Seasonal variations in the concentrations of ethylene,acetylene and propylene at Trombay,Bombay

Concentrations of ethylene, acetylene and propylene at Trombay, Bombay for the year 1982 are given in this paper. The method of measurement consisted of pre-concentrating the atmospheric hydrocarbons in short U-columns kept at dry ice temperature and then analysing in a gas chromatograph with a chemiluminescent detector. The data is based on 2-h samples collected daily in the forenoon and afternoon periods. A minimum concentration of 0.2 ppb of ethylene could be detected by this method. The ground level ozone concentrations at Trombay correlated with ethylene concentrations (correlation coefficient = 0.70) and with the product of ethylene and propylene (correlation coefficient = 0.40). These correlations are significant at 99.5 and 95% confidence levels respectively, and indicate that these reactive hydrocarbons contribute to ground level ozone concentrations.Measurements at Trombay showed that the concentrations of the hydrocarbons are below the air quality standards. The chemiluminescent method of detection was found to be very convenient for selective determination of ethylene and other reactive hydrocarbons.