This is a working overview of HPLC-UV, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-05-13. Anything still debated is marked as such rather than presented as settled.
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.
Analytical methods for creatine monohydrate focus on identity, purity, and degradation products. High-performance liquid chromatography with ultraviolet detection is common, often at a wavelength near 210 nanometers. Titration and nuclear magnetic resonance spectroscopy can also quantify the parent compound. Pharmacopeial monographs specify tests for appearance, solubility, water content, and related substances, including creatinine. Purity values above 99 percent are typical for pharmaceutical-grade material, though supplement-grade products vary. Independent verification can detect label discrepancies.
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 the body, creatine is synthesized from the amino acids arginine, glycine, and methionine, primarily in the liver and kidneys. It is transported to muscle and other tissues, where it is phosphorylated to phosphocreatine by creatine kinase. This phosphagen system provides a rapid source of adenosine triphosphate during short, intense contractions. Dietary creatine comes mainly from meat and fish, and the body's total pool is influenced by both synthesis and intake.
As a supplement, creatine monohydrate is studied for its effects on muscle performance and recovery. The compound is often described as an ergogenic aid, meaning it may support physical work capacity. Research typically compares it with placebo or other forms, such as citrate or nitrate, under controlled conditions. Questions remain about the optimal dose and long-term effects in different populations, and findings are not uniform across all studies. The monohydrate form remains the most extensively tested.
Creatine monohydrate is a crystalline compound formed from creatine and one molecule of water. Its systematic name is N-(aminoiminomethyl)-N-methylglycine monohydrate, and it appears as a white, odorless powder with limited solubility in water. The monohydrate is the most common solid form used in research and commercial products because it is stable under dry conditions. The anhydrous form lacks the water of crystallization and differs slightly in molar mass. Both forms participate in the same biochemical reactions once dissolved.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | 15–25 °C | Cool, dry, away from moisture |
| Relative humidity | < 50% | High humidity promotes degradation |
| Primary degradation product | Creatinine | Formed via cyclization, especially in solution |
| Common analytical method | HPLC-UV | Often at 210 nm; also titration or NMR |
| Shelf life (solid) | 2–3 years | When kept sealed and dry; varies by manufacturer |
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.
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.
Stability studies examine how creatine monohydrate changes under controlled temperature and humidity. The solid is generally stable when kept dry, but moisture can promote hydrolysis to creatinine, especially in solution or at elevated temperatures. Color, odor, and assay values are monitored over time to detect degradation. Because degradation pathways depend on storage conditions, shelf-life claims should specify the tested packaging, temperature, and humidity. Open questions remain about the long-term behavior of different crystal habits and particle sizes.
Regulatory treatment of creatine monohydrate varies by country and intended use. In some jurisdictions it is sold as a dietary supplement, while in others it may be treated as a food ingredient or a pharmaceutical raw material. Pharmacopeial monographs, where available, define identification, assay limits, and impurity thresholds. Manufacturers often follow these monographs or internal specifications to ensure batch-to-batch consistency. Analytical method validation is important because different methods can yield different apparent purity values if sample preparation or detection conditions are not controlled.
Quality control for creatine monohydrate begins with identity confirmation and assay determination. Laboratories commonly use high-performance liquid chromatography with ultraviolet detection, often after derivatization or using a suitable column, to quantify creatine. Karl Fischer titration measures water content, which helps verify the monohydrate stoichiometry. Additional tests screen for heavy metals, residual solvents, and microbial contamination depending on the intended use. These tests establish composition and purity rather than biological effect.
== Discovery and development == Tralokinumab was discovered by Cambridge Antibody Technology scientists using protein optimization based on Ribosome Display. They used the extensive data sets from ribosome display to patent protect CAT-354 in a world-first of sequence-activity-relationship claims. In 2004, clinical development of CAT-354 was initiated with this first study completing in 2005. On 21 July 2011, MedImmune LLC initiated a Phase IIb, randomized, double-blind study to evaluate the efficacy of tralokinumab in adults with asthma. In 2016, MedImmune and AstraZeneca started developing tralokinumab for asthma (Phase III) and atopic dermatitis (Phase IIb) while clinical development for moderate-to-severe ulcerative colitis and idiopathic pulmonary fibrosis (IPF) have been discontinued. In July of that year AstraZeneca licensed tralokinumab to Leo Pharma for skin diseases. A phase IIb study of tralokinumab found that treatment was associated with early and sustained improvements in atopic dermatitis symptoms and tralokinumab had an acceptable safety and tolerability profile, thereby providing evidence for targeting IL-13 in patients with atopic dermatitis. In June 2017, Leo Pharma started phase III clinical trials with tralokinumab in atopic dermatitis.
=== Mitral stenosis === Patients with mitral stenosis may present with heart failure symptoms, such as dyspnea on exertion, orthopnea and paroxysmal nocturnal dyspnea, palpitations, chest pain, hemoptysis, thromboembolism, or ascites and edema (if right-sided heart failure develops). Symptoms of mitral stenosis increase with exercise and pregnancy On auscultation of a patient with mitral stenosis, typically the most prominent sign is a loud S1. Another finding is an opening snap followed by a low-pitched diastolic rumble with presystolic accentuation. The opening snap follows closer to the S2 heart tone with worsening stenosis. The murmur is heard best with the bell of the stethoscope lying on the left side and its duration increases with worsening disease. Advanced disease may present with signs of right-sided heart failure such as parasternal heave, jugular venous distension, hepatomegaly, ascites and/or pulmonary hypertension (presenting with a loud P2). Signs increase with exercise and pregnancy.
== Sponsorship == In April 2022, the team announced their sponsorship with car retailer Cazoo starting in July 2022. The Cazoo brand is visible on the front of the new jerseys as the team's main sponsor. In addition to the Bundesliga professionals, Cazoo appeared as shirt sponsor and advertising partner of the second team of SC Freiburg in the third division and as co-sponsor of the Freiburg Football School, and became visible at all matches of the SC junior teams. Cazoo also became a co-sponsor and sleeve sponsor of SC Freiburg's Bundesliga women.
The benzene rings in indigo can be modified to give a variety of related dyestuffs. Thioindigo, where the two NH groups are replaced by S atoms, is deep red. Tyrian purple is a dull purple dye that is secreted by a common Mediterranean snail. It was highly prized in antiquity. In 1909, its structure was shown to be 6,6'-dibromoindigo (red). 6-bromoindigo (purple) is a component as well. It has never been produced on a commercial basis. The related Ciba blue (5,7,5',7'-tetrabromoindigo) is, however, of commercial value. Indigo and its derivatives featuring intra- and intermolecular hydrogen bonding have very low solubility in organic solvents. They can be made soluble using transient protecting groups such as the tBOC group, which suppresses intermolecular bonding. Heating of the tBOC indigo results in efficient thermal deprotection and regeneration of the parent H-bonded pigment. Treatment with sulfuric acid converts indigo into a blue-green derivative called indigo carmine (sulfonated indigo). It became available in the mid-18th century. It is used as a colorant for food, pharmaceuticals, and cosmetics as FD&C Blue No. 2.
Sources: en.wikipedia.org
In August 2019, BASF agreed to sell its global pigments business to Japanese fine chemical company DIC for €1.15 billion ($1.28 billion) on a cash and debt-free basis. In September 2019, BASF signed an agreement with DuPont Safety & Construction, a subsidiary business unit of DuPont, to sell its ultrafiltration membrane business, Inge GmbH. According to BASF executives, Inge GmbH and its products fit better with DuPont and their business strategy. In February 2023, BASF announced that the company is planning to close one of its two ammonia factories at its site in Ludwigshafen, this comes as part of the companies plans to cut costs as the organisation has struggled with high energy costs. The result of the organisations plans will lead to increased production in China while resulting in the loss of 2,600 jobs. The Zhanjiang plant extends over 400 hectares and serves mainly the electronic industry and the automotive industry. In September 2023 BASF broke ground on its Zhanjiang syngas plant; the plant was due to be commissioned by 2025. In November 2023 the firm closed a $5bn 15-year investment deal in China, with Chinese banks. As of April 2023, BASF had 30 production facilities in China. CEO Martin Brudermüller held that Chinese revenue is essential to grow his European business in the face of "Europe’s high energy costs and stringent environmental rules."
Principal cells: columnar cells that, with the basal cells, form the majority of the epithelium. In the caput (head) region, these cells have long stereocilia that are tuft-like extensions that project into the lumen. The stereocilia are much shorter in the cauda (tail) segment. They also secrete carnitine, sialic acid, glycoproteins, and glycerylphosphorylcholine into the lumen. Basal cells: shorter, pyramid-shaped cells, which contact the basal lamina but taper off before their apical surfaces reach the lumen. These are thought to be undifferentiated precursors of principal cells. Apical cells: predominantly found in the head region Clear cells: predominant in the tail region Intraepithelial lymphocytes: distributed throughout the tissue. Intraepithelial macrophages
=== Laboratory solvent === It is a common solvent for the Grignard reaction in addition to other reactions involving organometallic reagents. These uses exploit its basicity. Diethyl ether is a popular non-polar solvent in liquid-liquid extraction. As an extractant, it is immiscible with and less dense than water. Although immiscible, it has significant solubility in water (6.05 g/(100 ml) at 25 °C) and dissolves 1.5 g/(100 g) (1.0 g/(100 ml)) water at 25 °C.
Sources: en.wikipedia.org
==== Breast cancer ==== The comparison of forward and backward SHG images gives insight about the microstructure of collagen, itself related to the grade and stage of a tumor, and its progression in breast. Comparison of SHG and 2PEF can also show the change of collagen orientation in tumors. Even if SHG microscopy has contributed a lot to breast cancer research, it is not yet established as a reliable technique in hospitals, or for diagnostic of this pathology in general.
=== Topical/symptomatic === Topical treatment for the skin changes of scleroderma do not alter the disease course, but may improve pain and ulceration. A range of nonsteroidal anti-inflammatory drugs, such as naproxen, can be used to ease painful symptoms. The benefit from steroids such as prednisone is limited. Episodes of Raynaud's phenomenon sometimes respond to nifedipine or other calcium channel blockers; severe digital ulceration may respond to prostacyclin analogue iloprost, and the dual endothelin-receptor antagonist bosentan may be beneficial for Raynaud's phenomenon. Skin tightness may be treated systemically with methotrexate and ciclosporin. and the skin thickness can be treated with penicillamine.
The shear strength between two collagen molecules is controlled by weak dispersive and hydrogen bond interactions and by some molecular covalent crosslinks. Slip in the system occur when these intermolecular bonds face an applied stress greater than their interaction strength. Intermolecular bonds breaking do not immediately lead to failure, in contrast they play an essential role in energy dissipation that lower the stress felt overall by the material and enable it to withstand fracture. These bonds, often hydrogen bonding and dispersive Van der Waals interactions, act as "sacrificial" bonds, existing for the purpose of lowering stress in the network. Molecular covalent crosslinks also play a key role in the formation of fibril networks. While crosslinking molecules can lead to strong structures, too much crosslinking in biopolymer networks are more likely to fracture as the network is not able to dissipate the energy, leading to a material that is strong but not tough. This is observed in dehydrated or aged collagen, explaining why with age human tissues become more brittle. Differences in structure between fibrils of different origin is typically determined by x-ray diffraction. A scanning electron microscope (SEM) can be used to observe specific details on larger fibril species such as the characteristic 67 nm bands in collagen, but often is not fine enough to determine the full structure.
== Personal life and death == French met Patricia Anne "Pat" Soule while attending Pasadena City College, and the two married in June 1950. They were married for 66 years, until her death in February 2017, and had two children. Pat worked as an acting teacher at Bellevue College and later worked with her husband on Imagination Theatre. French died in Seattle on December 20, 2017, at age 89.
Sources: en.wikipedia.org
Yes, especially when exposed to moisture or heat, where it converts to creatinine. In dry, sealed containers at room temperature, degradation is slow and the product may remain within specification for two to three years.
Common methods include high-performance liquid chromatography, titration, and nuclear magnetic resonance spectroscopy. These techniques quantify the parent compound and detect related substances such as creatinine.
Keep the powder in a tightly sealed container in a cool, dry place, ideally between 15 and 25 degrees Celsius with low humidity. Avoid storing aqueous solutions for extended periods because degradation occurs faster in solution.
It is a compound made of creatine bound to one water molecule. It appears as a white crystalline powder and is the most common solid form of creatine used in research and supplements.