The work presented in this chapter is designed to forward the development of an optical probe for the remote monitoring of liquid hydrocarbons. A series of experiments were carried out to differentiate between classes of hydrocarbons and to discriminate between compounds within a class of similar molecular structures. It was observed that unique absorption spectra can be obtained for each hydrocarbon, and this uniqueness can be used to discriminate between hydrocarbons from different families. Results summarize measurements of the Near-Infrared optical absorption of alkanes, aromatics, and chlorinated hydrocarbons. This approach was selected to assess the feasibility of remote in situ measurements using optical waveguides.