Boswellic Acid content

Method for the estimation of Boswellic acid content

Reagent  Required:

Dimethyl formamide (LR), Methanol, Benzene, 0.02N Sodium methoxide, Thymol blue indicator (0.1% w/v solution in methanol)

Glass wares and Apparatus Required:

250mL conical flask, Burette

Procedure:

Weigh accurately about 0.5gm of extract or 1.0gm raw material in a conical flask containing 100mL of DMF previously neutralized to 0.02 N sodium methoxide. Dissolve by shaking (gentle warming in case of raw material) and titrate with sodium methoxide upto blue end point. Note the volume of 0.02N sodium methoxide consumed.

Calculation:

Percentage of Boswellic acid is calculated as:

                           Titre X 0.00912 x Normality x 100

           =      -----------------------------------------------------

                             Weight of sample X 0.1

Method for preparation of 0.02N Sodium Methoxide :

Cool in ice water approximately 40mL methanol contained in a 250mL volumetric flask and add in small pieces about 0.5gm of freshly cut sodium. When the metal has dissolved add benzene to make upto 250mL and mix. Store the solution preferably in the amber coloured bottle. Standardize the solution before analysis as follows.

Standardization:

Weigh accurately about 100mg of benzoic acid and dissolve in 50mL of dimethyl formamide. Add three drops of 0.1 percent w/v solution of Thymol blue in dimethylformamide and titrate with the sodium methoxide solution to blue end point. Correct for the volume of the solution of sodium methoxide consumed by 50 mL of the dimethyl formamide and calculate the normality. Each 0.002442 gm benzoic acid is equivalent to 1ml of 0.02N Sodium methoxide.

Note: In this analysis glassware should be properly dried and normality of sodium methoxide must be freshly determined before each analysis.