The answer to your question depends on your experimental plant. Ther second important subject is the purpose of your experiment. What pigments do you want to separate and study by HPLC. After clarifying these, you may get proper answers.
Madhhu: More information is needed to assist you. Which pigments? What exactly did you try and what results did you obtain? Please be detailed in your response.
Additionally, if you do a simple keyword search on the web using the specific pigment chemical names (or chemical group) plus "HPLC", then you will obtain many related papers and methods quickly (far faster than asking here).