Objective:To optimize extraction technology of sulfur dioxide from Dioscorea opposita by Plackett-Burman design and central composite design-response surface methodology. Method: With yield of sulfur dioxide as index

effect of extraction method

solvent amount

extraction temperature

extraction time and the mass fraction of NaOH solution on extraction technology of sulfur dioxide was investigated by single-factor test.Significant influencing factors were screened by Plackett-Burman design

independent variables were the concentration of NaOH and solvent amount

dependent variable was yield of sulfur dioxide

each level of independent variables was handled with multiple linear regression and binomial fitting

response surface methodology was used to optimize extraction process

and prediction was carried out through comparing the observed and predicted value. Result: Optimal extraction technology conditions were as followings:the mass fraction of NaOH 0.7%

solid-liquid ratio 1∶50.99

Bias of the observed value and the predicted value 3.23%. Conclusion: Optimized extraction technology was simple with good predictability

it could provide reference for sample pretreatment in determination of sulfur dioxide residues of traditional Chinese medicine.