摘要
[Objective] The aim was to explore the application of terahertz (THz) technique in pesticide recognition and residue determination. [Method] THz far-infrared spectral characteristics of 2 herbicides (butachlor and metolachlor) were measured by THz time-domain spectroscopy (THz-TDS) under conditions of room temperature and nitrogen,meanwhile their refractive index and absorption coefficient between 0.2 and 2.2 THz were calculated by using models based on Fresenl equations. [Result] The 2 pesticides both had a series of different characteristic absorption peaks between 0.2 and 2.2 THz,respectively. Their molecular structures were similar,but there were great difference in absorption and refractive index spectrum between them. [Conclusion] THz-TDS technique is feasible to detect pesticide residues,especially there is a greater advantage in identifying the structure of similar substances.
[目的]探讨THz技术在农药识别和残留量检测中的应用。[方法]利用太赫兹时域光谱(THz-TDS)技术对2种除草剂丁草胺和异丙甲草胺在室温氮气环境下的THz远红外光谱特性进行测定,并利用菲涅尔公式的数据处理模型得到其在0.2~2.2THz波段的折射率和吸收系数。[结果]2种农药在0.2~2.2THz波段内分别存在不同的特征吸收峰。尽管2种农药分子结构相似,但其吸收谱和折射率却存在很大差异。[结论]THz-TDS技术在农药微量残留检测方面是可行的,特别是在识别结构较为相似的物质上有较大优势。
基金
Supported by Special Fund for Scientific Research on Public Welfare by China Quality Monitoring Bureau (200910181)
National Natural Science Foundation of China (60902095)~~