(L.U.Q.C.A), Laboratorio Universitario de Química y Contaminación del Aire, Instituto de Investigaciones en Fisicoquímica de Córdoba (I.N.F.I.Q.C.), Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000, Córdoba, Argentina.
(L.U.Q.C.A), Laboratorio Universitario de Química y Contaminación del Aire, Instituto de Investigaciones en Fisicoquímica de Córdoba (I.N.F.I.Q.C.), Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000, Córdoba, Argentina; Institute for Atmospheric and Environmental Research, University of Wuppertal, DE-42097, Wuppertal, Germany.
Chemosphere. 2023 Oct;339:139726. doi: 10.1016/j.chemosphere.2023.139726. Epub 2023 Aug 3.
Kinetic studies of the reaction of ethyl glycolate HOCHC(O)OCHCH with OH radicals (k) and Cl atoms (k) have been conducted by the relative method using a glass atmospheric reactor by "in situ" Fourier Transform Infrared (FTIR) and Gas Chromatography equipped with flame ionization detection by Solid Phase Micro Extraction (GC-FID/SPME) at room temperature and atmospheric pressure. The following relative rate coefficients were determined using several reference compounds and two different techniques: k = (4.36 ± 1.21) × 10; k = (3.90 ± 0.74) × 10; and k = (6.40 ± 0.72) × 10 all values in units of cm.molecule.s. Complementary product studies were performed under comparable conditions to the kinetic tests, in order to identify the reaction products and to postulate their tropospheric oxidation mechanisms. The reaction of OH radicals and Cl atoms with ethyl glycolate initiates via H-atom abstraction from alkyl groups of the molecule. Formic acid was positively identified as a reaction product by FTIR. On the other hand, formaldehyde, acetaldehyde, glycolic acid; and formic acid were identified by the GC-MS technique. The Structure-Activity Relationship, (SAR) calculations were also implemented to estimate the more favorable reaction pathways and compare them with the products identified. Tropospheric lifetimes of τ = 34 h and τ = 5.5 days were estimated to determine how these investigated reactions might affect the air quality. In this sense, average ozone production of [O] = 0.75 and a Photochemical Ozone Creation Potential, POCP, of 38 were calculated for the hydroxyl ester studied.
采用“原位”傅里叶变换红外（FTIR）和气相色谱配备固相微萃取（GC-FID/SPME），在室温常压下，通过玻璃大气反应器，相对法研究了乙醇酸乙酯 HOCHC（O）OCHCH 与 OH 自由基（k）和 Cl 原子（k）的反应的动力学。使用几种参考化合物和两种不同的技术，确定了以下相对速率系数：k =（4.36 ± 1.21）×10; k =（3.90 ± 0.74）×10; 和 k =（6.40 ± 0.72）×10，所有值均为 cm.molecule.s 单位。在与动力学测试相当的条件下进行了补充产物研究，以鉴定反应产物并提出其对流层氧化机制。OH 自由基和 Cl 原子与乙醇酸乙酯的反应通过分子烷基中的 H 原子提取引发。通过 FTIR 确证甲酸是反应产物。另一方面，通过 GC-MS 技术鉴定了甲醛、乙醛、乙醇酸和甲酸。还实施了结构-活性关系（SAR）计算，以估算更有利的反应途径，并将其与鉴定的产物进行比较。估算出 τ = 34 h 和 τ = 5.5 天的对流层寿命，以确定这些研究的反应如何影响空气质量。在这种情况下，为研究的羟基酯计算了平均臭氧生成量 [O] = 0.75 和光化学臭氧产生潜能 POCP = 38。
