Help to Seperate Ibu Impurities

[suresh]

Dear All.
I Have a problem in seperating two impurities in Ibuprofen soft Gel.
The Impurity One is 2-(4-butylphenyl)-Propionic acid and other impurity is 4-isobutylacetophenone.
the problem is the first impurity is as per BP and second one is as per USP but these two will measure at 214nm and 254nm respectevly/
Now i want to seperate these two impurities in one method.
I will be very greatful if any one give suggestion. I have ISOCRATIC HPLC only. :id ea:

[maris]

First, try USP method.

[michaelcarolus]

Hi

I have succesfully separated ibuprofen and 4 isobutylacetophenone using the following method.

USP mehtod modified:
Column: Waters Symmetry C18 (5 µm)(15 cm x 3.9 mm i.d.) column at ambient temperature
Mobile phase: acetonitrile : 0.01 M phosphoric acid (50 : 50)
Flow rate: 1.5 ml per minute.
Ibuprofen elutes at about 7 min and 4 isobutylacetophenone at about 9.5 min.

Ibuprofen and Impurity B as per BP method:
BP method modified:
Column: Phenomenex Luna C18 (5 µm)(25 cm x 4.6 mm i.d.) column at ambient temperature
Mobile phase: water : acetonitrile : phosphoric acid. Add 0.5 ml of phosphoric acid to 550 ml of water, mix well. To this add 450 ml of acetonitrile.
Flow rate: 2.0 ml per minute.
Ibuprofen elutes at about 17 min and 2-(4-butylphenyl)-Propionic acid elutes at about 18.5 min.

Hope this helps
MC

[suresh]

Thanks for the reply.
I required single method which can seperate both impurity. but both impurities are at difference nm. Can i get the Abs Max for 4 isobutylacetophenone ie USP IMP

[michaelcarolus]

Why don't your try a detector with dual wavelength capability or use a PDA.

[sastry]

Dear suresh can you share the integrated method for both the impurities I don't mind in using dual wavelength detector for this analysis.