Gas Chromatography— Measuring Exhaust Hydrocarbons Down to Parts Per Billion

Several methods for determining hydrocarbons in automotive exhaust are presented and discussed. These include: nondispersive infrared, ultraviolet, flame-ionization detection, and gas chromatography. A gas chromatographic method is presented for determining individual hydrocarbon components in automotive exhaust. The method has thus far detected over 200 hydrocarbons of all classes in exhaust. A technique for collecting the exhaust sample in small plastic bags is described along with a brief study on the selection of suitable bag material. Techniques for sampling, calibration, and standardization are also discussed. Applications of the method are presented along with a discussion of the results.