If you have been reading about LC-MS/MS 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 2025-12-07. Numbers and descriptions here follow the published literature rather than marketing material.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
Several misconceptions surround SR9009. It is often described as a SARM, a steroid, or an exercise pill, but its known target is the REV-ERB receptor family. Rodent studies have examined exercise capacity and metabolic markers, yet human outcomes remain unproven. Oral bioavailability appears low in animals, and human pharmacokinetics are not well characterized. Online products may contain impurities or different compounds, so identity and purity testing are important for research use.
Analytical chemists detect SR9009 with liquid chromatography-tandem mass spectrometry, commonly abbreviated LC-MS/MS. Sample preparation may involve protein precipitation, liquid-liquid extraction, or solid-phase extraction before analysis. Laboratories can target the parent compound or its metabolites, depending on the matrix and the purpose of testing. Anti-doping methods require sensitive and specific assays because concentrations in biological samples can be low. Reference standards and validated methods are essential for reliable identification and quantification.
| Property | Value | Notes |
|---|---|---|
| Appearance | Off-white to pale yellow solid | Visual description varies with purity and source |
| Solubility | Soluble in DMSO and ethanol; poorly soluble in water | Organic stock solutions are common in research |
| Typical storage | -20 °C, desiccated, protected from light | Avoid repeated freeze-thaw cycles |
| Typical analytical method | LC-MS or HPLC-UV | Reference standards are needed for quantification |
| Molar mass | Approximately 437.9 g/mol | Calculated from the reported free-base formula |
Handling recommendations for SR9009 in a laboratory setting include storing the solid at low temperature, protected from light and moisture. The compound is often dissolved in dimethyl sulfoxide or ethanol for experiments. Solutions should be prepared with appropriate personal protective equipment and disposed of according to local rules. Stability data for long-term storage are limited, so stock solutions are typically kept cold and used within defined periods. Records of preparation date and concentration support reproducibility.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
Detection of SR9009 in biological samples usually employs liquid chromatography coupled with tandem mass spectrometry. This method can identify the parent compound and sometimes metabolites in urine or blood. Because exposure can be low and clearance may be rapid, sample timing and limits of detection matter. Laboratories validate assays for sensitivity and specificity. Results are interpreted alongside chain-of-custody and quality-control records. Urine is the common matrix for anti-doping analysis, while blood may be used in research settings.
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
Detection of SR9009 in biological samples usually relies on liquid chromatography coupled to tandem mass spectrometry. This approach separates the compound from matrix components and identifies it by mass transitions. Because SR9009 can undergo metabolism, laboratories often look for both parent drug and specific metabolites. Sample preparation may involve protein precipitation or solid-phase extraction. Method validation examines sensitivity, carryover, and interference from related substances, and reference standards are required for accurate calibration.
Storage recommendations for SR9009 reference material typically specify a freezer at -20 °C or lower, with protection from moisture and light. Repeated freeze-thaw cycles can degrade small molecules and introduce variability. Stock solutions in dimethyl sulfoxide are often aliquoted to avoid repeated handling. Stability studies may examine degradation under heat, humidity, and light exposure. The compound's thiophene and nitro groups can participate in reactions that alter analytical signals over time, so such changes affect quantitative results.
== C == Calcium channel A type of ion channel located on the cell membrane that allows the selective entry of calcium ions (Ca²⁺) into the neuron, playing a crucial role in neurotransmitter release, gene expression, and synaptic plasticity. Capsaicin A compound found in chili peppers that activates TRPV1 receptors on sensory neurons, leading to the sensation of heat or burning. It is used in research and in topical analgesics for chronic pain. Caudate nucleus A C-shaped structure located in the basal ganglia, involved in motor control, learning, memory, and reward processing. It works closely with the putamen and globus pallidus. Central nervous system (CNS) Consists of the brain and spinal cord, responsible for processing and coordinating sensory data and motor commands. Cerebellum A brain structure located at the back of the skull that plays a central role in motor coordination, balance, posture, and some cognitive functions such as attention and language. Cerebral cortex The outermost layer of the cerebrum, composed of gray matter. It is involved in higher-order brain functions such as sensory perception, language, decision-making, and voluntary motor control. Cerebral hemisphere One of the two halves of the cerebrum, divided into left and right hemispheres. Each hemisphere specializes in different functions but communicates via the corpus callosum. Cerebrospinal fluid (CSF) A clear fluid found in the brain and spinal cord that cushions neural tissue, removes waste, and provides nutrients. It circulates through the ventricular system and subarachnoid space.
Former First Minister Humza Yousaf announces he will step down as an MSP at the 2026 Scottish Parliament election. Edinburgh City Council says it is taking steps to prevent harmful content from being accessed on school-issued iPads after it emerged content such as pornography and violence can be viewed by students, even with internet filters in place. 18 December – Reform UK confirms that Craig Campbell, a party official in Scotland, has been removed from his post after revelations his family has links to Ulster Loyalists and has a relatives who was convicted of murdering a Celtic fan. 19 December – A double-decker bus has its roof torn off after crashing into a railway bridge in Kilmarnock. Jane Meagher is voted to replace Cammy Day as leader of Edinburgh City Council, and will lead a Labour minority administration. Alan Edwards, an extremist who holds homophobic and antisemitic views and amassed an "armoury" at his home in Falkirk, and discussed launching an attack on a local LGBT group, is sentenced to ten years imprisonment. His sentence also includes a five year supervision order upon release. 23 December – The pilot of a light aircraft is killed in an air crash near Fife Airport. An investigation into the December 2023 Broughty Ferry train crash finds that a train collided with a fallen tree because a warning did not reach the driver in time. 24 December – The Scottish Ambulance Service is put on the highest level of emergency due to "significant pressure" placed on services.
Joints are structures that connect individual bones and may allow bones to move against each other to cause movement. There are three divisions of joints: diarthroses, which allow extensive mobility between two or more articular heads; amphiarthroses, which allow some movement; and false joints or synarthroses, which allow little or no movement and are predominantly fibrous. Synovial joints, joints that are not directly joined, are lubricated by a solution called synovial fluid that is produced by the synovial membranes. This fluid lowers the friction between the articular surfaces and is kept within an articular capsule, binding the joint with its taut tissue.
CTCs can also be detected by using the acidification of the tumor microenvironment and the difference in membrane capacitance. CTCs are isolated from blood by a microfluidic device, and are cultured on-chip, which can be a method to capture more biological information in a single analysis. For example, it can be used to test the cell survival rate of 40 different drugs or drug combinations. Tumor‐derived extracellular vesicles can be isolated from urine and detected by an integrated double‐filtration microfluidic device; they also can be isolated from blood and detected by electrochemical sensing method with a two‐level amplification enzymatic assay. Tumor materials can directly be used for detection through microfluidic devices. To screen primary cells for drugs, it is often necessary to distinguish cancerous cells from non-cancerous cells. A microfluidic chip based on the capacity of cells to pass small constrictions can sort the cell types, metastases. Droplet‐based microfluidic devices have the potential to screen different drugs or combinations of drugs, directly on the primary tumor sample with high accuracy. To improve this strategy, the microfluidic program with a sequential manner of drug cocktails, coupled with fluorescent barcodes, is more efficient. Another advanced strategy is detecting growth rates of single-cell by using suspended microchannel resonators, which can predict drug sensitivities of rare CTCs. Microfluidics devices also can simulate the tumor microenvironment, to help to test anticancer drugs.
Since then, however, most researchers have adopted a more moderate position, which identifies the Chicxulub impact as the primary progenitor of the extinction while also recognizing that the Deccan Traps may also have played a role. Walter Alvarez himself has acknowledged that the Deccan Traps and other ecological factors may have contributed to the extinctions in addition to the Chicxulub impact. Some estimates have placed the start of the second phase in the Deccan Traps eruptions within 50,000 years after the Chicxulub impact. Combined with mathematical modelling of the seismic waves that would have been generated by the impact, this has led to the suggestion that the Chicxulub impact may have triggered these eruptions by increasing the permeability of the mantle plume underlying the Deccan Traps. Whether the Deccan Traps were a major cause of the extinction, on par with the Chicxulub impact, remains uncertain. Proponents consider the climatic impact of the sulfur dioxide released to have been on par with the Chicxulub impact, and also note the role of flood basalt volcanism in other mass extinctions like the Permian-Triassic extinction event. They consider the Chicxulub impact to have worsened the ongoing climate change caused by the eruptions. Meanwhile, detractors point out the sudden nature of the extinction and that other pulses in Deccan Traps activity of comparable magnitude did not appear to have caused extinctions. They also contend that the causes of different mass extinctions should be assessed separately.
Sources: en.wikipedia.org
A quadrupole mass analyzers uses four parallel metal rods to create a quadrupole electrical field oscillating at radio frequency (RF), to selectively stabilize or destabilize the paths of ions passing through. With each oscillation pattern, the ions passing through would undergo a helical motion. If the ion has m/z within a certain range, the helical motion is stable. Otherwise, the helical motion will increase in amplitude until the ion collides with the rods. This means that only ions with m/z within a narrow range can go through it. The full spectrogram can be swept through by changing the potentials on the rods, continuously or in a succession of discrete hops. They are typically of low resolution ~1000, but they are cheap and small, so are good for "desktop" mass spectrometers. The quadrupole mass filter is closely related to the quadrupole ion trap, particularly the linear quadrupole ion trap except that it is designed to pass the untrapped ions rather than collect the trapped ones, and is for that reason referred to as a transmission quadrupole. The quadrupole ion trap itself can be used as an analyzer, as in ion trap analyzers. A common variation of the transmission quadrupole is the triple quadrupole mass spectrometer. The "triple quad" has three consecutive quadrupole stages, the first acting as a mass filter to transmit a particular incoming ion to the second quadrupole, a collision chamber, wherein that ion can be broken into fragments. The third quadrupole also acts as a mass filter, to transmit a particular fragment ion to the detector.
Heavy-metal contamination of spirulina supplements has also raised concern. The Chinese State Food and Drug Administration reported that lead, mercury, and arsenic contamination was widespread in spirulina supplements marketed in China. One study reported the presence of lead up to 5.1 ppm in a sample from a commercial supplement. Spirulina doses of 10 to 19 grams per day over several months have been used safely.
=== Diet === Diet is a critical component of treatment and is in some cases effective on its own following treatment with insulin. For example, a recent mini-study showed that many diabetic cats stopped needing insulin after changing to a low carbohydrate diet. The rationale is that a low-carbohydrate diet reduces the amount of insulin needed and keeps the variation in blood sugar low and easier to predict. Additionally, research indicates that feeding cats low-carbohydrate meals increases their chances of obtaining diabetic remission by four times. Also, fats and proteins are metabolized slower than carbohydrates, reducing dangerous blood sugar peaks right after meals. Cats are obligate carnivores and must consume meat to survive, as their bodies are unable to produce certain amino acids such as taurine and arginine, and cannot process many of the nutrients that meat has from other dietary sources. It is recommended to see a veterinary professional to discuss the specific dietary needs a cat with diabetes needs to manage their diabetes while also ensuring they do not develop other health issues related to malnutrition.
=== World Anti-Doping Agency === World Anti-Doping Agency (WADA) is the foundation made by the International Olympic Committee in 1999 and its role is to promote, coordinate and monitor drug use within sports. WADA is responsible for the creation of the World Anti-Doping Code which is adopted by more than 600 sporting organizations. The main tasks that the agency are involved in are research, education, development of anti-doping bodies and regulating the World Anit-Doping Code. Recently, WADA has developed partnerships with pharmaceutical and biotechnology companies with the aim to try to facilitate drug detection methods.
As of 2024, it is unclear whether (S)-tetrahydropapaverine derives from (S)-reticuline or (S)-coclaurine: the difference is whether the piperidine nitrogen atom is methylated at any point during the biosynthetic sequence.
Sources: en.wikipedia.org
=== 1961 === January 3: President Eisenhower severs diplomatic relations with Cuba. January 13: Patrice Lumumba, elected President of the Republic of the Congo (Léopoldville) is assassinated with the support of the CIA in the context of the Congo Crisis January 20: John F. Kennedy becomes President of the United States. January 31: Ham is launched into space as a part of Project Mercury, a mission to successfully place a human into orbit and return them safely. February 4: Angolan nationalists, including communists, begin an insurgency against Portuguese rule. This marked the beginning of the Portuguese Colonial War. February 12: Venera 1 is successfully launched by the Soviet Union with the intention of conducting a flyby mission to Venus. April 12: Yuri Gagarin becomes the first human in space and first to orbit the Earth when the Soviet Union successfully launches Vostok 1. April 17–19: Bay of Pigs Invasion: A CIA-backed invasion of Cuba by counter-revolutionaries ends in failure. April 21: Sierra Leone becomes independent from the UK under Commonwealth status. May 5: Alan Shepard becomes the first American to go into space when Freedom 7 is launched successfully. May 19: Venera 1 successfully reaches Venus being the first spacecraft to do so, but is unable to transmit any data. May 25: John F. Kennedy announces the US intention to put a man on the Moon – kickstarting Project Mercury, America's first human spaceflight program. June 4: Kennedy meets with Khrushchev in Vienna.
Sales caps are also placed on the properties of the CLT to maintain affordability for generations of future buyers. Most of the skepticism surrounding CLTs is rooted in their reliance on external funding. As CLT organizations grow and their boards become more professionalized, they are often distanced from their original ideals of community-based land control which the organizations were founded upon. Most CLTs are not built upon economically self-sustaining models, so they are forced to compete for external funding, taking away the CLT's autonomy, as all of the power is transferred into the hands of grant-funding organizations and private foundations. This problem could be avoided if CLTs could somehow source their funding from community investors or funders who share their ideals of community empowerment.
Emus are farmed primarily for their meat, leather, feathers and oil, and 95% of the carcass can be used. Emu meat is a low-fat product (less than 1.5% fat), and is comparable to other lean meats. Most of the usable portions (the best cuts come from the thigh and the larger muscles of the drum or lower leg) are, like other poultry, dark meat; emu meat is considered for cooking purposes by the US Food and Drug Administration to be a red meat because its red colour and pH value approximate that of beef, but for inspection purposes it is considered to be poultry. Emu fat is rendered to produce oil for cosmetics, dietary supplements, and therapeutic products. The oil is obtained from the subcutaneous and retroperitoneal fat; the macerated adipose tissue is heated and the liquefied fat is filtered to get a clear oil. This consists mainly of fatty acids of which oleic acid (42%), linoleic and palmitic acids (21% each) are the most prominent components. It also contains various anti-oxidants, notably carotenoids and flavones. There is some evidence that the oil has anti-inflammatory properties; however, there have not yet been extensive tests, and the USDA regards pure emu oil as an unapproved drug and highlighted it in a 2009 article entitled "How to Spot Health Fraud". Nevertheless, the oil has been linked to the easing of gastrointestinal inflammation, and tests on rats have shown that it has a significant effect in treating arthritis and joint pain, more so than olive or fish oils.
== See also == World Institute of Kimchi – South Korean food R&D organization Foods containing tyramine – Trace aminePages displaying short descriptions of redirect targets Jangajji – Korean pickled vegetable dish Jeotgal – Korean salted seafood category Kimchi burger Korean radish – Variety of edible white radish Korean brining salt – Coarse salt Morkovcha – Koryo-saram spicy marinated carrot dish – a variety of kimchi made of carrots by Koryo-saram List of cabbage dishes List of English words of Korean origin List of pickled foods Pao cai – Pickle in Chinese cuisine. Sauerkraut – Finely sliced and fermented cabbage Torshi, also known as Tursu – Procedure of preserving food in brine or vinegarPages displaying short descriptions of redirect targets
The most important festivals are the Kiel Week, Schleswig-Holstein Musik Festival, an annual classic music festival all over the state, and the Lübeck Nordic Film Days, an annual film festival for movies from Scandinavian countries, held in Lübeck. The Kiel Week is an annual event, except for 2020 and 2021 due to the COVID19-Pandemic. It took place again in June 2022. The annual Wacken Open Air festival is considered to be the largest heavy metal rock festival in the world.
Sources: en.wikipedia.org
It is usually detected by LC-MS or HPLC-UV against a reference standard. In biological matrices, metabolite targeting can improve detection. No universal immunoassay is widely available.
The compound is generally handled as light-sensitive and stored cold and dry. Stability in solution depends on solvent, concentration, and storage time. Specific degradation rates are not fully standardized.
Limited water solubility affects formulation for cell and animal studies. Organic co-solvents are often used to dissolve it. Precipitation can confound assay results if not controlled.
Legality depends on the country and the intended use. In many places it is not approved as a medicine and may be sold only as a research chemical. Importation or possession can be restricted, and sports organizations prohibit it.