RP- HPLC simultaneous determination of gallic acid,catechin and epicatechin in extracts of grape seeds

Objective: To establish an RP- HPLC method for simultaneous determination of three monomers( gallic acid,catechin,epicatechin) in extracts of grape seeds. Methods: Chromatographic separation was performed on the Agilent zobax SB- C18column( 4. 6 mm × 250 mm,5 μm). The mobile phase was acetonitrile( A) – water( 1% methanol + 0. 15% TFA)( B) with the gradient elution( 0- 10 min,0% A →7% A; 10- 30 min,7% A →16% A;30- 40 min,16% A→90% A; 40- 50 min,90% A; 50- 55 min,90% A→0% A; 55- 65 min,0% A),at the flow rate of 1. 0 m L·min- 1. The detective wavelength was set at 280 nm,the column temperature was maintained at 40℃ and the injection volume was 20 μL. Results: The linear ranges were 1. 0- 54. 0 μg·m L- 1( r =0. 999 8) for gallic acid,2. 7- 136. 0 μg·m L- 1( r =0. 999 8) for catechin and 2. 7-136. 0 μg·m L- 1( r =0. 999 9) for epicatechin. The average recoveries( n = 6) of the three monomers were 100. 3%,99. 15% and 100. 3%. The contents of gallic acid,catechin and epicatechin in three lots of GSE samples were respectively 0. 69%,0. 69%,0. 68%; 3. 15%,3. 12%,3. 16%; and 2. 48%,2. 44%,2. 42%. Conclusion: Through method validation,the developed HPLC method is suitable for the simultaneous determination of gallic acid,catechin and epicatechin in extracts of grape seeds.