What absorbs at 1200 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1200 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.

Possible functional-group assignments

Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.

Possible materials

Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.

Spectrum logic

This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 1200 cm⁻¹ is usually not enough for material identification by itself.

Real-world usage

This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.

Common mistakes

• Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
• Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
• Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.

Verification advice

When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.

Literature behind these assignments

• Carbohydrate confidence 1.0

  “The FTIR bands in the region of 900fucoidan standard is due to more sulfation at 1200cm-1 are characteristic of carbohydrates equatorial at the position in C3 and C2 (Patankar, (Pielesz and Biniaś, 2010).”

  Artemisia 等 - 2019 - The Properties of Brown Marine Algae Sargassum tur DOI: 10.14499/indonesianjpharm30iss1pp43
• Hydroxyl (O-H) confidence 1.0

  “The baseline was subtracted from the raw nitrogencooledMCT-Adetector.Forpolarizedinfraredmeasurements,a spectrum and the OH absorption band area was calculated by 1200line/mmzincselenidewiregridpolarizerwasused.Spectrawere acquiredwitha100µ”

  Calibration of the infrared molar absorption coefficients for H in olivine, clinopyroxene and rhyolitic glass by elastic recoil detection analysis DOI: 10.1016/j.chemgeo.2009.01.001
• Silicon (Si) confidence 1.0

  “Short-term acid leaching of palygorskitesresultsinsignificantchangestoFTIRabsorptionbandsnear1200and790cm-1.Astheacidattackprogresses,thebandat1200cm-1 790cm-1, shifts to lower wavenumbers, whilst the band at which here is assigned to Si U-”

  Cai 等 - 2007 - A Fourier transform infrared spectroscopic study o DOI: 10.1016/j.saa.2006.02.053
• confidence 1.0

  “Changes in the peaks and cm-1) appearence of new bands (between 1200 and 1500 revealed on the interactions between RR 120 molecules and functional groups of MOS (e.g., amino, carbonyl and amide groups) play significant roles in this process”

  Adsorption Kinetic and Isotherms of Reactive Red 120 on <i>Moringa oleifera</i> Seed as an Eco-Friendly Process DOI: 10.1016/j.molstruc.2019.05.106
• Phosphate (PO4) confidence 1.0

  “6 also shows the average IR spectra of the carbonate and 1200cm-1 phosphate bands between 800 and for the calcified calcifieddepositsoftendonandmusclesamples(Fig.6).Ithasbeen reportedthatapeaknear1020cm-1isattributedtothe(cid:2) sample depo”

  Chiou 等 - 2011 - FT-IR microscopic imaging of calcified deposit of DOI: 10.1016/j.vibspec.2011.06.004
• Secondary amine confidence 1.0

  “1350cm(cid:3)1 1280cm(cid:3)1 Since the peaks in the range of till are 935cm(cid:3)1, 1151cm(cid:3)1, cm(cid:3)1 1230cm(cid:3)1 autopeaks at 1200 and in (CAN described as peaks for aromatic secondary amine stretch), M23/08.”

  Choong 等 - 2014 - Identification of geographical origin of Lignosus DOI: 10.1016/j.molstruc.2014.04.001
• Acetate confidence 1.0

  “The multiple bands between 1200 and 1000 may be assigned to C-O stretching of RIPT”

  Mesoporous magnetite nanoparticles synthesis using the Peltophorum pterocarpum pod extract, their antibacterial efficacy against pathogens and ability to remove a pollutant dye DOI: 10.1016/j.molstruc.2018.10.042
• Silicon carbon confidence 1.0

  “sic absorption band of chitosan at 1200 950 is less intense”

  New versatile approach for analysis of PEG content in conjugates and complexes with biomacromolecules based on FTIR spectroscopy. DOI: 10.1016/j.colsurfb.2016.01.030