![what is the difference between gc pro box and gc pro key what is the difference between gc pro box and gc pro key](https://i.ebayimg.com/images/g/UrMAAOSwLhJesNWM/s-l640.png)
Mass spectrometer detector are also common. The carrier gas typically has high thermal conductivity but during elution the molecules within the sample often are less conductive which can be measured as a voltage drop at the filament. TCDs work by determining the conductivity of gas passing electricity to a tungsten -rhenium filament. Thermal conductivity detectors (TCD) are also common and are non-destructive so they are usually incorporated before an FID. Carbon atoms forms cations which can be detected by the electrodes. The flame breaks any up any organic compounds and hydrocarbons through a process call pyrolysis. FIDs use hydrogen to create a flame at the end of the chromatography column between two electrodes. Flame ionizing detectors (FID) are most commonly used. There are many different types of detectors for a GC instruments. Unlike other types of chromatography, GC columns are typically very long, a 100 meters or more. Chemicals within the sample will be absorbed by the column at different rates and are eluted at different temperatures, therefore different compounds within the sample can be separated. Often, the columns are capillary tubes that are coated with a silicone based oil that absorbs the chemicals within the gas passing through. Molecules that make up the sample interacts with the chromatography column differently allowing different compounds to be separated. An inert gas like Helium is the most common carrier gas for GC instruments. The mobile phase in reference to GC is the carrier gas which is a gas stream that moves the sample through the column. In GC, the sample is vaporized so that the the mobile phase can move it through the column. Gas chromatography works similar to other chromatography methods in that the sample flows through a chromatography column and is moved through the column using a mobile phase. Applications are wide spread, from environmental research to quality control testing and medical device residual analysis. Gas chromatography can be used to quantitate compounds that can be vaporized below 300 degrees Celsius.
![what is the difference between gc pro box and gc pro key what is the difference between gc pro box and gc pro key](https://venturebeat.com/wp-content/uploads/2020/04/superplus-Hills_of_Steel_2_Keyart_600x1200.jpg)
Gas chromatography instruments are now in almost every analytical chemistry lab. Martin published the first article describing gas chromatography system. Nobel Prize winner Archer John Porter Martin laid the foundation for Gas Chromatography with a gas-liquid chromatography system that he described in 1950.