Hi Folks,
I am trying to prepare ammonium acetate buffer as per client method. so based on their method it is addition of acetic acid to water and ammonia solution (all analytical grade) . the latter for pH adjustment . we have 10 Imps for this specific molecule all over the chromatogram with 18 min run time; but the blank injection (which is 50% ACN in water , also as diluent) has small interfering peaks. I did some trials and think it is because of physical issue maybe such as mixing as when I degassed it longer time the small peak at the end reduced significantly. the gradient is from 10% to 100 ACN due to difference in polarity of the imps. The unwanted peaks happens when ACN is almost 60% and greater.
- The instrument have the 350 uL static mixer.
- I also tried making adjustment with ammonium hydroxide , no difference in result.
- I am also (currently) trying making buffer from ammonium acetate salt to see the effect.
- I also see this article on the solubility of ammonium acetate in 100% ACN (limited to 90% -95% depending on the concertation of the buffer), that maybe another reason. having this said what you suggest to eluting the late eluting analyte if we are limited to end the program to 90% ACN
https://www.chromatographyonline.com/view/lcgc-blog-ammonium-acetate-woes
Do you have any thought/experience? I appreciate it in advance.
Cheers,
Mahboubeh (Mariah)
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Powders