Gas Chromatography Mass Spectrometry (GC/MS) are two very powerful and sensitive instruments used to detect and study trace amount of chemicals as small as one pictogram or 0.000000000001 gram. A clear representation of this minute amount is a drop of detergent in water enough to fill a 10-mile long railroad tank car. Air pollutants are present at concentrations that are even lower than 1 picogram in a cubic meter of air. GC/MS is generally used to detect volatile and semi-volatile compounds, but it can also be used to analyze solid, gaseous and liquid samples.
Gas chromatography (GC) is employed in analytical chemistry for analyzing and separating compounds that can be vaporized without decomposition. A gas chromatography test is commonly used to separate the various components of a mixture, to test the purity of a specific substance or to help identify a particular compound.
Mass spectrometry (MS) is a technique that analytically categorizes the ions based on their mass to charge ratio, and ionizes atoms, molecules, ions, molecular fragments and other chemical species. A mass spectrum measures a given sample’s masses. A mass spectrometry analysis may be used for both complex mixtures and pure samples.
Mass spectrometry often requires a very pure sample, and gas chromatography employ detectors that cannot separate varied molecules that travel at the same retention time through the GC column. At times, different molecules with related pattern of ionized fragments. Used together, these two machines present more precise substance identification.
What Does GC/MS Testing Do?
GC/MS analysis can readily and accurately segregate complex compounds found in water or air. Less volatile chemicals move slower than more volatile chemicals and are therefore separated by a GC/MS.
GC/MS can measure the amount of every chemical present in a given sample simply by comparing the particular chemical to pre-measured standard.
GC/MS identifies any unknown chemical in the sample. The mass spectrometry analysis aids in determining the chemical’s unique structure or its “fingerprint” which could be compared to an extensive library of identified chemical fingerprints.
Other Uses of a Gas Chromatography Mass Spectrometry Analysis Are:
- Testing for residual solvents
- Outgassing studies
- Evaluating extracts from plastics
- Evaluating contaminants on semiconductor wafers or other technology products
- Identifying trace impurities in liquids or gases
Applications of GC/MS Testing
Gas Chromatography Mass Spectrometry analysis has numerous applications that benefit mankind.
In the field of medicine, GC/MS is efficiently employed in a newborn screening test that can point to various congenital defects caused by genetic abnormalities or by infectious diseases transmitted by the mother. Inborn error of metabolism or IEM can now be determined in the urine of newborns even in small amounts by GC/MS analysis. Currently more than 100 genetic metabolic disorders can be determined in a urine test of a newborn based on Gas Chromatography Mass Spectrometry.
GC/MS is an effective tool in checking organic pollutants in the environment. Though there are herbicides and pesticides that cannot be identified by GC/MS, most organic pollutants and pesticides can be identified and analyzed by GC/MS.
GC/MS has been successfully used in analyzing particles from a human body for criminal forensics. The analysis of fire debris by GC/MS is also an accepted practice in the court of law.
Gas Chromatography Mass Spectrometry analysis has been used in the detection of illegal drugs and substances, as well as in forensic toxicology. Poisons and other drugs that may be taken by victims, suspects and dead bodies can be identified by a GC/MS test.
There are airport security systems that are based on GC/MS technology and other technologies.
GC/MS is also used in analyzing compounds such as alcohol, fatty acids, esters, aldehydes and more in beverages, foods and perfumes. The technology is employed in detecting and measuring adulteration and spoilage contaminants.
To date, several Gas Chromatography Mass Spectrometry analyzers have been sent to outer space to analyze the atmosphere of particular planets.