0.1 M Tetrabutylammonium Hydroxide Solution Preparation and Standardization

Preparation and Standardization of 0.1 M Tetrabutylammonium Hydroxide (C16H37NO) Solution in Pharmaceutical Labs.

Name: 0.1 M Tetrabutylammonium Hydroxide (C16H37NO)

0.1 M Tetrabutylammonium Hydroxide Solution

Reagents :

  • Tetrabutylammonium iodide
  • Methanol
  • Dimethylformamide
  • Thymol Blue
  • Benzoic Acid

Preparation of 0.1 M Tetrabutylammonium Hydroxide:

  • Mix 40 grams of Tetrabutylammonium iodide in 90 ml of dry methanol. Then, put in 20 grams of finely powdered Silver Oxide and shake hard for an hour.
  • Take a bit of the mix, spin it fast, and test the liquid on top for iodides. If it shows positive, add another 2 grams of silver oxide and shake for 30 minutes. Do this until there are no more iodides.
  • Then, strain the mix through a fine filter and wash the container, and filter with three 50 ml amounts of toluene.
  • Mix the washings with the strained and add more Toluene to make it 1000 ml.
  • Blow dry, carbon dioxide-free nitrogen into the mix for 5 minutes.

Method of Standardization:

  • Mix 10 ml of Dimethylformamide with 0.05 ml of a 0.3% solution of Thymol Blue in Methanol. Slowly add Tetrabutylammonium hydroxide solution until you get a clear blue color.
  • Now add 0.2 grams of Benzoic acid, stir till it dissolves, and add more Tetrabutylammonium hydroxide solution until the clear blue color comes back.
  • Make sure the mix doesn’t touch air throughout this check. The amount of solution used in the second round tells you how much tetrabutylammonium hydroxide you’ve got.
  • Remember, each ml of 0.1 M tetrabutylammonium hydroxide equals 12.21 milligrams of C7H6O2.


Store below 25°C & store in an amber-colored bottle. Protect exposure from CO2 & water.

Shelf life:

The shelf life of the above solution shall be one month from the date of preparation. Restandaridize the above solution daily before use.


calculating formula for Tetrabutylammonium Hydroxide

REFERENCE: Indian Pharmacopoeia

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