I used KTB for a reaction and found that unexpected impurity is formed. After investigation, it was found that KOH content in KTB is responsible for this impurity formation. So I need a method that monitors the KOH content in KTB.
run potassium tertiary butoxide in HPLC and after that run only K-OH in HPLC, then compare peak of KOH with peak of potassium tertiary butoxide, if KTB peak showing any peak at same Rt mean KOH present if no peak mean not present.
Thank you Conrad for your suggestions. Whatever you suggested is feasible for a gram scale process but what about the scale-up batches?. We are purchasing Solid KTB from vendors and its difficult to keep a check on quality with respect to KOH content. So I am looking for the MoA which provides KOH content in KTB.
Thanks Conrad, Abhimanyu and Eric for your prompt reply. I googled for this but unabale to find any method. Potentiometric Titration might be one choice but we can not use water as this will convert KTB to KOH. Yes, we can ask vendor for the desired quality but we need to confirm the same and for that as well we need a method of analysis.
Weigh a small amount of sample
Sublimates tert-butoxide. The residue will contain almost exclusively carbonate and potassium hydroxide.
Weigh accurately, then dissolve in distilled water and pass carbon dioxide up to saturation. The water was removed, the residue calcinate to 200C - it get a clean potassium carbonate
Weigh again and determine the portion of potassium hydroxide by increase in mass
If you run a Karl Fischer in the presence of a benzoic acid (excess), the reaction of KOH with the acid will free an equivalent mole of water which is titrated will the KF reagent. multiply the result by (MW KOH/MW H2O) or approx 3.1 to get a % KOH.
- Badges
- Science method
- Similar topics
- Chemistry
- General Biochemistry
- Biochemical Techniques
- Analytical Chemistry