氯化钠（NaCl）近红外光谱分析在生物医学上有着重要的意义。 钠离子(Na+)是人体血液中电解质的主要成分， 而电解质有助于维持身体的酸碱平衡。 采用近红外光谱技术测量氯化钠浓度， 在分析钠离子近红外光谱检测机理的基础上， 选定波长建立了NaCl浓度线性回归预测模型， 同时为了减小温度对水吸收的扰动， 使用选定光谱区建立偏最小二乘（PLS）非线性回归模型。 结果表明所建立的非线性校正模型决定系数（R2）=99.82％， 交叉验证均方误差（RMSECV）=14.5， 剩余预测偏差（RPD）=23.7。 完全满足日常生化检测精度要求， 该技术可以应用于医院实验室钠离子浓度定量分析。

The research on near infrared spectroscopy of sodium in biological and medicine is significant. Sodion is the main component of electrolytes in human blood and electrolytes help maintain the body’s acid-base balance. In the present paper the concentration of sodium was determined with the use of NIR spectra. On the basis of NIR spectroscopic measurement mechanism of sodion, prediction models of the concentration of sodium were developed with linear regression using the absorbance at selected wavelengths. In order to reduce temperature perturbations to water bands with the measurement of sodium, Partial least squares regression (PLS) was adopted using select spectra area. The result shows that the determination coefficients (R2)=99.82%， the root mean square error of cross validation (RMSECV)=14.5, and the residual prediction deviation (RPD)=23.7, for the calibration model. It meets the daily requirements of biochemical detection accuracy. This technique can be applied to quantitative analysis of sodion in the hospital laboratory.