ICARUS Chamber Experiment: Nguyen Group_20190808_ALPHA-PINENE/OZONE/10102-44-0/hydrogen peroxide_Nitrate radical_Ammonium sulfate

Goals: To quantify the nitrooxy-hydroperoxide yield and the SOA yield from nighttime RO2+HO2-dominated NO3-initiated chemistry of a-pinene by adding H2O2 + ozone + NO2 to the chamber. Part of a series of varying initial reactant concentrations slightly to target different chemical pathways. This one likely got high RO2+HO2, with some background RO2+RO2 chemistry.Summary: H2O2, NO2, and O3 were injected in the chamber and allowed to equilibrate, forming NO3 (and some N2O5) and probably HO2. Ammonium sulfate seed particles were injected. Then a-pinene was injected and decayed by simultaneous reaction with ozone and NO3. Gas phase was monitored by CF3O- CIMS and particle formation by SMPS.Organization: Nguyen Group Lab Affiliation: UC Davis Chamber: Tran's big bag of airExperiment Category: Gas phase chemical reaction, Aerosol formation Oxidant: Nitrate radical Reactants: ALPHA-PINENE, OZONE, 10102-44-0, hydrogen peroxide Reaction Type: Dark oxidation Relative Humidity: 5 Temperature: 22 Seed Name: Ammonium sulfate Pressure: 755 Torr

研究目标：通过向烟雾箱中加入过氧化氢（H₂O₂）、臭氧（O₃）与二氧化氮（NO₂），量化以夜间过氧自由基（RO₂）+过氧氢自由基（HO₂）为主导的硝酸根自由基（NO₃）引发的α-蒎烯化学反应所生成的硝基氧氢过氧化物产率与二次有机气溶胶（SOA，Secondary Organic Aerosol）产率。本实验属于一系列小幅调整初始反应物浓度以靶向不同化学路径的研究之一，本次实验体系中RO₂+HO₂占比颇高，同时伴随少量背景RO₂+RO₂反应。
实验概要：向烟雾箱中注入过氧化氢、二氧化氮与臭氧并使其平衡，生成硝酸根自由基（NO₃）及部分五氧化二氮（N₂O₅），大概率同时生成过氧氢自由基（HO₂）。注入硫酸铵种子颗粒。随后注入α-蒎烯，其同时与臭氧、硝酸根自由基发生反应并逐渐衰减。采用三氟甲氧基负离子化学电离质谱（CF₃O⁻ CIMS）监测气相组分，通过扫描迁移率粒径谱仪（SMPS，Scanning Mobility Particle Sizer）观测颗粒生成情况。
负责团队：阮氏课题组（Nguyen Group）
隶属机构：加州大学戴维斯分校（UC Davis）
所用烟雾箱：特兰大型空气袋烟雾箱（Tran's big bag of air）
实验分类：气相化学反应、气溶胶生成
氧化剂：硝酸根自由基
反应物：α-蒎烯、臭氧、CAS编号10102-44-0（过氧化氢）
反应类型：暗氧化反应
相对湿度：5%
温度：22℃
种子颗粒名称：硫酸铵
压力：755托（Torr）