Effect of Ozone on the Fluorescence and Ultra-violet Absorption Spectra of 3,4-Benzopyrene

Abstract

PREVIOUS investigations concerning the quantitative determination of the 3,4-benzopyrene content of the air by fluorescence emission spectroscopy¹ showed that the fluorescence intensity of the samples exposed for some hours to air decreased markedly. Experiments were carried out with benzene solutions of 3,4-benzopyrene to investigate this effect. Standard concentrations of 1.2, 12, 120 and 1,200 µgm./ml. were prepared. Ozone was generated in an experimental chamber with an electric spark generator, Kocsis system, and the ozone-contaminated air of the chamber was aspirated through an impinger filled with 6 ml. solution. The ozone content was determined with 2 N potassium iodide by the analytical method described by Thorp². The fluorescence emission spectra of the 3,4-benzopyrene solutions were taken with a fluorescence spectrophotometer specially designed for these investigations by one of us. At the same time, the ultra-violet absorption of the samples was measured with a Beckman UD spectrophotometer.