CAPILLARY GAS CHROMATOGRAPHIC METHOD FOR DETERMINING C3-C HYDROCARBONS IN FULL-RANGE MOTOR GASOLINES

A capillary gas-liquid chromatographic method has been developed to determine the individual C3-C12 hydrocarbons in full-range motor gasolines. The analyses are conducted on a 200-foot squalane capillary column in less than 2 hours. Approximately 240 chromatographic peaks are observed in the analysis of an average gasoline; 180 of them (amounting to 96–99% wt of the sample) have been specifically identified. The column temperature and column inlet pressure are both programmed to obtain resolution of close-boiling hydrocarbons. Standard deviations and the 95% confidence limits are given for the quantitative repeatability and reproducibility of the method. Chromatographic peak identifications and the detailed quantitative composition of typical premium and regular-grade gasolines are presented, as well as the detailed composition of the American Petroleum Institute Prototype Fuel No. 1-Premium Leaded Reference. Changes that can be made in the temperature and pressure programs to obtain resolution of specific groups of hydrocarbons are discussed. © 1968, American Chemical Society. All rights reserved.