Chromatography Forum

Hello,

Our lab has been mixing our own 0.5 mm H2SO4 mobile phase, but now I am thinking we should buy it pre-mixed to avoid variation... I think it is possible some of our questionable Chromatograms may be complicated by mobile changes. We have recently begun testing the pH after mixing - but since the acid is so dilute I'm not sure we would catch a bad batch that way.

How many labs are making their own mobile phase?
Can anyone refer me to a supplier for 0.5 mm H2SO4?

Can anyone refer me to a supplier for 0.5 mm H2SO4?

I don't think you'll find anyone supplying concentrations that low. I'd suggest buying the lowest concentration (traceable to approved standards) possible, which would involve a simple dilution to achieve the 0.5 mm concentration you need.

Update:
I found some, Midland Scientific has it down to .001 N This is going to help so much. Now I don't have to worry about my instrument being fouled!