Mass spectrometry in the context of "Biogenic"

In the physical sciences, spectrum describes any continuous range of either frequency or wavelength values. The term initially referred to the range of observed colors as white light is dispersed through a prism — introduced to optics by Isaac Newton in the 17th century.

The concept was later expanded to other waves, such as sound waves and sea waves that also present a variety of frequencies and wavelengths (e.g., noise spectrum, sea wave spectrum). Starting from Fourier analysis, the concept of spectrum expanded to signal theory, where the signal can be graphed as a function of frequency and information can be placed in selected ranges of frequency. Presently, any quantity directly dependent on, and measurable along the range of, a continuous independent variable can be graphed along its range or spectrum. Examples are the range of electron energy in electron spectroscopy or the range of mass-to-charge ratio in mass spectrometry.

Fourier-transform spectroscopy (FTS) is a measurement technique whereby spectra are collected based on measurements of the coherence of a radiative source, using time-domain or space-domain measurements of the radiation, electromagnetic or not. It can be applied to a variety of types of spectroscopy including optical spectroscopy, infrared spectroscopy (FTIR, FT-NIRS), nuclear magnetic resonance (NMR) and magnetic resonance spectroscopic imaging (MRSI), mass spectrometry and electron spin resonance spectroscopy.

There are several methods for measuring the temporal coherence of the light (see: field-autocorrelation), including the continuous-wave and the pulsed Fourier-transform spectrometer or Fourier-transform spectrograph.The term "Fourier-transform spectroscopy" reflects the fact that in all these techniques, a Fourier transform is required to turn the raw data into the actual spectrum, and in many of the cases in optics involving interferometers, is based on the Wiener–Khinchin theorem.

In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), usually denoted by H, to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include

• The protonation of water by sulfuric acid:

  H₂SO₄ + H₂O ⇌ H₃O + HSO
  ₄

• The protonation of isobutene in the formation of a carbocation:

  (CH₃)₂C=CH₂ + HBF₄ ⇌ (CH₃)₃C + BF
  ₄

• The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride:

  NH₃(g) + HCl(g) → NH₄Cl(s)

Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brønsted–Lowry acid is defined as a chemical substance that protonates another substance. Upon protonating a substrate, the mass and the charge of the species each increase by one unit, making it an essential step in certain analytical procedures such as electrospray mass spectrometry. Protonating or deprotonating a molecule or ion can change many other chemical properties, not just the charge and mass, for example solubility, hydrophilicity, reduction potential or oxidation potential, and optical properties can change.

Analytical chemistry (or chemical analysis) is the branch of chemistry concerned with the development and application of methods to identify the chemical composition of materials and quantify the amounts of components in mixtures. It focuses on methods to identify unknown compounds, possibly in a mixture or solution, and quantify a compound's presence in terms of amount of substance (in any phase), concentration (in aqueous or solution phase), percentage by mass or number of moles in a mixture of compounds (or partial pressure in the case of gas phase).

It encompasses both classical techniques (e.g. titration, gravimetric analysis) and modern instrumental approaches (e.g. spectroscopy, chromatography, mass spectrometry, electrochemical methods). Modern analytical chemistry is deeply intertwined with data analysis and chemometrics, and is increasingly shaped by trends such as automation, miniaturization, and real-time sensing, with applications across fields as diverse as biochemistry, medicinal chemistry, forensic science, archaeology, nutritional science, agricultural chemistry, chemical synthesis, metallurgy, chemical engineering and materials science.

Proteomics is the large-scale study of proteins. It is an interdisciplinary domain that has benefited greatly from the genetic information of various genome projects, including the Human Genome Project. It covers the exploration of proteomes from the overall level of protein composition, structure, and activity, and is an important component of functional genomics. The proteome is the entire set of proteins produced or modified by an organism or system.

Proteomics generally denotes the large-scale experimental analysis of proteins and proteomes, but often refers specifically to protein purification and mass spectrometry. Indeed, mass spectrometry is the most powerful method for analysis of proteomes, both in large samples composed of millions of cells, and in single cells.