ICARUS Chamber Experiment: 2014 FIXCIT Study_20140127_trans-beta-IEPOX/methyl nitrite_Hydroxyl radical_No Seed_Trans-beta-IEPOX + OH, moderate NO, dry, no seeds

Goals: Allow everyone to sample trans-beta-IEPOX for an intercomparison of sensitivities and a look at possible interferences; observe the products of IEPOX + OH oxidation, which we expect to include hydroxyacetone, glycolaldehyde, glyoxal, methylglyoxal, and C4H8O3 and C4H6O3 compounds.Summary: Today's experiment went largely according to plan. We successfully injected a large amount of IEPOX (we estimate 60 to 70 ppbv) over the course of 2.5 hours. Following the injection, the CF3O- CIMS saw significant wall loss, totaling ~25% in 3 hours. This is similar to the wall loss observed during IEPOX experiments last summer (~7%/hour in the same bag with high levels of HNO3), which may imply that the walls are currently highly acidified. When lights were turned on, IEPOX reacted quickly; ~50% of the IEPOX remaining when lights were turned on reacted away within an hour, and a further 20% was lost in the next two hours. The CF3O- CIMS observed many of the expected oxidation products, including hydroxyacetone, glycolaldehyde, C4H8O3, C4H6O3, and C5H8O3. Glyoxal did see an increase in signal, though they also had high noise levels. O3 reached 150 ppbv by the end of the experiment, and AMS did not see significant nucleation or aerosol growth.Organization: 2014 FIXCIT Study Lab Affiliation: California Institute of Technology Chamber: Seinfeld chambersExperiment Category: Gas phase chemical reaction Oxidant: Hydroxyl radical Reactants: trans-beta-IEPOX, methyl nitrite Reaction Type: Photooxidation Relative Humidity: 5 Temperature: 25 Pressure: 750 Torr

研究目标：为所有人员提供反式-β-IEPOX（trans-beta-IEPOX）的采样机会，以开展灵敏度比对实验并排查潜在干扰物；同时观测IEPOX与羟基自由基（OH）氧化反应的产物，预期产物包括羟基丙酮、乙醇醛、乙二醛、甲基乙二醛以及C4H8O3、C4H6O3类化合物。
实验概况：本次实验整体按计划顺利推进。我们在2.5小时内成功注入大量IEPOX，估算浓度为60~70 ppbv。注入完成后，三氟甲氧基负离子化学电离质谱仪（CF3O- CIMS）观测到显著的器壁损失现象，3小时内总损失率约25%。该结果与去年夏季IEPOX实验中观测到的器壁损失情况相近（在含高浓度硝酸（HNO3）的同一反应袋中，器壁损失速率约为7%/小时），这或表明当前反应腔内壁已发生高度酸化。开灯后，IEPOX快速发生反应：开灯时剩余的IEPOX中约50%在1小时内被消耗，后续2小时内又有20%的剩余IEPOX流失。CF3O- CIMS观测到多种预期的氧化产物，包括羟基丙酮、乙醇醛、C4H8O3、C4H6O3及C5H8O3。乙二醛的信号确实出现上升，但同时伴随较高的噪声水平。实验结束时，臭氧（O3）浓度达到150 ppbv，气溶胶质谱仪（AMS）未观测到显著的成核现象或气溶胶增长。
实验组织：2014 FIXCIT研究项目
实验室隶属：加州理工学院（California Institute of Technology）
实验腔：塞因费尔德反应腔（Seinfeld chambers）
实验类别：气相化学反应
氧化剂：羟基自由基
反应物：反式-β-IEPOX（trans-beta-IEPOX）、亚硝酸甲酯
反应类型：光氧化反应
相对湿度：5
温度：25℃
压力：750托（Torr）