Abstract: A method to determine prochloraz in orange peel by electrochemistry analysis after derivatization was developed. Prochloraz was stepwise extracted by acetone and ethyl acetate, and hydrolyzed into electrochemical active 2,4,6-trichlorophenol by pyridine hydrochloride. Differential pulse stripping voltammetry (DPSV) was utilized to determine prochloraz under the optimized conditions pH 4.0 and accumulation at 0 V potential for 300 s. The results showed that oxidative peak current of 2,4,6-trichlorophenol was positively linearly correlated with its concentration within the range of 9.0 × 10-9－8.0 × 10-5 mol/L. The detection limit was 9.7 × 10-10 mol/L, and the recovery between 98.5% and 113.0%.

Key words: derivatization, electrochemistry, prochloraz, orange peel