当前位置: X-MOL 学术Environ. Sci. Technol. Lett. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Heterogeneous Hydroxyl Radical Oxidation of Isoprene-Epoxydiol-Derived Methyltetrol Sulfates: Plausible Formation Mechanisms of Previously Unexplained Organosulfates in Ambient Fine Aerosols
Environmental Science & Technology Letters ( IF 8.9 ) Pub Date : 2020-05-18 , DOI: 10.1021/acs.estlett.0c00276
Yuzhi Chen 1 , Yue Zhang 1, 2 , Andrew T. Lambe 2 , Rongshuang Xu 3 , Ziying Lei 4 , Nicole E. Olson 5 , Zhenfa Zhang 1 , Tessa Szalkowski 1 , Tianqu Cui 1 , William Vizuete 1 , Avram Gold 1 , Barbara J. Turpin 1 , Andrew P. Ault 4, 5 , Man Nin Chan 3 , Jason D. Surratt 1
Affiliation  

Methyltetrol sulfates are unique tracers for secondary organic aerosols (SOA) formed from acid-driven multiphase chemistry of isoprene-derived epoxydiols. 2-Methyltetrol sulfate diastereomers (2-MTSs) are the dominant isomers and single most-abundant SOA tracers in atmospheric fine particulate matter (PM2.5), but their atmospheric sinks remain unknown. We investigated the oxidative aging of authentic 2-MTS aerosols by gas-phase hydroxyl radicals (OH) at a relative humidity of 61 ± 1%. The effective rate constant for this heterogeneous reaction was determined as 4.9 ± 0.6 × 10–13 cm3 molecules–1 s–1, corresponding to an atmospheric lifetime of 16 ± 2 days (assuming an OH concentration of 1.5 × 106 molecules cm–3). Chemical changes to 2-MTSs were monitored by hydrophilic interaction liquid chromatography interfaced to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (HILIC/ESI-HR-QTOFMS). Plausible reaction mechanisms are proposed for previously unknown OSs detected in atmospheric PM2.5 at mass-to-charge ratios (m/z) of 139 (C2H3O5S), 155 (C2H3O6S), 169 (C3H5O6S), 171 (C3H7O6S), 185 (C3H5O7S), 199 (C4H7O7S), 211 (C5H7O7S), 213 (C5H9O7S), 227 (C5H7O8S), 229 (C5H9O8S), and 231 (C5H11O8S). Heterogeneous OH oxidation of 2-MTSs redistributes the particulate sulfur speciation into more oxygenated/functionalized OSs, likely modifying the aerosol physicochemical properties of SOA containing 2-MTSs.

中文翻译:

异戊二烯-环氧二醇衍生的甲基四醇硫酸盐的异质羟基自由基氧化:周围环境精细气溶胶中以前无法解释的有机硫酸盐的可能的形成机理。

硫酸甲基四醇是由异戊二烯衍生的环氧二醇的酸驱动多相化学反应形成的次级有机气溶胶(SOA)的独特示踪剂。2-甲基四硫酸盐非对映异构体(2-MTS)是大气细颗粒物(PM 2.5)中的主要异构体和单一的最丰富的SOA示踪剂,但其大气汇仍是未知的。我们研究了气相中的羟基自由基( OH)在相对湿度为61±1%的情况下对真实的2-MTS气溶胶的氧化老化。该非均相反应的有效速率常数确定为4.9±0.6×10 –13 cm 3分子–1 s –1,对应于16±2天的大气寿命(假设OH浓度为1.5×10 6分子cm –3)。通过与电子喷雾电离高分辨率四极杆飞行时间质谱仪(HILIC / ESI-HR-QTOFMS)相连的亲水相互作用液相色谱法监测2-MTS的化学变化。对于在大气PM 2.5中以139(C 2 H 3 O 5 S ),155(C 2 H 3 O 6 S )的质荷比(m / z)检测到的先前未知的OS,提出了合理的反应机理。,169(C 3 H 5 O 6S ),171(C 3 H 7 O 6 S ),185(C 3 H 5 O 7 S ),199(C 4 H 7 O 7 S ),211(C 5 H 7 O 7 S ),213(C 5 H 9 O 7 S ),227(C 5 H 7 O 8 S ),229(C 5 H 9 O 8 S –))和231(C 5 H 11 O 8 S )。2-MTS的异质 OH氧化将颗粒硫的形态重新分布到更多的氧化/官能化OS中,可能会改变含2-MTS的SOA的气溶胶理化特性。
更新日期:2020-07-14
down
wechat
bug