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Acetic acid analysis
Posted: Tue Mar 01, 2011 4:17 pm
by danielcaro
Hello! I am working in a project in which I need to calculate the equilibrium data of the acetic acid/water mixture. For that, I need to take samples and therefore, I must analyze the cocnentration of acetic acid in these samples. What is the best method to analyse this? which stationary phase and compounds in the GC column I need? i am little lost..I will be really thankful for any help toy can give me.
Thank you very much!
Dani
Re: Acetic acid analysis
Posted: Tue Mar 01, 2011 4:50 pm
by jupp
Hi!
I am interested in this topic, since I will have to analyse organic acids like acetic acid in water samples too.
What internal standard would you recommend for these analytes?
Thanks in advance!
Re: Acetic acid analysis
Posted: Tue Mar 01, 2011 6:04 pm
by Consumer Products Guy
HPLC with conductivity detector or low-wavelength UV, organic acid column or Restek Ultra Aqueous C18?
Re: Acetic acid analysis
Posted: Tue Mar 01, 2011 6:59 pm
by chromatographer1
Acetic acid in water gives inconsistent results by GC unless the pH is adjusted.
Formic acid would be the acid of choice for adjustment. Then HoAc might be done with a FFAP capillary column with FID. But subtract the blank in case the formic is contaminated with acetic.
Matrix issues are paramount here.
Ion chromatography would be my best choice.
Spectroscopy would be the second choice.
Titration would be my third choice.
An analytical chemist uses whatever tools to do the job in the most efficient and accurate manner.
LC would be my last choice due to sensitivity issues.
Enjoy your work, it beats being unemployed.
Rod
Re: Acetic acid analysis
Posted: Tue Mar 01, 2011 7:09 pm
by jdezeeuw
For acetic acid /water mixtures you need TCD detection; Separation can be done using Thick-film PDMS, like 5 microns Rtx-1 on 0.32mm . We need thick film for loadability; alternative an acid-modified PEG can be used.
Biggest challenge will be injection. Do not use glass wool. use small injection volumes (for best evaporation) and a high surface liner (baffled, cyclosplitter).
Re: Acetic acid analysis
Posted: Wed Mar 02, 2011 2:47 pm
by dpr
I'm with Chromatographer 1.
Look at IC.
We are doing HOAC in process streams and pure HCN by IC on a Dionex AS column.
Re: Acetic acid analysis
Posted: Wed Mar 02, 2011 2:49 pm
by Peter Apps
Hello! I am working in a project in which I need to calculate the equilibrium data of the acetic acid/water mixture. Dani
Equilibrium between what and what ?
Peter