high quality ammonium acetate

[ym3142]

I am developing a method with 40mM NH4OAc and MeOH(50% to 95%). I saw many peaks in the blank. I am using J T Baker ammonium acetate, which is not labeled for its purity. Does any one know a quality good enough NH4OAc for LC gradient method?

Thanks,

[Kostas Petritis]

We use MS grade ammonium acetate from Fluka. It is sold by Sigma-Aldrich and is part number 73594. Have it mind that the longer the equilibration time the higher the amount of impurities accumulated (i.e. start the analysis just after column equilibration).

[Bruce Hamilton]

I use ammonium acetate Fractopur grade from Merck, catalogue 116103. It's for buffers, with specified UV limits. Works for me, but YMMV.

Please keep having fun,

Bruce Hamilton

[aceto_81]

Are you sure it comes from the ammonium acetate, and not from water, magnetic stirrer, glass ware, ....?

We ammonium acetate PA from Merck on our UPLC-PDA's with no problems, sometimes 1 or 2 peaks, but they don't disturb us as they fall far from our peaks in the gradient.

Ace

[ym3142]

Thanks for all and I will look into the possible water contamination.

[ym3142]

For the purpose of expressing my appreciation for people's help here, I like to report my result: In my test the Aldrich >99% NH4OAc does not gave the peak present in T J baker's NH4OAc.

Thanks and have a great Labor Day!!