Abstract: NKA-2 macoporous adsorption resin was the best resin for the separation and purification of crude tannin extract from Galla chinensis as demonstrated by a comparison of the effectiveness of 8 types of macoporous adsorption resin in static adsorption and desorption of tannin. One-factor-at-a-time and orthogonal array design were used to optimize dynamic adsorption and desorption parameters for the purification of the crude tannin extract. The optimal process parameters for maximum tannin yield were determined as follows: 6 BV of 5 mg/mL sample was loaded onto the column at a flow rate of 1 BV/h and after complete adsorption, the column was then eluted with 4 BV of 80% ethanol solution at a flow rate 1 BV/h, yielding a tannin yield of 85.37% and a tannin purity of 62.99%. However, the optimal process parameters for maximum tannin purity were determined as follows: 5 BV of 6 mg/mL sample was loaded onto the column at a flow rate of 2 BV/h and after complete adsorption, the column was then eluted with 4 BV of 80% ethanol solution at a flow rate 3 BV/h, yielding a tannin yield of 76.97% and a tannin purity of 67.78%.

Key words: Galla chinensis, tannin, macroporous resin, separation and purification