Fatty acid — FTIR-absorptions-toppe og tildelinger

Hurtigt svar

Fatty acid tildeles normalt ved at lede efter en tilbagevendende klynge af karakteristiske toppe frem for et præcist lærebogsnummer. Tabellen nedenfor viser, hvor litteraturen oftest placerer denne gruppe i FTIR, rangeret efter akkumuleret evidens.

Karakteristiske FTIR-toppe for Fatty acid

Viser de 30 bedst understøttede toppe ud af 152 i alt for Fatty acid.

Spektrumlogik

En funktionel gruppetildeling bliver mere sikker, når flere forventede bånd optræder sammen. Brug denne side til at finde de bedst understøttede peaks, og bekræft derefter, at den samme prøve udviser et sammenhængende mønster snarere end et enkelt isoleret hit.

Anvendelse i virkeligheden

Disse sider er nyttige til analyse af ukendte materialer, topforklaring i rapporter, polymerfejlfinding og verifikation af, om en kandidatmaterialefamilie er kemisk plausibel.

Almindelige fejl

• Brug af én funktionel-gruppe-side som en komplet materialebedømmelse uden at kontrollere resten af spektret.
• Antager, at det stærkeste bånd altid er det mest diagnostiske.
• At glemme, at forarbejdning, tilsætningsstoffer, ældning og blandinger kan flytte eller udvide forventede toppe.

Verifikationsrådgivning

Brug DSC, GC-MS eller TGA, når flere materialefamilier deler lignende bånd, eller når blandings-effekter gør FTIR-tildelingen usikker.

Litteratur bag disse tildelinger

• 3008 cm⁻¹ tillid 1,0

  “cm-1 absence of the vibration 3008 could be attributed to potential peroxidation of the U unsaturation of fatty acids as the worm ages.”

  Fourier transform infrared microspectroscopy detects biochemical changes during C. elegans lifespan DOI: 10.1016/j.vibspec.2019.04.005
• 1708 cm⁻¹ tillid 1,0

  “For free fatty acid (FFA) quantification, C=O cm-1 the band at 1708 was used, corresponding to the carboxylic acid, whereas for fatty acid cm-1 C=O methyl ester (FAME) quantification, the peak corresponding to at 1746 was considered, which”

  Monitoring Enzymatic Hydroesterification of Low-Cost Feedstocks by Fourier Transform InfraRed Spectroscopy DOI: 10.3390/catal9060535
• 990 cm⁻¹ tillid 1,0

  “different trans fatty acid contents and the other is to integrate 966cm(cid:2)1 945cm(cid:2)1 the area under band between 990 and limits.”

  Quantification of trans fatty acid content in French fries of local food service retailers using attenuated total reflection – Fourier transform infrared spectroscopy DOI: 10.1016/j.foodchem.2010.09.078
• 1749 cm⁻¹ tillid 1,0

  “(2004), this peak represents 1749cm(cid:1)1, impurities such as wax and pectin which contains carwhich indicates free fatty acids and cutin (COO(cid:1) esterified boxylate present in wax and free and carboxylic groups ) functional groups an”

  The removal of impurities from gray cotton fabric by atmospheric pressure plasma treatment and its characterization using ATR-FTIR spectroscopy DOI: 10.1080/00405000.2013.827900
• 1560 cm⁻¹ tillid 1,0

  “Findings COOcm-1 At low fatty acids concentration, the asymmetric stretching vibration of peaks at 1560 while, at higher concentration, this infrared band converts into a doublet peaking at 1535 and cm-1.”

  Adsorption mechanisms of fatty acids on fluorite unraveled by infrared spectroscopy and first-principles calculations DOI: 10.1016/j.jcis.2020.09.062
• 2015 cm⁻¹ tillid 1,0

  “Earlier 3 band of free amino acids.A broad band with the maxima at around 1698 researchers reported that the amorphous materials are unstable if stored - 1 and 1636 cm related to the bending vibrations of -OH from water at temperature close”

  Exploiting maltodextrin and whey protein isolate macromolecules as carriers for the development of freeze dried honey powder DOI: 10.1016/j.carpta.2021.100040
• 1126 cm⁻¹ tillid 1,0

  “The peaks at 1126 band at obvious in lard, beef, and mutton fat spectra, while were small in increase in saturated fatty acid content.”

  Comparison and chemical structure-related basis of species discrimination of animal fats by Raman spectroscopy using near-infrared and visible excitation lasers DOI: 10.1016/j.lwt.2020.110105
• 3006 cm⁻¹ tillid 1,0

  “182 cm-1 The weak signal at 3006 correspond to =C-H stretching groups of cis-unsaturated 183 fatty acid which gradually reduced with the order of poultry, porcine, ovine and bovine 184 MBMs (Koca et al., 2010).”

  Complementarity of FT-IR and Raman spectroscopies for the species discrimination of meat and bone meals related to lipid molecular profiles DOI: 10.1016/j.foodchem.2020.128754