Elaidic acid

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Structural formula
Structural formula of elaidic acid
General
Surname Elaidic acid
other names
  • trans -9-octadecenoic acid
  • (9 E ) -Octadeca-9-enoic acid ( IUPAC )
Molecular formula C 18 H 34 O 2
Brief description

colorless scales

External identifiers / databases
CAS number 112-79-8
EC number 204-006-6
ECHA InfoCard 100.003.642
PubChem 637517
ChemSpider 553123
DrugBank DB04224
Wikidata Q413491
properties
Molar mass 282.45 g · mol -1
Physical state

firmly

density

0.8734 g cm −3 (45 ° C)

Melting point

44-45 ° C

boiling point

288 ° C (133 hPa)

solubility

almost insoluble in water

Refractive index

1.4499 (45 ° C)

safety instructions
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 315-319-335
P: 264
Toxicological data

100 mg kg −1 ( LD 50 ,  mouse ,  iv )

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Elaidic acid (from Gr. Elaion , "oil") is a monounsaturated fatty acid . The molecule contains an unbranched chain of 18 carbon atoms with a single double bond in the middle . Since both parts of the chain are in a trans arrangement on the double bond, it is also referred to as a trans fatty acid .

The chemical formula is CH 3 - (CH 2 ) 7 –CH = CH– (CH 2 ) 7 –COOH, the systematic name trans -9-octadecenoic acid. The corresponding cis isomer , which occurs much more frequently in nature, is called oleic acid .

The elaidic acid forms colorless crystals of density 0.87 kg / l, melting at 44 to 45 ° C.

Fats (triester of glycerine ) with an elaidic acid residue can - undesirably - arise during fat hardening , but smaller proportions of such glycerides can also be found in milk fat , beef tallow and other fats from ruminants .

proof

The detection and determination of the content of elaidic acid is usually carried out by gas chromatography of the methyl ester; In addition, the unsaturated isomers can be separated using silver nitrate thin-layer chromatography .

Individual evidence

  1. ↑ a b c d Datasheet Elaidic acid, 98% from AlfaAesar, accessed December 7, 2019 ( PDF )(JavaScript required) .
  2. ↑ a b c David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 96th edition. (Internet version:), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-240.
  3. ↑ a b data sheet elaidic acid from Sigma-Aldrich , accessed on April 14, 2010 ( PDF ).
  4. ↑ B. Breuer, T. Stuhlfauth, HP Fock: Separation of fatty acids or methyl esters including positional and geometric isomers by alumina thin-layer chromatography. In: J. of Chromatogr. Science. 25 (7), 1987, pp. 302-306, PMID 3611285 .

Web links

Wiktionary: elaidic acid  - explanations of meanings, word origins, synonyms, translations