采用紫外吸光法采集浓度范围1～25 mg·L-1的邻苯二甲酸氢钾配置的标准液图谱, 对光谱进行不同的预处理后运用偏最小二乘法建立紫外吸光光谱下的COD定量分析模型, 并对所建模型进行了浊度、 pH值的影响分析。 结果显示采用平滑一阶导数预处理方法, 内部交叉验证均方根RMSECV值为0.122 27, 主成份数为4, 预测模型的平方相关系数r为0.999 8, 预测相对误差在0.03％～1.7％的范围内; 对0～100 NTU不同浊度的溶液, 应用所建模型补偿后相对标准偏差RSD达到2.3%; pH在3～10变化时, 影响可以忽略。

Configuration standard solution in the concentration range of 1~25 mg·L-1 of potassium hydrogen phthalate was usded as experimental subject, Ultraviolet absorption spectra was collected, the COD quantitative analysis model was established by partial least squares with different pretreatment methods and the turbidity of the compensation effect analysis was given. The results show the model uses smoothing first derivative pretreatment method, internal cross validation RMSECV root mean square value of 0.122 27, principal component number 4, the square of the prediction model correlation coefficient is 0.999 8, and the relative prediction error is in the range of 0.03%~1.7%; for 0~100 NTU’s turbidity solution, the relative standard deviation RSD is 2.3% after compensation; with pH in the range of 3~10, influence can be ignored.