Ácido araquídico
Nombre INCI: Arachidic Acid. Saponificado con NaOH figura como Sodium Arachidate. También: Ácido eicosanoico, Ácido icosanoico.
Calcular una pastilla 100 % de ácido araquídico
Eso es estequiometría sobre una composición medida y no una suposición, y está casi tan bien determinado como una cifra publicada: comprobado contra los 35 aceites del Codex en los que los dos campos vienen de la misma norma, el error mediano del método es del 0,90 % y su percentil 90 del 2,74 %, sin sesgo apreciable. La página de fórmulas enseña las cuentas. Si tiene un certificado de análisis de su lote, introduzca su valor medido en la calculadora y esta estimación se deja de lado.
Valores publicados
| Índice de saponificación | no publicado |
| Derivado de la composición | 179,5 ± 3 % mg KOH/g |
| Usado por la calculadora | 179,5 mg KOH/g (derivado) |
| SAP para NaOH | 0,1280 g/g |
| Índice de yodo | — |
| INS (SAP − índice de yodo) | — |
| Punto de fusión | 73–79 °C |
| Materia insaponificable | — |
Una pastilla hecha 100 % de ácido araquídico
Cualidades convencionales sumadas a partir de los grupos de ácidos grasos; una pastilla de un solo aceite es una referencia, no una receta.
Perfil de ácidos grasos
| Ácido graso | Rango publicado, % | Usado | |
|---|---|---|---|
| Ácido araquídico | C20:0 · saturados | ≥ 97,5 | 97,5 |
De dónde salen estos números
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Specifications table on the product page: Appearance (Color) white or translucent; Form crystals, crystalline powder or flakes; Assay (GC) >= 97.5%; Melting Point (clear melt) 73-79 C (the page prints the degree sign as '?'). Header: CAS 506-30-9, C20H40O2, 312.54 g/mol. No acid, saponification or iodine value. The page was saved as HTML and converted to text (scripts removed, tags to line breaks, html.unescape). Catalogue number found through PubChem's vendor listing for CID 10467.
Specifications: Appearance (Color) white to almost white; Appearance (Form) crystalline powder or crystals or flakes; Infrared spectrum conforms; Melting point 72 C to 78 C; Titration with TBAH 97.5 to 102.5 %; GC >= 97.5 %. The GC line sits behind the page's 'View more' and was read from the specification list in the page's embedded schema.org data; the other lines are in the visible table as well.
Product information: purity >99%, storage room temperature, supplied neat, physical state solid; identifiers CAS 506-30-9, molecular weight 312.53, lipid number C20:0; synonyms include arachidic acid. No titration values, no melting point.
Checked and not used, to show that C20 is sold only as a minor acid in behenic and hydrogenated long-chain cuts. RADIACID 0161 ('Hydrogenated long chain fatty acid with typical C22 content'): C16 2 - 6, C18 31 - 42, C20 7 - 13, C22 42 - 54 %(m/m). RADIACID 0560 (https://www.oleon.com/products-solutions/radiacid-0560, 'BEHENIC ACID'): C20 <= 9, C22 86.0 - 89.0 %(m/m). Found by reading every RADIACID page listed in oleon.com/sitemap.xml.
Arachidic acid is eicosanoic acid, C20:0, the saturated fatty acid two carbons longer than stearic; arachis (peanut) oil gave it its name. Sold on its own it is a fine chemical: no oleochemical producer checked for this record sells an arachidic acid grade. Oleon's C20-bearing products are behenic acids or hydrogenated long-chain cuts in which C20 is the minor acid (RADIACID 0161, hydrogenated long chain fatty acid: C16 2-6 %, C18 31-42 %, C20 7-13 %, C22 42-54 %; RADIACID 0560, behenic acid: C20 <= 9 %, C22 86.0-89.0 %), and Koster Keunen lists behenic acid but no arachidic acid. So the record rests on laboratory producers' specifications, which give purity and a melting range but no titration value in mg KOH/g. What this record holds: Thermo Scientific Chemicals' Arachidic acid, 98% (catalogue A19616, formerly Alfa Aesar) specifies Assay (GC) >= 97.5 %, melting point (clear melt) 73-79 C, appearance white or translucent, form crystals, crystalline powder or flakes; CAS 506-30-9, C20H40O2, 312.54 g/mol. The assay is recorded as arachidic min 97.5 and the clear-melt range as the melting point. The same producer's Eicosanoic acid, 98% (catalogue 117720010, formerly Acros Organics) specifies GC >= 97.5 %, titration with TBAH 97.5 to 102.5 %, melting point 72-78 C, appearance white to almost white, infrared spectrum conforms. Larodan's research-grade eicosanoic acid (product 10-2000) is >99 % pure, molecular weight 312.53, lipid number C20:0, solid. The two catalogue assays and Larodan's purity agree, and nothing else in any of these products is itemised, so the profile holds arachidic alone. sapKohMgPerG is null because no producer publishes a saponification value. The TBAH titration is an assay of carboxylic acid content, expressed as a percentage of pure eicosanoic acid; it is neither an acid value in mg KOH/g nor a saponification value, so it is not filed as either. On the arithmetic, which is arithmetic and not a measurement: a free fatty acid takes one KOH per molecule, so pure C20:0 (M 312.53) is 56106 / 312.53 = 179.5 mg KOH/g, between stearic acid's 56106 / 284.48 = 197.2 and behenic acid's 56106 / 340.58 = 164.7; the build derives the same figure from the recorded profile and labels it derived. iodineValue is null: nobody publishes one, though a fully saturated acid must be near zero. unsaponifiablePercent is null: not published. No source consulted prints an INCI name; the INCI name, CAS and EC numbers are CosIng's entry for Arachidic Acid, which also lists Sodium Arachidate (there is no potassium salt entry). In soap, arachidic acid behaves like a harder, slower-dissolving stearic acid: it raises the melting point and hardness of the bar, and like behenic acid it is better used at a few percent than as a major fat.
Esta ficha forma parte de la base de datos abierta de ingredientes (ODbL). ¿Ha encontrado un error o una fuente primaria mejor? El conjunto de datos está en GitHub; las correcciones con un enlace al documento son bienvenidas.