Ionic strength effect on the formation of organonitrate compounds through photochemical degradation of vanillin in liquid water of aerosols
Ionic strength effect on the formation of organonitrate compounds through photochemical degradation of vanillin in liquid water of aerosols
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离子强度对气溶胶液态水中香草醛光化学降解形成有机硝酸酯化合物的影响
DOI：
10.1016/j.atmosenv.2020.118140
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发表时间：
2020-12
影响因子：
5
通讯作者：
Gligorovski Sasho
中科院分区：
文献类型：
--
作者：
Loisel Gwendal;Mekic Majda;Liu Shiyang;Song Wei;Jiang Bin;Wang Yiqun;Deng Huifan;Gligorovski Sasho
离子强度可以影响气溶胶潮解颗粒的液核中发生的光化学反应。然而，有关离子强度对水相反应的影响的研究是有限的。在这里，我们评估的光化学降解的一个典型的木质素衍生的化合物，香草醛（VL），在添加硝酸钠（NaNO 3）或硫酸钠（Na 2SO 4）。VL的紫外-可见吸收光谱表现出增色效应，其n→π* 吸收带发生红移，由稀水相的λmax= 310 nm变为I = 0.3 M时的λ max= 346 nm（用Na 2SO 4调节）。当用NaNO 3调节离子强度时，观察到VL的n→π* 吸收带从稀液态水的λmax= 310 nm向Ieff= 0.124 M的λmax= 303 nm的蓝移。在固定pH = 1.4时，代表云滴和气溶胶颗粒液核的准一级速率常数，k1 st（Ieff.→0）=（1.5 ± 0.2）x 10 - 5s-1，在稀水溶液中（Ieff= 0 M，NaNO 3），在Ieff= 0.124 M（NaNO 3）时线性降低至（k1 st =（3.7 ± 0.2）x 10 - 6s-1），动力学成盐系数B = -（4.8 ± 0.2）L mol-1。由于形成羧酸、羟基化化合物和低聚物，观察到辐照VL的吸收光谱的非常细微的pH变化，其存在通过FT-ICR MS分析证实。最有可能的是，在稀水相中光降解VL时形成脂肪族类CHO化合物，而在硝酸根离子存在下产生稠合芳香族CHO和CHON化合物（Ieff= 0.124 M）。这些结果表明，存在于气溶胶的液态水的无机离子改变的动力学和有机化合物的光化学降解的产物的形成，这反过来又可以影响气溶胶的光吸收特性。
The ionic strength can affect the photochemical reactions occurring in the liquid core of the aerosol deliquescent particles. Yet, the investigations related to ionic strength effect on aqueous-phase reactions are limited. Here we assess the photochemical degradation of a typical lignin-derived compound, vanillin (VL), upon addition of either sodium nitrate (NaNO3) or sodium sulfate (Na2SO4). The UV-VIS absorption spectra of VL exhibits a hyperchromic effect and a bathochromic shift of the n→π* absorption band, in going fromλmax= 310 nm in the dilute aqueous phase toλmax= 346 nm at I = 0.3 M adjusted by Na2SO4. A hypsochromic shift of the n→π* absorption band of VL, in going fromλmax= 310 nm in the dilute liquid water toλmax= 303 nm at Ieff= 0.124 M is observed when the ionic strength was adjusted with NaNO3.At fixed pH ≈ 4, representing both the cloud droplets and the liquid core of the aerosol particles, the pseudo-first-order rate constant, k1st(Ieff.→0) = (1.5 ± 0.2) x 10−5s−1, in dilute aqueous solution (Ieff= 0 M, NaNO3), linearly decreases to (k1st= (3.7 ± 0.2) x 10−6s−1), at Ieff= 0.124 M (NaNO3) with kinetic salting coefficient b = -(4.8 ± 0.2) L mol−1. The very subtle pH change of the absorption spectra of irradiated VL is observed due to the formation of carboxylic acids, hydroxylated compounds and oligomers which presence was confirmed by FT-ICR MS analysis. Most likely aliphatic like CHO compounds are formed upon photodegradation of VL in dilute aqueous phase while the condensed aromatic CHO and CHON compounds are produced in presence of nitrate ions (Ieff= 0.124 M). These results suggest that inorganic ions present in the liquid water of aerosols alters the kinetics and the product formation of photochemical degradation of organic compounds which in turn can affect the light absorption properties of aerosols.
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影响因子：
5
作者：
J. Lagrange;C. Pallarès;G. Wenger;P. Lagrange
通讯作者：
J. Lagrange;C. Pallarès;G. Wenger;P. Lagrange
DOI：
10.1002/2017jd026930
发表时间：
2017-11
期刊：
Journal of Geophysical Research: Atmospheres
影响因子：
--
作者：
Xinke Wang;N. Hayeck;M. Brüggemann;L. Yao;Hangfei Chen;Ci Zhang;C. Emmelin;Jianmin Chen;
通讯作者：
Xinke Wang;N. Hayeck;M. Brüggemann;L. Yao;Hangfei Chen;Ci Zhang;C. Emmelin;Jianmin Chen;
影响因子：
3.4
作者：
Alexandra L. Klodt;Dian E. Romonosky;P. Lin;J. Laskin;A. Laskin;S. Nizkorodov
通讯作者：
Alexandra L. Klodt;Dian E. Romonosky;P. Lin;J. Laskin;A. Laskin;S. Nizkorodov
影响因子：
5
作者：
Wentao Zhou;Majda Mekic;Jiangping Liu;Gwendal Loisel;Biao Jin;D. Vione;S. Gligorovski
通讯作者：
Wentao Zhou;Majda Mekic;Jiangping Liu;Gwendal Loisel;Biao Jin;D. Vione;S. Gligorovski
影响因子：
5
作者：
D. Vione;A. Albinet;Francesco Barsotti;Majda Mekic;B. Jiang;C. Minero;M. Brigante;S. Gligorovski-
通讯作者：
D. Vione;A. Albinet;Francesco Barsotti;Majda Mekic;B. Jiang;C. Minero;M. Brigante;S. Gligorovski-