Abstract: A simple and sensitive spectrophotometric method for the accurate determination of ascorbic acid was developed in this paper. It was based on the scavenging effect of ascorbic acid on DPPH·. The detection limit was 5×10-8g/ml ascorbic acid. The calibration graph was linear over the range 7×10-8～7×10-6g/ml and relative standard deviation was 3.5%(C=3.3 × 10-7g/ml,n=6).The method was applied to the determination of ascorbic acid in pure solutions. medicinal tablets and vegetables.

Key words: Spectrophotometric Method 1. 1-dipheny1-2-picrylhydrazyl free radical(DPPH·, ) Ascorbic acid；