METHOD FOR THE COLLECTION AND HPLC ANALYSIS OF HYDROGEN-PEROXIDE AND C-1 AND C-2 HYDROPEROXIDES IN THE ATMOSPHERE

An HPLC (high-performance liquid chromatography) method was developed to quantify hydrogen peroxide, methyl hydroperoxide, hydroxymethyl hyd roperoxide, ethyl hydroperoxide, and peroxyacetic acid in the atmosphe re. Gas-phase hydroperoxides are collected in aqueous solution using a continuous-flow glass scrubbing coil and then analyzed by an HPLC pos tcolumn derivatization system. The detection system is based on fluore scence, produced by the product of the reaction of hydroperoxides with peroxidase and p-hydroxyphenylacetic acid. Reproducibilities are bett er 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 hydro peroxide, 2.9 X 10(-9) M for methyl hydroperoxide, 16 X 10(-9) M for p eroxyacetic acid, and 19 X 10(-9) hi for ethyl hydroperoxide. Correspo nding gas-phase detection limits are 5 pptv for hydrogen peroxide, 7 p ptv for hydroxymethyl hydroperoxide, 13 pptv for methyl hydroperoxide, 72 pptv for peroxyacetic acid, and 84 pptv for ethyl hydroperoxide fo r an air sample flow rate of two standard liters per minute and collec tion solution flow rate of 4 X 10(-4) L min(-1). The gas-phase detecti on limits for the latter three hydroperoxides vary depending on temper ature, pressure, air sample flow rate, and collection solution flow ra te. This system was used for several airborne and ground measurements and showed reliable performance.