Chromatography Forum

Hi.

I have just tried to run some of the columns from the Primesep Kit. The UV signal looks okay, but the MS signals and ELSD signals showed heavily column bleed. I have used the same Hplc condition that the columns have been tested with. I am wondering if Primesep have tried the last two detectors. It a shame because they give a new way to separate compounds.

Broesen,
You forget to state whether you have used other manufacturer's columns under the same conditions.
Did you get any bleed with those?
WK

Broesen,
You forget to state whether you have used other manufacturer's columns under the same conditions.
Did you get any bleed with those?
WK

Yes, with Waters Symmetry we don't see any column bleed, but with the new polar columns like Waters atlantis and Phenomenex Hydro we see some column bleed to. But only with Primesep the column bleed is heavily. We have complaid about it to Waters, but they said that the impurities came from our water, but the funny thing is that the "impurities" gives no UV signal but it gives a MS and ELSD signal. And after a short while the peaks looked like there was a void in the column. To mee it sounds like that it is column that bleeds.

I had same problem with Primesep at the beginning, but after I washed the column with ACN/water/TFA=80/20/0.2 for 2 hours column bleed almost disappeared. From my limited experience in LC/MS a lot of column with polar embedded group produce some bleed. Try not to go outside the pH recommended for the column.

Primesep column has more complex chemistry than any other column with
polar embedded groups. Typically the bleed almost completely
disappeared after short use of the column. And it is always better to use the column within recommended pH conditions. In UV you usually do not see any bleed problems.
We are now about to introduce a new line of Primesep-MS columns. They
will be significantly bleed free. The original Primesep line will be
still in production to maintain the needs of existing users.