By Anonymous on Thursday, November 27, 2003 - 05:45 am:
Hi
I'm performing a HIC (fluorescence) method with a mobile phase of ammonium sulfate buffer. The problem is that we get a terrible baseline (sloping down at about a 45 degree angle!) unless we use a very high grade of ammonium sulfate salt to prepare the buffer. We've found that the 'Trace Select' grade from Fluka works pretty
well, but it costs a fortune.
Does anyone know of any other manufacturers that supply a cheaper alternative of a similar purity?
By HW Mueller on Thursday, November 27, 2003 - 06:04 am:
Have you tried good grades of ammonium hydroxide and sulfuric acid?
By Anonymous on Thursday, November 27, 2003 - 06:10 am:
It's not really an option to be honest. It is written in stone that it must be ammonium sulfate.
By Anonymous on Thursday, November 27, 2003 - 10:07 pm:
Going back to basic chemistry, HW Mueller meant:
2NH4OH + H2SO4 --> (NH4)2SO4 + 2H2O
By Einar Pontén - SeQuant AB on Friday, November 28, 2003 - 11:58 am:
Is really HIC a chromatographic technique?
"Salting out" on a non polar stationary phase. What can one expect from that?
Think different!
By A.Mouse on Friday, November 28, 2003 - 04:49 pm:
Einar:
HIC is a terrific chromatographic technique, but it is used for proteins and not for small molecules.
I do not recommend to think differently!!! Your favorite technique - HILIC - won't work for this problem.
By Einar Pontén - SeQuant AB on Saturday, November 29, 2003 - 06:59 am:
Yes, I know. Quite a long time ago I worked with HIC.
I suppose problems as abovementioned are common. So what merits does it have?