{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.metaphosphoric-acid","code":"thing-q2622702","url":"https://ver.cy/models/thing/q2622702/","name":"metaphosphoric acid","alternateNames":["trioxidophosphate(1-)"],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.MAT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"Metaphosphoric acid is a condensed phosphoric acid material conventionally represented by the empirical formula HPO3 or polymeric formula (HPO3)n, whose phosphorus-oxygen units are joined through P-O-P linkages rather than existing as isolated orthophosphoric acid molecules.","purpose":"Enable an agent to identify metaphosphoric acid, assess its composition and changing chemical state, and determine whether a particular material is suitable for an intended operation.","scope":{"in":["Nominal metaphosphoric acid identity and evidence for the actual condensed phosphate species present","Acid content, water content, stabilizers, counterions and analytically relevant impurities","Solid and solution states, including preparation history and changes during storage","Measured properties with methods, conditions and composition-specific applicability","Material-specific handling constraints and suitability for analytical applications"],"out":["Orthophosphoric acid, pyrophosphoric acid and other neighbouring substances as independent models","Metaphosphate salts as independently registered substances","Commercial product packaging, procurement and inventory workflows","Industrial manufacture and dehydration process design","Complete analytical methods and biological samples treated with the reagent"],"boundaries":[]},"distinguishingFeatures":["Check whether the formula describes nominal metaphosphoric composition, (HPO3)n, or an identified molecular species; a repeat formula alone does not establish molecular size or topology. [Supplier identity record](https://www.sigmaaldrich.com/US/en/substance/metaphosphoricacid1234537267860)","Require evidence of phosphate condensation and speciation when distinguishing the material from orthophosphoric acid; acidity or total phosphorus alone cannot settle the boundary.","Measure or document counterions before treating a labelled reagent as acid alone: one commercial stabilized grade declares both HPO3 and NaPO3. [Supplier composition record](https://www.sigmaaldrich.com/LC/en/product/mm/100546)","Distinguish nominal acid identity from a particular oligomer: PubChem separately records a species with formula H4P4O12. [PubChem species record](https://pubchem.ncbi.nlm.nih.gov/compound/25952)","Assess an aqueous preparation using its current composition and preparation history rather than assuming that the solid reagent's label establishes its present phosphate speciation."],"structure":{"bundles":[{"id":"metaphosphoric-identity","name":"Metaphosphoric identity","description":"Establish what the registry name denotes and how a particular material realizes that identity.","layers":[{"id":"identifier-scope","name":"Identifier scope","description":"Connect external identities without collapsing distinct chemical representations.","findings":[{"id":"nominal-substance-identifiers","name":"Nominal substance identifiers","description":"The supplier associates (HPO3)n with CAS 37267-86-0 and EC 253-433-4; these identifiers require scope checks before attaching species-level properties. [Supplier record](https://www.sigmaaldrich.com/US/en/substance/metaphosphoricacid1234537267860)","questions":[{"text":"Does each identifier denote the nominal condensed acid, a defined species or the supplied formulation?","id":"nominal-substance-identifiers-q01","kind":"definition"},{"text":"Which authoritative record supports the identifier attached to this material?","id":"nominal-substance-identifiers-q02","kind":"provenance"}]}]},{"id":"condensation-boundaries","name":"Condensation boundaries","description":"Distinguish metaphosphoric identity from adjacent phosphate acids and salts.","findings":[{"id":"species-evidence","name":"Species evidence","description":"Record evidence for condensed phosphate species and acid versus salt character instead of inferring both from total phosphorus.","questions":[{"text":"What measurement distinguishes the present species from orthophosphate, pyrophosphate and other condensed phosphates?","id":"species-evidence-q01","kind":"measurement"},{"text":"Does the evidence support acid material, a metaphosphate salt or a mixture requiring component identities?","id":"species-evidence-q02","kind":"boundary"}]}]}]},{"id":"assay-and-formulation","name":"Assay and formulation","description":"Describe the actual acid loading and non-acid constituents.","layers":[{"id":"acid-equivalent-basis","name":"Acid equivalent basis","description":"Make concentration and assay interpretations explicit.","findings":[{"id":"assay-is-method-dependent","name":"Assay is method dependent","description":"Keep reported HPO3 assay separate from species-resolved purity and record the analytical endpoint.","questions":[{"text":"Is the reported percentage an acidimetric HPO3 equivalent, a mass fraction or a species-specific measurement?","id":"assay-is-method-dependent-q01","kind":"definition"},{"text":"What endpoint, sample treatment and uncertainty support the assay?","id":"assay-is-method-dependent-q02","kind":"measurement"}]}]},{"id":"stabilizers-and-impurities","name":"Stabilizers and impurities","description":"Account for constituents that affect preparation and analytical performance.","findings":[{"id":"stabilized-grade-composition","name":"Stabilized grade composition","description":"One supplier grade reports 40-50% HPO3 and 50-60% NaPO3 on an acidimetric basis; this is evidence about that formulation, not every metaphosphoric acid material. [Product specification](https://www.sigmaaldrich.com/LC/en/product/mm/100546)","questions":[{"text":"Which stabilizers and counterions are declared or measured in this lot?","id":"stabilized-grade-composition-q01","kind":"provenance"},{"text":"Which impurities or added salts could interfere with the intended assay?","id":"stabilized-grade-composition-q02","kind":"action"}]}]}]},{"id":"water-exposure-and-state","name":"Water exposure and state","description":"Track solid condition and the chemical state of aqueous preparations.","layers":[{"id":"solid-condition","name":"Solid condition","description":"Qualify physical observations and measurements of the supplied solid.","findings":[{"id":"condition-qualified-properties","name":"Condition-qualified properties","description":"Associate appearance, water content, density and thermal observations with the measured sample rather than treating them as universal constants.","questions":[{"text":"What are the sample's water content, physical appearance and storage conditions at measurement?","id":"condition-qualified-properties-q01","kind":"measurement"},{"text":"Does a reported thermal event represent melting, softening, water loss or chemical transformation?","id":"condition-qualified-properties-q02","kind":"boundary"}]}]},{"id":"aqueous-evolution","name":"Aqueous evolution","description":"Resolve the composition of a solution over its relevant lifetime.","findings":[{"id":"solution-age-and-speciation","name":"Solution age and speciation","description":"Treat changes in phosphate distribution after preparation as a condition to establish experimentally, without assigning an unsupported universal shelf life.","questions":[{"text":"How do measured phosphate fractions change with time, temperature and solution concentration?","id":"solution-age-and-speciation-q01","kind":"measurement"},{"text":"What evidence determines when this preparation must be retested or replaced?","id":"solution-age-and-speciation-q02","kind":"action"}]}]}]},{"id":"analytical-fitness","name":"Analytical fitness","description":"Connect material properties to a specified analytical use.","layers":[{"id":"preparation-accounting","name":"Preparation accounting","description":"Support reproducible concentration calculations for the actual material.","findings":[{"id":"loading-versus-active-basis","name":"Loading versus active basis","description":"Distinguish grams of supplied reagent from grams of HPO3 equivalent and from any measured species concentration.","questions":[{"text":"Does the method specify supplied-reagent mass, HPO3 equivalents or another concentration basis?","id":"loading-versus-active-basis-q01","kind":"definition"},{"text":"How should the lot assay and stabilizer fraction enter the preparation calculation?","id":"loading-versus-active-basis-q02","kind":"action"}]}]},{"id":"method-performance","name":"Method performance","description":"Determine whether the material meets the chosen procedure's acceptance criteria.","findings":[{"id":"use-specific-acceptance","name":"Use-specific acceptance","description":"For a proposed role such as protein precipitation or analyte preservation, require method-specific evidence linking composition and solution condition to performance.","questions":[{"text":"Which validated procedure establishes the intended role of metaphosphoric acid?","id":"use-specific-acceptance-q01","kind":"provenance"},{"text":"What recovery, blank, precipitation or stability criteria must this preparation satisfy?","id":"use-specific-acceptance-q02","kind":"measurement"}]}]}]},{"id":"formulation-specific-handling","name":"Formulation-specific handling","description":"Bind permissible operations to documented hazards of the actual material.","layers":[{"id":"hazard-record-applicability","name":"Hazard record applicability","description":"Establish which safety and regulatory records govern the material.","findings":[{"id":"matched-safety-record","name":"Matched safety record","description":"Record classification and exposure guidance only when the source's identity, formulation and jurisdiction match the material under assessment.","questions":[{"text":"Which current SDS and jurisdiction-specific classification apply to this composition?","id":"matched-safety-record-q01","kind":"provenance"},{"text":"Are any cited exposure limits explicitly applicable to this substance or formulation?","id":"matched-safety-record-q02","kind":"boundary"}]}]},{"id":"operation-constraints","name":"Operation constraints","description":"Translate applicable documentation into constraints on preparation, storage and disposal.","findings":[{"id":"documented-operating-conditions","name":"Documented operating conditions","description":"Determine handling requirements using the matched safety record and intended operation, including any change in concentration or physical form.","questions":[{"text":"What documented controls apply to dissolving, transferring or heating this specific material?","id":"documented-operating-conditions-q01","kind":"action"},{"text":"Which container, incompatibility and waste requirements apply after preparation or contamination?","id":"documented-operating-conditions-q02","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of metaphosphoric acid this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of metaphosphoric acid this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of metaphosphoric acid this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of metaphosphoric acid this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of metaphosphoric acid this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of metaphosphoric acid this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of metaphosphoric acid this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Report hazard classification, storage and handling rules from a safety data sheet.","Describe its uses in laboratories, such as protein precipitation and sample preservation, from published methods.","Track stock and storage conditions in a laboratory the agent is authorized to manage."],"mustNot":["Advise using laboratory-grade metaphosphoric acid in food or on people.","Give handling advice that contradicts the safety data sheet.","Store it with incompatible chemicals or in damp conditions.","Dispose of it outside the site's chemical waste process."],"requiresHuman":["Responding to a spill or exposure, which must follow the site's emergency plan."]},"ethics":{"considerations":["It is corrosive and can injure workers who handle it carelessly.","Phosphate discharges contribute to water pollution."],"affectedParties":["Laboratory workers","Students","Waste and water workers"]},"owners":{"steward":"The operator of the laboratory or plant that holds it.","roles":[],"masterSystems":["Chemical inventories and safety data sheet systems"]},"relations":[{"target":"Q11173","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.metaphosphoric-acid","Wikidata: Q2622702 (https://www.wikidata.org/wiki/Q2622702)"]},"properties":{"applicability":"required","items":["Chemical identity and identifier scope: Registry id plus source-qualified CAS, EC and PubChem identifiers; nominal substance versus explicit species","Condensed phosphate distribution: Species fractions on a stated phosphorus basis; analytical method and uncertainty","Acid assay and reporting basis: % as HPO3, with mass or other basis, titration endpoint and method specified","Stabilizer and counterion content: Component identity and mass fraction; sodium or other cation concentration","Water content: % by mass with method, sampling time and handling conditions","Physical presentation: Glassy solid, pieces, other characterized solid, or aqueous preparation; temperature and observation date","Solution concentration and acidity: g/L as specified material or HPO3 equivalent; pH at stated temperature; titratable acidity in mol-equivalent/L","Preparation and storage history: Preparation timestamp, solvent, temperature history, container and moisture exposure","Composition-qualified physical constants: Density in g/cm3; thermal events in °C; pressure, method and sample composition required","Application-relevant impurities: mg/kg or mg/L, detection limits and methods for relevant metals, reducing substances and phosphate species","Safety and regulatory classification: Source-qualified GHS classification, jurisdiction, SDS revision and applicable formulation"]},"recognition":{"applicability":"required","items":["Glassy, colourless sticks, lumps or flakes that absorb moisture from the air."]},"capabilities":{"applicability":"required","items":["Reconcile a material label with substance identifiers and evidence of phosphate speciation.","Compare reagent lots using acid assay, stabilizer content and relevant impurity limits.","Calculate preparation quantities using an explicitly stated assay basis.","Evaluate whether an aged or moisture-exposed preparation needs recharacterization.","Assess suitability for a specified analytical procedure using composition and performance evidence.","Select handling and disposal instructions from documentation applicable to the actual formulation."]},"hazards":{"applicability":"required","items":["Causes burns to skin and eyes on contact.","Slowly turns into orthophosphoric acid in water, changing its properties in solution."]},"interfaces":{"applicability":"required","items":["Globally Harmonized System of Classification and Labelling of Chemicals (GHS), United Nations."]},"context":{"applicability":"required","items":["Metaphosphoric acid is encountered as a laboratory reagent and as a condensed phosphate material in chemical research.","Analytical laboratories use it in sample preparation, including protein precipitation and the stabilisation of vitamin C for measurement.","Its suitability depends on the supplied composition and its chemical changes during storage or contact with water."]}},"sources":[{"title":"Wikidata item Q2622702: metaphosphoric acid","url":"https://www.wikidata.org/wiki/Q2622702","note":"identity and sense of the item"},{"title":"Wikipedia (fr): Acide métaphosphorique","url":"https://fr.wikipedia.org/wiki/Acide_m%C3%A9taphosphorique","note":"general description of the item"}],"openQuestions":["Does the registry intend nominal condensed metaphosphoric acid broadly, or a particular species, and does an existing world model already own that concept?","Which structural and analytical evidence establishes the cyclic, chain or mixed phosphate composition of representative materials sold under this name?","How should broad substance identifiers and species-specific PubChem records be mapped without asserting chemical equivalence?","What measured hydrolysis behaviour and acceptance limits establish usable lifetimes for the intended aqueous preparations?","Which composition-qualified physical constants, current hazard classifications and directly applicable exposure limits can be supported by authoritative records?"],"resources":{"spec":"/models/things/publications/thing-q2622702/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q2622702/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T11:17:09Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-08T19:09:52+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}