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The performance of a soft ionization mass spectrometer (MS) has been investigated using nearly one hundred hydrocarbon components and nine inorganic components. Based on a list of typical hydrocarbon emissions from automotive exhaust, synthesized samples have been used to discuss the cross-sensitivity of the target components. The system has been shown to measure hazardous air pollutants (HAPs) such as 1,3-butadiene, benzene and toluene in the vehicle exhaust. As a result, the technique will prove to be very useful in emissions monitoring in the development of low emissions vehicles.

With the need for emission measurements of super ultra low emission vehicles (SULEV), analyzer manufacturers have been required to produce more precise and accurate analyzers. In order to compare analyzers, the customer must understand the different specifications used by the analyzer manufacturers. One specification that some manufacturers have used is the limit of detection (LOD) to indicate the reliability of the analyzer output at low concentrations. There are various methods for determining the LOD for a given analyzer. The authors will demonstrate how variations in methodology can produce different LOD values for a specific analyzer and what it means for the automotive emission analyzers. It is also demonstrated that the standard deviations of a zero signal, which is related to LOD, can be heavily influenced by data processing, such as data length in use and/or data smoothing. The LOD values obtained will be compared to the limit of quantification (LOQ) for that analyzer.