Gómez Alvarez E, Viidanoja J, Muñoz A, Wirtz K, Hjorth J
Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), C/Charles Darwin 14, 46980 Paterna, Valencia, Spain.
Environ Sci Technol. 2007 Dec 15;41(24):8362-9. doi: 10.1021/es0713274.
The methodology of solid phase microextraction (SPME) with O-(2,3,4,5,6)-pentafluorobenzylhydroxylamine hydrochloride (PFBHA) on-fiber derivatization for the determination of carbonyls has been applied to the photo-oxidation of benzene and toluene carried out in the EUPHORE chambers. This work focuses on the results obtained for a number of highly reactive carbonyls, crucial in the determination of branching ratios and confirmation of the carbonylic route. The observed yields and kinetic behavior were compared to simulations with the Master Chemical Mechanism model, version 3.1 (MCMv3.1). The following yields were measured in the toluene system: glyoxal, (37 +/- 2)%; methylglyoxal, (37 +/- 2)%; 4-oxo-2-pentenal, > (13.8 +/- 1.5)%; and total butenedial, (13 +/- 7)% (cis-butenedial, (6 +/- 3)%; trans-butenedial, (7 +/- 4)%]. For benzene, the experimental glyoxal yields were (42 +/- 3) and (36 +/- 2)% for the two successive experiments (September 24 and 25, 2003), (17 +/- 9)% for total butenedial [(8 +/- 4)% cis-butenedial and (9 +/- 5)% trans-butenedial (September 24, 2003)] and (15 +/- 6)% total butenedial (September 25, 2003) [(7 +/- 3) and (7 +/- 3)% for the cis and trans isomers, respectively]. PTR-MS estimations for butenedial also allowed the two isomers of butenedial to be distinguished, but the measurements showed signs of interference from other products. The results presented confirm the fast ring cleavage and provide further experimental confirmation of the dicarbonylic route.
采用盐酸O-(2,3,4,5,6)-五氟苄基羟胺（PFBHA）纤维上衍生化的固相微萃取（SPME）方法测定羰基化合物，已应用于在EUPHORE反应室中进行的苯和甲苯的光氧化反应。这项工作聚焦于一些高活性羰基化合物的测定结果，这些化合物对于确定分支比和确认羰基途径至关重要。将观察到的产率和动力学行为与主化学机理模型版本3.1（MCMv3.1）的模拟结果进行了比较。在甲苯体系中测得的产率如下：乙二醛，(37±2)%；甲基乙二醛，(37±2)%；4-氧代-2-戊烯醛，> (13.8±1.5)%；总丁烯二醛，(13±7)%（顺式丁烯二醛，(6±3)%；反式丁烯二醛，(7±4)%）。对于苯，在两次连续实验（2003年9月24日和25日）中，实验测得的乙二醛产率分别为(42±3)%和(36±2)%，总丁烯二醛的产率为(17±9)%（顺式丁烯二醛(8±4)%，反式丁烯二醛(9±5)%，2003年9月24日）以及(15±6)%（总丁烯二醛，2003年9月25日）（顺式和反式异构体分别为(7±3)%和(7±3)%）。对丁烯二醛的质子转移反应质谱（PTR-MS）估算也能够区分丁烯二醛的两种异构体，但测量结果显示存在来自其他产物的干扰迹象。所呈现的结果证实了快速的环裂解，并为二羰基途径提供了进一步的实验证据。
