The Quantum Yield of N03 from Peroxyacetyl Nitrate Photolysis

Peroxyacetyl nitrate (PAN) vapor was photolyzedat 248 nmandthe N03 photoproduct wasdetected bylaser induced fluorescence. Thequantum yield fortheproduction of N03 was determined by comparison to N 205 photolysis data taken under identical experimental conditions. Contributions to the observed laser induced fluorescence were found to arise from excited state photoproducts such as N02* . The excited state fluorescence contributions were investigated and a data analysis methodology was established to minimize their effects. The average of data collected over a range of total pressures, precursor concentrations, and buffer gases was 0.3 + 0.1 for the N03 quantum yield, where the quoted statistical uncertainty represents two standard deviations. This result, combined with our previously reported value of 0.83 + 0.09 for the N02 quantum yield from the photolysis of PAN, suggests that N02 and N03 represent the only nitrogen containing products in the 248 nm photolysis of PAN. The atmospheric implications of a N03 producing channel in PAN photolysis are considered.