凯式定氮仪碱解蒸馏法测定青藏高原草甸土壤中的有效氮

摘要

采用全自动凯式定氮仪碱解蒸馏法测定青藏高原草甸土壤中的有效氮,从试验方法及试验过程中的氢氧化钠的加入量的选择、不同的蒸馏时间等方面影响因素进行研究,通过改变蒸馏条件和蒸馏时间,使水解扩散时间由24h降低到5min,结果表明,当选用c(NaOH)=1.8mol·L-120mL,蒸馏时间为5min时,测定结果与标准值相吻合,准确度和精密度均符合国家标准的要求.本方法与传统的碱解扩散法相比具有碱解时间短,操作简便,且测定结果更准确可靠,精密度高等优点.本法提供了一种更加准确、快速、简便测定有效氮的方法,适合于批量测定有效氮,值得大面积的推广和应用.%In this paper, Determination of effective nitrogen in meadow soil samples in Qinghai-tibet plateau by alkaline Hydrolysis Distillation with Automatic Kjeldahl Analyzer,by study the influence factors fron the method and test procedure,choice the sdium hydroxide addition,different distillation time,By changing the distillation conditions and distillation time,the hydrolysis diffusion time was reduced from 24h to 5min. The results indicate that the election in c(NaOH)=1.8mol·L-120mL, distillation time for 5 min, the determination results in conformity with the standard values, the accuracy and precision are accord with the requirement of national standard.Compared with the traditional method of alkali solution, the method has a short time, simple operation and more accurate and reliable results. This method provides a more accurate, rapid and simple method for determining effective nitrogen, which is suitable for the mass determination of effective nitrogen, worthy of promotion and application of large area.