FTIR ANALYSIS REPORT

Spectrum Analysis Result

No.: 20260511144355029453270 Date: 2026-05-11 06:48:00 Reported by: FTIR.fun Contact: [email protected]

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Executive conclusion

Polyethylene (PE)

Entity identified
Moderate confidence
#548 Initial rank 1 Current rank 1 Library lead match 89.6%
Key findings
  1. Tri-axis gate did not pass: agreement 0.000, dual-axis confidence 0.400, dynamic threshold 0.780
  2. Library retrieval keeps Polyethylene (PE) (#548) as the nearest match
  3. Blocked external aggregate proposal: long-chain aliphatic hydrocarbon material
Primary risk

Independent LLM flags conflicting groups: strong ester/carboxyl specific assignment not securely supported

Library comparison

Reference spectrum for the identified material type vs. uploaded sample

This comparison uses a reference spectrum chosen by the analyzer for the identified material type (e.g. siloxane). It may differ from the library similarity Top-1 shown in the verification workbench below, because the Top-1 is ranked purely by spectral similarity without material-type reasoning.

Figure 1. Overlay of the chosen library reference and the uploaded sample (teal curve).
Show Top-15 verification workbench (similarity-ranked) These 15 candidates are ranked by spectral similarity only, without material-type reasoning. The top match here may differ from the reference spectrum above.
Library spectrum loads when this workbench opens.
Library spectrum Interactive sample curve Move the pointer to show the vertical guide line.
Top 15 candidates

Reference library candidates

This list is a verification appendix. It helps you compare nearby candidates without repeating the report conclusion.

Rank Match % Compound Name Formula / SMILES Library preview Action
Reference candidates load when this verification workbench opens.
Peak analysis

Detected peaks and interpretation

Rows marked with ★ are the characteristic peaks selected by the LLM analyzer.

Index Characteristic Wavenumber Absorbance Sources One-line interpretation KG citation LLM confidence
1 ★ 2915 0.98 LLM / KG 2915 cm-1: possible source: long-chain aliphatic hydrocarbon / paraffin-like material; mixed material or surface contamination scenario; KG hint: aromatic; ester. [1][2] High confidence
2 ★ 2849 0.70 LLM 2849 cm-1: possible source: long-chain aliphatic hydrocarbon / paraffin-like material; mixed material or surface contamination scenario. [1][2] High confidence
3 ★ 1464 0.35 LLM / KG 1464 cm-1: possible source: long-chain aliphatic hydrocarbon / paraffin-like material; KG hint: aromatic; ester. [2][3][1] High confidence
4 ★ 718 0.28 LLM / KG 718 cm-1: possible source: long-chain aliphatic hydrocarbon / paraffin-like material; KG hint: aromatic; ester. [2][1] High confidence
5 ★ 406 0.08 KG 406 cm-1: possible source: aromatic; alkyl c h. [1][2] -
6 ★ 3322 0.05 LLM 3322 cm-1: possible source: mixed material or surface contamination scenario. [3] High confidence
7 ★ 3271 0.04 LLM / KG 3271 cm-1: possible source: mixed material or surface contamination scenario; KG hint: aromatic; alkyl c h. [1][2] High confidence
8 ★ 1328 0.04 KG 1328 cm-1: possible source: aromatic; ester. [2][1] -
9 ★ 3193 0.04 LLM 3193 cm-1: possible source: mixed material or surface contamination scenario. - High confidence
10 ★ 3225 0.04 LLM 3225 cm-1: possible source: mixed material or surface contamination scenario. - High confidence
11 ★ 1004 0.04 LLM / KG 1004 cm-1: possible source: organic material with possible carbonyl/oxygenated functionality; KG hint: aromatic; ester. [2][1] High confidence
12 ★ 1607 0.04 KG 1607 cm-1: possible source: aromatic; ester. [1][2][3] -
13 ★ 2651 0.04 KG 2651 cm-1: possible source: aromatic; alkyl c h. [2][1] -
14 ★ 1175 0.04 LLM / KG 1175 cm-1: possible source: organic material with possible carbonyl/oxygenated functionality; KG hint: aromatic; ester. [1][2][3] High confidence
15 · 3991 0.04 - 3991 cm-1: possible source: Possible background: possible high band background. - -
16 ★ 1085 0.03 LLM / KG 1085 cm-1: possible source: organic material with possible carbonyl/oxygenated functionality; KG hint: aromatic; ester. [2][1] High confidence
17 · 3347 0.03 - 3347 cm-1: possible source: Refer to AI conclusion. [3] -
18 ★ 1216 0.03 LLM / KG 1216 cm-1: possible source: organic material with possible carbonyl/oxygenated functionality; KG hint: aromatic; ester. [1][3][2] High confidence
19 · 3399 0.03 - 3399 cm-1: possible source: Refer to AI conclusion. [1][3] -
20 ★ 1746 0.01 LLM / KG 1746 cm-1: possible source: organic material with possible carbonyl/oxygenated functionality; mixed material or surface contamination scenario; KG hint: aromatic; ester. [1][2] High confidence
Show full reasoning, evidence, and recommendations Expand to read the conclusion evidence, reasoning chain, full risk list, recommendations, and mixture notes.
Evidence

Conclusion evidence

Only evidence already present in the current result contract is shown here.

Library lead candidate LIB
Polyethylene (PE) #548 | match 89.6%
Material direction AGG
Polyethylene (PE) No external material-direction override was promoted because the tri-axis gate did not pass.
Reasoning

Reasoning chain

This section explains how the current conclusion was reached from the available evidence.

  1. Library retrieval remains the displayed lead because the external aggregate class proposal was withheld because the configured tri-axis gate did not pass.
  2. The nearest library entity is stable, but class-level corroboration is less complete.
  3. No external material-direction override was promoted because the tri-axis gate did not pass.
  4. Recommended candidate: Polyethylene (PE) (#548) with a current matching score of 0.896.
  5. Library retrieval remains the displayed lead: Polyethylene (PE) (#548). External class-level evidence was not promoted because the tri-axis gate did not pass.
  6. Library retrieval keeps Polyethylene (PE) (#548) as the nearest match.
  7. KG derives the material direction oxygen containing from group-level evidence. top graph recall is spectrum #11865. 3 literature source(s) reinforce this path; groups acetyl, aldehyde, alkyl_c_h, amide; peaks 718, 1085, 1175, 1216, 1464, 1607.. semantic bridge links the current direction to known directions such as "N-(4-Hydroxyphenyl)acetamide", "N-(4-Hydroxyphenyl)acetamide". secondary component clues remain visible through carbonyl like, aromatic like.
  8. The strongest and most coherent pattern is a methylene-rich aliphatic material: very strong C-H stretches at 2915 and 2849 cm-1, a CH2 deformation near 1464 cm-1, and a chain-related rocking band near 718 cm-1. This combination is highly consistent with a long-chain hydrocarbon or paraffin-like component. The sample note also warns that 2850-2950 cm-1 may include aliphatic background or mineral-oil contamination, so this direction is strong at the class level but should be interpreted with contamination caution.
  9. Peak notes: 2915: LLM: long-chain aliphatic hydrocarbon / paraffin-like material; mixed material or surface contamination scenario | KG: aromatic; ester; 2849: LLM: long-chain aliphatic hydrocarbon / paraffin-like material; mixed material or surface contamination scenario; 1464: LLM: long-chain aliphatic hydrocarbon / paraffin-like material | KG: aromatic; ester; 718: LLM: long-chain aliphatic hydrocarbon / paraffin-like material | KG: aromatic; ester.
Risk

Uncertainty and blockers

These items limit how far the current conclusion can be trusted or refined.

  • Independent LLM flags conflicting groups: strong ester/carboxyl specific assignment not securely supported
  • Blocked external class proposal: long-chain aliphatic hydrocarbon material
  • dual-axis confidence 0.400 is below dynamic threshold 0.780
  • LLM/KG agreement 0.000 is below 0.600
  • The external aggregate class proposal was withheld because the configured tri-axis gate did not pass
  • Library lead over the runner-up remains narrow (gap 0.019)
  • Aliphatic background or mineral oil contamination may contribute near 2850-2950 cm-1
  • External aggregate proposal was not promoted: long-chain aliphatic hydrocarbon material
  • KG limit: graph fact coverage is missing for observed peaks: 2849, 3193, 3225, 3322, 3347, 3399, 3991
  • KG limit: KG co-occurrence evidence was skipped for this high-peak-count sample: compressed graph peak count 14 exceeds FTIRFUN_KG_GRAPH_CONTEXT_COOCCURRENCE_MAX_PEAKS=10; window/pair co-occurrence SQL was skipped and only direct peak-group facts were used
  • graph fact coverage is missing for observed peaks: 2849, 3193, 3225, 3322, 3347, 3399, 3991
  • KG co-occurrence evidence was skipped for this high-peak-count sample: compressed graph peak count 14 exceeds FTIRFUN_KG_GRAPH_CONTEXT_COOCCURRENCE_MAX_PEAKS=10; window/pair co-occurrence SQL was skipped and only direct peak-group facts were used
  • Add or derive project facts around currently uncovered peaks.
Recommendation

Recommended next steps

These are the next verification actions suggested by the current reasoning output.

  • Reacquire or reprocess the spectrum before making a stronger identification claim because Aliphatic background or mineral oil contamination may contribute near 2850-2950 cm-1.
  • Prioritize KG and literature enrichment for uncovered peaks 2849, 3193, 3225, 3322, 3347, 3399, 3991 because those missing anchors are currently blocking graph-side confirmation.
  • Use discriminative bands around 2915, 2849, 1464, 718, 406, 1004 to decide between the LLM-supported long-chain aliphatic hydrocarbon / paraffin-like material direction and the KG-supported oxygen containing direction.
  • Compare the library lead against the nearest runner-up explicitly because the current lead gap is only 0.019.
Mixture

Component and mixture notes

When present, mixture or component-peeling diagnostics are summarized here.

  • Two-component formulation analysis is paused because the current library does not have enough coverage for reliable formulation-level inference.
  • The old two-component code path is kept in the repository, but the runtime no longer uses it to avoid pushing the search toward unsupported composition claims.
  • Component peeling is paused in runtime because conservative low-match replay did not produce verified wins after excluding self-peeling.
  • The exploration was still useful: relaxing the gates restored peelability, but most new extractions were self-peeling or chemically implausible, which clarified the current boundary of the library and gating design.
  • The peeling implementation remains in the repository for later reactivation after stronger low-match evidence appears.
Literature

References

Knowledge-graph literature citations used to support the spectral assignment.

3 literature source(s) reinforce this path; groups acetyl, aldehyde, alkyl_c_h, amide; peaks 718, 1085, 1175, 1216, 1464, 1607.

  1. [1] 10.1371/journal.
    Supports: 1175 cm⁻¹ 1216 cm⁻¹ 1607 cm⁻¹ 1746 cm⁻¹ 2849 cm⁻¹ 2915 cm⁻¹ 3399 cm⁻¹
  2. [2] 10.1155/2018/7823248
    Supports: 718 cm⁻¹ 1085 cm⁻¹ 1175 cm⁻¹ 1464 cm⁻¹ 1607 cm⁻¹ 1746 cm⁻¹ 2651 cm⁻¹ 2849 cm⁻¹
  3. [3] 10.1021/jp0313122
    Supports: 1175 cm⁻¹ 1216 cm⁻¹ 1464 cm⁻¹ 1607 cm⁻¹ 3322 cm⁻¹ 3347 cm⁻¹ 3399 cm⁻¹
Appendix

Sample information and raw spectrum

The raw uploaded spectrum is retained here for audit and manual review.

Baseline correction method: Asymmetric Least Squares Smoothing

The wavelength range for analysis(cm-1): [(400, 4000)]

Raw spectrum without baseline correction or other processing:

Raw spectrum image