为快速检测餐厨垃圾堆肥样品腐殖酸含量,提出了基于近红外光谱分析技术测定腐殖酸含量的快速检测方法.利用近红外光谱仪采集堆肥样品的漫反射光谱,通过容量法测定腐殖酸含量,采用Savitzky-Golay卷积平滑(SG)、滑动平均平滑(MA)、标准正态变量变换(SNV)、SNV+一阶导数(FD)+MA、SNV+二阶导数(SD)+MA、SNV+FD+SG和SNV+SD+SG等方法对原始光谱进行预处理,结合区间偏最小二乘法(iPLS)、反向区间偏最小二乘法(biPLS)和联合区间偏最小二乘法(siPLS),优选光谱特征波段,建立腐殖酸含量分析模型.结果表明,采用SNV+FD+SG预处理结合siPLS提取的光谱特征波段(4 389~4 775、7 583~7 976 cm-1),建立的siPLS模型预测效果最佳,建模集的交互验证均方根误差(RMSECV)和校正相关系数(Rc)分别为0.423 1、0.967 8,验证集的预测均方根误差(RMSEP)和预测相关系数(Rp)分别为0.573 2、0.932 4.利用近红外光谱结合siPLS可准确快速检测餐厨垃圾堆肥样品腐殖酸含量,为快速检测和表征有机废弃物堆肥样品腐殖酸含量提供改进参考.
A rapid detection method based on near infrared spectroscopy analysis was proposed to determine the humic acid content of kitchen waste compost samples.This paper used near infrared spectrometer to collect the diffuse reflectance spectra of compost samples,and the humic acid content was determined by the volumetric method.The raw spectra were pretreated and analyzed by Savitzky-Golay convolution smoothing(SG),moving average smoothing(MA),standard normal variable transformation(SNV),SNV+first order derivative(FD)+MA,SNV+second order derivative(SD)+MA,SNV+FD+SG and SNV+SD+SG.The interval partial least squares(iPLS),backward interval partial least squares(biPLS)and synergy interval partial least squares(siPLS)were used to preferably select the spectral feature intervals and the analysis model of humic acid content was established.The results showed that when the SNV+FD+SG spectrum pretreatment combined with siPLS extracted spectral feature band of 4 389-4 775,7 583-7 976 cm 1,the siPLS model had the best prediction results.The root-mean-square error of cross-validation(RMSECV)and coefficient of correction(Rc)for the modeling set were 0.423 1 and 0.967 8,and the root-mean-square error of prediction(RMSEP)and coefficient of prediction(Rp)for the prediction set were 0.573 2 and 0.932 4.The results showed that the near infrared spectroscopy combined with the siPLS method accurately and quickly detected the humic acid content of kitchen waste compost samples,which provided a reference for improved detection means for rapid detection and characterization of humic acid content in organic waste compost samples.