A triarylimidazole derivative of the formula:
 wherein X is O or S; Y is an arylsulfonyl group, an alkyl group, etc.; R², R³ and R⁴ are independently an aryl group, etc., is stable in water or a buffer solution, high in measuring sensitivity and is suitable as an oxidizable color producing reagent for determining hydrogen peroxide, etc. generated by enzymatic reaction in a living body sample.  
                            式中的三芳基
咪唑衍
生物:
 其中,X 为 O 或 S;Y 为芳基磺酰基、烷基等;R²、R³ 和 R⁴ 独立地为芳基等,在
水或缓冲溶液中稳定,测量灵敏度高,适合作为可氧化的显色试剂,用于测定活体样本中酶反应产生的
过氧化氢等。