基于碳纳米材料光电效应离子源的研制与应用

Currently, it is still very serious for the situation of global anti-terrorism. The public security incidents occur frequently. It is valuable for the study of rapid on-site detection of potential threats such as explosives. The technique of ion mobility spectrometry(IMS) is widely used in this field due to its high sensitivity and good robustness. The most of traditional ionization part for IMS is radioactive source. Due to policy supervision and its potential safety risks, it is urgent to develop a new non-radioactive ionization technique. In this proposal, a novel ambient pulsed ionization source will be developed based on the photoemission effect of carbon nanomaterials with the pulsed light source. This source will overcome the problem of instability for metal materials which are easily oxidized and surface modified. Through investigating and optimizing process and material properties, this proposed project aims to study the mechanism of electron generation and emission and improve the emission efficiency. And the mechanism of photoelectron ionization source under atmosphere pressure will be studied. In combination with ion drift tube, a low-cost and good performance rapid detector will be developed which is not necessary to manufacture a complicated ion gate with high installation precision. Through the application research of more than 10 explosives, the application value of this instrument will be demonstrated in the field of public security. This ionization source technology is also expected to be extended to ionized samples at low pressure and vacuum in other mass spectrometry techniques.

当前全球反恐态势严峻，公共安全事件频发，对爆炸物威胁的现场快速检测的技术研究具有重要意义。离子迁移谱技术具备灵敏度高、鲁棒性好等优势，广泛应用于此领域。传统的技术方案主要是采用放射性源，受政策监管及其安全风险影响，急需开发一种新型非放射性离子源。本项目提出基于碳纳米材料的光电效应产生的光电子以电离样品，并结合脉冲式光源，研制一种新型脉冲式常压离子源，克服以往金属材料易被氧化、表面改性等引起的稳定性问题。通过对碳纳米材料的制备工艺和条件的优化，研究其中电子发射机制与影响因素，提高光电发射量子效率。并开展常压下光电子电离样品的电离机理。将此离子源应用于离子迁移谱技术，无需制作复杂、安装精度要求高的离子门，降低仪器的设计难度和成本的同时又保持良好的分析性能。通过开展10种以上的爆炸物检测的应用研究，探索此技术在公共安全领域的应用价值。此离子源技术还有望扩展至低压及真空下用于电离样品，应用于其它质谱技术中。

当前全球反恐态势严峻，公共安全事件频发，对爆炸物威胁的现场快速检测具有重要意义。离子迁移谱技术具备灵敏度高、鲁棒性好等优势，广泛应用于此领域。传统的技术方案主要是采用放射性源，受政策监管及其安全风险影响，急需开发一种新型非放射性离子源。本项目提出了一种基于碳纳米材料光电效应的新型离子源，并将其应用于离子迁移谱仪中。主要的研究内容有：金属薄膜与碳纳米管和石墨烯纳米材料薄膜的制备工艺探索；基于光电效应的新型常压脉冲式离子源的研制与表征优化；光电效应的新型常压脉冲式离子源的电离机理的研究；热解析进样与吸气进样的光电效应离子源离子迁移谱仪的研制与爆炸物、挥发性有机物的检测应用研究；串级离子迁移谱仪初步探索。本项目研制出一类基于碳纳米材料光电效应的新型离子源，克服以往金属材料易被氧化、表面改性等引起的稳定性问题，具备离子流强度高，稳定性好，电离产物简单等特点。所研制的新型脉冲式光电效应离子源离子迁移谱存在十分优异的性能。产生离子浓度上远超放射性离子源，仅用1W左右的功耗的氙灯产生的RIP离子信号可以比放射性离子源高出40倍以上。同时也展现出优异的灵敏度与很低的探测限。对于爆炸物的检测限可低于100pg（TNT为例），对气体样品的检测限可在ppb量级。脉冲式离子源存在分辨率更高的潜力，且仪器结构制作更简单。也可与离子门配合使用，实现串级离子迁移谱的功能，进一步提高样品的检测能力。此离子源技术还有望扩展至低压及真空下用于电离样品，应用于其它质谱技术中。该技术在国家公共安全、环境安全及食品安全领域也展现出有着广阔的应用前景。