Other forms of mass spectrometry

Mass spectrometers can be combined with other instruments to form powerful analytical tools. One such example is the Gas Chromatography-Mass Spectrometer (GC-MS), which combines a gas chromatograph with a mass spectrometer.

The concept of gas chromatography is similar to that of paper chromatography with the exception of the sample and the mobile phase being gases instead of liquids. The sample travels through gas chromatograph part of GC-MS first, where the different types of molecules in the sample are retained by the stationary phase for different durations before they flow into the mass spectrometer portion where they are fragmented and analysed. The data is plotted on a three dimensional graph with retention time, mass-to-charge ratio and relative abundance as the axes. As such, the GC-MS spectrum contains more information regarding the sample as compared to that of TIMS. GC-MS is commonly used by border security forces to detect narcotics and explosives in luggage or on human beings and by environmental agencies to monitor pollutants in the air.

Another important instrument is the Inductively Coupled Plasma Mass Spectrometer (ICP-MS), which is capable of detecting trace amounts of metals and non-metals. The main difference between an ICP-MS and a TIMS is the use of an inductively coupled plasma (a concentration of argon ions and electrons that is produced by inductively heating argon with an electromagnetic coil) to ionise the sample. ICP-MS has greater speed, precision, and sensitivity over TIMS and is used in the fields of medicine, toxicology, forensics, radiometric dating, pharmacy, etc.

 

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