I hv started Method development for samples of All vitamins ie B complex, C, D, A, K.
I have found one method using Trifluoroacetic acid in water n ACN in gradient mode.
the thing is I have column in pH range of 2 to 7. n method mentioned above shows pH 1.4.
I tried with OPA in DW at pH 2.7 n at 3.4 n got some resolution using methanol. but consistingly changing gradient profile Im not abl to resolve them. wht other mobile phases n organic modifiers I may try to resolve them?
Also method time I want to reduce as it has to be less than conventional HPLC.
Can you help me out??