光谱学传感技术测量水体COD是现代环境监测发展的趋势, 相比于传统的化学分析方法具有在线连续检测的突出优势, 适合对环境水体COD的实时监测。 采集实际水样, 利用激光诱导击穿光谱技术(LIBS)获取水样的光谱数据。 通过不同的光谱预处理方法结合偏最小二乘法建立水样的COD定量预测模型, 对水体COD的LIBS光谱测量方法的定量预测及相关模型参数进行分析。 发现用基线校正叠加S-G求导预处理后的光谱建立的PLS模型得到最佳预测效果, 校正集集R2为0.9958, 预测集R2为0.975 3, RMSEC为4.438 7, RMSEP为9.733 9。 通过实验结果分析表明光谱传感技术可用于环境实际水体COD的定量预测分析, 为开发便携式水体检测设备奠定了理论基础。

Using spectroscopy sensing technology to measure water COD is the trend of development of modern environmental monitoring. Compared to the traditional chemical analysis is has the benefits of online continuous detection of environmental water samples for real-time monitoring of water COD. This paper collected real water samples, using laser-induced breakdown spectroscopy (LIBS) to obtain water samples of spectral data. Establish water sample COD quantitative prediction model combining Partial Least Squares regression (PLS) by different spectral pretreatment method, then quantitative prediction of LIBS spectrum measurement method of water COD and the relevant model parameters were analyzed. Found that the baseline correction superimposed S-Golay derivative partial least-squares model had better prediction results. The determination coefficient of calibration samples were 0.995 8, while the determination coefficient of prediction were 0.975 3, with RMSEC of 4.438 7 and RMSEP of 9.733 9. The experimental results showed that spectrum sensing technology can be used in the actual environment of water COD quantitative predictive analysis, laid the theoretical foundation for the development of portable water testing equipment.