Chemistry: Gas-Liquid Chromatography

Steam distillation is usually used to obtain oil from extracted plant material. Solvent extraction is also used for resin manufacture (as well as resin properties). Solvent extraction is often used with volatile substances that can be lost by distillation. The solvent used is pentane, a mixture of hexane and a solvent such as ethyl acetate and hexane, which are usually used instead of benzene (see FIG. 2). Gas Liquid Chromatography Gas liquid chromatography is a process of separating complex mixtures into components and measuring each component.

Several types of chromatography are commonly used, including paper chromatography, thin layer chromatography or TLC, liquid-liquid chromatography, gas chromatography, and high performance liquid chromatography or HPLC. Chromatography is very useful and can be found in most scientific laboratories around the world. For example, in Forensic Chemistry Crime Lab, FBI manages commercially available ink chromatography libraries. In the first case of ink chromatography, Miami's man spoofed travel and expenses documents

Gas chromatography (GC) performs the same function as liquid chromatography, but it is used for volatile mixtures. In forensic medicine, the most common GC instruments use mass spectrometry as their detector. GC - MS is used to investigate arson, poisoning, explosion, and can identify the exact content being used. In theory, GC - MS instruments can detect substances in the concentration range of Feike (10 - 15). In practice, however, the actual detection limit of GC - MS is in the range of pico (10 to 12) due to other limiting factors such as signal - to - noise ratio and the life span of the various components of the instrument. GC - MS can also quantify the substances it detects; chemists can use this information to determine the personal influence on individuals. The GC - MS instrument needs about 1000 times the amount of material to quantify, rather than simply detecting it. The quantization limit is usually in the range of nanogram (10 - 9)

Chromatography - chromatography is an analytical method used to separate compounds / drugs, usually based on high performance liquid chromatography (HPLC) or gas chromatography (GC) combined with MS. This is a deterministic approach for toxicology used to establish evidence of the structure of unknown substances. With extensive development and affordable commercial MS technology, GC / MS and HPLC-MS (commonly called LC / MS) are becoming increasingly popular tools in modern toxicology laboratories. Learn more about medicinal chemistry ▸