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Environmental analysis of Hazardous Air Pollutants (HAPs) fall into three categories: laboratory analysis of captured sample, broad-area real-time analysis (along a fence line for example) and pointspecific real-time analysis. The latter might include point source emissions from stacks or fugitive emissions measured at strategically located test points. The preferred technologies for mufti-component pointspecific analysis include extractive FTIR and magnetic sector mass spectrometry. The FTIR analyzer takes advantage of the fact that most molecules absorb infrared radiation and the absorbance occurs in a characteristic pattern that is very reproducible. The modern process FTIR analyzer provides high spectral resolution for a quantitative breakdown of the composition of potentially contaminated air or stack gas.The different vibrational modes that result in the absorbance spectrum can be used to identify compounds ftom a library of standard spectra. On the other hand, the mass spectrometer identifies the trace components in air by fragmenting sample molecules in order to generate a mass spectrum that can also be used to quantify target compounds. This paper considers the advantages and disadvantages of these complimentary technologies and provides some guidelines to help with the selection of the most appropriate technology for a given environmental application.