title: Kinetic studies of heterogeneous reactions of particulate phosmet and parathion with NO3 radicals.
abstract: Organophosphorous pesticides (OPPs) are ubiquitous pollutants in the atmospheric environment with adverse effects on human health. In this study, heterogeneous kinetics of particulate phosmet and parathion with NO3 radicals were investigated with a mixed-phase relative rate method. A vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS) and an atmospheric gas analysis mass spectrometer were used to monitor online the decays of particulate OPPs and reference compound, respectively. Reactive uptake coefficients of NO3 radicals on phosmet and parathion particles were (0.12±0.03) and (0.14±0.04), respectively, calculated according to the measured OPPs loss ratios and the average NO3 concentrations. Additionally, the average effective rate constants for heterogeneous reactions of particulate phosmet and parathion with NO3 radicals measured under experimental conditions were (2.80±0.16)×10(-12) and (2.97±0.13)×10(-12) cm(3) molecule(-1) s(-1), respectively. The experimental results of these heterogeneous reactions in the aerosol state provide supplementary knowledge for kinetic behaviors of airborne OPPs particles.
authors.affiliation: School of Resources and Environmental Engineering, Panzhihua University, Panzhihua 617000, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: changwyx@163.com.
authors.forename: Changgeng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: School of Resources and Environmental Engineering, Panzhihua University, Panzhihua 617000, China.
authors.forename: Chenghua
authors.initials: C
authors.lastname: Zeng
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000737:chemistry*; D007700:Kinetics; D013058:Mass Spectrometry; D009566:Nitrates / Q000737:chemistry*; D010278:Parathion / Q000737:chemistry*; D010575:Pesticides / Q000737:chemistry*; D010706:Phosmet / Q000737:chemistry*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D009566:Nitrates; D010575:Pesticides; D010278:Parathion; D010706:Phosmet
keywords: Aerosol mass spectrometry; Heterogeneous kinetics; NO(3) radicals; Organophosphorous pesticides