The new photometry for determination of hydroxyl radocals by using the reaction between the mixed rare earths and trace H 2O 2 has been established in this paper.

• 利用混合稀土与微量过氧化氢催化氧化二苯基碳酰肼,建立了萃取-催化氧化光度法测定过氧化氢的羟基自由基的新方法。