Gas chromatography (GC) is an analytical technique that can determine the presence or absence of specific chemical components in mixtures. These include organic compounds or gases. It is commonly used in analytical chemistry to separate compounds that can be easily vaporized. More importantly, it can be used to test the purity of a specific substance or to separate the various components of a given mixture. Another type of GC is called preparative, which can be utilized to prepare pure compounds. The GC-UV INSCAN™ products is an integrated system with hyphenated technologies combining gas chromatography and UV spectrometry.
The concept of chromatography was first introduced in 1903 by Mikhail Semenovich Tswett, a Russian scientist. He used a liquid column chromatography technique to separate plant pigments. The gas chromatograph was developed by Archer Martin and Anthony James. Due to the development of flame ionization detectors, the scope of gas chromatography’s popularity has increased. In an earlier study, Martin and his colleague Richard Synge noted that this process could also remove gases.
A gas chromatography technique involves separating compounds by injecting a liquid or gaseous sample into a mobile phase, also known as carrier gas. This phase is usually an inert or unreactive gas, such as hydrogen, nitrogen, helium, or argon. The stationary phase is a layer of viscous liquid on the surface of solid particles inside a column. This can be referred to as the stationary phase of the process. In some columns, the solid particles’ surface may act as the stationary phase. The gas phase passes through an oven, where the temperature can be controlled. A computerized detector then monitors the eluent coming out of the column. Different types of gas chromatography techniques, such as vapour-phase and gas-liquid partition, are often referred to as these in scientific literature.
A sample port is required for introducing the sample to the column of the system. In modern injection techniques, the model can be heated up and then vaporized in a manner that’s fast and easy to perform. A micro-syringing device is also commonly used to deliver a small sample into the vaporizing chamber. A sample splitter is also sometimes used to separate excess pieces. In most cases, a small fraction of the initial sample volume can be reduced by a sample port. A split and splitless injection technique is commonly used in commercial gas chromatographic systems. This method involves alternating between the packed and unpacked columns. The vaporizing chamber is usually heated to around 50 degrees Celsius. In addition to the carrier gas, the other components used in the GC process also play an essential role. For instance, the carrier gas should be oxygen-free and have mobile-phase chemistry. Helium is commonly used because it’s safer than hydrogen but comparable in efficiency to hydrogen.
Hydrogen, nitrogen, and helium are commonly used depending on the detector’s performance and the desired results. These are widely used on devices that are known to feature flame ignition, thermal conductivity, and electron capture. These two substances offer a shorter analysis time than other detectors due to their low molecular weight and high flow rates. H2 or helium provide the most heightened sensitivity to thermal conductivity detectors (TCD) due to their thermal conductivity difference from organic vapour. On the other hand, some detectors use nitrogen or argon as carrier gas. These two substances have higher molecular weights and are more efficient than hydrogen or helium.
The conditions used to accommodate a specific analysis can be adjusted. These include the detector temperature, inlet and temperature program, column temperature, sample size, flow rates, and the stationary phase. In addition, the conditions used to accommodate a specific analysis can be adjusted. For instance, the detector’s inlet and temperature program can be changed. Also, certain types of GCs feature valves that can change the route of the sample and carrier flow. GC is widely used in forensic science for various applications and in, such as identifying solid drug doses and quantifying crime-scene evidence. Other disciplines that use this technique include toxicology and arson investigations. The GC-UV methodology was developed by researchers from the Linköping University Hospital.
