Abstract:
Several catalyst mixtures were studied about digesting conditions of plant total nitrogen,four kinds of catalyst mixtures used for the plant analysis of total nitrogen by J.Kjeldahl method were compared,four kinds of botanical materials including Purple medic,Sorghum hybrid Sudan grass,Kikuyu grass and Rape pollen were digested.The total Nitrogen obtained at digestion temperature of 380 ℃ were significant different among K2SO4+CuSO4,H2O2,K2SO4+CuSO4+Se and Na2SO4+Se after clearing 120 min.Conc.H2SO4 with K2SO4+CuSO4+Se K2SO4+CuSO4 or Na2SO4+Se decomposed out more N than H2O2;it took less time for the catalyst mixtures containing Se to digest the plant tissues to clear,H2SO4_H2O2 method was slowest;Digestion should be at 380℃ for an additional 40 minutes after clearing to ensure complete reaction;Compared with H2SO4+H2O2,Na2SO4+Se was more convenient for determining plant total N,total P and total K simultaneously.
Key words:
J.Kjeldahl method,
Total nitrogen,
Catalyst mixtures,
Digestion time
CLC Number:
CHEN Shu-ping, WANG Xue-zheng, QIAN Xiao-zhe, LI Jie. Comparation and Relative Analyses on the Digesting Time and Results of Catalyst Mixtures of Plant Total Nitrogen in Kjeldahl Method[J]. ACTA AGRICULTURAE BOREALI-SINICA, 2006, 21(S2): 19-22. doi: 10.3321/j.issn:1000-7091.2006.z2.005.