What absorbs at 3279 cm⁻¹ in an FTIR spectrum?
A band near 3279 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
A band near 3279 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
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 8 | 7 | 1.0 |
| N h | 3 | 3 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Carbohydrate | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| pectin | 3279, 1746, 1150 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| rGO | 3279, 2358, 2930 | Hydroxyl (O-H), Alkyl C-H, N h | 1 |
| hydrogels | 3279, 3281, 1700 | Alkyl C-H, N h | 1 |
| curcumin | 3279, 1063, 1153 | Alkyl C-H, Hydroxyl (O-H) | 1 |
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 3279 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
-
confidence 1.0
“The FTIR spectrum of WPI with CQ still displayed rod-shaped morphology after drug cm-1 displayed characteristic peaks at 3279 for N-H stretch, release at pH 7.4 over a period of 48 h (Fig.”
Owonubi 等 - 2018 - Characterization and in vitro release kinetics of DOI: 10.1007/s40090-018-0139-2 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Dhal 等 - 2023 - Formulation and Characterization of Emulgel-Based DOI: 10.3390/gels9060466 -
Hydroxyl (O-H) confidence 1.0
“As was seen, from the same figure, the peaks 3279.28 cm-1 Surface morphology of the activated carbon and 3565.02 for the AC are attributed respectively to the O-H hydroxyl groups and the hydrogen bonding possibly due Inthepresentstudy,SEMis”
Removal efficiency of pharmaceutical drugs (Mebeverine hydrochloride MEB) by an activated carbon prepared from dates stems DOI: 10.1007/s40201-021-00658-1 -
Hydroxyl (O-H) confidence 1.0
“cm-1 In the FTIR spectrum of the RF film, the bands at 3278.59 and 2923.57 were attributed to the -OH group stretching and the C-H stretching vibration of CH of starch, 2 Polymers2022,14,1872 10of13”
Mechanical and Physicochemical Properties of Composite Biopolymer Films Based on Carboxymethyl Cellulose from Young Palmyra Palm Fruit Husk and Rice Flour DOI: 10.3390/polym14091872 -
Hydroxyl (O-H) confidence 1.0
“After the juice concentration experiments, certain specific peaks on the pristine CTA An amount of 3279 cm-1 represented the stretching and vibration of the O-H bond in FO membrane decreased or disappeared.”
Membrane Fouling Behavior of Forward Osmosis for FruitJuice Concentration DOI: 10.3390/membranes11080611 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Development of functional pectin edible films with fillers obtained from red cabbage and beetroot DOI: 10.1111/ijfs.14886 -
Amide confidence 1.0
“LLM confirmed rule peak-group candidate”
Sharma 等 - 2009 - One-Dimensional Gold Nanoparticle Arrays by Electr DOI: 10.1002/anie.200901621. -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Ulag 等 - 2020 - 3D printed artificial cornea for corneal stromal t DOI: 10.1016/j.eurpolymj.2020.109744
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