If you have been reading about mass spectrometry and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-12-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
Quality control for collagen peptides may include identity, purity, and contaminant testing. Identity can be supported by amino acid profile and hydroxyproline content; purity checks may examine moisture, ash, protein content, and peptide size range. Heavy metals, microbial counts, and residual solvents are relevant for materials intended for ingestion. Some suppliers use peptide fingerprinting or source-specific markers, though these methods are not universally standardized. Documentation such as certificates of analysis helps verify that a batch meets agreed specifications.
Analytical characterization of collagen peptides often begins with peptide size distribution. Size-exclusion chromatography can separate peptides by hydrodynamic volume, while mass spectrometry provides more detailed mass information. Amino acid analysis quantifies residues such as glycine, proline, and hydroxyproline. Hydroxyproline assays are widely used because this amino acid is uncommon in many other proteins; nitrogen content and ash values help assess purity and residual minerals. No single method captures all relevant properties, so laboratories commonly combine several techniques.
One challenge in collagen peptide analysis is the absence of a single reference standard that covers all possible molecular weight fractions. Products from different sources or hydrolysis conditions yield different peptide profiles, complicating direct comparisons. Some laboratories use gelatin or a defined peptide mixture as a calibration standard, but this approach has limitations. Additionally, the term "collagen peptide" itself lacks a universally accepted molecular weight cutoff. Ongoing discussions aim to establish more consistent definitions and testing protocols for regulatory and research purposes.
Quality control of collagen peptides relies on methods that characterize molecular weight distribution, amino acid composition, and purity. Size exclusion chromatography (SEC) is commonly used to estimate the molecular weight profile of peptide mixtures. High-performance liquid chromatography (HPLC) can separate and quantify individual peptide fractions. Mass spectrometry provides detailed information on peptide sequences and modifications. These techniques help verify that a product meets declared specifications, though standardization across laboratories remains limited.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | 15–25 °C | Keep dry and protect from direct light |
| Moisture content | ≤ 6–8% | Higher moisture can reduce stability |
| Solubility class | Water-soluble | Insoluble in nonpolar solvents |
| Common analytical method | Size-exclusion chromatography | Used for molecular weight distribution |
| Microbial limits | Total aerobic count < 10³ CFU/g | Specifications vary by market and application |
== Sources == This article incorporates text from a free content work. Licensed under CC BY-SA IGO 3.0 (license statement/permission). Text taken from World Food and Agriculture – Statistical Yearbook 2023, FAO, FAO.
=== Fermentation === Possibly the world's oldest fermented beverage, dating from 9,000 years ago, mead ("honey wine") is the alcoholic product made by adding yeast to honey-water must and fermenting it for weeks or months. The yeast Saccharomyces cerevisiae is commonly used in modern mead production. Mead varieties include drinks called metheglin (with spices or herbs), melomel (with fruit juices, such as grape, specifically called pyment), hippocras (with cinnamon), and sack mead (high concentration of honey), many of which have been developed as commercial products numbering in the hundreds in the United States. Honey is also used to make mead beer, called "braggot".
Before drying to make copra, raw coconut meat is 47% water, 33% fat, 15% carbohydrates, and 3% protein (table). In a reference amount of 100 grams (3.5 oz), raw coconut flesh supplies 354 calories of food energy, and is a rich source (20% or more of the Daily Value, DV) of manganese (65% DV), with various other dietary minerals in moderate amounts (10–18% DV; table). It is a poor source of vitamins. Raw coconut meat has a high content of saturated fatty acids (89% of total fats), with lauric acid as the main saturated fat (15% of total; USDA source in table).
Comatose patients may aspirate their vomit (resulting in vomitus in the lungs, which may cause "drowning" and later pneumonia if survived). CNS depression and impaired motor coordination along with poor judgment increase the likelihood of accidental injury occurring. It is estimated that about one-third of alcohol-related deaths are due to accidents and another 14% are from intentional injury. In addition to respiratory failure and accidents caused by its effects on the central nervous system, alcohol causes significant metabolic derangements. Hypoglycaemia occurs due to ethanol's inhibition of gluconeogenesis, especially in children, and may cause lactic acidosis, ketoacidosis, and acute kidney injury. Metabolic acidosis is compounded by respiratory failure. Patients may also present with hypothermia.
=== Recoded synthetic genome === One way to achieve the encoding of multiple unnatural amino acids is by synthesising a rewritten genome. In 2010, at the cost of $40 million an organism, Mycoplasma laboratorium, was constructed that was controlled by a synthetic, but not recoded, genome. The first genetically recoded organism was created by a collaboration between George Church's and Farren Isaacs' labs, when the wild type E. coli MG1655 was recoded in such a way that all 321 known UAG stop codons were substituted with synonymous UAA codons and release factor 1 was knocked out in order to eliminate the interaction with the exogenous stop codon and improve unnatural protein synthesis. In 2019, Escherichia coli Syn61 was created, with a 4 megabase recoded genome consisting of only 61 codons instead of the natural 64. In addition to the elimination of the usage of rare codons, the specificity of the system needs to be increased as many tRNA recognise several codons
Sources: en.wikipedia.org
The United Kingdom was represented by its 1st Armoured Division known as the Desert Rats. The British 1st Armoured Division fielded approximately 176 Challenger 1 tanks. British infantry rode into battle on the Warrior tracked armoured vehicle. It had reasonable armour protection and a 30mm gun. Modified versions of the vehicle included mortar carriers, MILAN antitank systems, and command and control vehicles; and the British possessed a variety of excellent light armoured vehicles built on their FV101 Scorpion chassis. British artillery was primarily American made M109 howitzers (155mm), M110 howitzers (203mm), and M270 MLRS which were compatible with American systems. Their air support consisted of Gazelle helicopters, used for reconnaissance, and the Lynx helicopter which was comparable to the American AH-1 Cobra. The British had their full contingent of engineer, logistics, and medical units. The British 1st Armoured Division was responsible for protecting the right flank of VII Corps. It was assumed by the Corps' planners the Iraqi 52nd Armored Division would counterattack VII Corps once their penetration into Iraqi defenses was discovered. The British 1st Armoured Division had two brigades (the 4th and 7th) which participated in Operation Granby, the name given to the British military operations during the 1991 Gulf War. The British 1st Armoured Division had traveled 217 miles in 97 hours. The British 1st Armoured Division had captured or destroyed about 300 Iraqi tanks and a very large number of armored personnel carriers, trucks, reconnaissance vehicles, etc.
It was not until he [Trask] had exercised for some time that he could perform any labor ... [H]is neck and back have continued to curve drawing his head downward on his breast. The account of Trask became the first documented case of AS in the United States, owing to its indisputable description of inflammatory disease characteristics of AS and the hallmark of deforming injury in AS. In the late nineteenth century, the neurophysiologist Vladimir Bekhterev of Russia in 1893, Adolf Strümpell of Germany in 1897, and Pierre Marie of France in 1898 were the first to give adequate descriptions which permitted an accurate diagnosis of AS prior to severe spinal deformity. For this reason, AS is also known as Bekhterev disease, Bechterew's disease or Marie–Strümpell disease. The word is from Greek ankylos meaning crooked, curved or rounded, spondylos meaning vertebra, and -itis meaning inflammation.
=== Liquid crystals === DSC is used in the study of liquid crystals. As some forms of matter go from solid to liquid they go through a third state, which displays properties of both phases. This anisotropic liquid is known as a liquid crystalline or mesomorphous state. Using DSC, it is possible to observe the small energy changes that occur as matter transitions from a solid to a liquid crystal and from a liquid crystal to an isotropic liquid.
=== 2020–present === In January 2020, Merck acquired ArQule, developer of ARQ 531, an oral Bruton's tyrosine kinase (BTK) inhibitor, for $2.7 billion. In March 2020, Merck was one of ten companies recognised at the inaugural Manufacturing Awards by New Jersey Business magazine and the New Jersey Business and Industry Association. In June 2020, Merck acquired Themis Bioscience, a company focused on vaccines and immune-modulation therapies for infectious diseases including COVID-19 and cancer. Also in June 2020, Merck Animal Health acquired Quantified Ag, a data and analytics company that monitors cattle body temperature and movement in order to detect illness early. In August 2020, Merck Animal Health acquired IdentiGEN, engaged in DNA-based animal traceability. In September 2020, Merck acquired $1 billion of Seattle Genetics common stock, and agreed to co-develop ladiratuzumab vedotin. In November 2020, Merck announced it would acquire VelosBio for $2.75 billion, developer of VLS-101, an antibody-drug conjugate designed to target Tyrosine kinase-like orphan receptor 1 (ROR1) in both hematological and solid tumors. VLS-101 is currently Phase I and Phase II clinical trials. The company also announced it would acquire OncoImmune for $425 million and its phase 3 candidate, CD24Fc, used in the treatment of patients with severe and critical COVID-19. In February 2021, Merck Animal Health acquired PrognostiX Poultry. In April 2021, Merck acquired Pandion Therapeutics for $1.85 billion, expanding its offering in treating autoimmune diseases. In June 2021, the U.S.
As the head group forms such compact bicycle structure, the head group area is quite small relative to the big tail region consisting of 4 acyl chains. Based on this special structure, the fluorescent mitochondrial indicator, nonyl acridine orange (NAO) was introduced in 1982, and was later found to target mitochondria by binding to CL. NAO has a very large head and small tail structure which can compensate with cardiolipin's small head and large tail structure, and arrange in a highly ordered way. Several studies were published utilizing NAO both as a quantitative mitochondrial indicator and an indicator of CL content in mitochondria. However, NAO is influenced by membrane potential and/or the spatial arrangement of CL, so it's not proper to use NAO for CL or mitochondria quantitative studies of intact respiring mitochondria. But NAO still represents a simple method of assessing CL content.
Sources: en.wikipedia.org
Common methods include size-exclusion chromatography and mass spectrometry. Amino acid analysis provides composition data but not chain length. Results depend on calibration standards and sample preparation.
A cool, dry place protected from moisture and direct light is typical. Sealed containers help prevent clumping and contamination. Solution forms usually require refrigeration or preservatives.
It may report appearance, moisture, ash, protein content, molecular weight distribution, and microbial limits. Heavy metal results and amino acid profiles are also common. The exact panel depends on the supplier and intended use.
Size exclusion chromatography is the most common method, often coupled with detectors such as refractive index or ultraviolet. Mass spectrometry can provide more detailed sequence information for individual peptides.