在醋酸铵 -醋酸缓冲溶液中 ,1 3 -二羟甲基 -5 ,5 -二甲基乙内酰脲与乙酰丙酮发生Hantzsch反应生成二氢吡啶衍生物。通过测定二氢吡啶衍生物的荧光强度可计算 1,3 -二羟甲基 -5 ,5 -二甲基乙内酰脲的含量。其结果 :甲醛回收率 93 %～ 10 6 %。测定 1 3-二羟甲基 -5 5 -二甲基乙丙酰脲的相对偏差为 0 3 % Hantzsch reaction of 1 3 - dimethylol - 5, 5 - dimethylhydantoin and acetylacetone in diammonium acetate - acetic acid buffer solution produces dihydropyridine derivatives. The content of 1,3 - dimethylol - 5, 5 - dimethylhydantoin can be calculated by measuring the fluorescence intensity of dihydropyridine derivatives. The result: Formaldehyde recovery 93% ~ 106%. The relative deviation of 1 3-dimethylol-5 5 -dimethylpropionylurea was 0 3%