Everything below concerns HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Analytical laboratories commonly identify creatine monohydrate by high-performance liquid chromatography with ultraviolet detection, often after dissolving the sample in water or dilute acid. Ion-exchange or reversed-phase columns separate creatine from creatinine and related guanidino compounds. Nitrogen content can be checked by Kjeldahl or combustion methods, while moisture is measured by Karl Fischer titration or loss on drying. These techniques give complementary views: chromatographic purity addresses related substances, whereas moisture and elemental data confirm hydrate stoichiometry. No single test defines quality by itself; a combination is used in specifications.
| 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 |
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.
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.
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.
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.
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.
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.
== Uses == Irradiation is used to reduce or eliminate pests and the risk of food-borne illnesses as well as prevent or slow spoilage and plant maturation or sprouting. Depending on the dose, some or all of the organisms, microorganisms, bacteria, and viruses present are destroyed, slowed, or rendered incapable of reproduction. When targeting bacteria, most foods are irradiated to significantly reduce the number of active microbes, not to sterilize all microbes in the product. Irradiation cannot return spoiled or over-ripe food to a fresh state. If this food was processed by irradiation, further spoilage would cease and ripening would slow, yet the irradiation would not destroy the toxins or repair the texture, color, or taste of the food. Irradiation slows the speed at which enzymes change the food. By reducing or removing spoilage organisms and slowing ripening and sprouting (e.g. potato, onion, and garlic) irradiation is used to reduce the amount of food that goes bad between harvest and final use. Shelf-stable products are created by irradiating foods in sealed packages, as irradiation reduces chance of spoilage, the packaging prevents re-contamination of the final product. Foods that can tolerate the higher doses of radiation required to do so can be sterilized. This is useful for people at high risk of infection in hospitals as well as situations where proper food storage is not feasible, such as rations for astronauts.
== Manufacture == Banana powder is formed by using banana pulp, which is mechanically chopped and then processed with hydraulic shear using a colloid mill, turning it into a paste. Sodium metabisulfite is then used to brighten the yellow color of the paste. The paste is then dried by either spray- or drum-drying, although the latter is more common, because none of the paste is lost while drying. Drum-drying also produces about 2% more powder and dries it more thoroughly. Regardless of the drying process, banana powder can generally only stay fresh on the shelf for about a year.
DszB, the final enzyme in the pathway, is also one of the slowest with a turnover rate of 1.7 ± 0.2 min−1, becoming a major bottleneck of the 4S pathway. A computational rational design approach determined a set of mutations that could accelerate the charge transfer occurring in the active site during DszB reaction mechanism, reducing the activation energy for the reaction and potentially increasing its turnover rate. DszB's catalytic efficiency and thermostability was also addressed in an experimental mutagenesis approach, the Y63F/Q65H double mutant revealed an increase in the enzyme's thermostability without loss of catalytic efficiency. DszD has also been targeted for rate enhancing mutation on the Thr62 residue. Mutation of Thr62 by Asn and Ala residues managed to increase its activity 5- and 7-fold, respectively. A computational study demonstrated that substitutions in position 62 of DszD sequence have a major impact in the activation energy for the hydride transfer reaction from NADH to FAD. The Thr62 mutation by an Asp residue returns the lowest activation energy from all possible mutants at this position due to the stabilization effect induced by Asp negative charge.
== Steps of cap snatching == Cap-snatching occurs in three general steps: 1) The viral RdRp or N protein binds to the host mRNA 5'-methylated cap-1 or cap-2 structure. 2) Viral endonuclease cleaves mRNA several nucleotides downstream of the cap. 3) Capped RNA utilized as a primer to initiate viral mRNA synthesis carried out by the RdRp.
=== Antimicrobial peptides === As an arthropod, S. mutilans has no acquired immune system, which leads to the development of numerous antimicrobial peptides in its innate immune system. An antimicrobial peptide named scolopendrasin VII was discovered in S. mutilans . The peptide stimulates actin polymerization; the subsequent chemotactic migration of macrophages was also stimulated by this peptide through activating ERK (extracellular signal-regulated kinases) and protein kinase B (Akt) activity. Scolopendrasin VII was also found to stimulate chemotactic migration of FPR1-transfected RBL-2H3 cells (mast cells), and directly binds to FPR1. Scolopin 1 and 2 are antimicrobial peptides identified from the venom of S. mutilans. These peptides were identified by Sephadex gel filtration and RP-high-performance liquid chromatography. Both scolopin 1 and 2 were reported to show intense antimicrobial activities, which includes both Gram-positive and Gram-negative bacteria and fungi. It was also reported to have moderate haemolytic effects on human and rabbit red blood cells. Scolopin 1 holds the potential as an antimicrobial agent. Scolopin 2 was found able to inhibit HeLa cell proliferation in cancer research; it was also found to combine with mitochondria, which allows it to regulate apoptosis in pathways in HeLa cells. Scolopin 2 is able to significantly suppress tumour growth in mice trials without causing any side effects. It was hence considered a strong candidate for HeLa cervical cancer treatment.
Sources: en.wikipedia.org
Ion Torrent Systems Inc. (now owned by Life Technologies) developed a system based on using standard sequencing chemistry, but with a novel, semiconductor-based detection system. This method of sequencing is based on the detection of hydrogen ions that are released during the polymerisation of DNA, as opposed to the optical methods used in other sequencing systems. A microwell containing a template DNA strand to be sequenced is flooded with a single type of nucleotide. If the introduced nucleotide is complementary to the leading template nucleotide it is incorporated into the growing complementary strand. This causes the release of a hydrogen ion that triggers a hypersensitive ion sensor, which indicates that a reaction has occurred. If homopolymer repeats are present in the template sequence, multiple nucleotides will be incorporated in a single cycle. This leads to a corresponding number of released hydrogens and a proportionally higher electronic signal.
Following the sale of lots, Knoxville's leaders set about constructing a courthouse and jail. A garrison of federal soldiers, under the command of David Henley, erected a blockhouse in Knoxville in 1792. The Cowan brothers, Nathaniel and Samuel, opened the city's first general store in August 1792, and John Chisholm's tavern was in operation by December 1792. The city's first newspaper, the Knoxville Gazette, was established by George Roulstone in November 1791. In 1794, Blount College, the forerunner of the University of Tennessee, was chartered, with Samuel Carrick as its first president. Carrick also established the city's first church, the First Presbyterian Church, though a building wasn't constructed until 1816.
=== Oily skin === Healthy sebaceous glands produce a substance called sebum, a naturally healthy skin lubricant. When the skin produces excessive sebum, it becomes heavy and thick in texture, known as oily skin. Oily skin is typified by shininess, blemishes and pimples. The oily-skin type is not necessarily bad, since such skin is less prone to wrinkling, or other signs of ageing, because the oil helps to keep needed moisture locked into the epidermis (outermost layer of skin). The negative aspect of the oily-skin type is that oily complexions are especially susceptible to clogged pores, blackheads, and buildup of dead skin cells on the surface of the skin. Oily skin can be sallow and rough in texture and tends to have large, clearly visible pores everywhere, except around the eyes and neck. A high glycemic-index diet and dairy products (except for cheese) consumption increase IGF-1 generation, which in turn increases sebum production. Overwashing the skin does not cause sebum overproduction but may cause dryness; it is possible to have skin that is both dry and oily.
India will allow foreign groups to own up to 51 per cent in "multi-brand retailers", as supermarkets are known in India, in the most radical pro-liberalisation reform passed by an Indian cabinet in years; single brand retailers, such as Apple and Ikea, can own 100 percent of their Indian stores, up from the previous cap of 51 percent; both multi-brand and single brand stores in India will have to source nearly a third of their goods from small and medium-sized Indian suppliers; all multi-brand and single brand stores in India must confine their operations to 53-odd cities with a population over one million, out of some 7935 towns and cities in India. It is expected that these stores will now have full access to over 200 million urban consumers in India; multi-brand retailers must have a minimum investment of US$100 million with at least half of the amount invested in back end infrastructure, including cold chains, refrigeration, transportation, packing, sorting and processing to considerably reduce the post harvest losses and bring remunerative prices to farmers; the opening of retail competition will be within India's federal structure of government. In other words, the policy is an enabling legal framework for India. The states of India have the prerogative to accept it and implement it, or they can decide to not implement it if they so choose. Actual implementation of policy will be within the parameters of state laws and regulations. The opening of retail industry to global competition is expected to spur a retail rush to India.
==== Maya Belizeans ==== The Maya are thought to have been in the Yucatán region and thus in Belize since the second millennium BCE. Classical Maya culture collapsed between the 7th and 9th centuries CE which left vast areas of Belize without population. Many Mayas also died in internal conflict and several hundred years later by catching disease from invading Europeans. Three Maya groups inhabit the country:
Sources: en.wikipedia.org
=== Senses === As with other varanids, Komodo dragons have only a single ear bone, the stapes, for transferring vibrations from the tympanic membrane to the cochlea. This arrangement means they are likely restricted to sounds in the 400 to 2,000 hertz range, compared to humans who hear between 20 and 20,000 hertz. They were formerly thought to be deaf when a study reported no agitation in wild Komodo dragons in response to whispers, raised voices, or shouts. This was disputed when London Zoo employee Joan Procter trained a captive specimen to come out to feed at the sound of her voice, even when she could not be seen.
Dehydrogenases oxidize a substrate by transferring hydrogen to an electron acceptor, common electron acceptors being NAD+ or FAD. This would be considered an oxidation of the substrate, in which the substrate either loses hydrogen atoms or gains an oxygen atom (from water). The name "dehydrogenase" is based on the idea that it facilitates the removal (de-) of hydrogen (-hydrogen-) and is an enzyme (-ase). Dehydrogenase reactions come most commonly in two forms: the transfer of a hydride and release of a proton (often with water as a second reactant), and the transfer of two hydrogens.
=== Pesticide === Streptomycin is also used as a pesticide, to combat the growth of bacteria. Streptomycin controls bacterial diseases of certain fruit, vegetables, seed, and ornamental crops. A major use is in the control of fireblight on apple and pear trees. As in medical applications, extensive use can be associated with the development of resistant strains. Streptomycin could potentially be used to control cyanobacterial blooms in ornamental ponds and aquaria. While some antibacterial antibiotics are inhibitory to certain eukaryotes, this seems not to be the case for streptomycin, especially in the case of anti-fungal activity.
=== Hydraulics === Liquid is the primary component of hydraulic systems, which take advantage of Pascal's law to provide fluid power. Devices such as pumps and waterwheels have been used to change liquid motion into mechanical work since ancient times. Oils are forced through hydraulic pumps, which transmit this force to hydraulic cylinders. Hydraulics can be found in many applications, such as automotive brakes and transmissions, heavy equipment, and airplane control systems. Various hydraulic presses are used extensively in repair and manufacturing, for lifting, pressing, clamping and forming.
The amorphous regions contribute elasticity and the crystalline regions contribute strength and rigidity. More complex polymers such as proteins, with various interacting chemical groups attached to their backbones, self-assemble into well-defined structures. But segments of proteins, and polypeptides that lack secondary structure, are often assumed to exhibit a random-coil conformation in which the only fixed relationship is the joining of adjacent amino acid residues by a peptide bond. This is not actually the case, since the ensemble will be energy weighted due to interactions between amino acid side-chains, with lower-energy conformations being present more frequently. In addition, even arbitrary sequences of amino acids tend to exhibit some hydrogen bonding and secondary structure. For this reason, the term "statistical coil" is occasionally preferred. The conformational entropy of the random-coil stabilizes the unfolded protein state and represents main free energy contribution that opposes to protein folding.
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.
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.