I am currently validating analysis of water soluble vitamins (Vit. B1, B2, B3, B6 & C) in presence of ferronyl iron (elemental iron) using HPLC.
I have a problem with the ferronyl iron that seems reducing the vit. B2 & C so i cannot get good recovery ( usually less than 96% )
I use triethylamin pH 7,0 as the solvent (best solvent for vit. B2).

please give me suggestion to avoid the reduction of that vitamins.

you should use EDTA in the mobile phase and solvent, so it can chelate the iron

to: moksie

my best assay for this product that currently validated is using this condition:
solvent for sample preparation: TEA-PO4 buffer pH 7,0
column: Waters Atlantis
mobile phase: TFA 0,1% in aquadest : Acetonitril HPLC grade in gradien mode (0->5 minute: 100 --> 85% TFA 5--> 10 min :85 --> 65% TFA 10 --> 15 min: 65--> 100 %)
run time: about 15 minutes
detector: UV 290 nm

note:
1.you must use column that are stable enough to withstand against low pH and high aqueous mobile phase.
2. sample stability is very poor. usually less than 30 minute. I suggest prepare the sample right before inject to the HPLC (dont queue in the sample set).

to: gamal mostafa,

I ever use EDTA in the mobile phase and in the solvent before and it dont solve the problem.
thank for the suggestion.

Thank you very much for the information given Mr. Kharrir. I will try to experiment on this parameter. I do hope to be successful on this.

Have a nice day! God Bless!!!

Moksie

Dear All sorry for delay to reply, I know that the stabiliy is low without EDTA but I attached a method try to apply it, the stability of test and standard solution is about 7 hours. I am waiting your reply. I need your email to give you the method of analysis where I can not attach in the attachment place.