新型挥发性有机物吸附浓缩在线监测系统的研制
|
摘要
采用独特的双级深冷浓缩富集技术,研制了一种新型大气挥发性有机物(VOCs)吸附浓缩在线监测系统。通过对VOCs的深冷捕集和聚焦,并结合气相色谱-质谱/氢火焰离子化检测器(GC-MS/FID)技术,该系统可对C_2～C_(12)烃类、含氧有机物及卤代烃、有机硫化物等在内的100多种VOCs进行在线分析。通过测试PAMS和TO15混合标样(共计108种组分),95%化合物的定量标准曲线的线性相关系数R大于0.99,91%化合物的相对标准偏差(RSD)小于5%,对苯的检测限可达1×10~(-12) mol/mol。该方法能够满足大气中挥发性有机物的在线监测需求。
In order to meet the requirement of monitoring VOCs for qualitative, quantitative analysis at low level, a new online monitoring system of adsorption and concentration was developed and preliminarily tested, which included a sampling gas path system with a dual channel, a ultra-low temperature trap system, a power supply, a control system, and an analysis system with gas chromatography-mass spectrometry/flame ionization detector(GC-MS/FID). A unique technology of two-stage cryogenic enrichment was adopted for the ultra-low temperature trap system, which included two trap tubes of first stage and two focusing tubes of second stage. Each tube was able to reach an ultra-low temperature of-160 ℃ and covered with a heating structure. A sampling gas path system with a dual channel was used as a processing device of front injection for analyzing application of MS and FID, before which sample was separated by GC. Each channel included a trap tube and a focusing tube. VOCs and water were cryogenically trapped in the tube of first stage during sampling and focused in the tube of second stage after the tube of first stage had been heated, but the water was still remained in the tube of first stage because the temperature was less than 100 ℃. All VOCs in the tube of second stage were heated to 170 ℃ and analyzed in the GC-MS/FID by carrier gas, when the twelve-way valve was switched. The valve was switched to the original position in two minutes later, and the gas path was completely purged for 10 min in the opposite direction of the trapping state, when all the tubes were heated to 180 ℃, then the system was going to be in the state of waiting for the sample to be trapped. This technology could adsorb and concentrate 100 kinds of VOCs including C_2-C_(12) hydrocarbons, oxygenated organic compounds, halogenated hydrocarbons, organic sulfides and so on, as well as conducting online real-time monitoring and analysis. It was easy to get data about the information of VOCs concentration in less 60 min. The system was tested in performance using mixed sample of standard gas of PAMS and TO15(a total of 108 components). The quantitative standard curve R of 95% of compounds is greater than 0.99, and the relative standard deviation(RSD) of 91% of compounds is less than 5%. The limit of detection(LOD) of benzene can achieve 1×10~(-12) mol/mol. The system is applied for testing the VOCs of air, and 76 kinds of VOCs are qualitatively and quantitatively analyzed. In short, the new online monitoring system of adsorption and concentration can meet the online monitoring requirements of volatile organic compounds in the atmosphere.
In order to meet the requirement of monitoring VOCs for qualitative, quantitative analysis at low level, a new online monitoring system of adsorption and concentration was developed and preliminarily tested, which included a sampling gas path system with a dual channel, a ultra-low temperature trap system, a power supply, a control system, and an analysis system with gas chromatography-mass spectrometry/flame ionization detector(GC-MS/FID). A unique technology of two-stage cryogenic enrichment was adopted for the ultra-low temperature trap system, which included two trap tubes of first stage and two focusing tubes of second stage. Each tube was able to reach an ultra-low temperature of-160 ℃ and covered with a heating structure. A sampling gas path system with a dual channel was used as a processing device of front injection for analyzing application of MS and FID, before which sample was separated by GC. Each channel included a trap tube and a focusing tube. VOCs and water were cryogenically trapped in the tube of first stage during sampling and focused in the tube of second stage after the tube of first stage had been heated, but the water was still remained in the tube of first stage because the temperature was less than 100 ℃. All VOCs in the tube of second stage were heated to 170 ℃ and analyzed in the GC-MS/FID by carrier gas, when the twelve-way valve was switched. The valve was switched to the original position in two minutes later, and the gas path was completely purged for 10 min in the opposite direction of the trapping state, when all the tubes were heated to 180 ℃, then the system was going to be in the state of waiting for the sample to be trapped. This technology could adsorb and concentrate 100 kinds of VOCs including C_2-C_(12) hydrocarbons, oxygenated organic compounds, halogenated hydrocarbons, organic sulfides and so on, as well as conducting online real-time monitoring and analysis. It was easy to get data about the information of VOCs concentration in less 60 min. The system was tested in performance using mixed sample of standard gas of PAMS and TO15(a total of 108 components). The quantitative standard curve R of 95% of compounds is greater than 0.99, and the relative standard deviation(RSD) of 91% of compounds is less than 5%. The limit of detection(LOD) of benzene can achieve 1×10~(-12) mol/mol. The system is applied for testing the VOCs of air, and 76 kinds of VOCs are qualitatively and quantitatively analyzed. In short, the new online monitoring system of adsorption and concentration can meet the online monitoring requirements of volatile organic compounds in the atmosphere.
引文
[1] DERWENT R G, JENKIN M E, SAUNDERS S M, PILLING M J, SIMMONDS P G, PASSANT N R, DOLLARD G J, DUMITREAN P, KENT A. Photochemical ozone formation in north west Europe and its control[J]. Atmospheric Environment, 2003, 37(14): 1 983-1 991.
[2] WATSON N, DAVIES S, WEVILL D. Air monitoring: new advances in sampling and detection[J]. Scientific World Journal, 2011, 11(7): 2 582-2 598.
[3] MISHRA N, BARTSCH J, AYOKO G A, SALTHAMMER T, MORAWSKA L. Volatile organic compounds: characteristics, distribution and sources in urban schools[J]. Atmospheric Environment, 2015, 106: 485-491.
[4] 沈朝烨,蒋志宏,徐以盛,汪国权. 测定室内空气中挥发性有机污染物的SUMMA罐采样-GC-MS联用方法研究[J]. 环境与职业医学,2009,26(1):70-73. SHEN Chaoye, JIANG Zhihong, XU Yisheng, WANG Guoquan. Research on the determination of volatile organic compounds in indoor air using SUMMA canisters with subsequent analysis by GC/MS[J]. Journal of Environmental & Occupational Medicine, 2009, 26(1): 70-73(in Chinese).
[5] 王芳,吴少清,王巍. 苏码罐采样预浓缩-GC-MS分析空气中的挥发性有机物[J]. 广东化工,2012,39(2):193-194. WANG Fang, WU Shaoqing, WANG Wei. Determination of volatile organic compounds in ambient air using SUMMA canisters with subsequent analysis by GC-MS[J]. Guangdong Chemical Industry, 2012, 39(2): 193-194(in Chinese).
[6] 李悦,邵敏,陆思华. 城市大气中挥发性有机化合物监测技术进展[J]. 中国环境监测,2015,31(4):1-7. LI Yue, SHAO Min, LU Sihua. Review on technologies of ambient volatile organic compounds measurement[J]. Environmental Monitoring in China, 2015, 31(4): 1-7(in Chinese).
[7] PLASHNITSA V V, ELUMALAI P, FUJIO Y, MIURA N. Zirconia-based electrochemical gas sensors using nano-structured sensing materials aiming at detection of automotive exhausts[J]. Electrochimica Acta, 2009, 54(25): 6 099-6 106.
[8] SOMOV S, REINHARDT G, GUTH U, GOPEL W. Gas analysis with arrays of solid state electrochemical sensors: implications to monitor HCs and NOx in exhausts[J]. Sensors & Actuators B Chemical, 1996, 36(1/2/3): 409-418.
[9] MITRA S, ZHU N, ZHANG X, KEBBEKUS B. Continuous monitoring of volatile organic compounds in air emissions using an on-line membrane extraction-microtrap-gas chromatographic system[J]. Journal of Chromatography A, 1996, 736(1/2): 165-173.
[10] LINDINGER C, POLLIEN P, ALI S, YERETZIAN C, BLANK I, MARK T. Unambiguous identification of volatile organic compounds by proton-transfer reaction mass spectrometry coupled with GC/MS[J]. Analytical Chemistry, 2005, 77(13): 4 117-4 124.
[11] MALEKNIA S D, BELL T L, ADAMS M A. PTR-MS analysis of reference and plant-emitted volatile organic compounds[J]. International Journal of Mass Spectrometry, 2007, 262(3): 203-210.
[12] 谭国斌,高伟,黄正旭,洪义,傅忠,董俊国,程平,周振. 真空紫外灯单光子电离源飞行时间质谱仪的研制[J]. 分析化学,2011,39(10):1 470-1 475. TAN Guobin, GAO Wei, HUANG Zhengxu, HONG Yi, FU Zhong, DONG Junguo, CHENG Ping, ZHOU Zhen. Vacuum ultraviolet single photon ionization time-of-flight mass spectrometer[J]. Chinese Journal of Analytical Chemistry, 2011, 39(10): 1 470-1 475(in Chinese).
[13] YAMAMOTO Y, KANNO N, TONOKURA K, YABUSHITA A, KAWASAKI M. Membrane introduction system for trace analysis of volatile organic compounds using a single photon ionization time-of-flight mass spectrometer[J]. International Journal of Mass Spectrometry, 2010, 296(1): 25-29.
[14] RICHARDSON S D. Environmental Mass Spectrometry: emerging contaminants and current issues[J]. Analytical Chemistry, 2006, 78(2): 4 021-4 046.
[15] DUNMORE R E, HOPKINS J R, LIDSTER R T, LEE J D, EVANS M J, RICKARD A R, LEWIS A C, HAMILTON J F. Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities[J]. Atmospheric Chemistry & Physics, 2015, 15(6): 9 983-9 996.
[16] DUNMORE R E, WHALLEY L K, SHERWEN T, EVANS M J, HEARD D E, HOPKINS J R, LEE J D, LEWIS A C, LIDSTER R T, RICKARD A R, HAMILTON J F. Atmospheric ethanol in London and the potential impacts of future fuel formulations[J]. Faraday Discussions, 2015, 189: 105-120.
[17] 李虹杰,肖庆,韩长绵,刘琳,范新峰,陈楠,潘怡沛. 低温空管冷冻浓缩技术-GC-MS-FID法自动监测环境空气中VOCs[J]. 中国环境监测,2017,33(6):100-110. LI Hongjie, XIAO Qing, HAN Changmian, LIU Lin, FAN Xinfeng, CHEN Nan, PAN Yipei. On-line monitoring of VOCs in ambient air based on Cryo-Trapping-GC-MS-FID[J]. Environmental Monitoring in China, 2017, 33(6): 100-110(in Chinese).
[18] WANG M, ZENG L, LU S, SHAO M, LIU X, YU X, CHEN W, YUAN B, ZHANG Q, HU M, ZHANG Z. Development and validation of a cryogen-free automatic gas chromatograph system (GC-MS/FID) for online measurements of volatile organic compounds[J]. Analytical Methods, 2014, 6(23): 9 424-9 434.
[19] 刘兴隆,曾立民,陆思华,于雪娜. 大气中挥发性有机物在线监测系统[J]. 环境科学学报,2009,29(12):2 471-2 477. LIU Xinglong, ZENG Limin, LU Sihua, YU Xuena. Online monitoring system for volatile organic compounds in the atmosphere[J]. Acta Scientiae Circumstantiae, 2009, 29(12): 2 471-2 477(in Chinese).
[20] 母应锋,傅寅,陆晓波,喻义勇,张予燕,朱志锋. 对TH_PKU-300B挥发性有机物快速在线监测系统的改进[J]. 环境监控与预警,2016,8(1):19-23. MU Yingfeng, FU Yin, LU Xiaobo, YU Yi-yong, ZHANG Yuyan, ZHU Zhifeng. Improvement on the TH_PKU-300B Fast On-line monitoring system for volatile organic compounds[J]. Environmental Monitoring & Forewarning, 2016, 8(1): 19-23(in Chinese).
[21] ZHANG Z, WANG H, CHEN D, LI Q, THAI P, GONG D, LI Y, ZHANG C, GU Y, ZHOU L, MORAWSKA L, WANG B. Emission characteristics of volatile organic compounds and their secondary organic aerosol formation potentials from a petroleum refinery in Pearl River Delta, China[J]. Science of the Total Environment, 2017, (584/585): 1 162-1 174.
[2] WATSON N, DAVIES S, WEVILL D. Air monitoring: new advances in sampling and detection[J]. Scientific World Journal, 2011, 11(7): 2 582-2 598.
[3] MISHRA N, BARTSCH J, AYOKO G A, SALTHAMMER T, MORAWSKA L. Volatile organic compounds: characteristics, distribution and sources in urban schools[J]. Atmospheric Environment, 2015, 106: 485-491.
[4] 沈朝烨,蒋志宏,徐以盛,汪国权. 测定室内空气中挥发性有机污染物的SUMMA罐采样-GC-MS联用方法研究[J]. 环境与职业医学,2009,26(1):70-73. SHEN Chaoye, JIANG Zhihong, XU Yisheng, WANG Guoquan. Research on the determination of volatile organic compounds in indoor air using SUMMA canisters with subsequent analysis by GC/MS[J]. Journal of Environmental & Occupational Medicine, 2009, 26(1): 70-73(in Chinese).
[5] 王芳,吴少清,王巍. 苏码罐采样预浓缩-GC-MS分析空气中的挥发性有机物[J]. 广东化工,2012,39(2):193-194. WANG Fang, WU Shaoqing, WANG Wei. Determination of volatile organic compounds in ambient air using SUMMA canisters with subsequent analysis by GC-MS[J]. Guangdong Chemical Industry, 2012, 39(2): 193-194(in Chinese).
[6] 李悦,邵敏,陆思华. 城市大气中挥发性有机化合物监测技术进展[J]. 中国环境监测,2015,31(4):1-7. LI Yue, SHAO Min, LU Sihua. Review on technologies of ambient volatile organic compounds measurement[J]. Environmental Monitoring in China, 2015, 31(4): 1-7(in Chinese).
[7] PLASHNITSA V V, ELUMALAI P, FUJIO Y, MIURA N. Zirconia-based electrochemical gas sensors using nano-structured sensing materials aiming at detection of automotive exhausts[J]. Electrochimica Acta, 2009, 54(25): 6 099-6 106.
[8] SOMOV S, REINHARDT G, GUTH U, GOPEL W. Gas analysis with arrays of solid state electrochemical sensors: implications to monitor HCs and NOx in exhausts[J]. Sensors & Actuators B Chemical, 1996, 36(1/2/3): 409-418.
[9] MITRA S, ZHU N, ZHANG X, KEBBEKUS B. Continuous monitoring of volatile organic compounds in air emissions using an on-line membrane extraction-microtrap-gas chromatographic system[J]. Journal of Chromatography A, 1996, 736(1/2): 165-173.
[10] LINDINGER C, POLLIEN P, ALI S, YERETZIAN C, BLANK I, MARK T. Unambiguous identification of volatile organic compounds by proton-transfer reaction mass spectrometry coupled with GC/MS[J]. Analytical Chemistry, 2005, 77(13): 4 117-4 124.
[11] MALEKNIA S D, BELL T L, ADAMS M A. PTR-MS analysis of reference and plant-emitted volatile organic compounds[J]. International Journal of Mass Spectrometry, 2007, 262(3): 203-210.
[12] 谭国斌,高伟,黄正旭,洪义,傅忠,董俊国,程平,周振. 真空紫外灯单光子电离源飞行时间质谱仪的研制[J]. 分析化学,2011,39(10):1 470-1 475. TAN Guobin, GAO Wei, HUANG Zhengxu, HONG Yi, FU Zhong, DONG Junguo, CHENG Ping, ZHOU Zhen. Vacuum ultraviolet single photon ionization time-of-flight mass spectrometer[J]. Chinese Journal of Analytical Chemistry, 2011, 39(10): 1 470-1 475(in Chinese).
[13] YAMAMOTO Y, KANNO N, TONOKURA K, YABUSHITA A, KAWASAKI M. Membrane introduction system for trace analysis of volatile organic compounds using a single photon ionization time-of-flight mass spectrometer[J]. International Journal of Mass Spectrometry, 2010, 296(1): 25-29.
[14] RICHARDSON S D. Environmental Mass Spectrometry: emerging contaminants and current issues[J]. Analytical Chemistry, 2006, 78(2): 4 021-4 046.
[15] DUNMORE R E, HOPKINS J R, LIDSTER R T, LEE J D, EVANS M J, RICKARD A R, LEWIS A C, HAMILTON J F. Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities[J]. Atmospheric Chemistry & Physics, 2015, 15(6): 9 983-9 996.
[16] DUNMORE R E, WHALLEY L K, SHERWEN T, EVANS M J, HEARD D E, HOPKINS J R, LEE J D, LEWIS A C, LIDSTER R T, RICKARD A R, HAMILTON J F. Atmospheric ethanol in London and the potential impacts of future fuel formulations[J]. Faraday Discussions, 2015, 189: 105-120.
[17] 李虹杰,肖庆,韩长绵,刘琳,范新峰,陈楠,潘怡沛. 低温空管冷冻浓缩技术-GC-MS-FID法自动监测环境空气中VOCs[J]. 中国环境监测,2017,33(6):100-110. LI Hongjie, XIAO Qing, HAN Changmian, LIU Lin, FAN Xinfeng, CHEN Nan, PAN Yipei. On-line monitoring of VOCs in ambient air based on Cryo-Trapping-GC-MS-FID[J]. Environmental Monitoring in China, 2017, 33(6): 100-110(in Chinese).
[18] WANG M, ZENG L, LU S, SHAO M, LIU X, YU X, CHEN W, YUAN B, ZHANG Q, HU M, ZHANG Z. Development and validation of a cryogen-free automatic gas chromatograph system (GC-MS/FID) for online measurements of volatile organic compounds[J]. Analytical Methods, 2014, 6(23): 9 424-9 434.
[19] 刘兴隆,曾立民,陆思华,于雪娜. 大气中挥发性有机物在线监测系统[J]. 环境科学学报,2009,29(12):2 471-2 477. LIU Xinglong, ZENG Limin, LU Sihua, YU Xuena. Online monitoring system for volatile organic compounds in the atmosphere[J]. Acta Scientiae Circumstantiae, 2009, 29(12): 2 471-2 477(in Chinese).
[20] 母应锋,傅寅,陆晓波,喻义勇,张予燕,朱志锋. 对TH_PKU-300B挥发性有机物快速在线监测系统的改进[J]. 环境监控与预警,2016,8(1):19-23. MU Yingfeng, FU Yin, LU Xiaobo, YU Yi-yong, ZHANG Yuyan, ZHU Zhifeng. Improvement on the TH_PKU-300B Fast On-line monitoring system for volatile organic compounds[J]. Environmental Monitoring & Forewarning, 2016, 8(1): 19-23(in Chinese).
[21] ZHANG Z, WANG H, CHEN D, LI Q, THAI P, GONG D, LI Y, ZHANG C, GU Y, ZHOU L, MORAWSKA L, WANG B. Emission characteristics of volatile organic compounds and their secondary organic aerosol formation potentials from a petroleum refinery in Pearl River Delta, China[J]. Science of the Total Environment, 2017, (584/585): 1 162-1 174.