If you have been reading about HPLC-UV 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 2025-12-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
Analytical laboratories commonly use high-performance liquid chromatography to separate creatine from creatinine and related impurities. Ion chromatography, nuclear magnetic resonance, and titration assays can also quantify the compound. Water content is measured by Karl Fischer titration or loss on drying, because the monohydrate has a defined theoretical water fraction. Particle size, bulk density, and flowability are physical properties that affect blending and capsule filling. These measurements support quality control and help verify that a lot matches its specification.
Regulatory status varies by country. In the United States, creatine monohydrate is sold as a dietary supplement ingredient, while in the European Union it is placed on the market as a food supplement component. Some jurisdictions have established purity monographs or permitted health claims, while others treat it as a novel food or require notification. Product labels may state the amount of creatine monohydrate or the equivalent creatine content, and the two figures can differ. Independent testing programs sometimes check identity, potency, and contaminant limits.
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 |
|---|---|---|
| Typical storage temperature | 15-25 °C | Sealed container; protect from moisture and direct heat. |
| Theoretical water content | About 12.1% | One water molecule per creatine molecule. |
| Primary degradation product | Creatinine | Formed by cyclization, especially in aqueous solution. |
| Common analytical method | HPLC-UV | Used to separate creatine from creatinine and related impurities. |
| Regulatory classification (U.S.) | Dietary supplement ingredient | Other jurisdictions may classify it as a food supplement or novel food depending on rules. |
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.
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.
== Undergraduate Research Program == The College of Science and Technology offers the CST Undergraduate Research Program (URP). Students selected to participate work with a faculty sponsor to perform research in the faculty member's lab. Students may be asked to participate in conferences, author papers or to showcase their research work in the department or at the URP Research Symposium.
=== Cancer research === There is research investigating whether high dose intravenous vitamin C administration as a co-treatment will suppress cancer stem cells, which are responsible for tumor recurrence, metastasis and chemoresistance.
Intraocular pressure can sometimes reach 80 mmHg (11 kPa). It characteristically manifests as ciliary body inflammation and massive trabecular edema that sometimes extends to Schlemm's canal. This condition is differentiated from malignant glaucoma by the presence of a deep and clear anterior chamber and a lack of aqueous misdirection. Also, the corneal appearance is not as hazy. A reduction in visual acuity can occur, followed by neuroretinal breakdown.
Black tar heroin is a form of heroin that is sticky like tar or hard like coal. Its dark color is the result of crude processing methods that leave behind impurities. Despite its name, black tar heroin can also be dark orange or dark brown in appearance. The chemical name of heroin is diacetylmorphine. Other forms of heroin require additional steps of purification post acetylation. With black tar, the product's processing stops immediately after acetylation. Its unique consistency however is due to acetylation without a reflux apparatus; as is the case with homebake heroin in Australia and New Zealand, this crude acetylation results in a gelatinous mass. Black tar as a type holds a variable admixture of morphine derivatives—predominantly 6-MAM (6-monoacetylmorphine), which is another result of crude acetylation. The lack of proper reflux during acetylation fails to remove much of the moisture retained in the acetylating agent, acetic anhydride. The acetic anhydride reacts with the moisture to produce the milder acetylating agent glacial acetic acid which is unable to acetylate the 3 position of the morphine molecule. It is harder to acetylate the 6 position without affecting the 3 position in vitro because of the conditions required for the 3 position, so 6-MAM is usually a product of opioid metabolism inside the body. Black tar heroin is often produced in Latin America, and is most commonly found in the western and southern parts of the United States, while also being occasionally found in Western Africa.
Remimazolam, sold under the brand name Byfavo, is a medication for the induction and maintenance of procedural sedation in adults for invasive diagnostic or surgical procedures lasting 30 minutes or less. It is a benzodiazepine drug, developed by PAION AG in collaboration with several regional licensees as an alternative to the short-acting imidazobenzodiazepine midazolam, for use in the induction of anesthesia and conscious sedation for minor invasive procedures. Remimazolam was found to have both a more rapid onset and a shorter duration than midazolam, and human clinical trials showed a faster recovery time and predictable, consistent pharmacokinetics, suggesting some advantages over existing drugs for these applications. The most common side effects for procedural sedation include low blood pressure, high blood pressure, diastolic hypertension, systolic hypertension, low blood oxygen level, and diastolic hypotension. Remimazolam was approved for medical use in the United States in July 2020, and in the European Union in March 2021.
Sources: en.wikipedia.org
=== Vertebrates === Serotonin, also referred to as 5-hydroxytryptamine (5-HT), is a neurotransmitter most known for its involvement in mood disorders in humans. It is also a widely present neuromodulator among vertebrates and invertebrates. Serotonin has been found having associations with many physiological systems such as cardiovascular, thermoregulation, and behavioral functions, including: circadian rhythm, appetite, aggressive and sexual behavior, sensorimotor reactivity and learning, and pain sensitivity. Serotonin's function in neurological systems along with specific behaviors among vertebrates found to be strongly associated with serotonin will be further discussed. Two relevant case studies are also mentioned regarding serotonin development involving teleost fish and mice. In mammals, 5-HT is highly concentrated in the substantia nigra, ventral tegmental area and raphe nuclei. Lesser concentrated areas include other brain regions and the spinal cord. 5-HT neurons are also shown to be highly branched, indicating that they are structurally prominent for influencing multiple areas of the CNS at the same time, although this trend is exclusive solely to mammals.
In large retail stores, pneumatic tube systems were used to transport sales slips and money from the salesperson to a centralized tube room, where cashiers could make change, reference credit records, and so on. Many banks with drive-throughs also use pneumatic tubes.
Several methods have been used to determine the mechanisms of antimicrobial peptide activity. In particular, solid-state NMR studies have provided an atomic-level resolution explanation of membrane disruption by antimicrobial peptides. In more recent years, X-ray crystallography has been used to delineate in atomic detail how the family of plant defensins rupture membranes by identifying key phospholipids in the cell membranes of the pathogen. Human defensins have been thought to act through a similar mechanism, targeting cell membrane lipids as part of their function. In fact human beta-defensin 2 have now been shown to kill the pathogenic fungi Candida albicans through interactions with specific phospholipids. From the computational point of view, Molecular Dynamics simulations can provide detailed information about the structure and dynamics of the peptide-membrane interactions, including the orientation, conformation, and insertion of the peptide in the membrane, as well as specific peptide interactions with lipids, ions and solvent.
== Safety == A review of the literature regarding hypnotics including the nonbenzodiazepine Z-drugs concluded that these drugs carry a significant risk to the individual. The risks include dependence, accidents, and other adverse effects. Gradual discontinuation of hypnotics may lead to improved health without worsening of sleep. It is preferred that they should be prescribed for only a few days at the lowest effective dose and avoided wherever possible in the elderly.
Sources: en.wikipedia.org
Sex reassignment operations (gender-affirming surgery) have been performed in Thailand since 1975, and Thailand is among the most popular destinations globally for patients seeking such operations. Puberty blockers and cross sex hormones are also available to minors in Thailand. Transgender people are quite common in Thai popular entertainment, television shows and nightclub performances, however, transgender people lack various legal rights compared to the rest of the population, and may face discrimination from society. Transgender women, known as kathoeys, have access to hormones through non-prescription sources. This kind of access is a result of the low availability and expense of transgender health care clinics. However, transgender men have difficulty gaining access to hormones such as testosterone in Thailand because it is not as readily available as hormones for kathoeys. As a result, just a third of all trans men surveyed are taking hormones to transition whereas almost three quarters of kathoeys surveyed are taking hormones.
Common generators (or producers) of biomedical waste include hospitals, health clinics, nursing homes, emergency medical services, medical research laboratories, offices of physicians, dentists, veterinarians, home health care and morgues or funeral homes. In healthcare facilities (i.e. hospitals, clinics, doctor's offices, veterinary hospitals and clinical laboratories), waste with these characteristics may alternatively be called medical or clinical waste. Within healthcare facilities, operating rooms (ORs) generate the most waste, contributing to the polluted environment. Biomedical waste is distinct from normal trash or general waste, and differs from other types of hazardous waste, such as chemical, radioactive, universal or industrial waste. Medical facilities generate waste hazardous chemicals and radioactive materials. While such wastes are normally not infectious, they require proper disposal. Some wastes are considered multihazardous, such as tissue samples preserved in formalin.
n RCHNHC(O)OC(O) → [N(H)CH(R)CO)]n + n CO2 Poly-L-lysine has been prepared from N-carbobenzyloxy-α-N-carboxy-L-lysine anhydride, followed by deprotection with phosphonium iodide. Peptide synthesis from NCAs does not require protection of the amino acid functional groups. N-Substituted NCAs, such as sulfenamide derivatives have also been examined. The ring-opening polymerization of NCAs is catalyzed by metal catalysts. The polymerization of NCA’s have been considered as a prebiotic route to polypeptides. NCAs can also be used to form amides and lactams by reaction of carboxylic acids and isocyanates.
Sources: en.wikipedia.org
A sealed container at room temperature, away from moisture and direct heat, is suitable for most solid material. Keeping the lid closed limits water uptake and caking. Long-term storage in a refrigerator is not necessary if the powder remains dry.
Heat, moisture, and prolonged time in solution promote conversion to creatinine. The reaction is faster at higher temperatures and at pH values far from neutral. Dry powder is much more stable than dissolved material.
Common methods include high-performance liquid chromatography for creatine and creatinine, plus water-content analysis by Karl Fischer titration. Heavy metals, residual solvents, and microbial limits may also be tested. A specification may list total creatine content and impurity 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.