i think its possible to use anonline column to derivatize your sample and with DAD it can give a wide range of wavelngths so its okay Also you can use the tag molecule i.e a flourescent agent to tag your sample and this relly helps and you use the flourescence detector, or chemiluminiscence

so main thing here on line column derivatization which is simple thanks i hope i have helped

Thank you Paul for your response !!! I will try this technique .