In-situ calibration of the hydroperoxyl radical using an immobilized TiO2 photocatalyst in the atmosphere

被引：0

作者：

Environmental and Whole Information System , #804 Byuksan Digital Valley III 212-13, Guro-3-dong Guro-gu, Seoul 152-848, Korea, Republic of ^{[1
]}

不详 ^{[2
]}

机构：

[1] Environmental and Whole Information System (E and WIS), #804 Byuksan Digital Valley III 212-13, Seoul 152-848

[2] School of Chemical Engineering, College of Engineering, Seoul National University

来源：

Bull. Korean Chem. Soc. | 2008年 / 4卷 / 785-789期

关键词：

Hydroperoxyl radical; In-situ calibration; Kinetic method; TiO[!sub]2[!/sub;

D O I：

10.5012/bkcs.2008.29.4.785

中图分类号：

学科分类号：

摘要：

The present study is the first report of utilizing TiO2 photocatalyst to analytically calibrate the hydroperoxyl radical (HO 2.). An in-situ calibration method of HO2 . is proposed for air monitoring by using an 2-methyl-6-(p- methoxyphenyl)-3,7-dihydroimidazo-[1,2-a]pyrazin-3-one (MCLA)-chemiluminescence (CL) technique. In this method, HO2. (pKa = 4.80) is produced by the ultraviolet (UV) photolysis of immobilized TiO 2 using a constant flow rate of air equilibrated water, in which HO2. is controlled by using various lengths of knotted tubing reactor (KTR). The principle of the proposed calibration is based on the experimentally determined halflife (t1/2) of HO2 . and its empirically observed pH-dependent rate constant, k obs, at a given pH. The concentration of HO2 ./O2.- is increased as pH increases. This pH dependence is due to the different disproportionative reactivities between HO2./O2.- and HO2 ./O2.-. Experimental results indicate the practical feasibility of the approach, producing very promising method.

引用

页码：785 / 789

页数：4