固相磷提取剂对钼锑抗法测磷的影响及校正

Impact and Correction of Solid Phase Phosphorus Extractants on Determination of Phosphorus by Molybdenum-Antimony-Ascorbic Spectrophotometry

摘要: 固相磷作为磷循环过程中的重要组成部分，对其含量和形态的分析在生态环境和地球化学领域具有广泛的需求。研究中常用一定浓度的HCl、NaOH、MgCl2溶液作为固相磷提取剂，并采用钼锑抗分光光度法测定溶液中磷含量。而本研究发现酸、碱、镁离子提取剂投加量过高时均会对磷测定结果产生影响，造成测定结果准确度低。本实验通过定量控制每毫升溶液中加入酸提取剂的最大摩尔量为0.15 mmol，氢氧化钠提取剂为0.3 mmol、以及绘制不同Mg2+浓度下的工作曲线对该方法进行优化，从而提高磷测定结果的准确度，为进一步完善固相中磷形态提取和分析的方法提供可靠的依据。

Abstract: Solid-phase phosphorus, as an important component in the phosphorus cycling process, has a broad demand for its analysis of content and forms in the fields of ecological environment and geochemistry. In these studies, certain concentrations of HCl, NaOH, and MgCl2 solutions are commonly used as solid phase phosphorus extractants, and the phosphorus content in the solution is determined using the molybdenum-antimony-ascorbic spectrophotometry method. However, this study has found that excessive addition of acid, alkali, and magnesium ion extractants can all have an impact on the phosphorus determination results, resulting in low accuracy. In this experiment, the method was optimized by quantitatively controlling the maximum mole amount of acid extractant added per milliliter of solution to be 0.15 mmol, sodium hydroxide extractant to be 0.3 mmol, and by constructing a working curve under different Mg2+ concentrations. These optimizations aimed to improve the accuracy of phosphorus determination results, providing a reliable basis for further enhancement of methods for extraction and analysis of phosphorus forms in solid-phase samples.