为适应快速发展的在线自动监测技术,将非线性最小二乘算法应用于多成分红外光谱信号的定量分 析,通过拟合设定的气溶胶无机离子成分标准光谱和测量光谱,得到测量光谱的定量信息。结果表明非线 性最小二乘法在多成分红外光谱信号定量分析方面具有一定优势,硝酸根的均方根值(RMS)为0.340%。 利用计算结果分析了合肥董铺岛气溶胶无机离子浓度趋势,得到硫酸根和硝酸根的时间变化趋势。可见 非线性最小二乘法可以进行气溶胶离子化学成分浓度的红外光谱定量分析,且不需实时标定。

In order to adapt to the rapid development of online automatic monitoring technology, nonlinear least squares algorithm is applied to quantitative analysis of multi-component infrared spectral signals. The quantitative information of measured spectrum is obtained by fitting the standard spectrum and measured spectrum of aerosol inorganic ion composition. Results show that the nonlinear least squares algorithm has some advantages in quantitative analysis of multi-component infrared spectral signals, and the root mean square(RMS) of nitrate is 0.340%. The trend of aerosol inorganic ion concentration in Dongpu Island of Hefei, China is analyzed using the calculation results, and the temporal trends of sulfate and nitrate are obtained. It’s indicated that the nonlinear least squares method can be used for infrared spectroscopy quantitative analysis of the aerosol ion chemical composition concentration without real-time calibration.