• thin layer chromato
  • Thin-layer chromatography is performed on a sheet of glass, plastic, or aluminium foil, which is coated with a thin layer of adsorbent material, usually silica gel, aluminium oxide (alumina), or cellulose. (wikipedia.org)
  • Thin-layer chromatography can be used to monitor the progress of a reaction, identify compounds present in a given mixture, and determine the purity of a substance. (wikipedia.org)
  • To run a thin layer chromatography plate, the following procedure is carried out: Using a capillary, a small spot of solution containing the sample is applied to a plate, about 1.5 centimeters from the bottom edge. (wikipedia.org)
  • HPLC
  • HPLC is distinguished from traditional ("low pressure") liquid chromatography because operational pressures are significantly higher (50-350 bar), while ordinary liquid chromatography typically relies on the force of gravity to pass the mobile phase through the column. (wikipedia.org)
  • Some models of mechanical pumps in a HPLC instrument can mix multiple solvents together in ratios changing in time, generating a composition gradient in the mobile phase. (wikipedia.org)
  • mixture
  • The mobile phase may be a mixture, allowing chemists to fine-tune the bulk properties of the mobile phase. (wikipedia.org)
  • The sampler brings the sample mixture into the mobile phase stream which carries it into the column. (wikipedia.org)
  • The sample mixture to be separated and analyzed is introduced, in a discrete small volume (typically microliters), into the stream of mobile phase percolating through the column. (wikipedia.org)
  • Solid-phase extraction (SPE) is a sample preparation process by which compounds that are dissolved or suspended in a liquid mixture are separated from other compounds in the mixture according to their physical and chemical properties. (wikipedia.org)
  • silanol
  • Hydrophobicity and polar surface activity are often used as axes for these maps, and the obtained classification is usually in agreement with the data provided by the manufacturers in terms of carbon content (%), specific surface area (m 2 /g), and the presence of residual silanol groups or hydrophilic endcapping groups. (chromatographyonline.com)
  • Surface functionalization of silica can be performed in a monomeric or a polymeric reaction with different short-chain organosilanes used in a second step to cover remaining silanol groups (end-capping). (wikipedia.org)
  • octadecyl
  • The most popular column is an octadecyl carbon chain (C18)-bonded silica (USP classification L1) with 297 columns commercially available. (wikipedia.org)
  • technique
  • Chromatography technique developed substantially as a result of the work of Archer John Porter Martin and Richard Laurence Millington Synge during the 1940s and 1950s, for which they won the 1952 Nobel Prize in Chemistry. (wikipedia.org)
  • biological
  • Its utility has increased due to the simplified sample preparation for biological samples, when analyzing for metabolites, since the metabolic process generally results in the addition of polar groups to enhance elimination from the cellular tissue. (wikipedia.org)
  • Lipids are a diverse and ubiquitous group of compounds which have many key biological functions, such as acting as structural components of cell membranes, serving as energy storage sources and participating in signaling pathways. (wikipedia.org)
  • composition
  • The pumps deliver the desired flow and composition of the mobile phase through the column. (wikipedia.org)
  • Then water, or buffer of the same composition as the sample, is typically washed through the column to wet the silica surface. (wikipedia.org)
  • Typical
  • A typical solid phase extraction involves five basic steps. (wikipedia.org)
  • That it differed from other ethers - particularly by its propensity to engage in addition reactions, which are typical of unsaturated compounds - had long been a matter of debate. (wikipedia.org)
  • acidic
  • These tests did not provide any information related to the durability of the column when working with acidic or basic conditions-that is, phase aging. (chromatographyonline.com)