基于非相干宽带腔增强吸收光谱技术对碘氧自由基的定量研究  

Quantification of iodine monoxide based on incoherent broadband cavity enhanced absorption spectroscopy

作　　者：张鹤露 秦敏 方武 唐科 段俊[1] 孟凡昊 邵豆 华卉 廖知堂 谢品华 Zhang He-Lu;Qin Min;Fang Wu;Tang Ke;Duan Jun;Meng Fan-Hao;Shao Dou;Hua Hui;Liao Zhi-Tang;Xie Pin-Hua(Anhui Institute of Optics and Fine Mechanics,Hefei Institute of Material Science,Chinese Academy of Sciences,Key Laboratory of Environmental Optics and Technology,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所,中国科学院环境光学与技术重点实验室,合肥230031 [2]中国科学技术大学,合肥230026

出　　处：《物理学报》2021年第15期57-66,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:41875154,U19A2044);安徽省重点研究与开发计划(批准号:202104i07020010)资助的课题.

摘　　要：介绍了 435-465 nm波段非相干宽带腔增强吸收光谱(IBBCEAS)技术对碘氧自由基(IO)的定量方法.为准确获取IO的浓度信息,对IBBCEAS系统高反镜的镜片反射率、有效腔长及损耗等参数进行了标定.利用氮气和氦气之间瑞利散射的差异性标定了高反镜的反射率曲线,在IO吸收峰436.1 nm处镜片反射率及为0.99982,真空状态下有效吸收光程达到3.83 km.根据O4的吸收,修正后系统的有效腔长为60.7 cm.采用艾伦方差对系统的性能进行评估,在60 s时间分辨率下,系统对IO和NO_(2)的探测限(2σ)分别为1.9 pptv和20 pptv (1 pptv (part per trillion by volume)=10^(-12)).通过鼓泡法将溶于碘化钾(KI)溶液的碘带出,并将其光解后与臭氧反应产生稳定浓度的IO样气,对IO在采样管内的损耗进行了标定,结果表明IO的损耗可以忽略.利用IBBCEAS系统对IO的线性进行测定,在39-530 pptv的浓度范围下IO的测量浓度与配比浓度的相关系数R2为0.99.进而,利用该系统对海带排放的碘与臭氧反应生成的IO进行了测量.The quantitative method of iodine monoxide radical(IO)using incoherent broadband cavity enhanced absorption spectroscopy(IBBCEAS)in the 435-465 nm band is described in this paper.In order to obtain the concentration of IO accurately,the parameters such as the mirror reflectivity,effective cavity length and sample loss of the IBBCEAS system are evaluated.Using the difference of Rayleigh scattering between nitrogen and helium,the reflectivity curve of the high-reflection mirror is obtained.The reflectivity R of the mirror at 436.1 nm of the IO absorption peak is about 0.99982,and the effective absorption optical path reaches 3.83 km under vacuum condition.According to the absorption of O_(4),the effective cavity length of the modified system is 60.7 cm.The Allan deviation is used to evaluate the performance of the system,and the standard deviation is used to analyze the detection sensitivity of the system.When the time resolution is 60 s,the detection sensitivity(2σ)of the system for IO and NO_(2) are 1.9 pptv and 20 pptv(part per trillion by volume),respectively.The iodine dissolved in potassium iodide(KI)solution is taken out by the bubbling method and react with ozone after photolysis to produce a stable concentration of IO sample gas.The IO loss in the sampling tube is calibrated,and the results show that the sampling tube has no significant effect on the IO loss.The IBBCEAS system is used to determine the linearity of IO,and the correlation coefficient R2 between the measured concentration of IO and the proportioned concentration in a concentration range from 39 to 530 pptv is 0.99.The IO produced by the reaction of iodine released from kelp with ozone is measured.

关 键 词：碘氧自由基 非相干光宽带腔增强吸收光谱技术 定量 

分 类 号：O657.3[理学—分析化学]