Devices, assemblies, systems and methods useful in the detection of hydrocarbons in well-related fluids such as drilling fluids during well-related operations are disclosed. Such devices, assemblies, systems and methods may be used for real-time analysis of gas(es) extracted from a fluid associated with an ongoing well-related operation. An exemplary method may comprise: receiving gas extracted from the fluid associated with the well-related operation; analyzing the gas using Fourier Transform Infrared (FTIR) spectroscopy; and generating one or more signals useful in the determination of a composition of the gas extracted from the fluid.