Desorption Electrospray Ionization
Desorption electrospray ionization (DESI) is an ambient ionization technique that can be coupled to mass spectrometry (MS) for chemical analysis of samples at atmospheric conditions. Coupled ionization sources-MS systems are popular in chemical analysis because the individual capabilities of various sources combined with different MS systems allow for chemical determinations of samples. DESI employs a fast-moving charged solvent stream, at an angle relative to the sample surface, to extract analytes from the surfaces and propel the secondary ions toward the mass analyzer. This tandem technique can be used to analyze forensics analyses, pharmaceuticals, plant tissues, fruits, intact biological tissues, enzyme-substrate complexes, metabolites and polymers. Therefore, DESI-MS may be applied in a wide variety of sectors including food and drug administration, pharmaceuticals, environmental monitoring, and biotechnology. History DESI has been widely studied since its inception in 2004 ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

DESI Ion Source
DESI may refer to * Desorption electrospray ionization * Drug Efficacy Study Implementation * Dark Energy Spectroscopic Instrument See also * Desi (other) Desi or Deshi is a self-referential term used by South Asian people. Desi may also refer to: *Desi (raga), a raga (also known as Deshi) in Indian classical music *Desi daru, an Indian alcoholic beverage *Desi ghee, a term used to differentiate b ...

Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

Ion-mobility Spectrometry
Ion mobility spectrometry (IMS) is an analytical technique used to separate and identify ionized molecules in the gas phase based on their mobility in a carrier buffer gas. Though heavily employed for military or security purposes, such as detecting drugs and explosives, the technique also has many laboratory analytical applications, including the analysis of both small and large biomolecules. IMS instruments are extremely sensitive stand-alone devices, but are often coupled with mass spectrometry, gas chromatography or high-performance liquid chromatography in order to achieve a multi-dimensional separation. They come in various sizes, ranging from a few millimeters to several meters depending on the specific application, and are capable of operating under a broad range of conditions. IMS instruments such as microscale high-field asymmetric-waveform ion mobility spectrometry can be palm-portable for use in a range of applications including volatile organic compound (VOC) monitori ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

Matrix-assisted Laser Desorption Electrospray Ionization
Matrix-assisted laser desorption electrospray ionization (MALDESI) was first introduced in 2006 as a novel Ambient ionization, ambient ionization technique which combines the benefits of Electrospray ionization, electrospray ionization (ESI) and Matrix-assisted laser desorption/ionization, matrix-assisted laser desorption/ionization (MALDI). An Infrared, infrared (IR) or Ultraviolet, ultraviolet (UV) laser can be utilized in MALDESI to Excited state, resonantly excite an endogenous or exogenous matrix. The term ‘Matrix (mass spectrometry), matrix’ refers to any molecule that is present in large excess and absorbs the energy of the laser, thus facilitating desorption of analyte molecules. The original MALDESI design was implemented using common Matrix-assisted laser desorption/ionization, organic matrices, similar to those used in MALDI, along with a UV laser. The current MALDESI source employs endogenous water or a thin layer of exogenously deposited ice as the energy-absorbing ma ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

Laser Ablation Electrospray Ionization
Laser ablation electrospray ionization (LAESI) is an ambient ionization method for mass spectrometry that combines laser ablation from a mid-infrared (mid-IR) laser with a secondary electrospray ionization (ESI) process. The mid-IR laser is used to generate gas phase particles which are then ionized through interactions with charged droplets from the ESI source. LAESI was developed in Professor Akos Vertes lab by Dr. Peter Nemes in 2007 and it was marketed commercially by Protea Biosciences, Inc until 2017. Fiber-LAESI for single-cell analysis approach was developed by Dr. Bindesh Shrestha in Professor Vertes lab in 2009. LAESI is a novel ionization source for mass spectrometry (MS) that has been used to perform MS imaging of plants, tissues, cell pellets, and even single cells. In addition, LAESI has been used to analyze historic documents and untreated biofluids such as urine and blood. The technique of LAESI is performed at atmospheric pressure and therefore overcomes many of ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

Ionization Efficiency
Ionization, or Ionisation is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecule is called an ion. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules and ions, or through the interaction with electromagnetic radiation. Heterolytic bond cleavage and heterolytic substitution reactions can result in the formation of ion pairs. Ionization can occur through radioactive decay by the internal conversion process, in which an excited nucleus transfers its energy to one of the inner-shell electrons causing it to be ejected. Uses Everyday examples of gas ionization are such as within a fluorescent lamp or other electrical discharge lamps. It is also used in radiation detectors such as the Geiger-Müller counter or the ionization chamber. The ioniza ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

DESI Side View
DESI may refer to * Desorption electrospray ionization * Drug Efficacy Study Implementation * Dark Energy Spectroscopic Instrument See also * Desi (other) Desi or Deshi is a self-referential term used by South Asian people. Desi may also refer to: *Desi (raga), a raga (also known as Deshi) in Indian classical music *Desi daru, an Indian alcoholic beverage *Desi ghee, a term used to differentiate b ...

Gas Phase
In the outline of physical science, physical sciences, a phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, refractive index, index of refraction, magnetization and chemical composition. A simple description is that a phase is a region of material that is chemically uniform, physically distinct, and (often) mechanically separable. In a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air is a third phase over the ice and water. The glass of the jar is another separate phase. (See ) The term ''phase'' is sometimes used as a synonym for state of matter, but there can be several Miscibility, immiscible phases of the same state of matter. Also, the term ''phase'' is sometimes used to refer to a set of equilibrium states demarcated in terms of state variables such as pressure and ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

Analyte
An analyte, component (in clinical chemistry), or chemical species is a substance or chemical constituent that is of interest in an analytical procedure. The purest substances are referred to as analytes, such as 24 karat gold, NaCl, water, etc. In reality, no substance has been found to be 100% pure in its quality, so a substance that is found to be most pure (for some metals, 99% after electrolysis) is called an analyte. See also *Analytical chemistry *Immunoassay *Magnetic immunoassay Magnetic immunoassay (MIA) is a type of diagnostic immunoassay using magnetic beads as labels in lieu of conventional enzymes (ELISA), radioisotopes (RIA) or fluorescent moieties ( fluorescent immunoassays) to detect a specified analyte. MIA involv ... References Analytical chemistry {{Analytical-chemistry-stub ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

Proton
A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ratio). Protons and neutrons, each with masses of approximately one atomic mass unit, are jointly referred to as "nucleons" (particles present in atomic nuclei). One or more protons are present in the nucleus of every atom. They provide the attractive electrostatic central force which binds the atomic electrons. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol ''Z''). Since each element has a unique number of protons, each element has its own unique atomic number, which determines the number of atomic electrons and consequently the chemical characteristics of the element. The word ''proton'' is Greek for "first", and this name was given to the ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]