FTIR spectroscopy comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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.
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.
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.
The Gulf War was an armed conflict between Iraq and a 42-country coalition led by the United States in response to Saddam Hussein invading neighboring Kuwait on 2 August 1990. The coalition's efforts were in two phases: Operation Desert Shield, which marked the military buildup from August 1990 to January 1991; and Operation Desert Storm, from the bombing campaign against Iraq on 17 January until the American-led liberation of Kuwait on 28 February. The invasion of Kuwait was met with immediate international condemnation. The UN Security Council demanded Iraq's immediate withdrawal and imposed a total embargo on products from Iraq and Kuwait. A coalition began a military buildup in the Persian Gulf region. The broadest military alliance since World War II, its largest contributors were the US, Saudi Arabia, the United Kingdom, and Egypt. The Security Council issued an ultimatum to Iraq on 29 November 1990, expiring on 15 January 1991, to withdraw from Kuwait, with member-states thereafter empowered to use "all necessary means" to force withdrawal. On 17 January, the coalition began aerial and naval bombardment of Iraq and Kuwait, which continued for five weeks. Iraq fired missiles at Israel and at Saudi Arabia, but failed to split Muslim-majority countries from the coalition. On 24 February 1991, the coalition launched a decisive ground assault liberating Kuwait and promptly advancing into Iraqi territory. The coalition halted its ground advance after one hundred hours, and declared a ceasefire.
=== Prokaryotes expression vector === Promoter - commonly used inducible promoters are promoters derived from lac operon and the T7 promoter. Other strong promoters used include Trp promoter and Tac-Promoter, which are a hybrid of both the Trp and Lac Operon promoters. Ribosome binding site (RBS) - follows the promoter, and promotes efficient translation of the protein of interest. Translation initiation site - Shine-Dalgarno sequence enclosed in the RBS, 8 base-pairs upstream of the AUG start codon.
== Technology applications == In its earliest form, liquid chromatography was used to separate the pigments of chlorophyll by a Russian botanist. Decades later, other chemists used the procedure for the study of carotins. Liquid chromatography was then used for the isolation of small molecules and organic compounds like amino acids, and most recently has been used in peptide and DNA research. Monolith columns have been instrumental in advancing the field of biomolecular research. In recent trade shows and international meetings for HPLC, interest in column monoliths and biomolecular applications has grown steadily, and this correlation is no coincidence. Monoliths have been shown to possess great potential in the “omics” fields- genomics, proteomics, metabolomics, and pharmacogenomics, among others. The reductionist approach to understanding the chemical pathways of the body and reactions to different stimuli, like drugs, are essential to new waves of healthcare like personalized medicine. Pharmacogenomics studies how responses to pharmaceutical products differ in efficacy and toxicity based on variations in the patient's genome; it is a correlation of drug response to gene expression in a patient. Jeremy K. Nicholson of the Imperial College, London, used a postgenomic viewpoint to understand adverse drug reactions and the molecular basis of human disesase. His group studied gut microbial metabolic profiles and were able to see distinct differences in reactions to drug toxicity and metabolism even among various geographical distributions of the same race.
Sources: en.wikipedia.org
== Research == Gepirone is under development for the treatment of decreased libido and generalized anxiety disorder (GAD). As of October 2023, it is in phase III clinical trials for these indications. The pro-sexual effects of gepirone appear to be independent of its antidepressant and anxiolytic effects.
When one German soldier was shot and one seriously wounded in Pancevo, Wehrmacht soldiers and the Waffen SS rounded up about 100 civilians at random...the town commander, Lt. Col. Fritz Bandelow conducted the Courts Martial...The presiding judge, SS-Sturmbannführer Rudolf Hoffmann sentenced 36 of those arrested to death. On April 21, 1941, four of the civilians were the first to be shot...On the following day, eighteen victims were hanged in a cemetery and fourteen more were shot at the cemetery wall by an execution squad of the Wehrmacht's Großdeutschland regiment. Part of the photographic presentation for the book includes a photo in which the Großdeutschland cuff title on an officer is clearly visible. Großdeutschland's complicity in many subsequent war crimes in Russia and Ukraine was a subject of the book by Omer Bartov The Eastern Front, 1941–45, German Troops, and the Barbarization of Warfare (1986, ISBN 0-312-22486-9). Under existing international law at the time, reprisals were permitted, though the Allied nations and Nazi Germany had differing interpretations of the law. In postwar war crimes trials, reprisal killings were deemed to be illegal, a conclusion enshrined in international law by the United Nations.
== Incomplete list of secreted proteins == α-Amylase (1A, 1B, 1C) – begins break down of carbohydrates, especially starch. Antileukoproteinase (SLPI) – antimicrobial protein that acts as a protease inhibitor. It is also found in mucous membranes located in other parts of the body. Carbonic anhydrase 6 (CA6) – enzyme that can convert carbonic acid into water and CO2, which may function to regulate saliva pH. Histatin (HTN1, HTN3) – have a variety of roles from inhibiting fungus growth, acting as precursors for enamel, and promoting wound healing. Lactoperoxidase – reacts with thiocyanate ions to produce antimicrobial molecules. Lactoferrin – antimicrobial protein that binds to iron, and is also found in high concentrations in milk. Proline rich proteins – inhibit calcium phosphate crystal formation and provide a suitable environment for enamel protection and repair. Basic (1, 2, 3, 4) Acidic (1, 2) Proline-rich protein 4 (PRR4) – also produced by lacrimal acinar cells Statherin – helps stabilize saliva and prevent calcium precipitation.
=== The 53Mn – 53Cr chronometer === The short-lived 53Mn-53Cr chronometer is based on the radioactive decay of 53Mn to 53Cr with a half-life of 3.80 ± 0.23 million years. Because manganese and chromium are moderately volatile elements, their fractionation in the cooling solar nebula makes this chronometer particularly suited for dating volatile element depletion events in early Solar System materials. The initial homogeneous distribution of 53Mn in the Solar System, a prerequisite for its use as a chronometer, was established in early studies of Solar System materials. Applied to meteorites, 53Mn-53Cr systematics have provided key insights into the origin of chondrite parent bodies and the volatile element depletion history of the early Earth. The volatile element depletion of proto-Earth was established no later than ~3 million years after the formation of calcium-aluminium-rich inclusions (CAIs), contemporaneous with the dissipation of the protoplanetary disk, while full planetary accretion was completed within ~70 million years.
Sources: en.wikipedia.org
Birds and bats have homologous limbs because they are both ultimately derived from terrestrial tetrapods, but their flight mechanisms are only analogous, so their wings are examples of functional convergence. The two groups have independently evolved their own means of powered flight. Their wings differ substantially in construction. The bat wing is a membrane stretched across four extremely elongated fingers and the legs. The airfoil of the bird wing is made of feathers, strongly attached to the forearm (the ulna) and the highly fused bones of the wrist and hand (the carpometacarpus), with only tiny remnants of two fingers remaining, each anchoring a single feather. So, while the wings of bats and birds are functionally convergent, they are not anatomically convergent. Birds and bats also share a high concentration of cerebrosides in the skin of their wings. This improves skin flexibility, a trait useful for flying animals; other mammals have a far lower concentration. The extinct pterosaurs independently evolved wings from their fore- and hindlimbs, while insects have wings that evolved separately from different organs. Flying squirrels and sugar gliders are much alike in their mammalian body plans, with gliding wings stretched between their limbs, but flying squirrels are placentals while sugar gliders are marsupials, widely separated within the mammal lineage from the placentals. Hummingbird hawk-moths and hummingbirds have evolved similar flight and feeding patterns.
MnO−4 + 8 H+ + 5 e− ⇌ Mn2+ + 4 H2O to be taken into account. The equilibrium constant for a full redox reaction can be obtained from the standard redox potentials of the constituent half-reactions. At equilibrium the potential for the two half-reactions must be equal to each other and, of course, the number of electrons exchanged must be the same in the two half reactions. Redox equilibrium play an important role in the electron transport chain. The various cytochromes in the chain have different standard redox potentials, each one adapted for a specific redox reaction. This allows, for example, atmospheric oxygen to be reduced in photosynthesis. A distinct family of cytochromes, the cytochrome P450 oxidases, are involved in steroidogenesis and detoxification.
=== Pluvicto and Xofigo for prostate cancer === Pluvicto also uses Lu-177 as the radioisotope (which is a beta emitter that decays to Hf-177) but its ligand is a prostate-specific membrane antigen (PSMA) targeted ligand as this radioligand therapy addresses metastatic prostate cancer. It was FDA approved in 2022. The difference between Lutathera and Pluvicto is shown in the chemical linkages in the images above. The production, transportation, and storage is the same as Lutathera. The therapy is administered intravenously through gravity, syringe, or a Peristaltic Infusion Pump. The major warnings include renal toxicity, infertility in males, and embryo/fetal harm. General side effects of this radioligand therapy include fatigue, nausea, dry mouth, anemia, decreased appetite, and constipation. Regular blood tests and imaging post-therapy are needed to see if the radioligand therapy is working and its side effects.
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.