植物和食品全氮含量测定方法的改进和优化

付宇新 胡燕 王莉 贺义昌 曹冰 王召滢 华小菊 曾凡新

摘要 [目的]为了减少化学废液排放，降低检测成本，提高检测效率，对测定植物、食品全氮或蛋白质含量的标准方法提出改进和优化。[方法]选择国家标准物质辽宁大米和芹菜作为检测样品，采用减少称样量、硫酸、加速剂及蒸馏试剂量的改进方法和现行植物食品全氮测定标准方法进行试验，并对结果进行比较。[结果]使用改进方法测定样品中全氮含量，其结果的RSD值小于5%，与标准物质指定值的相对误差均小于5%，说明改进优化后的测定方法的精密度及准确性符合检测分析的要求。[结论]该方法减少了试剂药品的试验用量，尤其是浓硫酸的使用量，降低了检测成本，效率有所提升，对环境污染减少，适合植物、食品全氮或蛋白质的测定，可以推广使用。

关键词 全氮;蛋白质;凯氏定氮;植物;食品;测定方法;改进优化

中图分类号 TS207.3  文献标识码 A

文章编号 0517-6611（2021）04-0198-03

doi：10.3969/j.issn.0517-6611.2021.04.053

Improvement and Optimization of the Determination Method of Total Nitrogen in Plants and Food

FU Yu-xin1，2，HU Yan1，WANG Li1 et al （1.Jiangxi Academy of Forestry，Nanchang，Jiangxi 330013;2.College of Forestry，Jiangxi Agricultural University，Nanchang，Jiangxi 330045）

Abstract [Objective]In order to reduce the discharge of chemical waste liquid，reduce the cost of detection and improve the efficiency of detection，the improvement and optimization of the standard method for the determination of total nitrogen or protein content in plants and food were proposed.[Method]The national standard substances Liaoning rice and celery were selected as the test samples，and the improved method of reducing the sample amount，sulfuric acid，accelerant and distillation reagent，and the current standard method of determination of total nitrogen in plant food were used for the test，and the results were compared.[Result]The improved method was used to determine the total nitrogen content in the sample.The RSD value of the result was less than 5%，and the relative error with the standard material value was less than 5%，indicating that the precision and accuracy of the improved and optimized determination method met the requirements of detection and analysis.[Conclusion]The method reduces the test dosage of reagents and drugs，especially the use of concentrated sulfuric acid，reduces the detection cost，improves efficiency，reduces environmental pollution.It is suitable for the determination of total nitrogen or protein in plants and food，and can be popularized and used.

Key words Total nitrogen;Protein;Kjeldahl nitrogen;Plant;Food;Determination method;Improvement and optimization

基金項目 江西省林业科学院重大科技项目（2018512101）。

作者简介 付宇新（1983—），男，湖北黄冈人，助理研究员，硕士，从事森林培育研究。

收稿日期 2020-08-04;修回日期 2020-08-18

氮是植物生长发育过程中必不可少的大量营养元素，是构成蛋白质、核酸、叶绿素及各种酶等的重要成分，一般占植物组织干物重的0.3%～5.0%，它直接影响到植物生长发育、产量和品质[1-2]。及时掌握植物的全氮或蛋白质含量，在生产经营和科学研究上有着非常重要的意义[3-6]。因此，植物或食品样品中氮含量的测定成为营养分析和评价中最重要的项目之一。……