| 1. | In the course of oxidation , reaction temperature should rise step by step , and in the late stage , reduced pressure distillation should follow so that the concertration of glyoxalic acid can rise and production rate of allantoin can rise up to 40 % 在氧化反应的过程中逐步地提高反应温度,反应后期进行减压浓缩,提高了乙醛酸的浓度,缩短了氧化时间,并使尿囊素产率达到40 % 。 |