What type of substances can a Flame Ionization Detector (FID) detect?

A Flame Ionization Detector (FID) is specifically designed to detect organic compounds, particularly hydrocarbons and their derivatives. The operational principle of an FID relies on the ionization of organic molecules in a flame. In this process, the organic compounds are burned, producing ions and electrons that create a measurable current. This makes the FID particularly sensitive to hydrocarbons, which are prevalent in many industrial and environmental settings.

Hydrocarbons include compounds such as alkanes, alkenes, and aromatics, and their derivatives, which frequently appear in petroleum products, solvents, and various chemical processes. The FID is widely used in applications such as gas chromatography because of its capability to provide real-time measurements of these substances, contributing to effective monitoring and analysis.

In contrast, inorganic acids do not generate ions in the same way that hydrocarbons do, making them less detectable by an FID. Heavy metals and radioactive materials involve different detection techniques, often requiring methods such as atomic absorption spectroscopy or radiation detectors, respectively, due to their distinct chemical properties and detection mechanisms.