If you have been reading about zwitterion 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 2026-03-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
Manufacturing processes can leave trace amounts of dicyandiamide, creatinine, or residual solvents, depending on the synthetic route and purification steps. Heavy metals, arsenic, and microbial contamination are also monitored for food or pharmaceutical grades. Particle size distribution can affect dissolution behavior and blending uniformity, so it may be specified for certain applications. Analytical results are reported on a dry basis or as-is basis, and the difference matters when comparing certificates of analysis. Open questions remain about how minor impurities influence long-term stability under varied storage conditions.
Stability studies typically examine the effects of temperature, humidity, and light on creatine monohydrate. Sealed containers stored in cool, dry conditions help limit moisture uptake and hydrolysis. Elevated temperature and high relative humidity can accelerate conversion to creatinine, especially in aqueous solutions. In solid dosage forms, excipients and processing steps may also affect stability. Published stability data are not fully consistent across studies because test conditions and analytical methods vary.
Quality control of creatine monohydrate relies on a combination of identity, purity, and moisture tests. High-performance liquid chromatography with ultraviolet detection is widely used to separate creatine from creatinine and other related nitrogenous compounds. Spectroscopic methods such as infrared and nuclear magnetic resonance provide structural confirmation. Because the material is a hydrate, water content is measured separately, often by Karl Fischer titration. These tests together establish whether a lot meets a defined specification.
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.
Identity and purity are commonly assessed by high-performance liquid chromatography, often with ultraviolet detection, and by spectroscopic techniques such as infrared or nuclear magnetic resonance. These methods can distinguish creatine from creatinine and detect related impurities. Moisture content may be measured by Karl Fischer titration or loss on drying. Particle size, bulk density, and heavy metal limits are additional quality parameters. Not every product is tested by every method, so specifications depend on the intended use and regulatory framework.
| Property | Value | Notes |
|---|---|---|
| Assay method | HPLC with UV detection | Commonly used for content and purity |
| Water content | Karl Fischer titration | Measures total water including hydration |
| Identity test | FTIR or NMR spectroscopy | Confirms chemical structure |
| Common impurities | Dicyandiamide, creatinine | Process-related or degradation markers |
| Storage condition | Dry, sealed, 15–25 °C | Protect from moisture and heat |
In aqueous solution, creatine monohydrate undergoes a slow conversion to creatinine, a cyclized degradation product. This reaction is pH- and temperature-dependent, and it proceeds faster in warm or alkaline conditions. Because the conversion is gradual, analytical measurements of creatine in solution must account for time and storage history. The equilibrium favors creatinine more strongly at higher temperatures, which is relevant to sample handling in laboratories and to beverage formulations. Refrigeration slows but does not entirely stop this process.
Quality assessment of creatine monohydrate typically uses high-performance liquid chromatography to separate creatine from creatinine and other impurities. Other methods include nuclear magnetic resonance spectroscopy, titration, and infrared spectroscopy for identity confirmation. Purity is often reported as a percentage of the labeled compound on a dry basis, while moisture content is measured separately. Because different analytical methods have different selectivity, comparing purity values across sources requires attention to the method and sample preparation.
In dry solid form, creatine monohydrate is relatively stable when protected from moisture and heat. The crystal lattice includes water, and exposure to high humidity can cause caking or gradual changes in powder flow. Elevated temperatures may accelerate decomposition, particularly if moisture is present. Studies generally report that sealed, dry material retains acceptable purity for extended periods, although exact shelf life depends on packaging and storage conditions. Light exposure is not usually considered a major factor for this compound.
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.
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.
Mankiewicz (1942), television and film writer; Academy Award nominee for I Want to Live! Steve Krantz (1943), screenwriter and film producer, Fritz the Cat Ernest Kinoy (1947), television writer of Murrow, Roots, and Victory at Entebbe Merrill Brockway (1948), Emmy Award-winning television producer Saul Turteltaub (1954), Emmy Award-nominated television writer and producer William Kronick (1955), film and television writer, director and producer Stephen Schenkel (1956), TV producer, All My Children Milton Moses Ginsberg (1957), director, Coming Apart Doran William Cannon (1959), screenwriter of Skidoo and Brewster McCloud Richard Pearlman (1959), former director of the Washington National Opera as well as the training program at the Lyric Opera of Chicago Terrence McNally (1960), Tony Award-winning playwright; author of Kiss of the Spider Woman and Ragtime Michael Kahn (1961), artistic director of the Shakespeare Theatre Company in Washington, D.C. Brian De Palma (1962), director of Scarface, The Untouchables and Carrie Crawford Kilian (1962), Canadian novelist and professor at Capilano University Thomas H.
cellular immunity Also cell-mediated immunity. A class of immune response that does not rely on the production of antibodies but rather the activation of specific cell types such as phagocytes or cytotoxic T-lymphocytes, or the secretion of various cytokines from cells, in response to an antigen.
In France, the French Section of the Workers' International (SFIO) was pulled between right-wing factions promoting a more top-down planned economy (Neosocialism, Nonconformism and left-wing factions urging more revolutionary solutions (Bataille socialiste and Marceau Pivert's Gauche révolutionnaire). The party entered into [[Cartel des Gauches|alliance]] with groups to its right, who formed a coalition government in 1932. In Canada, the Co-operative Commonwealth Federation (CCF) was founded in 1932 as an agrarian socialist party. Its first platform was the Regina Manifesto, adopted in 1930. The CCF gained popularity among industrial workers throughout the 1930s. In 1944, the Saskatchewan wing of the party formed the first Socialist government in a Canadian province and stayed in power until 1964.
Sources: en.wikipedia.org
=== Splitting monolayer carbon allotropes === Graphene can be created by opening carbon nanotubes by cutting or etching. In one such method, multi-walled carbon nanotubes were cut open in solution by action of potassium permanganate and sulfuric acid. In 2014, carbon nanotube-reinforced graphene was made via spin coating and annealing functionalized carbon nanotubes. Another approach sprays buckyballs at supersonic speeds onto a substrate. The balls cracked open upon impact, and the resulting unzipped cages then bond together to form a graphene film.
=== Coronary heart disease risk === Arterial damage results from white blood cell invasion and inflammation within the wall. CRP is a general marker for inflammation and infection, so it can be used as a very rough proxy for heart disease risk. Since many things can cause elevated CRP, this is not a very specific prognostic indicator. Nevertheless, a level above 2.4 mg/L has been associated with a doubled risk of a coronary event compared to levels below 1 mg/L; however, the study group in this case consisted of patients who had been diagnosed with unstable angina pectoris; whether elevated CRP has any predictive value of acute coronary events in the general population of all age ranges remains unclear. Currently, C-reactive protein is not recommended as a cardiovascular disease screening test for average-risk adults without symptoms. The American Heart Association and U.S. Centers for Disease Control and Prevention have defined risk groups as follows:
The history of biochemistry can be said to have started with the ancient Greeks who were interested in the composition and processes of life, although biochemistry as a specific scientific discipline has its beginning around the early 19th century. Some argued that the beginning of biochemistry may have been the discovery of the first enzyme, diastase (today called amylase), in 1833 by Anselme Payen, while others considered Eduard Buchner's first demonstration of a complex biochemical process alcoholic fermentation in cell-free extracts to be the birth of biochemistry. Some might also point to the influential work of Justus von Liebig from 1842, Animal chemistry, or, Organic chemistry in its applications to physiology and pathology, which presented a chemical theory of metabolism, or even earlier to the 18th century studies on fermentation and respiration by Antoine Lavoisier. The term biochemistry itself is derived from the combining form bio-, meaning 'life', and chemistry. The word is first recorded in English in 1848, while in 1877, Felix Hoppe-Seyler used the term (Biochemie in German) in the foreword to the first issue of Zeitschrift für Physiologische Chemie (Journal of Physiological Chemistry) as a synonym for physiological chemistry and argued for the setting up of institutes dedicate to its studies. Nevertheless, several sources cite German chemist Carl Neuberg as having coined the term for the new discipline in 1903, and some credit it to Franz Hofmeister.
=== Common fundamentals === In any form of chromatography, the rate at which the solute moves down the column is a direct reflection of the percentage of time the solute spends in the mobile phase. To achieve separation in either elution or displacement chromatography, there must be appreciable differences in the affinity of the respective solutes for the stationary phase. Both methods rely on movement down the column to amplify the effect of small differences in distribution between the two phases. Distribution between the mobile and stationary phases is described by the binding isotherm, a plot of solute bound to (or partitioned into) the stationary phase as a function of concentration in the mobile phase. The isotherm is often linear, or approximately so, at low concentrations, but commonly curves (concave-downward) at higher concentrations as the stationary phase becomes saturated.
Sources: en.wikipedia.org
=== May === May 31, 2010: Canada Canadian factories hummed, consumers bought more houses, governments spent more money, prices increased and the economy posted its best quarter of growth in more than 10 years. The Canadian economy expanded at an annualized rate of 6.1% in the first quarter, surpassing analyst expectations and marking the best growth rate since 1999. Economists had expected annualized GDP growth of 5.9% in the last quarter, up from 5% in last year's fourth quarter. The growth in the first quarter is the third straight quarter of economic expansion in Canada, coming on the heels of three consecutive quarters of contraction. March growth came in at 0.6%, ahead of the 0.5% estimate.
== Academic fields == Critical legal studies, school of legal philosophy Constrained least square statistical estimator CLs method to set bounds on particle physics model parameters The .cls file extension, used to hold LaTeX manuscripts - see LaTeX § Compatibility and converters
== Symptoms == Soon after its discovery, scientists injected phalloidin into mice and discovered its LD50 is 2 mg/kg via IP injection. When exposed to the minimum lethal dose, it took several days for these mice to die. The only apparent side effect of phalloidin poisoning is extreme hunger. This is because phalloidin is only taken up by the liver via bile salt membrane transport proteins. Once inside the liver, phalloidin binds F-actin, preventing its depolymerization. It takes time for this process to destroy the liver cells. The kidneys can also take up phalloidin, but not as effectively as the liver. Here, phalloidin causes nephrosis.
The Bradford assay, a colorimetric protein assay, is based on an absorbance shift of the dye Coomassie brilliant blue G-250. The Coomassie brilliant blue G-250 dye exists in three forms: anionic (blue), neutral (green), and cationic (red). Under acidic conditions, the dye is red; when it is deprotonated, the red form of the dye is converted into its blue form, which can bind to the protein being assayed. If there is no protein present, then the solution will remain brown. Dye-protein interactions are driven by electrostatic interactions between positively charged arginine (and to a lesser extent, lysine and histidine) and the deprotonated negatively charged sulfonate groups on the dye, as well as hydrophobic interactions with the aromatic amino acids (tryptophan, tyrosine, phenylalanine). Binding of the dye to the protein stabilizes the anionic form of the dye, which can be detected colorimetrically by a shift from 465 nm to 595 nm. The cationic (unbound) form is red and has an absorption spectrum maximum at 465 nm, whereas the anionic bound form has an absorption spectrum maximum at 595 nm. The increase of absorbance at 595 nm is proportional to the amount of bound dye, and thus to the amount (concentration) of protein present in the sample. Unlike other protein assays, the Bradford protein assay is less susceptible to interference by various chemical compounds such as sodium, potassium or even carbohydrates like sucrose, that may be present in protein samples. An exception of note is elevated concentrations of detergent.
Damage-associated molecular patterns (DAMPs) are molecules within cells that are a component of the innate immune response released from damaged or dying cells due to trauma or an infection by a pathogen. They are also known as danger signals, and alarmins because they serve as warning signs to alert the organism to any damage or infection to its cells. DAMPs are endogenous danger signals that are discharged to the extracellular space in response to damage to the cell from mechanical trauma or a pathogen. Once a DAMP is released from the cell, it promotes a noninfectious inflammatory response by binding to a pattern recognition receptor (PRR). Inflammation is a key aspect of the innate immune response; it is used to help mitigate future damage to the organism by removing harmful invaders from the affected area and start the healing process. As an example, the cytokine IL-1α is a DAMP that originates within the nucleus of the cell which, once released to the extracellular space, binds to the PRR IL-1R, which in turn initiates an inflammatory response to the trauma or pathogen that initiated the release of IL-1α. In contrast to the noninfectious inflammatory response produced by DAMPs, pathogen-associated molecular patterns (PAMPs) initiate and perpetuate the infectious pathogen-induced inflammatory response. Many DAMPs are nuclear or cytosolic proteins with defined intracellular function that are released outside the cell following tissue injury.
Sources: en.wikipedia.org
Purity is commonly assessed by HPLC, which separates creatine from related compounds such as creatinine. Water content is measured separately by Karl Fischer titration. Together these results help calculate the actual creatine content in a sample.
Creatine monohydrate contains water as part of its crystal structure, so some water is expected. Excess moisture can promote clumping, hydrolysis, or microbial growth. Karl Fischer titration measures total water and helps distinguish expected hydration from residual moisture.
Dicyandiamide, creatinine, and related nitrogenous compounds are common markers. Their levels are controlled by manufacturing processes and product specifications. Heavy metals and microbial limits may also be tested depending on the intended grade.
Solid product can remain within specification for years when stored dry and sealed, but expiration dates reflect manufacturer testing and regulatory conventions. Moisture and heat increase conversion to creatinine, so storage conditions matter more than the printed date alone. Degradation is gradual and can be monitored by purity testing.