基于太赫兹成像技术的茶叶基质表面多菌灵农残分布与检测分析  

Localization and Analysis of Carbendazim Pesticide Residues on The Surface of Tea Leaves Based on Terahertz Spectral Imaging Technology

作　　者：唐鑫 邹佳岐 祝诗平[1] 周胜灵[1] TANG Xin;ZOU Jiaqi;ZHU Shiping;ZHOU Shengling(College of Engineering and Technology,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学工程技术学院,重庆400715

出　　处：《西南大学学报（自然科学版）》2024年第6期176-185,共10页Journal of Southwest University(Natural Science Edition)

基　　金：国家自然科学基金项目(62005227,31771670);重庆市自然科学基金面上项目(cstc2020jcyj-msxmX0300);中央高校基本科研业务费专项资金项目(XDJK2019C081).

摘　　要：采用太赫兹(THz)成像技术实现茶叶复杂基质上多菌灵定位及质量浓度分析.首先提取多菌灵压片THz光谱,得到位于1.15 THz和1.32 THz处的特征吸收峰,证明了太赫兹光谱检测多菌灵成分的有效性.其次,对比不同茶叶基质上多菌灵成像效果,确定最佳样本制备条件;制备800,1700,2300,3000,3700,4500,5000 mg/L 7个不同质量浓度的茶叶农残样本,采用时域切片法,选择时间延迟为13.98 ps进行成像,并进行超分辨率重建,实现多菌灵区域精确定位.鉴于THz叶片图像难以获得参考图像,采用自然图像质量评价(NIQE)、基于空间和光谱熵的无参考图像评估(SSEQ)和无参考空间域质量评估(BRISQUE)3种评价方法对重建前后的图像进行质量评估.结果表明,重建得到的图像评分更优,可以有效提高图像分辨率.最后,采用图像分割算法提取农残分布区域,建立光谱透射强度与农药质量浓度的关系方程,实现多菌灵定量分析.This paper adopted terahertz(THz)imaging technology to realize the localization and concentration analysis of pesticide residues on such a complex matrix of tea sample.Firstly,the THz spectra of carbendazim compressed tablets were extracted and the characteristic absorption peaks were obtained to be located at 1.15 THz and 1.32 THz,proving that using terahertz spectral for the determination of carbendazim constituents were effective.Secondly,the imaging effect of pesticide residues on tea substrates with different water contents was compared to determine the optimal sample preparation conditions.Tea samples with different concentrations of pesticide residues were prepared at 800,1700,2300,3000,3700,4500 and 5000 mg/L,respectively.The time-domain slicing method was adopted and a time delay of 13.98 ps was chosen to image the samples.The samples were reconstructed with super-resolution to realize the precise localization of the pesticide residue areas.As it is difficult to obtain the reference image of the blade,this paper adopted three reference-free image evaluation methods,NIQE,SSEQ,and BRISQUE,to evaluate the quality of the images before and after reconstruction.The evaluation results showed that the scores of the reconstructed images were even better,indicating that the method was effective in improving the image quality.After extracting the distribution area of pesticide residues by using image segmentation algorithm,the correlation equation between transmittance intensity and concentration was established,and finally the quantitative analysis of pesticide residues was realized.This research demonstrated that it was feasible to visualize and quantitatively detect the distribution of pesticide residues on the surface of tea matrices based on THz imaging,and the study made a useful exploration for the localization and detection of pesticide residues on the surface of the matrices of complex crop samples.

关 键 词：茶叶 太赫兹 超分辨率 农药残留 多菌灵 

分 类 号：TS272[农业科学—茶叶生产加工]