Objective: To optimize purification technology of salvianolic acid B by Zn2+ precipitation method. Method: HPLC was adopted to determine the content of salvianolic acid B

chromatographic conditions were as follows:mobile phase of acetonitrile-0.05% phosphoric acid gradient elution

column temperature 30℃

detection wavelength 286 nm

injection volume 10 μL.With yile of salvianolic acid B as index

extraction technology was optimized by single factor tests;With transfer rate of salvianolic acid B as index

single factor tests were adopted to optimize purification technology by taking alkali liquor species

dosage of ZnCl2

the molar concentration of HCl and pH as factors. Result: Optimized purification technology of salvianolic acid B was as following:soaked 3 times with 6-fold the amount of pH 2-3 HCl

1 h each time

adjusted pH to 6.0-6.5 by 1%Na2CO3

dosage of ZnCl230% as quality of medicinal materials

dissolved precipitate with 2 mol·L-1HCl

adjusted pH to 2-3

extracted 2 times with the same times the amount of ethyl acetate

dried it with vacuum and low temperature

yield of salvianolic acid B 3.47%

purity of 80%. Conclusion: Optimized technology was stable and feasible

it could avoid damage of salvianolic acid B under prolonged high temperature and pH conditions.