拉曼光谱法定量分析焦磷酸根离子的含量

Quantitative analysis of pyrophosphate radical ion using raman spectroscopy

应用拉曼光谱技术研究了焦磷酸钾、硝酸钾、磷酸二氢钾、乙二胺四乙酸钠等十余种可溶性盐水溶液以及它们的混合物溶液的拉曼光谱特征,考察了共存组分对焦磷酸根拉曼光谱特征峰的影响;建立了基于拉曼光谱技术定量分析溶液中焦磷酸根离子含量的方法。结果表明,以硝酸钾为内标物,保持被测溶液pH 11,焦磷酸根离子拉曼光谱特征峰强度与硝酸根离子拉曼光谱特征峰强度之比值对焦磷酸根浓度呈良好的线性关系,所得线性回归方程为y=1.2110x+0.1515,相关系数R2=0.9996;已经研究过的十余种可溶性盐共存物几乎不干扰焦磷酸根离子的定量分析。

Raman spectroscopic characteristics of more than ten kinds of soluble salt solutions like K4P2OT, KNO3, KH2PO4, EDTA - 2Na, also their mixed solution were studied by Raman spectrometry, respectively. Then effects of the coexisting components on Raman spectral characteristic peak of pyrophosphate radical were investigated. A quantitative analysis method for determination of the concentration of pyrophosphate radical ion in solutions by Raman spectroscopy was created at last. A good linear relationship between the concentration of P2074- and the intensity ratio of Raman spectral characteristic peaks of P2074- and NO3 was displayed using potassium nitrate as an internal standard and maintaining the pH of measured solution as 11. The linear regression equation was y = 1. 2110x ＋ 0. 1515 ,and the correlation coefficient R2 was 0. 9996. The method has the advantages of speediness, simplicity and repeatability. The quantitative analysis of pyrophosphate radical ion was almost not affected by the studied coexisting substances.