Study on Detecting Method of Toxic Agent Containing Phosphorus
(Simulation Agent) by Optical Emission Spectroscopy of
Atmospheric Pressure Low-Temperature Plasma
YANG Jin-chuan1, 2, AN Jing-long1, 2, LI Cong3, ZHU Wen-chao3*, HUANG Bang-dou4*, ZHANG Cheng4, 5, SHAO Tao4, 5
1. Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjian 300130, China
2. State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China
3. State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
4. Beijing International S&T Cooperation Base for Plasma Science and Energy Conversion, Institute of Electrical Engineering Chinese Academy of Sciences, Beijing 100190, China
5. University of Chinese Academy of Sciences, Beijing 100049, China
Abstract：Gas chemical agent is fast-killing, highly diffusible, and difficult to decontaminate, threatening national security and social stability if used or leaked. Therefore, it is necessary to develop a gas detection method that can be used in real-time and on-site. Existing gas detection methods include infrared absorption spectroscopy, gas chromatography/mass spectroscopy, ion mobility spectrometry, and different gas sensors. Even so, these methods cannot achieve portability, sensitivity, and broad-spectrum simultaneously and meet the requirement of real-time and on-site detection. Based on the unique advantages of optical emission spectroscopy (OES), such as fast response, high sensitivity, broad-spectrum, and good repeatability, this work proposes a gas detection technology with OES from low-temperature plasma (LTP) at atmospheric pressure. Three excitation sources, i.e., nanosecond pulse, direct current (DC) self-pulse, and microwave (MW) generate LTP. Dimethyl methylphosphonate (DMMP) is used as the stimulant of sarin, of which OES is obtained. Ethanol is used as the organic interference in the environment. The principal component analysis (PCA) of OES from ethanol and DMMP is carried out. The relationship between pulse repetition rate and OES intensity from DMMP is explored. Results show that three sources can distinguish the characteristic OES from DMMP: the wavelengths of P atom are 213.82 and 215.09 nm, and those of PO radical are 253.67 and 255.6 nm. Regarding spectral discrimination, OES from DMMP in MW plasma is the clearest, while the continuous background is strong when using nanosecond pulse and DC self-pulse. In terms of device applicability, MW plasma, sustained with argon, can avoid electrode contamination and be an effective method to establish an OES database for chemical agents. Nanosecond pulse and DC self-pulse discharges can be directly operated in ambient air. The gas temperature (Tg) of MW plasma is the highest (about 1 300 K), whileTg of nanosecond pulse and DC self-pulse is similar (980 K vs 880 K). A linear relationship between OES intensity from DMMP and pulse repetition rate is observed in the range of 1~40 kHz, with correlation coefficients greater than 0.98. The OES detection method proposed in this work has the advantage of fast response and easy operation, and the potential of extensibility and miniaturization. This work verifies the feasibility of OES from LTP for chemical agent detection and provides a technical reference for equipment development in the future.
Key words：Atmospheric pressure plasma; Spectral diagnosis; Gas detection
[1] MEI Dan-hua, FANG Zhi, SHAO Tao(梅丹华, 方 志, 邵 涛). Proceedings of the CSEE(中国电机工程学报), 2020, 40(4): 1339.
[2] DAI Dong, NING Wen-jun, SHAO Tao(戴 栋, 宁文军, 邵 涛). Transactions of China Electrotechnical Society(电工技术学报), 2017, 32(20): 1.
[3] LI Shou-zhe(李寿哲). High Voltage Engineering(高电压技术), 2019, 45(11): 3730.
[4] WANG Hao-yu, CHEN Sha, YIN Peng-kun, et al(王皓宇, 陈 莎, 殷鹏鲲, 等). Chinese Journal of Analytical Chemistry(分析化学), 2020, 48(10): 1296.
[5] WANG Hong-ying, HAO Huan-ming, WANG Jin-sheng, et al(王红英, 郝焕明, 王金生, 等). Chinese Journal of Analysis Laboratory(分析试验室), 2020, 39(10): 1218.
[6] Han B J, Li Y, Qian B, et al. Analyst, 2018, 143(12): 2790.
[7] Li M, Huang S, Xu K, et al. Talanta, 2018, 188: 378.
[8] Qian B, Zhao J, He Y, et al. Journal of Chromatography A, 2019, 1608: 460406.
[9] Yuan H, Yang D Z, Li X, et al. Physics of Plasmas, 2019, 26(5): 053505.
[10] PAN Ru-zheng, ZANG Zi-hao, HUANG Bang-dou, et al(潘如政, 臧子豪, 黄邦斗, 等). High Voltage Engineering(高电压技术)，2021, 47(10): 3696.
[11] JIANG Hui, SHAO Tao, ZHANG Cheng, et al(姜 慧, 邵 涛, 章 程, 等). Transactions of China Electrotechnical Society(电工技术学报), 2017, 32(2): 33.
[12] ZENG Hui, OU Dong-bin(曾 徽, 欧东斌). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2020, 40(6): 1685.
