||A laboratory instrument that separates and analyses gas mixtures in water or air using gas chromatography. In a standard configuration, the instrument accommodates up to three injectors, an autosampler, a column oven with three or more capillary columns and up to three detectors running simulaneously. The sample is vapourised then transported along the column within an inert gas flow. The carrier gas may be air, helium, hydrogen, nitrogen or argon-methane depending on the type of detector used. The system interfaces with traditional liquid autosamplers as well as a wide range of automated sample preparation devices. The column oven accepts packed or fused silica capillary columns and a range of injectors may be used including Split/Splitless, Programmable Temperature Vaporising, Septum-Equipped, On-Column,/Packed and Flash injectors. The system can be fitted with a variety of detectors including Flame Ionization (FID), Thermal Conductivity (TCD), Electron Capture (ECD), Thermionic Specific (TSD) and Pulsed Flame Photometric (PFPD). The PFPD provides selective detection for sulfur, phosphorus, nitrogen, and 25 additional elements. A time-gated electrometer and optical filters eliminate background signal from hydrocarbon interferences. The platform supports a wide range of GC analyzers from a single Gas Sampling Valve with packed column for permanent gas analysis to an advanced four-valve, three-channel system with multiple columns for Refinery Gas Analysis. The instrument was originally manufactured by Varian, Inc., which was bought by Agilent Technologies in 2010.