水体中总氮测定方法的改进  

Improvement of Determination Method of Total Nitrogen in Water

作　　者：张利[1] 田浏[1] 郑海腾[1] 冯志江[1] 刘文[1] 戴捷[1] 

机构地区：[1]长江大学化学与环境工程学院,湖北荆州434023

出　　处：《湖北农业科学》2013年第19期4779-4781,共3页Hubei Agricultural Sciences

基　　金：国家自然科学基金项目(21173026);国家大学生创新训练项目(201210489316)

摘　　要：用碱性过硫酸钾法测定水体中总氮含量时经常出现高空白吸光值、标准曲线线性相关性较差以及测定结果不准等问题。采用正交法对各种测定组合进行对比,并探讨了各种因素对空白吸光值和线性方程的影响。结果表明,各种影响因素从大到小的次序为过硫酸钾重结晶次数、消解时间、氢氧化钠和盐酸的用量。最优测定组合为:过硫酸钾重结晶2次、消解时间不少于40 min、氢氧化钠用量为12 g、不加盐酸。线性方程相关系数检验符合标准。Problems such as high blank absorbance value,poor linearity and low accuracy often arise in the determination of total nitrogen content of water.The impacts on the blank value and the linear equation were studied by orthogonal experiment.Results indicated that the sequence of various influencing factors ranked from big to small was as follows：times of recrystallization for potassium persulfate,digestion time,dosage of sodium hydroxide and hydrochloric acid.The optimal experimental combination was as follows：recrystallized potassium persulfate twice,the time of digestion no less than 40 min,and the dosage of sodium hydroxide 12 g without additional hydrochloric acid.Correlation coefficient of linear equation test accorded with standard.

关 键 词：总氮 过硫酸钾 空白吸光度 改进 

分 类 号：O661.1[理学—分析化学]