【作者】 张旭；

【导师】 储焰南； 黄超群；

【作者基本信息】 中国科学技术大学 ， 检测技术与自动化装置， 2024， 硕士

【摘要】 离子迁移谱检测技术是一种起源于上世纪六十年代痕量检测技术,主要依赖于样品与反应离子之间的化学反应,由于样品的特性各异,能够发生作用的反应离子种类也不尽相同。根据离子所带电荷的不同,此技术分为正离子检测模式和负离子检测模式。传统离子迁移谱检测仪只能工作在一种检测模式下,无法做到对正负两种离子的同时分析。本研究设计并搭建了一套双迁移管离子迁移谱检测系统,该系统使用电晕放电电离源产生反应离子,样品跟随载气分别进入两个迁移管进行反应和迁移,随后运动到法拉第板产生信号,经放大和处理后在上位机上显示。主要的工作包括以下几个方面:(1)硬件电路设计。设计并制作了双路离子门电路、温控电路、电源电路、进样电路和信号采集电路,各电路之间相互独立,通过导线连接,方便功能的调试和后期维护。(2)控制程序和采集软件。编写了单片机控制程序,包括传感器数据采集和传输,PID温度控制算法,串口通信等控制程序。利用C++和LabView编写了上位机显示和控制软件。(3)热解析进样装置与气路搭建。为拓展双迁移管离子迁移谱检测系统的应用场景,设计了新的热解析进样装置。使用洁净后的空气作为载气和迁移气,并搭建了独立的气路系统。(4)系统性能验证。利用双迁移管离子迁移谱检测系统对TNT代谢产物进行检测,从而验证系统性能。实验结果表明,本研究所搭建的双迁移管离子迁移谱检测系统能够同时对正负离子进行检测。在正负离子检测模式下,TNT代谢产物的检测限均能达到pg量级。此外,对TNT代谢产物在迁移管温度变化下的影响进行了研究,并使用人工尿液模拟真实环境中的检测。这些结果显示,该检测系统具有优异的检测性能,能够完成TNT代谢产物的现场检测。更多还原

【Abstract】 Ion mobility spectrometry(IMS),which is a trace detection technology,originated in the 1960s.IMS detection relies on the chemical reactions between the sample and reactant ions.Due to the diverse characteristics of the samples,the types of reactant ions capable of interacting also vary.This technology is divided into positive ion detection mode and negative ion detection mode based on the different charges carried by ions.Traditional IMS detectors can only operate in one detection mode and cannot simultaneously analyze both positive and negative ions.This study designed and constructed a dual-drift tube IMS detection system that employs a corona discharge ion source to generate reaction ions,which,compared to radioactive ion sources,does not have strict transportation and usage constraints.After the samples undergo thermal desorption,they enter two drift tubes for reaction and migration separately,and then are collected and further processed through the Faraday plate.The main work includes the following aspects:(1)Design of hardware circuits.Dual-channel ion gate circuits,temperature control circuits,power supply circuits,injection circuits,and signal acquisition circuits were designed and fabricated,with each circuit being independent and interconnected by wires for easy debugging and maintenance of functions.(2)Control program and acquisition software.Microcontroller control programs were written,including sensor data acquisition and transmission,PID control algorithms,serial communication,and other related control programs.Additionally,C++and Lab VIEW were used to write upper computer display and control software.(3)Improvement of drift tubes and construction of thermal desorption injection structure.To expand the application scenarios of the dual-drift tube IMS detection system,a new thermal desorption sample introduction device was designed.Cleaned air was utilized as the carrier and drift gas,and an independent gas path system was constructed.(4)Verification of system performance.The constructed detection system was used to detect TNT metabolites to verify the detection performance of the system.The experimental analysis indicates that the dual-tube drift tube IMS detection system constructed in this study is capable of simultaneously detecting positive and negative ions.Under both positive and negative ion detection modes,the detection limits for TNT metabolites reach the pg level.Furthermore,the impact of TNT metabolites under varying drift tube temperatures was investigated,and artificial urine was used to simulate detection in real-environment.There results demonstrate that detection system exhibits excellent performance in detecting TNT metabolites on-site.更多还原