Thanks sir.

what If we dnt have a gradient RP-HPLC ? 

You could try Hydrophilic Interaction Liquid Chromatography (HILIC), where aqueous-organic mobile phases are used, with a polar stationary phase. Have a look at this review http://www.ncbi.nlm.nih.gov/pubmed/21501708

Thank you so much !!!

Dear Batool

to obtain a detailed phenolic acids profiles you can use the reversed HPLC, normal HPLC or LC/MS it's same but the mobile phase change. in HPLC/UV Solvents used to analysis were acetic acid 2.5% (A), HPLC grade acetonitrile (B), ultra-pure water (C) and acetic acid 2.5% HPLC-grade acetonitrile (90:10) (D) at a flow rate of 0.5 mL min1. In HPLC/MS Solvents used were ultrapure water (A), HPLC-grade acetonitrile (B), formic acid 1% (C) and formic acid 1% HPLC-grade acetonitrile (90:10) (D) at a flow rate of 1 mL min1. Elution program start with 100% C, the gradient was the following: from 100% C to 100% D in 3 min, from 100% D to 1% B in 4 min, isocratically 1% B in 3 min, from 1% B to 12% B in 20 min, from 12% B to 50% B in 5 min, isocratically 50% B in 5 min, from 50% B to 100% C in 2 min.

Good LUCK

Article Wild grown red and yellow hawthorn fruits from Tunisia as so...

Hi, you could try the solvent system with the corresponding gradient described in the publication attached. Good luck!