Determination of Total Nitrogen in Wild Hypocrella bambusae

LIU Wei et al(College of Science,Honghe University,Mengzi,Yunnan 661100)

Hypocrella bambusae;Kjeldahl;Total nitrogen

[Objective] The aim of this study was to lay foundation for studying Hypocrella bambusae further.[Method] The total nitrogen(N) content was determined with Kjeldahl to study the influences of temperature,digesting time and sample dosage on the course of digesting wild H.bambusae.[Result] When the ratios of wild H.bambusae sample to potassium sulfate,copper sulfate and sulfate acid were 1∶5,2∶1 and 1∶15 resp.,the digestion was best.The pretreatment condition of sample accorded with digesting time.When the temperature was at 250～350 ℃,the total N amount determined with different sample dosages had no bigger difference.The higher the digesting temperature was,the more the crude protein and total N obtained from sample was.Temperature was the key factor influencing digestion and the higher the digesting temperature was,the shorter the consumed time in the digestion was.[Conclusion] The optimum digesting condition of determining total N in H.bambusae with Kjeldahl was with about 0.5 g sample,initial digesting temperature at 300 ℃ and ascending to 350 ℃ after the foam reduced and smog whitened,and the digesting time of about 4 h,under which,the crude protein content was 22.50% and the total N content was 3.60% in H.bambusae.