消落带土壤全氮测定方法比较

采用开氏法和过硫酸钾消化法对24个消落带土壤样品全氮含量进行测定，并对测定结果进行比较分析。结果表明:由于开氏法测定全氮的结果不包括硝态氮和亚硝态氮，因而开氏法测定结果均低于过硫酸钾消化法；2种方法之间高度正相关，相关系数为0.928(sig < 0.01)；过硫酸钾消化法操作简单、成本低、速度快、测定结果更可靠，可以代替开氏法进行消落带土壤氮含量的测定。  

Comparative Methods for Determining Total Nitrogen in Sediment of Resevoir

Total nitrogen（ TN） of 24 sediment samples was determined in this paper by Kelvin digestion-macro-sample distillation-Nessler＇s reagent colorimetric method（ Kelvin method） and potassium persulfate digestion method. It was found that the contents of TN measured by kelvin method were lower than those of potassium persulfate digestion. That was because the contents of nitrate nitrogen and nitrite nitrogen did not include the results determined by Kelvin method. It also showed that determination results from two methods showed characteristics of high positive correlation,and its correlation coefficient reached 0. 928（ Sig 0. 01）. Because potassium persulfate digestion method was simple and the cost of the method is low,the determination results were more reliable; therefore, it can be used to measure TN of soils in water-level-fluctuating zone.