Measurements of Hydrogen Peroxide and Formaldehyde in Glendora,California

Gas-phase hydrogen peroxide (H₂O₂) and formaldehyde (HCHO) were measured in Glendora, CA from August 14 to 21, 1986. These measurements were part of the Carbonaceous Species Methods Comparison Study sponsored by the California Air Resources Board. Both of these species were measured using enzymatic techniques, H₂O₂ by the peroxidase catalyzed dimerization of p-hydroxyphenylacetic acid and formaldehyde by the formaldehyde dehydrogenase catalyzed reduction of NAD+ to NADH. Both H₂O₂ and HCHO showed a strong diurnal variation with the highest concentrations measured during the period of maximum photochemical activity. H₂O₂ concentrations ranged from < 0.1 ppbv at night to a maximum of 3 ppbv for the hourly average on one day. The HCHO concentrations ranged from a low of 5 ppbv a night to a maximum of 20 ppbv during the day.