{"id":2542,"date":"2021-03-16T09:32:13","date_gmt":"2021-03-16T09:32:13","guid":{"rendered":"https:\/\/laboratoryinfo.com\/?p=2542"},"modified":"2022-03-07T19:57:42","modified_gmt":"2022-03-07T19:57:42","slug":"gas-chromatography-principle-applications-procedure-and-diagrams","status":"publish","type":"post","link":"https:\/\/laboratoryinfo.com\/gas-chromatography-principle-applications-procedure-and-diagrams\/","title":{"rendered":"Gas Chromatography &#8211; Principle, Application, Procedure and Diagram"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">What is Gas Chromatography?<\/h2>\n\n\n<style>.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-content-wrap{padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-right:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);padding-left:var(--global-kb-spacing-sm, 1.5rem);background-color:#ecf2f7;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-contents-title-wrap{padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-contents-title{font-weight:regular;font-style:normal;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-content-wrap .kb-table-of-content-list{font-weight:regular;font-style:normal;margin-top:var(--global-kb-spacing-sm, 1.5rem);margin-right:0px;margin-bottom:0px;margin-left:0px;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-basiccircle .kb-table-of-contents-icon-trigger:after, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-basiccircle .kb-table-of-contents-icon-trigger:before, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-arrowcircle .kb-table-of-contents-icon-trigger:after, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-arrowcircle .kb-table-of-contents-icon-trigger:before, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-xclosecircle .kb-table-of-contents-icon-trigger:after, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-xclosecircle .kb-table-of-contents-icon-trigger:before{background-color:#ecf2f7;}<\/style>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-a-gas-chromatograph-looks-like-1.jpg\" alt=\"how a gas chromatograph looks like\" class=\"wp-image-2664\" width=\"350\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-a-gas-chromatograph-looks-like-1.jpg 423w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-a-gas-chromatograph-looks-like-1-300x246.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-a-gas-chromatograph-looks-like-1-20x16.jpg 20w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 1:<\/strong><\/b> The image above shows how a gas chromatograph looks like.<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>hiq.linde-gas.com<\/p>\n\n\n\n<p>It is a term used to describe analytical separation methods used to check volatile substances in their gas phase. What happens during gas chromatography is that the components of a sample are dissolved in a solvent and vaporized to separate the analytes. It is made possible by distributing the sample into two phases:<\/p>\n\n\n\n<ul><li><strong>Stationary phase<\/strong> \u2013 It is either in the forms of solid adsorbent (gas-solid chromatography) or liquid on an inert support (gas-liquid chromatography).<\/li><li><strong>Mobile phase<\/strong> \u2013 It is a chemically inert gas that carries analyte molecules through the heated column.<\/li><\/ul>\n\n\n\n<p>The gas chromatography is the only form of chromatography that does not use the mobile phase when interacting with the analyte. For gas chromatography to take place a gas chromatograph has to be used. (1, 2, and 3)<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/actual-gas-chromatograph-device.jpg\" alt=\"actual gas chromatograph device\" class=\"wp-image-2655\" width=\"400\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/actual-gas-chromatograph-device.jpg 494w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/actual-gas-chromatograph-device-297x300.jpg 297w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/actual-gas-chromatograph-device-20x20.jpg 20w\" sizes=\"(max-width: 494px) 100vw, 494px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 2:<\/strong><\/b> An actual gas chromatograph device.<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>imimg.com<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What is a gas chromatograph?<\/h2>\n\n\n\n<p>It is an analytical instrument used to measure the content of different components in a given sample.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Gas chromatography principles<\/h2>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-gas-chromatography-works.jpg\" alt=\"how gas chromatography works\" class=\"wp-image-2656\" width=\"400\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-gas-chromatography-works.jpg 498w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-gas-chromatography-works-300x227.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/how-gas-chromatography-works-20x15.jpg 20w\" sizes=\"(max-width: 498px) 100vw, 498px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 3:<\/strong><\/b> The image above shows how gas chromatography works (diagram).<b><br><strong>Picture Source: <\/strong><\/b>shimadzu.com<\/p>\n\n\n\n<p>The sample solution is placed into the gas chromatograph and enters the gas stream which transports the sample into the column (separation tube). A carrier gas is used in the form of helium or nitrogen. The components of the sample are separated inside the column.<\/p>\n\n\n\n<p>The number of components that exit the column is measured by the detector. If a sample with an unknown concentration is measured, a standard sample with known concentration is being injected into the gas chromatograph. <sup><em><strong>(2, 3, 4, and 5)<\/strong><\/em><\/sup><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The discovery of gas chromatography<\/h2>\n\n\n\n<p>Gas chromatography was discovered in the early 1900s by Mikhail Semenovich Tsvett. He used it as a separation method of separating compounds. Liquid-solid column chromatography is used to separate the organic compounds in a given solution.<\/p>\n\n\n\n<p>There are different types of gas chromatography, but the most commonly used method in separating organic compounds in gas-liquid chromatography.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Uses of gas chromatography<\/h2>\n\n\n\n<ul><li>It aids in identifying the composition of a liquid mixture and find out the relative concentration.<\/li><li>It helps separate and purify components in a given mixture.<\/li><li>It is used to find out vapor pressure, activity coefficients, and heart of the solution.<\/li><li>It is used to detect processes to check for contamination and to make sure that the process is going according to plan.<\/li><li>It can also be used to check for blood alcohol, food purity, drug purity, and quality of essential oil. <sup><em><strong>(4, 5, and 6)<\/strong><\/em><\/sup><\/li><\/ul>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/different-components-of-gas-chromatography.jpg\" alt=\"different components of gas chromatography\" class=\"wp-image-2657\" width=\"500\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/different-components-of-gas-chromatography.jpg 773w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/different-components-of-gas-chromatography-300x136.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/different-components-of-gas-chromatography-768x348.jpg 768w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/different-components-of-gas-chromatography-20x9.jpg 20w\" sizes=\"(max-width: 773px) 100vw, 773px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 4<\/strong><\/b><b><strong>:<\/strong><\/b> The image above outlines the different components of gas chromatography (diagram).<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>bitesizebio.com<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Parts of a gas chromatograph<\/h2>\n\n\n\n<ol><li><strong>Carrier gas<\/strong> \u2013 it is important to make sure that the carrier gas is chemically inert. There are different types of carrier gas but the most common ones are:<\/li><\/ol>\n\n\n\n<ul><li>Nitrogen<\/li><li>Argon<\/li><li>Helium<\/li><li>Carbon dioxide <sup><em><strong>(6, 7)<\/strong><\/em><\/sup><\/li><\/ul>\n\n\n\n<p><em><strong>Which carrier gas to choose?<\/strong> It depends on the type of detector.<\/em><\/p>\n\n\n\n<ol start=\"2\"><li><strong>Sample injection port<\/strong> \u2013 it is a must to make sure that the sample is not too large and introduced onto the column as a plug of vapor. What happens when slowly injecting a large sample is it leads to a band broadening and loss of resolution. A micro-syringe is used to inject a sample through the rubber septum and into a flash vaporizer port which is located at the head of the column.<\/li><li><strong>Columns<\/strong> \u2013 The columns are available in two types \u2013 packed and capillary\/open tubular.<\/li><\/ol>\n\n\n\n<p>a. <strong>Packed columns<\/strong> \u2013 It has a divided, inert, and solid support material coated with the liquid stationary phase.<\/p>\n\n\n\n<p>b. <strong>Capillary columns<\/strong> \u2013 It has an internal diameter that is about a few tenths of a millimeter. It could be a wall-coated (has a papillary tube with walls coated with liquid stationary phase) or open tubular or support-coated open tubular (the capillary\u2019s inner wall has a thin layer of support material like diatomaceous earth wherein the stationary phase is absorbed). <sup><em><strong>(2, 5, 7, and 8)<\/strong><\/em><\/sup><\/p>\n\n\n\n<p>The two types of capillary columns are more efficient than the packed columns, but the support-coated open tubular is less efficient than the wall-coated open tubular.<\/p>\n\n\n\n<ol start=\"4\"><li><strong>Column temperature<\/strong> \u2013 It is controlled within tenths of a degree. The maximum column temperature depends on the boiling point of a particular sample. A temperature that is way above the average boiling point of a particular sample could lead to an elution time of 2 minutes to 30 minutes. If a particular sample has a wide boiling range, it would be of help if temperature programming is used.<\/li><li><strong>Detectors<\/strong> \u2013 Various detectors are used in gas chromatography. Keep in mind that different detectors yield different types of selectivity.<\/li><li><strong>Non-selective detectors<\/strong> \u2013 They respond to all compounds with the exception of the carrier gas.<\/li><li><strong>Selective detectors<\/strong> \u2013 They respond to a wide array of compounds with common physical\/chemical properties.<\/li><li><strong>Specific detectors<\/strong> \u2013 They respond to just a single chemical compound.<\/li><li><strong>Dependant detectors<\/strong> \u2013 They are related to solute concentration in the detector. They do not destroy the sample dilution of makeup gas and will lower the response of detectors.<\/li><li><strong>Mass flow&nbsp;dependant&nbsp;detectors<\/strong> \u2013 They destroy the sample. The signal is dependent on the rate for which the molecules of solute enter the detector. <sup><em><strong>(8, 9, and 10)<\/strong><\/em><\/sup><\/li><\/ol>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-mass-spectrometer.jpg\" alt=\"gas chromatograph with a mass spectrometer\" class=\"wp-image-2658\" width=\"400\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-mass-spectrometer.jpg 600w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-mass-spectrometer-300x173.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-mass-spectrometer-20x12.jpg 20w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 5<\/strong><strong>:<\/strong><\/b>A gas chromatograph with a mass spectrometer.<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>utm.my<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-flame-ionization-detector.jpg\" alt=\"gas chromatograph with a flame ionization detector\" class=\"wp-image-2659\" width=\"400\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-flame-ionization-detector.jpg 600w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-flame-ionization-detector-300x209.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-a-flame-ionization-detector-20x14.jpg 20w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 6<\/strong><\/b><b><strong>:<\/strong><\/b> A gas chromatograph with a flame ionization detector.<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>forschungsinfrastruktur.bmbwf.gv.at<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-with-a-thermal-conductivity-detector.jpg\" alt=\"gas chromatography with a thermal conductivity detector\" class=\"wp-image-2660\" width=\"400\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-with-a-thermal-conductivity-detector.jpg 600w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-with-a-thermal-conductivity-detector-300x300.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-with-a-thermal-conductivity-detector-150x150.jpg 150w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-with-a-thermal-conductivity-detector-20x20.jpg 20w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 7<\/strong><\/b><b><strong>:<\/strong><\/b> A gas chromatography with a thermal conductivity detector.<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>directindustry.com<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-electron-capture-detector.jpg\" alt=\"gas chromatograph with electron capture detector\" class=\"wp-image-2661\" width=\"500\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-electron-capture-detector.jpg 495w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-electron-capture-detector-300x173.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatograph-with-electron-capture-detector-20x12.jpg 20w\" sizes=\"(max-width: 495px) 100vw, 495px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 8<\/strong><strong>: <\/strong><\/b>A gas chromatograph with electron capture detector.<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>made-in-china.com<\/p>\n\n\n\n<p><b>What detectors are used in a gas chromatograph?<\/b><\/p>\n\n\n\n<ul><li><strong>Mass spectrometer<\/strong> \u2013 The majority of gas chromatography instruments have a mass spectrometer. The gas chromatograph separates the compounds and the mass spectrometer identifies the compound according to fragmentation pattern.<\/li><li><strong>Flame Ionization Detector<\/strong> \u2013 It is highly sensitive to organic molecules but insensitive to small molecules.<\/li><li><strong>Thermal conductivity detector<\/strong> \u2013 It is less sensitive than a flame ionization detector but is perfect for preparative applications because it keeps the sample intact. It detects the molecules of the sample based on two gas streams comparison. One has the carrier gas while the other has the carrier gas and the compound.<\/li><li><strong>Electron capture detector<\/strong> \u2013 It has a cavity that has two electrodes and a radiation source that emits radiation. The collision of electrons and carrier gas creates a plasma-containing electron and a positive ion. <sup><em><strong>(1, 4, 7, and 9)<\/strong><\/em><\/sup><\/li><\/ul>\n\n\n\n<p><b>Factors that could affect the separation of components<\/b><b>&nbsp;<\/b><\/p>\n\n\n\n<p>There are different factors that could significantly influence the separation of components. They are the following:<\/p>\n\n\n\n<p>\u2219&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong>Vapor pressure<\/strong> \u2013 The polarity of a particular compound can greatly affect its boiling point. The vapor pressure is high is the boiling point is low. The retention time is shorter because the compound being examined spends more time in the gas state. Hence, a low boiling solvent is typically used to dissolve a given sample.<\/p>\n\n\n\n<p>\u2219&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong>Polarity of components vs polarity of the stationary phase on the column<\/strong> \u2013 the retention time increases if the compound and stationary phase\u2019s polarity is the same. A polar compound has a long retention time on its polar stationary phase. However, the retention time is shorter on the non-polar columns of the same temperature.<\/p>\n\n\n\n<p>\u2219&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong>Column temperature<\/strong> \u2013 A too high column temperature could lead to an extremely short retention time but yields in a poor separation because the majority of the components stay in the gas phase. For the components to be separated, it needs to interact with the stationary phase. If it won\u2019t, then it could lead to a decrease in retention time. On top of it, the quality of separation deteriorates.<\/p>\n\n\n\n<p>\u2219&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong>Rate of carrier gas flow<\/strong> \u2013 The retention time is reduced significantly at a high flow rate. However, it would yield a poor separation as the component takes little time to interact with the stationary phase. The components are just pushed through the column.<\/p>\n\n\n\n<p>\u2219&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong>Length of the column<\/strong> \u2013 the separation is better in the longer column than the shorter column. With a lengthy column, the retention times increases and a peak broadening is observed secondary to increased longitudinal diffusion inside the column. It is because of the principle that the molecules of gasses do not only travel in one direction. They also travel backward and sideways.<\/p>\n\n\n\n<p>\u2219&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong>Amount of material injected<\/strong> \u2013 A poor separation is observed if you inject too much sample in the gas chromatograph. There is no need to inject too many samples as the detectors are highly sensitive. They can detect even just a small sample. <sup><em><strong>(2, 4, 6, 9, and 10)<\/strong><\/em><\/sup><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"500\" height=\"281\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-is-essential-in-forensic-science.jpg\" alt=\"gas chromatography is essential in forensic science\" class=\"wp-image-2662\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-is-essential-in-forensic-science.jpg 500w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-is-essential-in-forensic-science-300x169.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2019\/12\/gas-chromatography-is-essential-in-forensic-science-20x11.jpg 20w\" sizes=\"(max-width: 500px) 100vw, 500px\" \/><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><b><strong>Image 9<\/strong><strong>:<\/strong><\/b>A gas chromatography is essential in forensic science.<b><br><strong>Picture Source:&nbsp;<\/strong><\/b>sites.google.com<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Use of gas chromatography in forensics<\/h2>\n\n\n\n<p>Gas chromatography is useful in forensic science. it is used through the following ways:<\/p>\n\n\n\n<p><strong>Forensic pathology<\/strong> \u2013 The ability of gas chromatography to identify individual elements and molecules in a given compound can be extremely useful in forensic pathology. It helps in determining the fluids and compounds present in the human body after death.<\/p>\n\n\n\n<p>It is essential in finding out whether the person was intoxicated from alcohol or drug at the time of death. It also helps detect if there is a poison or other harmful substances in the human body. It helps in finding out the possible cause of death and the motive and culprit, especially if foul play is suspected.<\/p>\n\n\n\n<p><strong>Crime scene testing<\/strong> \u2013 A gas chromatography is integral in checking the sample in a crime scene. It tests all possible samples such as blood, fiber from clothing, and other materials. It will enable the scientist to determine what and who were present in the crime scene.<\/p>\n\n\n\n<p>It will help the authority to come up with theories about the suspect and what transpires before the crime. With gas chromatography, the error of margin is close to none making it a substantial evidence in court.<\/p>\n\n\n\n<p><strong>Arson investigation<\/strong> \u2013 A gas chromatography is helpful when investigating for arson. In the United States, arson is one of the leading causes of fires and the second cause of injuries and death. To start a fire, you would need different compounds and components.<\/p>\n\n\n\n<p>The number of compounds and components depends on the strength and concentration. It is important to note that many compounds are dissolved during the fire. A gas chromatography is a low-cost alternative to identifying flammable liquids on-site. <sup><em><strong>(1, 4, 6, 9, and 10)<\/strong><\/em><\/sup><\/p>\n\n\n\n<p><strong>References<\/strong><\/p>\n\n\n\n<ol><li><em>https:\/\/www.sciencedirect.com\/topics\/agricultural-and-biological-sciences\/gas-chromatography<\/em><\/li><li><em>https:\/\/chem.libretexts.org\/Bookshelves\/Analytical_Chemistry\/Supplemental_Modules_(Analytical_Chemistry)\/Instrumental_Analysis\/Chromatography\/Gas_Chromatography<\/em><\/li><li><em>https:\/\/en.wikipedia.org\/wiki\/Gas_chromatography<\/em><\/li><li><em>https:\/\/teaching.shu.ac.uk\/hwb\/chemistry\/tutorials\/chrom\/gaschrm.htm<\/em><\/li><li><em>http:\/\/www.chem.ucla.edu\/~bacher\/General\/30BL\/gc\/theory.html<\/em><\/li><li><em>http:\/\/hiq.linde-gas.com\/en\/analytical_methods\/gas_chromatography\/index.html<\/em><\/li><li><em>https:\/\/www.shimadzu.com\/an\/gc\/index.html<\/em><\/li><li><em>https:\/\/www.chemguide.co.uk\/analysis\/chromatography\/gas.html<\/em><\/li><li><em>https:\/\/www.intechopen.com\/books\/gas-chromatography-derivatization-sample-preparation-application\/introductory-chapter-gas-chromatography-the-most-versatile-analytical-technique<\/em><\/li><li><em>https:\/\/bitesizebio.com\/28687\/carrying-gas-chromatography\/<\/em><\/li><\/ol>\n","protected":false},"excerpt":{"rendered":"<p>What is Gas Chromatography? Image 1: The image above shows how a gas chromatograph looks like.Picture Source:&nbsp;hiq.linde-gas.com It is a term used to describe analytical separation methods used to check volatile substances in their gas phase. What happens during gas chromatography is that the components of a sample are dissolved in a solvent and vaporized&#8230;<\/p>\n","protected":false},"author":4,"featured_media":2655,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rank_math_lock_modified_date":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[163],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/posts\/2542"}],"collection":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/comments?post=2542"}],"version-history":[{"count":0,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/posts\/2542\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/media\/2655"}],"wp:attachment":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/media?parent=2542"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/categories?post=2542"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/tags?post=2542"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}