Determination of catechin, epicatechin, gallic acid and procyanidin B₂ in procyanidins by RP-HPLC

To determine catechin(C), epicatechin(EC), gallic acid(GA)and procyanidin B₂(PCB₂)in procyanidins and compare their contents in procyanidins from different manufacturers, an A RP-HPLC method was developed. The determination was carried out on a Hypersil ODS2 column(4. 0 mm×200 mm, 5 μm). The mobile phase consisted of methanol and 2% acetic acid with gradient elution and the detection wave-length at 280 nm. There was a good linear relationship between concentration and the peak area in the range of 0. 1-50 μg/mL(r=0. 998 6)for catechin, 0. 1-50 μg/mL(r=0. 994 5)for epicatechin, 0. 05-50 μg/mL(r=0. 999 9)for gallic acid and 0. 1-50 μg/mL(r=0. 992 2)for procyanidin B₂, respectively. The average recoveries of catechin, epicatechin, gallic acid and PCB₂ were 98. 36%, 98. 21%, 89. 60% and 98. 47%, respectively and the RSDs were 1. 39%, 0. 84%, 2. 12% and 2. 46%, respectively. The method is simple, accurate, reproducible and can be used for assay of C, EC, GA, PCB₂ in procyanidins. There was a great difference in the content of four substance in procyanidins from different manufacturers.