氢氧化钠熔融法测定土壤全磷的优化  

Optimization of total soil phosphorus determination by sodium hydroxide fusion method

作　　者：李小涵[1] 董昭芸 惠晓丽[1] 彭兰芳 左瑜平 刘金山[1] 王朝辉[1] LI Xiaohan;DONG Zhaoyun;HUI Xiaoli;PENG Lanfang;ZUO Yuping;LIU Jinshan;WANG Zhaohui(College of Natural Resources and Environment,Northwest A&F University/Key Laboratory of Plant Nutrition and Agro-environment in Northwest China,Ministry of Agriculture and Rural Affairs,Yangling 712100,China)

机构地区：[1]西北农林科技大学资源环境学院农业农村部西北植物营养与农业环境重点实验室,陕西杨凌712100

出　　处：《农业环境科学学报》2023年第8期1905-1910,共6页Journal of Agro-Environment Science

基　　金：国家现代农业产业技术体系建设专项(CARS-3);西北农林科技大学教改项目(JY2103088);西北农林科技大学实验技术研究与实验室管理创新项目(SY20210106)。

摘　　要：为了完善氢氧化钠熔融和测定土壤全磷的方法,提高测试效率及测定精度,本研究利用采自我国不同地区的7种土壤,研究了碱熔温度、溶解所用酸的类型以及显色液酸度对测定结果的影响,并比较了流动分析仪(AA3)和电感耦合等离子体光谱仪(ICP-OES)测定结果的差异。研究表明:用氢氧化钠熔融土壤时,温度达到450℃即可完全熔解土壤,无需升至传统方法中的720℃;熔融后的土壤样品用酸溶解时,盐酸和硫酸都有较好的溶解性,但不同仪器的测定结果存在差异,盐酸溶解的样品适合用ICP-OES测定,硫酸溶解的样品更适合用AA3比色测定;在进行比色测定时,显色液酸度应控制在0.53~0.59 mol·L^(-1),以保持显色稳定、减少结果变异。Foroptimizing the method of soil alkali fusion and its total phosphorus(TP)content,and increasing the efficiency and accuracy of TP measurement,this study focuses on the effects of the alkali fusion temperature,acids of the dissolving solution,and acidity of the reagents used in colorimetric analysis with seven soils samples collected from different regions of China.The differences in the results from different measuring instruments[continuous flow analyzer(AA3,)and inductively coupled plasma mass spectrometer(ICP-OES)]were also compared.The results showed that TP could be melted completely when the sodium hydroxide temperature reached 450℃,and therefore did not need to be increased to 720℃.Both hydrochloric acid and sulfuric acid had good solubility for molten soil samples.The results of samples dissolved in different acids changed according to the determination instruments.Samples dissolved in sulfuric acid were more suitable for AA3,while those dissolved in hydrochloric acid were more suitable for ICP-OES.In addition,the chromogenic results were more stable when the acidity of the coloring reagent was controlled between 0.53 mol·L^(-1) to 0.59 mol·L^(-1).

关 键 词：土壤全磷 氢氧化钠熔融 熔融温度 酸类 显色液酸度 

分 类 号：O652[理学—分析化学] S153.6[理学—化学]