Method for the Collection and HPLC Analysis of Hydrogen Peroxide and C l and C 2 Hydroperoxides in the Atmosphere

Abstract

An HPLC (high-performance liquid chromatography) method was developed to quantify hydrogen peroxide, methyl hydroperoxide, hydroxymethyl hydroperoxide, ethyl hydroperoxide, and peroxyacetic acid in the atmosphere. Gas-phase hydroperoxides are collected in aqueous solution using a continuous-flow glass scrubbing coil and then analyzed by an HPLC postcolumn derivatization system. The detection system is based on fluorescence, produced by the product of the reaction of hydroperoxides with peroxidase and p-hydroxyphenylacetic acid. Reproducibilities are better than 3% for all hydroperoxides in aqueous concentrations of 1 x 10(-7)-6 X 10(-7) M. Detection limits in aqueous concentration are 1.2 X 10(-9) M for hydrogen peroxide, 1.5 X 10(-9) M for hydroxymethyl hydroperoxide, 2.9 X 10(-9) M for methyl hydroperoxide, 16 X 10(-9) M for peroxyacetic acid, and 19 X 10(-9) hi for ethyl hydroperoxide. Corresponding gas-phase detection limits are 5 pptv for hydrogen peroxide, 7 pptv for hydroxymethyl hydroperoxide, 13 pptv for methyl hydroperoxide, 72 pptv for peroxyacetic acid, and 84 pptv for ethyl hydroperoxide for an air sample flow rate of two standard liters per minute and collection solution flow rate of 4 X 10(-4) L min(-1). The gas-phase detection limits for the latter three hydroperoxides vary depending on temperature, pressure, air sample flow rate, and collection solution flow rate. This system was used for several airborne and ground measurements and showed reliable performance.