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.

You can purchase sublimed grade KOtBu (from SigmaAldrich for example) which is 99.9% pure, or you could sublime it yourself. Also, you could consider making it in situ using K-metal in excess dry tert-butanol prior to adding other reagents. Good Luck!

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.