Separation Cortisone acetate and hydrocortisone

[shanmukhpatil]

I am using BDS Thermo C18 250x4.6 column, with ACN/water (0.1%TFA), in Beckmann coulter HPLC.

I am facing lot of problem in separating cortisone acetate and hydrocortisone as I have seen good separation in several papers with 40:60 acn:water...however i am not getting the same. During my several runs i got good separation once but not able to reproduce the same.

Can some body help me in this regard..any modification in mobile phase or ....

regards
skpatil

[dr_Pyrex]

I do not have experience with your substances, but I determine corticosteroids (dexamethasone, betamethasone, flumethasone, prednisolone and triamcinolone) by LC-MS. I had a problem with dexamethason and bethametazon separation on C18 column, so I bought Thermo HYPERCARB (100% porous graphitic carbon ). With this column I separate my drugs succesfully. Maybe it can work with hydrocortisone....
[url]http://www.thermo.com/com/cda/product/detail/1,1055,1000002109518,00.html

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