This document discusses gas chromatography (GC), including its principles, requirements, and components. GC uses a gas as the mobile phase to separate compounds based on how soluble they are in the stationary liquid phase. Key components of a GC system include the carrier gas, injection port, column located in a temperature-controlled oven, and detector. Common detectors are the thermal conductivity detector and flame ionization detector. The document provides details on the operation and applications of GC.