Everything below concerns Electrospray ionization. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-06. Numbers and descriptions here follow the published literature rather than marketing material.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
== Host systems == Genes are subjected to heterologous expression often to study specific protein interactions. E. coli, yeast (S. cerevisiae, P. pastoris), immortalized mammalian cells, and amphibian oocytes (i.e. unfertilized eggs) are commonly for studies that require heterologous expression. In choosing a particular system, economic and qualitative aspects have to be considered. Prokaryotic expression is widely used in recombinant DNA technology to form easily manipulated proteins by well-known genetic methods with a low costing medium. Some limitations include intracellular accumulation of heterologous proteins, improper folding of the peptide, lack of post-transcriptional modifications, the potential for product degradation due to traces of protease impurities, and production of endotoxin. Prokaryotic and eukaryotic systems, most commonly bacteria, yeast, insects, and mammalian cells, and occasionally amphibians, fungi, and protists are used for studies that require heterologous expression. Bacteria, especially E. coli, yeast (S. cerevisiae, P. pastoris), insects, and amphibian (oocyte) cells have been used as effective hosts for expressing foreign proteins. Generally, prokaryotes are easier to work with and better understood and are often the preferable host system. It is widely used in recombinant DNA technology to form easily manipulated proteins by well-known genetic methods with a low costing medium. For membrane proteins though, researchers have observed that mammalian cells are more effective.
In a clandestine setting, DMT is not typically synthesized due to the lack of availability of the starting materials, namely tryptamine and oxalyl chloride. Instead, it is more often extracted from plant-sources using a nonpolar hydrocarbon solvent such as naphtha or heptane, and a base such as sodium hydroxide. Alternatively, an acid-base extraction is sometimes used instead. A variety of plants contain DMT at sufficient levels for being viable sources such as Mimosa tenuiflora, Acacia acuminata, Acacia confusa, Acacia maidenii, Arundo donax, 'Diplopterys cabrerana, Psychotria viridis. The chemicals involved in the extraction are commonly available. The plant-material may be illegal to procure in some countries. The end-product (DMT) is illegal in most countries.
Wolpoff, anthropologist of the University of Michigan; John Shea (archaeologist), anthropologist of Stony Brook University; Lewis Binford, anthropologist of Southern Methodist University in Texas; Neanderthals are thought to have lived similar unevolved uncultured lives for 200,000 years; Brigitte Delluc of Abri Pataud; in the 1980s, a completely new paradigm was thought up by British anthropologist Chris Stringer whereby a new group originated about 200,000 years ago, replacing the former human evolution, known as recent African origin of modern humans, but this paradigm was countered by Milford Wolpoff and his multiregional origin of modern humans, arguing that Neanderthals hadn't died out; Dorothy Garrod, the first female professor at the University of Cambridge in 1939 - the Disney Professor of Archaeology, completed important research in the middle East on how Neanderthals would have encountered much more culturally advanced modern humans in that region; archaeologist Ofer Bar-Yosef described how radiocarbon dating does not work beyond 50,000 years, and modern humans were found there at least 100,000 years ago; the dating methods remained in dispute until reliable genetic ancestry methods arrived in the late 1980s, with Mark Stoneking, a molecular anthropologist of Penn State University, who introduced the Mitochondrial Eve theory in 1987; geneticist Kenneth Kidd and how genetic data had superseded much of the anthropological research, which had been inherently unreliable due to not enough solid data; essentially Neanderthals died out possibly due to insufficient language ability, and were less able in overall cognitive planning. Directed by Lawrence Simanowitz, narrated and produced by William Woollard, made by InCA Productions 6 October Staying Alive, survivors of terrible accidents speak, with Sylvia Chapell of the August 1985 British Airtours Flight 28M; Paul Barney of the September 1994 Sinking of the MS Estonia; survival cognitive psychologist John Leach of Lancaster University; Robert Sapolsky, a neuroendocrinologist, on how glucocorticoids are secreted; Jeffrey Alan Gray, Professor of Psychology at the Institute of Psychiatry, Psychology and Neuroscience; the 336th Training Group at Fairchild Air Force Base; medical researchers at DRDC Toronto; the October 1991 Operation Boxtop 435 Transport and Rescue Squadron from CFB Trenton Hercules crash, which resulted in the 1993 film Ordeal in the Arctic; the brain neurotransmitters affect survival outcomes, controlled by the enzyme monoamine oxidase; Helicopter Underwater Escape Training at Survival Systems in Dartmouth, Nova Scotia. Narrated by Bill Paterson, the consultant was Edward Bullmore, directed by Denman Rooke, produced by Adam Bullmore, made by October Films 13 October Killer Bees, about a catastrophic genetic experiment in southern Brazil in the late 1950s - the Africanized bee; the East African lowland honey bee was introduced in 1956 by Warwick Estevam Kerr; the bees were introduced to help the honey industry, instead the new bees killed off the native bees, as well as many people too, with bees terrorising Apache Junction, Arizona; one swarm of thousand led to 20,000 other swarms in one year; the bees have killed over 600 people; a climber in Costa Rica disturbed a swarm, and received 8,000 stings, killing him. Directed by Martin Gorst, made by Windfall Films 27 October Double Identity, largely about the nature versus nurture argument, as opposed to the less-scientific tabula rasa argument; the Twins Days annual festival held in Twinsburg, Ohio; the heritability of IQ and Robert Plomin of the Institute of Psychiatry, Psychology and Neuroscience at King's College London; Nick Martin of the Queensland Institute of Medical Research; 75% of intelligence is genetic from twin studies, and David T. Lykken of the University of Minnesota; vanishing twins; Neil Sebire of King's College Hospital and Alessandra Piontelli of the University of Milan; country music The LeGarde Twins; Dorothy V. M. Bishop of the University of Cambridge; heritability of IQ and Peter Conrad (sociologist) of Brandeis University; the Louisville Twin Study at the University of Louisville in Kentucky, which also found the Scarr–Rowe effect. Narrated by Jenni Murray, directed by Selina Macnair, produced by Amanda Theunissen, made by Fulcrum Productions West 3 November Identified Flying Objects, about Marfa, Texas and the Marfa lights, and other earthquake lights; Paul Devereux and computer scientist Erling Strand, of Østfold University College and Project Hessdalen, visits the Min Min lights in Australia in 1995; Paul Devereux investigated lights that had been seen at Llanegryn in 1904, which followed the Mochras geological fault; there had been seismic activity at the time which had culminated in the 1906 Swansea earthquake; lights had been seen at Toppenish ridge in the US, in the Cascade Mountains, which had a thrust fault; geologist Peter Sammonds at the UCL Department of Earth Sciences; geophysicist Jim Byerlee, known for Byerlee's law; Mexican television presenter Jaime Maussan; the Popocatépetl volcano in Mexico. Narrated by David Jessel, directed by Chris Hale, made by Real World Pictures, with the Discovery Channel 10 November What's in a Number?, poetry by Lavinia Greenlaw, with dyscalculia which is connected to the parietal lobe and Prof Brian Butterworth of UCL Neuroscience; the artist Sir Michael Craig-Martin; a 1950s educational film about pi made by Coronet Films; the Chudnovsky brothers; fractals come from plotting on a graph imaginary numbers against real numbers and have self-similarity, and Ian Stewart of the University of Warwick; Steven Weinberg of the University of Texas at Austin. Directed by Edmund Coulthard, produced by Duncan Dallas, who founded Café Scientifique in 1998, made by XYTV 24 November The Men with Nine Lives, about the British Army bomb disposal course, with 321 EOD Squadron RLC and the Army School of Ammunition (now the Defence Explosive Ordnance Disposal, Munitions and Search Training Regiment); twenty British Army bomb disposal personnel were killed defusing bombs in Northern Ireland; early IRA explosives were in tin cans filled with nails; 42-year-old Shane O'Doherty, a former IRA operative, who received thirty life sentences in 1974 for letter bombs; IRA personnel called themselves 'explosive operatives'; the IRA moved on to bombs in mail packages, triggered by tilt switches, and on to much-bigger car bombs; Lieutenant-Colonel Peter Miller invented a remote-control mechanical device that could set off a controlled explosion, so disabling most of the bomb components; projected water disruptors could remove explosive devices under vehicles; the IRA put car explosive devices inside a half of a beer keg; letter bombs would contain three to four ounces of semtex (mostly pentaerythritol tetranitrate); the Downing Street mortar attack of 7 February 1991; the hostage bomb; the IRA would lure army bomb disposal personnel, and metal-detectors would find how the IRA had lured army personnel; south Armagh, controlled by the Provisional IRA South Armagh Brigade was the most-dangerous part of Northern Ireland, and all army personnel travelled on operations only by helicopter. Directed by David Dugan, made by Windfall Films. Shown on Nova on 21 October 1997 as Bomb Squad 1 December Day Return to Space about the new proposals for craft; in 1995, NASA proposed the X-33, chosen on 2 July 1996, to fly by March 1999; Daniel Goldin, head of NASA from 1992 to 2001; Saturn from The Planets; The Blue Danube; the McDonnell Douglas DC-X; Maxwell Hunter; Jupiter from The Planets; Hans Mark of NASA; David Urie and Paul Landry; the Rutan Voyager, which flew around the world without refuelling; the aerospike engine; the Ansari X Prize and the EAA AirVenture Oshkosh air show; Mitchell Burnside Clapp; Gary Hudson, Bevin McKinney, and their Rotary Rocket (Roton); Steve Bennett and his Starchaser Industries. Narrated, similarly to the Adam Curtis series, by Jack Fortune, produced by Richard Reisz, directed by Stephen White, made by TV6 8 December Superhighway Robbery, about 26-year-old Russian computer programmer Vladimir Levin and computer hacking, who was caught when he arrived at Stansted Airport in March 1995 (he was trying to evade extradition to the US, but failed and was extradited in September 1997; an average bank robbery took $1900, but was prosecuted around 82%, a robbery via computer took around $250,000 and prosecution was around 2%; Willie Sutton and his Sutton's law. Narrated by Robin Ellis, directed by Patrick Forbes, produced by Jenny Crowther, made by Hart Ryan. 15 December Dr Satan's Robot, it refers to the film Mysterious Doctor Satan; it shows surgeon Robert J. White and his many macabre experiments on animals; the documentary would have not been appointment viewing for supporters of PETA; John Frankenheimer, director of the film Island of Dr Moreau; Terry Gilliam and his film Twelve Monkeys; the film The City of Lost Children; novelist Michael Marshall Smith, and his novel Spares; Cold Lazarus by Dennis Potter; Conservative MP for Birmingham Edgbaston, Jill Knight, and her disagreements with Roger Gosden; John Gillott; film director John Carpenter; David King, and disagreements with Robert Plomin, which led to his MRC funding being withheld; James Wilson (scientist) of the Perelman School of Medicine at the University of Pennsylvania; Julliet Tizzard of the Progress Trust. Narrated by Seán Barrett (actor), produced by Cathy Rogers, directed by Martin Durkin, made by RDF Television, with the Learning Channel
==== Infrared spectroscopy ==== The C-H stretching mode gives strong absorptions between 2850 and 2960 cm−1 and weaker bands for the C-C stretching mode absorbs between 800 and 1300 cm−1. The carbon–hydrogen bending modes depend on the nature of the group: methyl groups show bands at 1450 cm−1 and 1375 cm−1, while methylene groups show bands at 1465 cm−1 and 1450 cm−1. Carbon chains with more than four carbon atoms show a weak absorption at around 725 cm−1.
Sources: en.wikipedia.org
=== 1980s === The compact disk was invented in the 1980s, initially to store and play digital audio recordings but a few years later also as general data storage. Vacuum is used for the metallization of CD surfaces. In 1984, Edwards' Henry Wycliffe invented the Drystar roots/claw dry pump, patented by Edwards. The Drystar was a positive-displacement roots/claw pump that does not require oil for lubrication. The semiconductor industry in particular moved away quickly from oil-sealed pumps in favour of the new dry pumps. In the harsh semiconductor processes, oil-sealed pumps required frequent servicing and oil changes: this new dry pump technology enabled more complex production processes in the semiconductor industry.
Alkaloids are generated by various living organisms, especially by higher plants – about 10 to 25% of those contain alkaloids. Therefore, in the past the term "alkaloid" was associated with plants. The alkaloids content in plants is usually within a few percent and is inhomogeneous over the plant tissues. Depending on the type of plants, the maximum concentration is observed in the leaves (for example, black henbane), fruits or seeds (Strychnine tree), root (Rauvolfia serpentina) or bark (cinchona). Furthermore, different tissues of the same plants may contain different alkaloids. Beside plants, alkaloids are found in certain types of fungus, such as psilocybin in the fruiting bodies of the genus Psilocybe, and in animals, such as bufotenin in the skin of some toads and a number of insects, markedly ants. Some amines, such as adrenaline and serotonin, which play an important role in higher animals, are similar to alkaloids in their structure and biosynthesis and are sometimes called alkaloids.
Ohanin, a minor vespryn protein component specific to this species, causes hypolocomotion and hyperalgesia in experimental mice. It is believed that it contributes to neurotoxicity on the central nervous system of the victim.
== Analysis == The analysis of YTXs is necessary because of the possible health risks and the limits put in place by the European Commission directive. It is complex due to the large number of YTX analogues that can be present in the sample. Analysis is also problematic because YTXs have similar properties to other lipophilic toxins present in the samples, so methods can be subject to false negative or false positive results due to sample interferences. Several experimental techniques have been developed to detect YTXs, each offering varying levels of selectivity and sensitivity, whilst having numerous advantages and disadvantages.
=== Sugar manufacturing === Ion-exchange resins are used in the manufacturing of sugar from various sources. They are used to help convert one type of sugar into another type of sugar (e.g. glucose isomerization resins convert glucose to fructose under mild conditions, enabling high-fructose syrup production) and to decolorize and purify sugar syrups. This is due to the strong-acid cation resins which exchange metal and color impurities, producing the desired clear, and light-colored sugar syrup.
Sources: en.wikipedia.org
Rush toured Permanent Waves for six months through 1980 to more than 650,000 people across 96 shows, becoming their first tour to make a profit. After the tour, Rush joined rock band Max Webster from Toronto and recorded "Battle Scar" for their 1980 album, Universal Juveniles. Max Webster's lyricist, Pye Dubois, offered the band lyrics to a song he had written. The band accepted, and after reworking by Peart the song became "Tom Sawyer".
As part of the American Expeditionary Forces (AEF) deployed during WWI, the 82nd Division began training with British forces in Picardy as early as 10 May 1918. From there they moved to the hotly contested French border region of Lorraine, which they occupied from 16 June to 11 September in preparation for the Saint-Mihiel offensive. As the attack on the Saint-Mihiel salient began on 12 September, the division engaged in a holding mission to prevent Imperial German Army forces from attacking the right flank of the First Army. This defensive action allowed the 163rd Brigade and 327th Infantry Regiment to advance north-east, raiding the communes of Port-sur-Seille, Eply, Bois de Cheminot, and Bois Fréhaut. Meanwhile, the 328th Infantry Regiment advanced on the west of the Moselle River, made contact with the 90th Division, and entered the town of Norroy, to consolidate American troop positions. By 17 September, the Saint-Mihiel offensive had stabilized, and preparations for the infamous Meuse-Argonne offensive began. On 20 September, the 82nd Division was relieved by the French 69th Division. The 82nd Division was then stationed near Triaucourt and Rarécourt, near the First Army. During this operation, the 82nd Division suffered casualties from heavy artillery fire which the fresh American soldiers were completely unused to. The division was moved into reserve from 26 September to 3 October while it assembled near Varennes-en-Argonne to train and prepare for the Meuse-Argonne offensive.
=== Health care === The Government of India had focused primarily on increasing the hospital-based services for gas victims; thus, hospitals had been built after the disaster. When UCC wanted to sell its shares in UCIL, it was directed by the Supreme Court to finance a 500-bed hospital for the medical care of the survivors. Thus, Bhopal Memorial Hospital and Research Centre (BMHRC) was inaugurated in 1998 and was obliged to give free care for survivors for eight years. BMHRC was a 350-bedded super speciality hospital where heart surgery and hemodialysis were done. There was a dearth of gynaecology, obstetrics and paediatrics. Eight mini-units (outreach health centres) were started and free health care for gas victims was to be offered until 2006. The management had also faced problems with strikes, and the quality of the health care being disputed. Sambhavna Trust is a charitable trust, registered in 1995, that gives modern as well as ayurvedic treatments to gas victims, free of charge.
MNPs vaccination might be an alternative from direct injection. Able to deliver bigger molecules than transdermal patch, MNPs can also deliver bioactive molecules with different physical sizes. Meaning that inactive virus or pathogen can be introduced in the body without discomfort or skin irritation from conventional injection. Possibly it can also reduce the cost of storage that usually needs to be transported in a particular temperature and condition. Stated in cdc.gov website, Mark Prausnitz, co-developer of the microneedle, says "A major advantage of the microneedle patch would be the ease of delivery." The MNPs are small and thin compared to bottles of vial, making it possible to transport in massive quantities in a single trip. Medical waste such as syringes and dirty needles are also eliminated, reducing the possibility of pathogen transmission of blood-borne disease in rural areas. In a study, measles coated MNPs might be resistant to higher temperature compared to vial transport. Higher temperature resistance is a safe bet in low income countries, where there is no such luxury for refrigeration. Furthermore, the delivery of the vaccine is controlled by the MNPs. Less requiring highly trained medical workers in developing countries to apply the vaccine. However, the study in MNPs measles vaccine is still under development, but opening possibilities in the future for other types of vaccines
== Dosage == The delivery method determines the dose required to raise an effective immune response. Saline injections require variable amounts of DNA, from 10 μg to 1 mg, whereas gene gun deliveries require 100 to 1000 times less. Generally, 0.2 μg – 20 μg are required, although quantities as low as 16 ng have been reported. These quantities vary by species. Mice for example, require approximately 10 times less DNA than primates. Saline injections require more DNA because the DNA is delivered to the extracellular spaces of the target tissue (normally muscle), where it has to overcome physical barriers (such as the basal lamina and large amounts of connective tissue) before it is taken up by the cells, while gene gun deliveries drive/force DNA directly into the cells, resulting in less "wastage".
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.