Gas chromatography detectors (GC detectors) identify solutes as they exit a chromatographic column. As solutes are eluted from the column they interact with the gas chromatography detector. Gas chromatography detectors convert this interaction into an electrical signal that is sent to the data system. The magnitude of the signal is plotted from the time of injection and a chromatogram is generated. Gas chromatography detectors use one of several technology types to identify solutes as they exit the column. Choices include flame ionization, atomic emission, electron capture, photoionization, flame photometric, chemiluminescence spectroscopy, and nitrogen phosphorous.