a lot

[XL]

According to vendor's specification, the low operating pH limit of this column is 1.5. The pH you are using is quite close to pH2 thus should be ok. However, the stability of a column is not "digital" and the lifetime depends on the pH, exposure time, samples, pressures, and etc. How mang hours have you subject the column in the described mobile phase? How did you determine there was a phase loss, retention time trending down, or selectivity change?

[rick1112]

How mang hours have you subject the column in the described mobile phase?

need to check this
well we have observed that there was increase in tailing in the peak, so was suspecting there was a problem with the column

one of the collegue told me that "phenyl" column compartively require more equilibration time than other RP columns?

[XL]

Phase loss is often shown as retention decrease with time. Peak tailing may be sample or bed stability related, among other reasons.