This is a working overview of HPLC, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Identity and purity are assessed with several complementary methods. High-performance liquid chromatography can separate creatine from creatinine and related impurities, often with ultraviolet detection. Nuclear magnetic resonance and infrared spectroscopy provide structural confirmation, while Karl Fischer titration measures water content. Elemental analysis and mass spectrometry may be used for additional confirmation, especially in research or forensic settings. No single method captures every quality attribute, so laboratories typically combine results and compare them against a specification.
Creatine monohydrate is sold as a dietary ingredient in some countries and as a food supplement in others. Regulatory frameworks vary, so purity limits, labeling rules, and permitted claims are not globally uniform. In the United States, it falls under dietary supplement rules, whereas the European Union treats it as a food supplement ingredient. Pharmacopeial monographs, where they exist, can provide public quality standards, but not every product is required to meet them. Questions about long-term effects and patterns of use remain areas of active study rather than settled regulatory findings.
Solid creatine monohydrate is generally stable when kept cool and dry, but it can hydrolyze to creatinine over time. Moisture, heat, and acidic conditions accelerate this conversion, which reduces assay values and changes the material's properties. Creatinine is a cyclic dehydration product that is also a normal human metabolite, so its presence in a sample is not necessarily a health concern by itself. In quality testing, creatinine is monitored as a marker of degradation and purity.
In the body, creatine is obtained from dietary meat and fish and is also synthesized from arginine, glycine, and methionine. Muscle stores creatine and phosphocreatine, which participate in the rapid regeneration of adenosine triphosphate during short, intense activity. The monohydrate form is used in research because it is chemically defined, stable as a dry solid, and relatively inexpensive to produce. Questions remain about whether other creatine forms offer meaningful advantages in absorption or tissue retention, and findings vary across studies and populations.
Creatine monohydrate is a crystalline compound formed from creatine and one molecule of water. Creatine itself is a nitrogen-containing organic acid that occurs in vertebrate muscle and other tissues. The monohydrate designation refers to the water included in the crystal lattice, not to water added during manufacturing. Its chemical formula is commonly written as C4H9N3O2·H2O. The solid is typically a white, odorless powder with low solubility in water at room temperature. It is one of several creatine forms described in scientific and commercial literature.
The compound was identified in the nineteenth century after chemists isolated a nitrogenous substance from meat extracts. Later work established its role in muscle energy metabolism and its conversion to phosphocreatine. Chemical synthesis of creatine followed, and industrial production made the monohydrate widely available as a purified powder. Interest expanded in the late twentieth century when researchers began studying creatine supplementation and muscle physiology. Historical accounts sometimes differ on exact dates and attributions, but the broad sequence from tissue extracts to synthetic production is well documented.
| Property | Value | Notes |
|---|---|---|
| Purity (typical) | ≥99% by HPLC | Supplement and pharmacopeial grades vary |
| Water content | ≈12.1% theoretical | Measured by Karl Fischer titration |
| Creatinine limit | Often ≤0.1% in pharmacopeial grade | Supplement specifications may differ |
| Storage conditions | 15–25 °C, low humidity | Away from heat and acidic environments |
| Common analytical methods | HPLC–UV, NMR, FTIR, Karl Fischer | Used for identity, assay, and water content |
Sourcing and verification of creatine monohydrate involve both manufacturing origin and third-party testing. Industrial production commonly starts with sarcosine and cyanamide, followed by crystallization to obtain the monohydrate. Some products are derived from animal sources, while others are synthesized from non-animal precursors. Certificates of analysis report assay, heavy metals, and microbial limits. Regulations differ by country: in the United States it is sold as a dietary supplement, whereas in the European Union it falls under food supplement rules.
In solid form, creatine monohydrate is relatively stable when kept dry and away from heat. Moisture and elevated temperatures promote cyclization into creatinine, a related compound with no role in the phosphagen system. Degradation accelerates in aqueous solution, where the conversion can occur within hours to days depending on pH and temperature. Manufacturers typically recommend storage in sealed containers at room temperature, with relative humidity below 50 percent. Long-term stability data for opened containers are limited.
In chemical terms, creatine monohydrate is often described as N-(aminoiminomethyl)-N-methylglycine monohydrate, though nomenclature varies. Its solid state consists of zwitterionic creatine molecules linked with water through hydrogen bonding. The compound dissolves in water, but dissolution rate depends on particle size, temperature, and agitation. Once dissolved, the hydrate water becomes part of the solvent, leaving free creatine in solution. The monohydrate is not the same as creatine anhydrous, which lacks the water of crystallization and has a higher creatine fraction by mass.
Commercial creatine monohydrate is typically a white to off-white powder with low odor. It is commonly sold as a fine powder, micronized powder, or larger crystals, but these are physical forms of the same chemical. Purity grades vary, and products may contain small amounts of related substances such as creatinine, dicyandiamide, or moisture. The monohydrate is often selected for supplements and research because its production is well established and its behavior in water is predictable. Analytical certificates usually report assay, loss on drying, and heavy metals.
Creatine monohydrate is a crystalline compound formed from creatine and one water molecule in its solid lattice. Creatine itself is a nitrogen-containing organic acid involved in energy transfer in muscle and other tissues. The monohydrate form is the most common solid form used in research and commercial products because it is stable and easy to handle. The term "monohydrate" refers to the fixed one-to-one ratio of water to creatine in the crystal, not to moisture content. This distinction matters when comparing labels or calculating creatine content.
Handling practices aim to limit moisture uptake and thermal exposure. Containers should stay closed when not in use, and storage areas should avoid direct sunlight, strong heat, and high humidity. Caking can occur when powder absorbs water, even if the creatine itself has not fully degraded. Aqueous stock solutions are best prepared fresh when needed because they are less stable than the solid. Open questions include how different excipients, packaging materials, and climate conditions affect long-term stability across global supply chains.
Solid creatine monohydrate is relatively stable when kept dry and sealed, but heat and moisture accelerate its conversion to creatinine. This degradation involves intramolecular cyclization, a process that removes water and forms a less useful compound for phosphocreatine metabolism. Powder stored under cool, dry conditions can remain within specification for extended periods, though exact shelf life depends on packaging, humidity, and initial purity. Aqueous solutions degrade faster than dry powder, with pH and temperature influencing the rate. Because degradation is gradual, analytical testing is used to confirm potency at manufacture and during stability studies.
Ceremonial San Pedro use seems to be characterized by relatively strong spiritual experiences, and low incidence of challenging experiences. DMT (N,N-dimethyltryptamine) is an indole alkaloid found in various species of plants. Traditionally, it is consumed by tribes in South America in the form of ayahuasca. A brew is used that consists of DMT-containing plants as well as plants containing monoamine oxidase inhibitors (MAOIs), like harmine and harmaline, which allows DMT to be consumed orally without being rendered inactive by monoamine oxidase (MAO) enzymes in the digestive system. A pharmaceutical version of ayahuasca is called pharmahuasca. In the Western world, DMT is more commonly consumed via the vaporisation of freebase DMT. Whereas ayahuasca typically lasts for several hours, inhalation has an onset measured in seconds and has effects measured in minutes, being much more intense. Particularly in smoked or vaporised form, DMT has the ability to cause users to enter a hallucinatory realm fully detached from reality, being typically characterised by hyperbolic geometry, and described as defying visual or verbal description. Users have also reported encountering and communicating with entities within this hallucinatory state. DMT is the archetypal substituted tryptamine, being the structural scaffold of psilocybin and, to a lesser extent, the lysergamides. 5-MeO-DMT (5-methoxy-N,N-dimethyltryptamine; mebufotenin) is a naturally occurring substituted 5-methoxytryptamine which was first identified as having psychedelic effects in the 1960s.
=== Canada and United States === In the first decade of the 21st century, farmers in Canada and the United States began cultivating goji on a commercial scale to meet potential markets for fresh berries, juice, and processed products.
== Attempted murder trials == In 1982, von Bülow was arrested and tried for the attempted murders of Sunny on two occasions in two consecutive years. The main medical and scientific evidence against him was that Sunny had low blood sugar, common in many conditions, but a blood test showed a high insulin level. The test was not repeated. A needle was used as evidence against von Bülow in court, with the prosecution alleging that he had used it and a vial of insulin to try to kill his wife. His mistress of two years, the soap opera actress Alexandra Isles, testified "He said that they had been having a long argument, talk, about divorce that had gone on late into the night. She had drunk a great deal of eggnog. And then he said, 'I saw her take the Seconal.' And then he said that the next day when she was unconscious that he watched her knowing that she was in a bad way, all day, and watched her and watched her. And finally, when she was at the point of dying, he said that he couldn't go through with it and he called (the doctor) and saved her life." The discovery of these items became the focal point of von Bülow's appeal. At the trial in Newport, Rhode Island, von Bülow was found guilty and sentenced to 30 years in prison; he appealed, hiring Harvard Law School professor Alan Dershowitz to represent him. Dershowitz served as a consultant to the defence team led by Thomas Puccio, a former federal prosecutor.
It contended that the benefits were substantial and that even if bacteria became resistant, new antibiotics would soon be developed, and there was no evidence that bacterial resistance in animals impacted human health. The Netherthorpe committee's conclusions were undermined by new research even before they were published, and the committee was recalled to reconsider the issue in 1965. New studies had shown that bacteria were not only able to inherit the genes for antibiotic resistance, but they could also communicate them to each other. In 1967, a multiresistant strain of E. coli killed fifteen children in the UK. The use of antibiotics in animals for nontherapeutic use was banned there in 1971. Many other European countries soon followed. When Sweden acceded to the European Union (EU) in 1995, a total ban on antibiotic growth promoters (AGPs) had been in place there for ten years. This would be superseded by more relaxed EU rules unless Sweden could demonstrate scientific evidence in favour of a ban. Two Swedish scientists, Anders Franklin and Christina Greko, and two Danish scientists, Frank Aarestrup and Henrik Wegener, took up the fight. The odds seemed against them but this coincided with the United Kingdom BSE outbreak, which resulted in intense political pressure. In December 1996, the European Parliament's Standing Committee on Health and Welfare voted to ban the use of AGPs. The EU went further and recommended broad restrictions on the use of antibiotics. These regulations were adopted in 2019 and took effect in 2022.
2800 Polar Way is a cold storage facility located in Richland, Washington, United States. It is both the largest refrigerated warehouse and the largest automated freezer on Earth. Holliday Fenoglio Fowler (HFF) financed the build-to-suit refrigerated warehouse for tenant Preferred Freezer Services. The project broke ground on May 12, 2014, and opened in late July 2015. In 2016, HHF sold the property to Lexington Realty Trust, an S&P 600 REIT company. In 2019, Lineage Logistics acquired Preferred Freezer, and continues to operate the facility.
Sources: en.wikipedia.org
=== Recycling === When galvanised steel is fed into an electric arc furnace, the steel is melted but the zinc coating is vaporised and becomes furnace dust; an average steel mill generates tens of thousands of tonnes of dust a year with a zinc content of 15–35%. Zinc can recovered from the dust by a number of processes, predominantly the Waelz process (90% in 2014). Recycling zinc produces 6.5 tonnes of CO₂ equivalent per tonne of zinc, compared with an average of 3.64 tonnes in the mining process. A number of experimental processes aim to increase efficiency, reduce overall energy expenditure, and lower CO₂ production to less than that generated by mining. These include the rotary hearth treatment of pelletised zinc containing dust (Kimitsu works, Nippon Steel); the SDHL (Saage, Dittrich, Hasche, Langbein) process, an efficiency modification of the Waelz process; the "DK process" a modified blast furnace process producing pig iron and zinc (oxide) dust from blast furnace dusts, sludges and other wastes; and the PRIMUS process (multi-stage zinc volatilisation furnace).
This resulted in a surge of both Croatian nationalism and Slovene nationalism in response and the collapse of the League of Communists of Yugoslavia in 1990, the victory of nationalists in multi-party elections in most of Yugoslavia's constituent republics and eventually civil war between the various nationalities beginning in 1991. Yugoslavia was dissolved in 1992. The Soviet Union itself collapsed between 1990 and 1991, with a rise of secessionist nationalism and a political power dispute between Gorbachev and Boris Yeltsin, the new leader of the Russian Federation. With the Soviet Union collapsing, Gorbachev prepared the country to become a loose federation of independent states called the Commonwealth of Independent States. Hardline Marxist–Leninist leaders in the military reacted to Gorbachev's policies with the August Coup of 1991 in which hardline Marxist–Leninist military leaders overthrew Gorbachev and seized control of the government. This regime only lasted briefly as widespread popular opposition erupted in street protests and refused to submit. Gorbachev was restored to power, but the various Soviet republics were now set for independence. On 25 December 1991, Gorbachev officially announced the dissolution of the Soviet Union, ending the existence of the world's first Marxist–Leninist-led state.
Amyloid-beta precursor protein (APP) is an integral membrane protein expressed in many tissues and concentrated in the synapses of neurons. It functions as a cell surface receptor and has been implicated as a regulator of synapse formation, neural plasticity, antimicrobial activity, and iron export. It is coded for by the gene APP and regulated by substrate presentation. APP is best known as the precursor molecule whose proteolysis generates amyloid beta (Aβ), a polypeptide containing 37 to 49 amino acid residues, whose amyloid fibrillar form is the primary component of amyloid plaques found in the brains of Alzheimer's disease patients.
=== Indirect immunofluorescence === Indirect immunofluorescence is one of the most commonly used tests for ANAs. Typically, HEp-2 cells are used as a substrate to detect the antibodies in human serum. Microscope slides are coated with HEp-2 cells and the serum is incubated with the cells. If the said and targeted antibodies are present then they will bind to the antigens on the cells; in the case of ANAs, the antibodies will bind to the nucleus. These can be visualised by adding a fluorescent tagged (usually FITC or rhodopsin B) anti-human antibody that binds to the antibodies. The molecule will fluoresce when a specific wavelength of light shines on it, which can be seen under the microscope. Depending on the antibody present in the human serum and the localisation of the antigen in the cell, distinct patterns of fluorescence will be seen on the HEp-2 cells. Levels of antibodies are analysed by performing dilutions on blood serum. An ANA test is considered positive if fluorescence is seen at a titre of 1:40/1:80. Higher titres are more clinically significant as low positives (≤1:160) are found in up to 20% of healthy individuals, especially the elderly. Only around 5% of the healthy population have ANA titres of 1:160 or higher.
Single workplaces may have multiple unions, and in such cases an employer may apply to the FWC for an order that bargaining representatives meet to elect one to represent all of them if "the bargaining process is not proceeding efficiently or fairly because there are multiple bargaining representatives for the agreement."
Sources: en.wikipedia.org
No metal-adapted endemic taxa have been documented so far. There is, however, evidence for community shifts associated with heavy metals, with lower diversity associated with contaminated sites. On the other hand, soils naturally rich in heavy metals, such as serpentine soils, do not seem to affect the diversity of ectomycorrhizal fungal communities.
A quantity may decay via two or more different processes simultaneously. In general, these processes (often called "decay modes", "decay channels", "decay routes" etc.) have different probabilities of occurring, and thus occur at different rates with different half-lives, in parallel. The total decay rate of the quantity N is given by the sum of the decay routes; thus, in the case of two processes:
The endocrine reproductive system consists of the hypothalamus, the pituitary, the gonads, and the adrenal glands, with input and regulation from many other body systems. True puberty is often termed "central puberty" because it begins as a process of the central nervous system. A simple description of hormonal puberty is as follows:
== Use == Chipotles impart a relatively mild but earthy spiciness to many dishes in Mexican cuisine. The chilis are used to make various salsas. Chipotle can be ground and combined with other spices to make a meat marinade – adobo. Chipotle is used, typically in powdered form, as an ingredient in homemade and commercial products, including some brands of barbecue sauce and hot sauce, as well as in some chili con carnes and stews. Usually, when used commercially, the product is advertised as having chipotle in it. Chipotles are spicy and have a distinctive smoky flavor. The flesh is thick, so the chilis are usually used in a slow-cooked dish rather than raw. They can also be lightly toasted on a dry comal or skillet until they are fragrant and slightly swell. When overcooked, they can be bitter. For some traditional Mexican sauces, the toasted chilis would be sautéed in oil or lard before being pureed. The chilis can also be soaked in warm water or stock until they become pliable and then can be added to a dish. The different forms of chipotle can be added to soups, stews, and in the braising liquid for meat. They can also accompany beans, pickled vegetable mixes, scrambled eggs, or chilaquiles. They can also be stuffed, baked, and added to cake or brownies. Nutritional value
Sources: en.wikipedia.org
A sealed container kept at room temperature and away from moisture is typical. Heat and humidity promote conversion to creatinine and can reduce assay values. Long-term storage under dry conditions helps maintain the original crystalline form.
Creatinine is a degradation product formed when creatine loses water and cyclizes. It can appear during storage, processing, or analysis if conditions are harsh. Quality specifications often set a maximum limit for creatinine to control purity.
No universal testing protocol applies across all markets. Some products follow pharmacopeial monographs, while others rely on manufacturer specifications and third-party certificates. Common tests include assay, water content, heavy metals, and microbial limits.
It is a crystalline form of creatine that contains one water molecule per creatine molecule. The compound occurs naturally in muscle tissue and is also produced synthetically for research and consumer products. The monohydrate label describes the solid's hydration state.