A practical reference on HPLC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-21. Anything still debated is marked as such rather than presented as settled.
Storage recommendations generally emphasize a cool, dry place away from direct sunlight and strong oxidizers. Sealed containers limit humidity exchange, which helps prevent clumping and gradual conversion to creatinine. Long-term stability studies usually monitor appearance, moisture, and purity at intervals under defined temperature and humidity conditions. Accelerated tests at elevated temperature can reveal degradation pathways, but they do not perfectly predict room-temperature shelf life. Questions remain about how much creatinine formation is acceptable in different product categories and how packaging choices affect that rate over time.
Commercial creatine monohydrate is typically manufactured through chemical synthesis, often starting from sarcosine and cyanamide. The resulting material is crystallized, washed, and dried to a specified hydrate content. Finished lots are tested for identity, purity, moisture, and heavy metals before release. Because the compound can cyclize to creatinine under heat or prolonged storage in solution, manufacturers control temperature and humidity during processing. The solid itself is relatively stable when kept dry and sealed, but moisture uptake can cause caking and complicate accurate assay.
In aqueous solution, creatine monohydrate exists mainly as a zwitterion, carrying both a positive guanidinium charge and a negative carboxylate charge. This charge separation raises water solubility relative to many neutral organic solids and helps explain its behavior in analytical separations. The monohydrate can lose its water of crystallization under sustained heat or low humidity, converting toward anhydrous creatine. Such transitions matter for mass balance calculations because the hydrate contributes water mass that is not part of the active creatine molecule.
The term creatine monohydrate is often shortened to creatine in casual usage, though other creatine forms exist, including citrate, nitrate, and hydrochloride salts. These alternative forms differ in solubility, pH behavior, and the amount of creatine delivered per unit mass. Regulatory categories vary by country: some jurisdictions treat it as a food ingredient, while others place it under supplement or drug frameworks depending on claims and presentation. Standard reference texts list it as a naturally occurring nitrogenous organic acid rather than a vitamin or mineral.
Creatine monohydrate is a crystalline organic compound formed from creatine and water in a one-to-one ratio. It belongs to the guanidino family and contains a methylated guanidine group attached to an acetate-like chain. The solid is commonly described as a white, odorless powder with a mildly bitter taste. Its molecular formula is C4H11N3O3·H2O, and the hydrated form is the most widely traded grade. The compound occurs naturally in vertebrate muscle and brain tissue, where it participates in rapid energy buffering.
| Property | Value | Notes |
|---|---|---|
| Common analytical method | HPLC-UV | Separation from creatinine and related compounds. |
| Moisture content | Typically 12% theoretical | Monohydrate stoichiometry corresponds to about 12% water by mass. |
| Typical storage temperature | 15–25 °C | Cool, dry, sealed conditions limit moisture uptake. |
| Degradation marker | Creatinine | Formed by cyclization, especially in solution or with heat. |
| Solubility class | Moderately soluble in water | Solubility rises with temperature and varies with pH. |
Solid creatine monohydrate is generally stable when kept dry and protected from extremes of heat and humidity. In the presence of moisture, it can gradually convert to creatinine, a cyclic dehydration product that has little value for phosphocreatine synthesis. Elevated temperatures and acidic conditions accelerate this conversion in solution. Because the reaction is slow in cool, dry storage, typical shelf lives are measured in years rather than weeks. Packaging that limits moisture and oxygen exposure helps maintain purity.
Recommended storage usually involves a sealed container kept at room temperature, away from direct sunlight and moisture. High humidity can cause caking, which changes flow properties and may complicate accurate weighing. Repeated opening of containers exposes the powder to air and moisture, so smaller aliquots can reduce handling effects. Storage temperature ranges are not absolute requirements; they reflect conditions that slow degradation and preserve consistent physical characteristics. Clean, dry tools help prevent contamination during sampling.
In the body, creatine is synthesized from arginine, glycine, and methionine, mainly in the liver and kidneys, and is also obtained from foods such as meat and fish. About 95% of body creatine is stored in skeletal muscle, where a fraction is phosphorylated to phosphocreatine. Phosphocreatine serves as a rapid reserve of high-energy phosphate for short bursts of ATP regeneration. The monohydrate form supplies creatine after dissolution and absorption, but it is not itself the active phosphorylated species.
Creatine was first identified in skeletal muscle extracts in the nineteenth century, and its role in phosphagen energy buffering was clarified in the twentieth century. The monohydrate salt became widely studied after methods for inexpensive synthesis and crystallization were developed. Modern research examines its effects on muscle energetics, recovery, and cognitive performance under specific conditions. Findings vary with population, exercise protocol, baseline creatine status, and measurement method. Studies often compare supplementation with placebo during controlled training or testing schedules.
Creatine monohydrate is a hydrated form of creatine, a nitrogen-containing compound involved in cellular energy metabolism. Its molecular formula is C4H9N3O2·H2O, with a molar mass around 149.15 g/mol. The monohydrate is the most common solid form used in research and commercial settings because it crystallizes readily and remains stable under ordinary conditions. The term monohydrate indicates one water molecule per creatine molecule in the crystal lattice. It appears as a white crystalline powder with low odor.
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.
Quality control for creatine monohydrate typically combines identity, assay, and impurity tests. High-performance liquid chromatography with ultraviolet detection is common for separating creatine from creatinine and related substances. Nuclear magnetic resonance and infrared spectroscopy can confirm molecular structure, while titration may assess acid-base content. Moisture content, heavy metals, residual solvents, and microbial limits are checked according to applicable standards. These tests help distinguish compliant material from powders that have degraded, been diluted, or contain manufacturing residues.
=== Transport businesses === London North Eastern Railway, Britain (reporting mark: GR) Aurigny Air Services, Guernsey (IATA designator: GR) Gemini Air Cargo, Virginia, US (defunct IATA designator: GR) Goodrich Corporation, an American tire and aerospace manufacturer Toyota Gazoo Racing, a motorsports division
=== Co-evolution of rRNA and proteins === The structure of the 40S subunit revealed that the eukaryote-specific proteins (rpS7, rpS10, rpS12 and RACK1), as well as numerous eukaryote-specific extensions of proteins, are located on the solvent-exposed side of the small subunit. Here, they participate in the stabilization of rRNA expansion segments. Moreover, the beak of the 40S subunit is remodeled, as rRNA has been replaced by proteins rpS10 and rpS12. As observed for the 40S subunit, all eukaryote-specific proteins of the 60S subunit (RPL6, RPL22, RPL27, RPL28, RPL29 and RPL36) and many extensions are located at the solvent-exposed side, forming an intricate network of interactions with eukaryotic-specific RNA expansion segments. RPL6, RPL27 and RPL29 mediate contacts between the ES sets ES7–ES39, ES31–ES20–ES26 and ES9–ES12, respectively and RPL28 stabilized expansion segment ES7A.
==== Foreign policy ==== On June 12, 2017, U.S. senators agreed to legislation imposing new sanctions on Russia and Iran. The bill was opposed only by Sanders and Republican Rand Paul. He supported the sanctions on Russia, but voted against the bill because he believed the sanctions could endanger the Iran nuclear deal. In 2018, Sanders sponsored a bill and was joined by senators Chris Murphy (D–CT) and Mike Lee (R–UT) to invoke the 1973 War Powers Resolution to end US support for the Saudi-led military intervention in Yemen, which has resulted in hundreds of thousands of civilian casualties and "millions more suffering from starvation and disease". After the assassination of Jamal Khashoggi in October 2018 (which was ordered by Saudi Arabian crown prince Mohammad bin Salman, according to multiple intelligence agencies), his bill attracted bipartisan co-sponsors and support, and the Senate passed it by a vote of 56–41. The bill passed the House in February 2019 by a 247–175 vote and President Trump vetoed it in March, saying: "This resolution is an unnecessary, dangerous attempt to weaken my constitutional authorities, endangering the lives of American citizens and brave service members, both today and in the future." During the Gaza war, Sanders introduced several Joint Resolutions of Disapproval to block arms to Israel. All failed, but some Democrats voted for them. In November 2024, one such resolution garnered support from 18 senators. In April 2025, 15 senators supported another. In July 2025, 27 senators supported a resolution, a majority of Senate Democrats.
==== Season 1 ==== The following table represents viewership data for each episode's airing on The CW, as DC Universe did not release viewership information. The pilot episode was tied for the second-best series debut on The CW for the 2019–20 television season with Nancy Drew after Batwoman, and was the best summer series premiere on the network since Whose Line Is It Anyway? season nine in 2013. Through the first seven episodes of the season, Stargirl was averaging a 0.2 rating for adults 18–49 and close to 1 million initial viewers per episode, which was "on par" with The CW's Arrowverse series.
Sources: en.wikipedia.org
UR-AK49 is a drug used in scientific research which acts as a potent antagonist for the Neuropeptide Y / Pancreatic polypeptide receptor Y4, and also as a partial agonist at the histamine receptors H1 and H2. UR-AK49 is a pure antagonist at Y4 with no partial agonist effects, and although it is only slightly selective for Y4 over the related Y1 and Y5 receptors, as the first non-peptide Y4 antagonist developed UR-AK49 is expected to be useful in the study of this receptor and its role in the body.
The results were so impressive that lifters began taking more, and steroids spread to other sports. Paul Lowe, a former running back with the San Diego Chargers American football team, told a California legislative committee on drug abuse in 1970: "We had to take them [steroids] at lunchtime. He [an official] would put them on a little saucer and prescribed them for us to take them and if not he would suggest there might be a fine." Olympic statistics show the weight of shot putters increased 14 percent between 1956 and 1972, whereas steeplechasers weight increased 7.6 percent. The gold medalist pentathlete Mary Peters said: "A medical research team in the United States attempted to set up extensive research into the effects of steroids on weightlifters and throwers, only to discover that there were so few who weren't taking them that they couldn't establish any worthwhile comparisons." Brand name Dianabol is no longer produced but the drug methandrostenolone itself is still made in many countries and other, similar drugs are made elsewhere. The use of anabolic steroids is now banned by all major sporting bodies, including the ATP, WTA, ITF, International Olympic Committee, FIFA, UEFA, all major professional golf tours, the National Hockey League, Major League Baseball, the National Basketball Association, the European Athletic Association, WWE, the NFL, and the UCI. However, drug testing can be wildly inconsistent and, in some instances, has gone unenforced.
=== Attention-deficit hyperactivity disorder === One in four people who have a substance use disorder also have attention-deficit hyperactivity disorder, which makes the treatment of both conditions more difficult. ADHD is associated with an increased craving for drugs. Having ADHD makes it more likely that an individual will initiate substance misuse at a younger age than their peers. They are also more likely to experience poorer outcomes, such as longer time to remission, and to have increased psychiatric complications from substance misuse. While generally stimulant medications do not seem to worsen substance use, they are known to be non-medically used in some cases. Psychosocial therapy and/or nonstimulant medications and extended release stimulants are ADHD treatment options that reduce these risks.
Sources: en.wikipedia.org
Recent evidence has suggested that this macrophage activation may involve a phenomenon known as innate immune memory. Also known as trained immunity, innate immune memory is the innate immune system's ability, upon exposure to oxLDL or other atherogenic stimuli, to undergo epigenetic and metabolic reprogramming, leading to a hyperaugmented immune response following a secondary, non-specific restimulation. Under the microscope, the lesion now appears as a fatty streak. Foam cells eventually die and further propagate the inflammatory process. In addition to these cellular activities, there is also smooth muscle proliferation and migration from the tunica media into the intima in response to cytokines secreted by damaged endothelial cells. This leads to the formation of a fibrous capsule covering the fatty streak. Intact endothelium can prevent this smooth muscle proliferation by releasing nitric oxide.
In 63 BCE, the Roman Republic conquered the kingdom. In 37 BCE, the Romans appointed Herod the Great as king of a vassal Judea. In 6 CE, Judea was fully incorporated into the Roman Empire as the province of Judaea. During this period, the main areas of Jewish settlement in the Land of Israel were Judea, Galilee and Perea, while the Samaritans had their demographic center in Samaria. Growing dissatisfaction with Roman rule and civil disturbances eventually led to the First Jewish–Roman War (66–73 CE), resulting in the destruction of Jerusalem and its Temple, which ended the Second Temple period. This event marked a cataclysmic moment in Jewish history, prompting a reconfiguration of Jewish identity and practice to ensure continuity. The cessation of Temple worship and disappearance of Temple-based sects facilitated the rise of Rabbinic Judaism, which stemmed from the Pharisaic school of Second Temple Judaism, emphasizing communal synagogue worship and Torah study, eventually becoming the predominant expression of Judaism. Concurrently, Christianity began to diverge from Judaism, evolving into a predominantly Gentile religion. Decades later, the Bar Kokhba revolt (132–135 CE) further diminished the Jewish presence in Judea, leading to a geographical shift of Jewish life to Galilee and Babylonia, with smaller communities scattered across the Mediterranean.
Dekaranger, Ban acquires a variant of the SP License called the Fire Squad License (ファイヤースクワッドライセンス, Faiyā Sukuwaddo Raisensu), which allows him to transform Murphy K-9 into his armor to assume Battlizer Mode (バトライザーモード, Batoriza Mōdo) where he gains a rocket booster pack and a pair of siren lasers. In this form, he wields a sword/rifle hybrid, which allows him to perform the Battlize Fire Drive (バトライズファイヤードライブ, Batoraizu Faiyā Doraibu) finisher. As of the direct-to-video anniversary special Tokusou Sentai Dekaranger: 10 Years After, Ban has acquired a red-colored S.W.A.T. Mode vest to signify his membership in the Fire Squad. During the events of the direct-to-video anniversary special Tokusou Sentai Dekaranger 20th: Fireball Booster, he acquires a variant of the SP License called the SP1 License (SP1ライセンス, Esu Pī Wan Raisensu), which allows him to transform into the armored Premiere Deka Red (プレミアデカレッド, Puremia Deka Reddo). While transformed, he wields the D-Sword Vega, which allows him to perform the Boost Slash (ブーストスラッシュ, Būsuto Surasshu) finisher. Ban is portrayed by Ryuji Sainei (載寧 龍二, Sainei Ryūji).
==== Far-right politics ==== Many far right and nationalist parties in Europe, including Alternative for Germany, National Rally, Sweden Democrats, Brothers of Italy, and Reform UK were described as repulsed by Trump's threats against the sovereignty of a European country. Italian prime minister Giorgia Meloni called Trump's statements "unacceptable" and said, "friendship requires respect." Nigel Farage called Trump's threats against Greenland a "very hostile act" against Europe. According to a YouGov poll from February 2026, the crisis also led to an increase of people in Western Europe with an unfavourable opinion of the United States.
Sources: en.wikipedia.org
Laboratories typically combine chromatographic separation with moisture and elemental analysis. High-performance liquid chromatography can quantify creatine and related substances such as creatinine. Moisture methods confirm the hydrate form and help detect excess water.
The dry crystalline solid is relatively stable when protected from moisture and heat. In solution, it can convert to creatinine over time, especially at higher temperatures. Storage conditions and product form influence the rate of change.
Moisture uptake can cause particles to stick together, particularly in humid conditions or after opening a container. Clumping does not necessarily mean the creatine has degraded. It can make accurate measuring more difficult, so dry storage and sealed packaging are used.
In common usage, yes, but technically creatine monohydrate is one specific hydrated salt form. Other creatine forms exist and differ in composition and properties. The monohydrate is the most studied and most widely available grade.