Dan Beacom beacom at mbi.org
Tue Mar 5 14:32:22 EST 1996

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


>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 

>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


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