Monitor for measuring the total concentration of reactive hydrocarbons in ambient air based on their chemiluminescence reaction with oxygen atoms

The monitor functions by measuring the intensity of the chemiluminescence radiation at 309 nm which is emitted during the reaction of hydrocarbons with O(³p) atoms. The system comprises a specially-developed stable source of atomic oxygen, a detection unit for measuring the intensity of the chemiluminescence radiation and a device for preconcentration of the hydrocarbons to be determined. The sensitivity of the monitor depends on the concentration and reactivity of the hydrocarbons, and is greatest for unsaturated compounds. For butadiene, the detection limit is 3 ppb, and response is linear over the range 0–2500 ppb. The monitor can also serve as a detector for unsaturated hydrocarbons in gas chromatography.