Peak shape of a phytochemical

[waqas.ahmad]

hello all,
I am working with a sample contains saponins from a plant extract. The sample solvent contains plant extract in Phospate buffer (pH 4.5). The mobile phase consists of gradient starts from (A,D 90-10) to (A,D 55-45) in 30 mints. The organic phase (D) is acetonitrile contains 0.05% TFA. The chromatogram contains some peaks having peak tailing. I am using C4 (300 A, 25cm, 4.6 id) column reverse phase at 25c.
1. How can i improve the peak tailing? Is the tailing normal in phytochemical analysis.
2. How can i improve the resolution of peaks? Is the weak resolution is normal in phytochemical analysis?

Thanks for your time.

Regards

[Gerhard Kratz]

C18 is good but I would first use a 100Angstrom (after bonding) pore size material and I would add a little bit of Triethylamine. A HILIC column I would also try. When you want later an MS as detector please replace the phosphate buffer with a volatile buffer system. Use always a guard column. Good luck.

[waqas.ahmad]

thank you for suggestions