An Emerging Use Of Mass Spectrometry

Essay by EssaySwap ContributorUniversity, Master's February 2008

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Today, more and more people are becoming aware of environmental pollution, and as a result, the government is taking a more active role in pollution clean up and prevention. Government limits on volatile organic compound emissions and other environmental pollutants are lowering, and a need to be able to detect at these limits is rising. Also, a need for real-time or near real-time sampling has risen due to a desire by everyone to clean up pollution and related spills/disasters as quickly as possible. To aid in these needs, direct sampling mass spectrometry in environmental screening is being developed as an alternative to traditional mass spectroscopic methods. Direct sampling mass spectrometry (DSMS) is a simple technique that provides real-time response, high sample throughput, and parts per billion (ppb) detection limits at low cost.

There are many different types of mass spectrometers, but they all share four common features: (1) a system for introducing the substance to be analyzed into the instrument; (2) a system for ionizing the substance; (3) an accelerator that directs the ions into the measuring apparatus; and (4) a system for separating the constituent ions and recording the mass spectrum of the substance.

(See illustration) This instrument is converts molecules into ions and then separates the ions according to their mass-to-charge ratio. Mass spectrometers are used to identify atoms and isotopes and determine the chemical composition of a sample. Although many different kinds of mass spectrometers are in use today, they are all related to a device developed by the British physicist Francis W. Aston in 1919. (World Book, 1978) As mentioned, environmental concerns have prompted development of quicker and cheaper methods of sampling. DSMS is the emerging method. DSMS refers to the introduction of analytes from a sample directly into a mass spectrometer using a simple interface...