method for phenoxy methyl penicillin in human plasma by hplc

[anilray1155]

i have done more than 100 method but no good result was found
here the problem was specificity
currently i try precipitation method +solvent washing
but here the problem was same and in some method the ISTD (internal standard )peak was splited
so suggest the proper solvent or solvent mixture for washing

[Uwe Neue]

Your main problem is the sample preparation method. Try solid phase extraction. Good methods can be found on the Waters website. Look for the Oasis applications notebook.