If you have been reading about Karl Fischer titration 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.
Updated 2025-11-25. Numbers and descriptions here follow the published literature rather than marketing material.
Several creatine forms are sold, including monohydrate, anhydrous, hydrochloride, nitrate, citrate, and blends. Once dissolved, these forms deliver creatine, but they differ in molar mass, solubility, counterions, and water content. Creatine monohydrate has the largest body of published human data among these forms. Questions remain about whether any alternative form offers meaningful advantages in absorption, tolerability, or tissue uptake under practical conditions. The hydrate form's lower creatine content by mass is a compositional fact, not a statement about effectiveness.
Creatine monohydrate is a crystalline compound formed when one molecule of creatine associates with one molecule of water in the solid lattice. Its molecular formula is C4H11N3O3, and its molar mass is about 149.15 grams per mole. The material appears as a white, odorless powder that dissolves sparingly in water at room temperature. The monohydrate designation distinguishes it from anhydrous creatine, which lacks the bound water and has a lower molar mass. This hydrate is the most common commercial form of creatine used in nutritional and research settings.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C4H11N3O3 | Often written C4H9N3O2·H2O |
| Molar mass | 149.15 g/mol | Anhydrous creatine is 131.13 g/mol |
| Appearance | White crystalline powder | Odorless, fine or granular |
| Water solubility | About 13 g/L at 25 °C | Low; increases with temperature |
| Common synonyms | Creatine hydrate; N-carbamimidoylsarcosine monohydrate | CAS 6020-87-7 |
In the human body, creatine is synthesized mainly in the liver and kidneys from the amino acids glycine, arginine, and methionine. Dietary sources include meat, fish, and other animal tissues, which supply preformed creatine. Because plant foods contain little or no creatine, dietary intake varies widely among populations. The compound is stored largely in skeletal muscle, where it is converted to phosphocreatine and used to regenerate adenosine triphosphate during short bursts of activity.
Creatine monohydrate is one of several solid forms of creatine described in the literature. Other forms include anhydrous creatine, creatine hydrochloride, and creatine ethyl ester, each with different solubility and stability characteristics. The monohydrate is distinct from creatinine, a spontaneous breakdown compound that forms when creatine loses water and cyclizes. Commercial descriptions sometimes use synonyms such as methylguanidoacetic acid or N-(aminoiminomethyl)-N-methylglycine, which refer to the same base molecule. These names appear in chemical databases and product labels.
Creatine monohydrate is a crystalline compound formed when one molecule of creatine binds with one molecule of water. Creatine itself is a nitrogen-containing organic acid involved in cellular energy transfer, particularly in muscle and nerve tissue. The monohydrate form is the most common solid form used in research and commercial products because it is relatively stable and easy to handle. Its molecular formula is C4H9N3O2·H2O, and its molar mass is about 149.15 grams per mole.
Creatine monohydrate is stable under dry, cool conditions but can degrade when exposed to moisture and heat. In solution, it undergoes hydrolysis to creatinine, a cyclic derivative with little role in phosphagen energy transfer. The rate of conversion increases with temperature, storage time, and acidic or alkaline pH. Solid material kept in a sealed container at room temperature generally retains its composition for extended periods. Moisture uptake is a primary concern because it can accelerate breakdown and caking.
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.
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.
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.
=== Pharmacodynamics === Compared to shorter-chain homologues such as DOM, DOET, and DOPR, which are all potent psychedelics, DOBU has even higher affinity for the serotonin 5-HT2A receptor. It has been found to act as a potent full agonist of the serotonin 5-HT2A and 5-HT2C receptors. The drug is also a serotonin 5-HT2B receptor full agonist but with far lower potency. Additional receptor interactions have also been described. DOBU fully substitutes for DOM in rodent drug discrimination tests, albeit several-fold less potently than DOET or DOPR. In addition, DOBU robustly induces the head-twitch response, a behavioral proxy of psychedelic-like effects, in rodents, and maximally does so about as strongly as other DOx drugs like DOM, DOET, DOPR, and DOC. The doses at which DOBU produces peak head twitches are similar to those of DOM and DOET. Other effects of DOBU in rodents include hyperlocomotion at lower doses, hypolocomotion at higher doses, and hypothermia at higher doses.
=== July === July 1 Recreational cannabis becomes legal in Connecticut and Virginia. Medical cannabis becomes legal in South Dakota. COVID-19 vaccination – Michigan Governor Gretchen Whitmer announces a month-long vaccination raffle in which residents can win a total of $5 million in cash (one grand prize of $2 million or three prizes of $1 million) and $500,000 total in college scholarships for children ages 12–17 years old (nine prizes of $55,000). The winners were drawn on August 4. July 2 – Hundreds of businesses are hit by a large-scale cyberattack, linked to the Russian REvil ransomware gang. July 2–5 – At least 233 people were killed and 618 people were injured in over 500 shootings nationwide during the Independence Day weekend. July 6 – 2021 New York City mayoral election – Eric Adams was declared the winner of the Democratic primary for mayor of New York City. July 7 – The Tampa Bay Lightning defeat the Montreal Canadiens (4-1) in the 2021 Stanley Cup Finals to win their second consecutive Stanley Cup. July 8 – Attorney Michael Avenatti is sentenced to 2.5 years in prison for attempting to extort Nike. July 9 Twitter suspensions – Twitter announces that they have suspended political commentator and nationalist Nick Fuentes. President Biden signs a 72-point executive order placing tighter regulations and scrutiny on major corporations in a variety of sectors, including Big Tech companies.
This behavior is somewhat peculiar to normal phase chromatography because it is governed almost exclusively by an adsorptive mechanism (i.e., analytes interact with a solid surface rather than with the solvated layer of a ligand attached to the sorbent surface; see also reversed-phase HPLC below). Adsorption chromatography is still somewhat used for structural isomer separations in both column and thin-layer chromatography formats on activated (dried) silica or alumina supports. Partition- and NP-HPLC fell out of favor in the 1970s with the development of reversed-phase HPLC because of poor reproducibility of retention times due to the presence of a water or protic organic solvent layer on the surface of the silica or alumina chromatographic media. This layer changes with any changes in the composition of the mobile phase (e.g., moisture level) causing drifting retention times. Recently, partition chromatography has become popular again with the development of Hilic bonded phases which demonstrate improved reproducibility, and due to a better understanding of the range of usefulness of the technique.
==== Body composition and strength improvements ==== Anabolic steroids influence muscle fiber characteristics, affecting both the size and type of muscle fibers. This alteration significantly contributes to enhanced muscle strength and endurance. Anabolic-androgenic steroids (AAS) cause these changes by directly impacting the muscle tissue's cellular components. Studies have shown that these changes are not merely superficial but represent a profound transformation in the muscle's structural and functional properties. This transformation is a key factor in the steroids' ability to enhance physical performance and endurance. Body weight in men may increase by 2 to 5 kg as a result of short-term (<10 weeks) AAS use, which may be attributed mainly to an increase of lean mass. Animal studies also found that fat mass was reduced, but most studies in humans failed to show significant fat mass decrements. The effects on lean body mass have been shown to be dose-dependent. Both muscle hypertrophy and the formation of new muscle fibers have been observed. The hydration of lean mass remains unaffected by AAS use, although small increments of blood volume cannot be ruled out. The upper region of the body (thorax, neck, shoulders, and upper arm) seems to be more susceptible for AAS than other body regions because of predominance of ARs in the upper body. The largest difference in muscle fiber size between AAS users and non-users was observed in type I muscle fibers of the vastus lateralis and the trapezius muscle as a result of long-term AAS self-administration.
Arthur Brouhard Robinson (born March 24, 1942) is an American biochemist, conservative activist, prominent climate change denier, and politician who served as the Oregon State Senator from the 2nd District from 2021 to 2025. He was the five-time Republican nominee for the United States House of Representatives for Oregon's 4th congressional district. A former faculty member of the University of California, San Diego, Robinson now runs a privately funded laboratory known as the Oregon Institute of Science and Medicine in Cave Junction, Oregon, a newsletter called Access to Energy, and publishes the Robinson Self-Teaching Home School Curriculum. As the Republican nominee for the Fourth District in Oregon, Robinson ran and lost to Democratic incumbent Peter DeFazio in five consecutive elections: 2010, 2012, 2014, 2016, and 2018. He served as chairman of the Oregon Republican Party from August 2013 to February 2015.
Sources: en.wikipedia.org
The elements listed below as "Essential in humans" are those listed by the US Food and Drug Administration as essential nutrients, as well as six additional elements: oxygen, carbon, hydrogen, and nitrogen (the fundamental building blocks of life on Earth), sulfur (essential to all cells) and cobalt (a necessary component of vitamin B12). Elements listed as "Possibly" or "Probably" essential are those cited by the US National Research Council as beneficial to human health and possibly or probably essential.
==== Tolerance ==== Tolerance and dependence are risks of chronic benzodiazepine use, and can result in doses within the therapeutic range ceasing to offer meaningful symptomatic relief after prolonged use. Tolerance develops at different rates and to different degrees to the sedative, hypnotic, anticonvulsant, muscle relaxant, and anxiolytic effects of benzodiazepines. A review of benzodiazepine tolerance concluded that it "appears that tolerance develops relatively quickly for the sedative and anticonvulsant actions of benzodiazepines, whereas tolerance to anxiolytic and amnesic effects probably does not develop at all", although the included randomized controlled trial evidence is limited to 22 weeks. A review of clonazepam in the treatment of psychiatric disorders concluded that longitudinal data supports anxiolytic benefit without tolerance during long-term use, including an open-label study finding continued benefit at three years. However, the review concludes that long-term RCT evidence is scant. A study of benzodiazepine sensitivity found that patients treated chronically with alprazolam did not differ from untreated patients in terms of anxiolytic response to diazepam, suggesting a lack of anxiolytic tolerance. However, controversy remains regarding tolerance to anxiolytic effects, with some publications reporting that there is little evidence of continued efficacy beyond 4–6 months or that dependence phenomena are common.
In 1998, Andrew Wakefield et al. published a now retracted and fraudulent The Lancet paper linking the MMR vaccine to autism, leading to a decline in vaccination rates. Wakefield was later found to have been "dishonest" by the General Medical Council and barred from practicing medicine in the UK. Numerous subsequent studies and reviews by organizations such as the US Centers for Disease Control and Prevention, Institute of Medicine, NHS and the Cochrane Library have found no evidence of a link between the MMR vaccine and autism. The controversy surrounding Wakefield's publication led to decreased MMR vaccination rates and a subsequent increase in measles cases in the UK. In Japan, where the MMR vaccine is not used as a combined vaccine, autism rates have remained unaffected, further disproving Wakefield's hypothesis. According to a 2019 Los Angeles Times article, concerns were raised about unvaccinated students contributing to the large number of measles outbreaks. While Robert F. Kennedy Jr—United States Secretary of Health and Human Services— publicly supported Wakefield's disproven theory that vaccines cause autism, and was the founder of the anti-vaccine Children's Health Defense, on 28 February, during the 2025 Southwest US measles outbreak, he announced that he would be sending 2,000 doses of the MMR vaccine to Texas along with other resources. A New York Times article reporting on the death of a child in Texas from measles—the first in ten years in the United States, said that vaccine hesitancy had been rising for many years.
Fatty acid metabolism consists of various metabolic processes involving or closely related to fatty acids, a family of molecules classified within the lipid macronutrient category. These processes can mainly be divided into (1) catabolic processes that generate energy and (2) anabolic processes where they serve as building blocks for other compounds. In catabolism, fatty acids are metabolized to produce energy, mainly in the form of adenosine triphosphate (ATP). When compared to other macronutrient classes (carbohydrates and protein), fatty acids yield the most ATP on an energy per gram basis, when they are completely oxidized to CO2 and water by beta oxidation and the citric acid cycle. Fatty acids (mainly in the form of triglycerides) are therefore the foremost storage form of fuel in most animals, and to a lesser extent in plants. In anabolism, intact fatty acids are important precursors to triglycerides, phospholipids, second messengers, hormones and ketone bodies. For example, phospholipids form the phospholipid bilayers out of which all the membranes of the cell are constructed from fatty acids. Phospholipids comprise the plasma membrane and other membranes that enclose all the organelles within the cells, such as the nucleus, the mitochondria, endoplasmic reticulum, and the Golgi apparatus. In another type of anabolism, fatty acids are modified to form other compounds such as second messengers and local hormones. The prostaglandins made from arachidonic acid stored in the cell membrane are probably the best-known of these local hormones.
Sources: en.wikipedia.org
Calcitriol is a hormone and the active form of vitamin D3, normally made in the kidney. It is also known as or 1,25-dihydroxycholecalciferol (1,25-(OH)2D3). It binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the expression of many genes. Calcitriol increases blood calcium mainly by increasing the uptake of calcium from the intestines. Calcitriol can be given as a medication for the treatment of osteoporosis, osteomalacia, familial hypophosphatemia, low blood calcium due to hypoparathyroidism, and low blood calcium and hyperparathyroidism due to kidney disease. It can be taken by mouth or by injection into a vein. Excessive amounts or intake can result in weakness, headache, nausea, constipation, urinary tract infections, and abdominal pain. Serious side effects may include high blood calcium and anaphylaxis. Calcitriol was identified as the active form of vitamin D3 in 1971 and the drug was approved for medical use in the United States in 1978. It is available as a generic medication. In 2023, it was the 249th most commonly prescribed medication in the United States, with more than 1 million prescriptions. It is on the World Health Organization's List of Essential Medicines.
== Prevention == Tooth extraction is the major risk factor for development of MRONJ. Prevention including the maintenance of good oral hygiene, comprehensive dental examination and dental treatment including extraction of teeth of poor prognosis and dentoalveolar surgery should be completed prior to commencing any medication which is likely to cause osteonecrosis (ONJ). Patients with removable prostheses should be examined for areas of mucosal irritation. Procedures which are likely to cause direct osseous trauma, e.g. tooth extraction, dental implants, complex restoration, deep root planning, should be avoided in preference of other dental treatments. There are limited data to support or refute the benefits of a drug holiday for osteoporotic patients receiving antiresorptive therapy. However, a theoretical benefit may still apply for those patients with extended exposure histories (>4 yr), and current recommendations are for a 2 month holiday for those at risk. There was low quality evidence suggesting taking antibiotics prior to the dental extraction, as well as the use of post operative techniques for wound closure lowered the risk of patients developing medication-related osteonecrosis of the jaw compared with the usual standard care received for regular dental extractions. Post operative wound closure has been suggested to prevent the contamination of the underlying bone. More evidence is needed to assess the use of antibiotics prior to treatment and the use of wound closure to prevent contamination of the bone, as the quality of evidence evaluated was low.
1842: The Western Railroad of Massachusetts experimented with innovative freight car designs capable of carrying all types of perishable goods without spoilage. 1851: The first refrigerated boxcar entered service on the Northern Railroad (New York). 1857: The first consignment of refrigerated, dressed beef traveled from Chicago to the East Coast in ordinary box cars packed with ice. 1866: Horticulturist Parker Earle shipped strawberries in iced boxes by rail from southern Illinois to Chicago on the Illinois Central Railroad. 1867: First U.S. refrigerated railroad car patent was issued. 1868: William Davis of Detroit, Michigan developed a refrigerator car cooled by a frozen ice-salt mixture, and patented it in the U.S. The patent was subsequently sold to George Hammond, a local meat packer who amassed a fortune in refrigerated shipping. 1875: Samuel Rumph invented a railcar specifically to ship peaches, and a mortised-end peach crate, making possible large-scale growing and long-distance shipping of peaches 1876: German engineer Carl von Linde developed one of the first mechanical refrigeration systems. 1878: Gustavus Swift (along with engineer Andrew Chase) developed the first practical ice-cooled railcar. Soon, Swift formed the Swift Refrigerator Line (SRL), the world's first. 1880: The first patent for a mechanically refrigerated railcar issued in the United States was granted to Charles William Cooper. 1884: The Santa Fe Refrigerator Despatch (SFRD) was established as a subsidiary of the Atchison, Topeka and Santa Fe Railway to carry perishable commodities.
Sources: en.wikipedia.org
It is the hydrated crystalline form of creatine, containing one bound water molecule per creatine unit. The compound is commonly used as a nutritional ingredient and as a research material.
Yes, endogenous synthesis occurs mainly in the liver, kidney, and pancreas. Meat and fish also contribute creatine to the diet.
Other forms contain creatine paired with different counterions or lacking water, so their mass and solubility differ. After dissolution, creatine itself is the shared active molecule.
Karl Fischer titration is a standard method for measuring water content in solid and liquid samples. The result helps confirm the expected monohydrate stoichiometry. Loss-on-drying can also indicate moisture but may not distinguish water from other volatile substances.