We run this column at 0.5ml/min, 55C, 0.012N H2SO4. We get reasonable
succinic/lactic separation. We use RI so we can quantity dextrose along with
fermentation products. We aggressively change out the cation H+ guard column
(catalog #125-0129) whenever our pressure goes above 1,000psi (about monthly
for us). We used and abused one column for 2+ years with very heavy
use-including organic contaminants and still had reasonable performance.
Last year year we got some bad guards which were replaced with minimum hassle.
Ask for Donna Hardy at Bio-rad Tech support for further advice.
I didn't see the original post-what was the problem?
Dan Beacom
MBI International
In article <4hgecg$3866 at yuma.ACNS.ColoState.EDU> "Stephen R. Decker"
<Sdecker at Vines.colostate.edu> writes:>From: "Stephen R. Decker"
<Sdecker at Vines.colostate.edu>>Subject: Re: HPLC-HPX-87H
>Date: 5 Mar 1996 04:02:24 GMT
>Trond,
>I'll assume that you mean the HPX-87H, not 47H. We also use this column extensively
>for fermentation analysis. Our parameters are 0.6 mL/min, 0.008N H2SO4 at 65oC with
>a 20 ul loop injection. This operates at about 35-40 bar. The higher temp allows
>better flow at lower pressure.
>We normally do not look for lactate or succinate in our fermentation, although when
>we have run lactate standards, they seem to generate split peaks which we never
>understood.
>In general, what you should look for are obvious column problems. Wide gentle peaks
>indicate that you column has collapsed and the head space created is causing sample
>dilution and mixing prior to entering the column. This problem is notorious in our
>lab with the BioRad columns. The first step is to reverse the column and run the
>flow backwards at 0.2 mL/min overnight. The return the column to its normal
>orientation and try it. If this doesn't work, remove the upstream column end where
>the sample enters and visually check to make sure the packing is not below the level
>of the frit (still in the fitting). If low, you can simply use a spatula and make a
>low conshape of packing using packing from an old column, does not even need to be
>the same resin, but should be close. then just screw on the end fitting and get it
>running again. I have found that this causes about 90% of our resolution problems.
>If you are still having problems, try cleaning the column by reversing it in the flow
>and running at 0.2mL/min, 5% Acetonitrile in 0.005N H2SO4 for 4 hours, followed by
>30% acetonitrile in 0.005N H2SO4 overnight.
>If it is a new column, then call up BioRad and have them replace the column. They
>periodically have bad batches of columns and quickly replace the defects.
>Good Luck
>Steve
