Linoleic Acid
INCI Linoleic Acid. Also: (9Z,12Z)-Octadeca-9,12-dienoic acid, cis,cis-9,12-Octadecadienoic acid, C18:2 fatty acid, Linoleic acid 99%.
Calculate a 100 % Linoleic Acid bar
That is stoichiometry on a measured composition rather than a guess, and it is about as well determined as a published figure: checked against the 35 Codex oils where both fields come from the same standard, the method's median error is 0.90 % and its 90th percentile 2.74 %, with no meaningful bias. The formula page shows the working. If you have a certificate of analysis for your lot, enter its measured value in the calculator and this estimate is set aside.
Published values
| Saponification value | not published |
| Derived from composition | 200.1 ± 3 % mg KOH/g |
| Used by the calculator | 200.1 mg KOH/g (derived) |
| SAP for NaOH | 0.1426 g/g |
| Iodine value | — |
| INS (SAP − IV) | — |
| Melting point | — |
| Unsaponifiable matter | — |
A bar made of 100 % Linoleic Acid
Conventional qualities summed from the fatty-acid groups; a single-oil bar is a reference point, not a recipe.
Fatty-acid profile
| Fatty acid | Published range, % | Used | |
|---|---|---|---|
| Linoleic acid | C18:2 | ≥ 98.5 | 98.5 |
Where these numbers come from
Specifications: Infrared spectrum conforms; Appearance (Color) clear colorless to light yellow; Refractive index 1.4687 to 1.4707 (20 C, 589 nm); Appearance (Form) liquid; GC 98.5 % min. CAS 60-33-3, C18H32O2, 280.45 g/mol. No acid value, saponification value or iodine value is published.
Specifications: Appearance (Color) clear colorless to yellow; Appearance (Form) liquid; Infrared spectrum conforms; Acid value 195 to 205 mg KOH/g; GC 65 % min. The only titrated figure found for any linoleic acid grade in an allowed document.
Acid value 198-203 mgKOH/g; iodine value 127-143 gI2/100g; Lovibond 5 1/4 in. yellow max 10, red max 1; composition C16 4-9 %, C18 max 6 %, C18:1 15-31 %, C18:2 56-67 %, C18:3 max 1 %. Cited as the bulk high-linoleic material a maker can actually buy, not as the single acid.
No allowed primary document publishes a saponification value for linoleic acid, so sapKohMgPerG is null. Purified C18:2 is a fine chemical, not an oleochemical cut: Wilmar, Emery and KLK OLEO have no linoleic grade at all, and Oleon's nearest equivalents are distilled seed-oil acids rather than the single acid (RADIACID 0132, sunflower fatty acids distilled, is C18:2 56-67 % with acid value 198-203 mg KOH/g and iodine value 127-143 g I2/100 g). The laboratory producers who do sell the pure acid publish purity and physical constants but no titration. What is published, and what this record holds: Thermo Scientific Chemicals' Linoleic acid, 99 % (catalogue 215041000, formerly Acros Organics) specifies GC 98.5 % min, refractive index 1.4687-1.4707 at 20 C and 589 nm, appearance clear colourless to light yellow liquid, infrared conforms - no acid, saponification or iodine value. Their technical Linoleic acid, 70 % (413195000) does print an acid value, 195 to 205 mg KOH/g at GC 65 % min; the balance in that grade is the oleic, palmitic and stearic acids of the safflower or sunflower feedstock and is not itemised, so it is not mapped here. On the arithmetic, which is arithmetic and not measurement: a free fatty acid takes one KOH per molecule, so the pure acid (M 280.45) is 56106 / 280.45 = 200.1 mg KOH/g, and two double bonds give a theoretical iodine value of 181 g I2/100 g. Neither number is filed in a field, because neither was measured by anyone in an allowed document; the build derives a saponification value from the recorded profile and labels it derived, which is the honest form of the same number. Note that the two independent routes agree - 200.1 from stoichiometry against 195-205 titrated on the 70 % grade, whose other acids are all C16-C18 and so barely move the mean molar mass. For the bench: neat linoleic acid is a liquid that oxidises fast, so a bar carrying much of it goes rancid and spots (DOS) long before the cure is interesting, and it lathers poorly; linoleic is wanted as the minority acid inside a seed oil, not as a neat addition. INCI is the standard entry and was not re-verified on CosIng in this session; the salt names were not established from an allowed document, so saponifiedInci is null.
This record is part of the open ingredient database (ODbL). Found an error or a better primary source? The dataset is on GitHub; corrections with a document link are welcome.