vitamin K

[rubypharma]

i've a problem in chromatographic separation of vitamin K using usp monograph ,, i just got one peak instead of 2 peaks of Z and E isomer

[remesquaddie]

Contact David at : DKLINE43@yahoo.com
I believe he can help.
Tony

i've a problem in chromatographic separation of vitamin K using usp monograph ,, i just got one peak instead of 2 peaks of Z and E isomer

[bomberang]

Hi Rubypharma,

I just caught your blog. Tony inadvertedly gave you my incorrect email address. Should be klined43@yahoo.com. Anyway, I did some vit. K1 work a while ago using zinc post-column reaction which converts vit. K1 to reduced form that is very sensitive to fluorescence detection. Work very well, but does not concern about cis-trans isomer separation which you mentioned having trouble from the USP monograph.

There are several publications regarding cis-trans K1 separation using C30 column. One recent (1910) AOAC article below uses methanol as mobile phase for the validation work. Might want to try this to see if it works for you.

http://www.ncbi.nlm.nih.gov/pubmed/20480913

Let me know if you have any more questions.

Regards,

David