FTIR Spectral Analysis Platform

ChemFitX provides an online FTIR spectral analysis workflow for researchers working with Fourier-transform infrared spectroscopy data from nanomaterials, polymers, catalysts, ceramics, biomaterials, pharmaceuticals, environmental samples, coatings, carbon materials and other organic or inorganic systems. The platform combines spectrum import, signal processing, baseline correction, peak detection, functional-group interpretation support, interactive visualization and export tools in one browser-based workspace.

Upload an FTIR spectrum, choose or automatically detect whether the signal is transmittance or absorbance, apply optional smoothing and baseline correction, detect bands, and inspect tentative functional-group assignments against curated infrared reference ranges. The platform is designed to make FTIR interpretation more transparent by showing the detected wavenumber, signal value, peak prominence, assignment, alternative matches and a ranking score rather than presenting a single unexplained identity.

The FTIR file is read and analyzed locally in your web browser by this application. Your uploaded spectrum is not sent to ChemFitX servers during the analysis.

What the FTIR Spectral Analysis Platform Can Do

Import FTIR spectra from CSV, TSV, TXT, XY, DAT, ASC, XLSX and XLS files.
Automatically infer whether uploaded data are transmittance or absorbance when possible, with a manual override.
Preserve the plotted spectrum in its uploaded signal scale while treating transmittance minima appropriately during band detection.
Apply optional spectral smoothing before interpretation.
Provide Savitzky-Golay, moving-average, Gaussian, Whittaker, LOWESS, median, Butterworth, Wiener, bilateral and exponential smoothing options.
Apply optional baseline correction with manual or automated methods.
Provide manual baseline drawing, ModPoly, IModPoly, rolling-ball, asymmetric least squares, polynomial, rubber-band, top-hat, SNIP, linear, spline and smart/automatic baseline options.
Use conservative prominence-based, multi-scale peak detection designed to reduce duplicate noise peaks while retaining narrow and broad FTIR bands.
Adjust peak-detection sensitivity and minimum peak separation.
Insert a missed peak manually and undo the most recent manual insertion.
Compare detected bands with a curated FTIR functional-group reference database.
Show a primary tentative assignment together with alternative reference matches when available.
Rank assignments using a match score that indicates agreement with the implemented reference-range logic rather than a probability of compound identity.
Apply context-specific analysis presets that re-rank assignments and focus the peak table on relevant FTIR regions.
Use presets for carbon nanomaterials, graphene/graphene oxide, metal oxides, quantum dots, nanocomposites, polymers, ceramics/glasses, biomaterials, catalysts, coatings, pharmaceuticals, environmental samples, food/biochemical samples and forensic/unknown organics.
Search and filter the curated FTIR reference database by functional group or assignment terms.
Pan and zoom the FTIR spectrum interactively.
Export the spectrum chart as PNG.
Export analysis results to CSV, JSON and Excel.
Generate a text report containing processing parameters, spectral range, detected bands and tentative assignments.

Supported FTIR Data Files

The platform accepts common text and spreadsheet formats used for exported FTIR spectra: CSV, TSV, TXT, XY, DAT, ASC, XLSX and XLS. ChemFitX searches for numeric spectral columns and expects a wavenumber axis together with a corresponding spectral signal.

For the most reliable analysis, use a file that preserves the original wavenumber values and spectral signal without screenshots, manual retyping or unnecessary resampling. If the file contains headers indicating transmittance or absorbance, those labels can support automatic spectrum-type detection.

Transmittance and Absorbance Handling

Automatic spectrum-type detection

When Auto-detect is selected, ChemFitX uses file-header information when available and also evaluates the uploaded signal statistics to infer whether the spectrum is more consistent with transmittance or absorbance. The detected interpretation can be overridden manually.

How transmittance peaks are handled

In a transmittance spectrum, an absorption band is normally represented by a downward minimum rather than an upward maximum. The platform accounts for this internally during peak detection while leaving the displayed spectrum in the uploaded transmittance scale.

Why the correct spectrum type matters

Selecting the wrong signal interpretation can cause real absorption bands to be missed or non-band features to be treated incorrectly. Confirm the signal type from the instrument export, axis label or known spectral appearance whenever possible.

FTIR Smoothing Options

Noise reduction can help stabilize band detection, but smoothing should be applied conservatively because every smoothing method can alter spectral detail if its strength or window is excessive. ChemFitX therefore keeps smoothing optional and provides several methods so the user can choose an approach suited to the data.

Savitzky-Golay

locally fits a polynomial and is commonly used when the goal is to reduce noise while retaining peak shape.

Moving average

replaces each point with a local average and provides simple noise suppression.

Gaussian filter

uses a Gaussian-weighted neighborhood for smooth local averaging.

Whittaker smoother

applies a smoothness-penalized representation of the signal.

LOWESS

uses local regression to obtain a smooth trend from neighboring points.

Median filter

can reduce isolated spikes while preserving some edge-like features.

Butterworth filter

provides frequency-selective smoothing behavior in the implemented browser workflow.

Wiener filter

uses local signal statistics for adaptive noise reduction.

Bilateral filter

weights neighboring points using both distance and signal similarity.

Exponential smoothing

uses weighted recursion that gives greater influence to recent neighboring values.

For publication-quality interpretation, always compare the processed trace with the raw spectrum. A band that appears only after aggressive smoothing should be treated cautiously.

Baseline Correction for FTIR Spectra

Baseline drift can influence apparent peak prominence and interfere with automated band detection. ChemFitX provides both manual and automated correction methods so users can test a correction strategy appropriate to their spectrum.

Manual baseline drawing

lets the user place baseline points directly on the spectrum and then apply a correction based on the selected points.

ModPoly and IModPoly

provide iterative polynomial-style background correction approaches.

Rolling ball

estimates a slowly varying background using a moving geometric baseline concept.

Asymmetric least squares (ALS)

uses asymmetric penalization to estimate a smooth background below spectral features.

Polynomial fitting

models the baseline using a polynomial trend.

Rubber-band correction

constructs a lower-envelope-style baseline across the spectrum.

Top-hat morphological correction

uses a morphology-based approach to separate narrow spectral features from a broader background.

SNIP

iteratively estimates a slowly varying background from neighboring spectral values.

Linear baseline

uses a straight-line background estimate.

Spline baseline

uses a smooth interpolated baseline representation.

Smart baseline

provides an automated correction option intended for users who want a starting baseline without drawing points manually.

No baseline method is universally correct for all FTIR spectra. The corrected trace should remain physically plausible, should not create artificial negative or positive features, and should be compared with the original spectrum before interpretation.

FTIR Peak Detection

ChemFitX uses a conservative multi-scale detection strategy. A candidate band normally needs to persist across more than one smoothing scale, or be exceptionally prominent at a single scale, before it is accepted. The purpose is to reduce duplicate detections and noise ripples while retaining meaningful narrow and broad FTIR bands.

Peak-detection sensitivity

The sensitivity control changes how readily weaker spectral features are accepted. A moderate setting is a useful starting point. Increase sensitivity only when visually evident weak bands are being missed, because excessive sensitivity can introduce noise-derived candidates.

Minimum peak separation

The minimum-separation control helps prevent neighboring detections from being reported as multiple copies of the same band. The appropriate value depends on spectral resolution, sampling density and how closely spaced the real bands are.

Manual peak insertion

If an important visible FTIR band is not captured by automatic detection, the Insert Peak function allows the user to place a peak manually on the chart. Manually inserted peaks remain distinguishable in the exported results.

Functional-Group Assignment Support

Detected FTIR bands are compared with curated reference ranges for common molecular vibrations and material-related spectral regions. The peak table can display the selected assignment, functional-group category, match score, alternative assignments and whether the band matches the currently active material/application preset.

These assignments are interpretation aids. A wavenumber by itself is rarely unique to one functional group or compound, particularly in the fingerprint region. Band width, intensity, companion bands, sample chemistry, hydrogen bonding, phase, measurement mode and reference spectra should all be considered.

What the match score means

The match score ranks how well a detected band agrees with the platform’s curated FTIR reference ranges and contextual rules. It is not a probability that a compound or functional group has been identified, and it should not be reported as analytical certainty.

Alternative assignments

When several reference ranges are compatible with the same wavenumber, ChemFitX can retain alternatives rather than hiding the ambiguity. This is especially important in overlapping regions where multiple vibrations can occur.

Context-Aware FTIR Analysis Presets

Presets provide material- or application-specific context for interpretation. Applying a preset can set recommended processing choices, re-rank functional-group matches and shortlist the peak table to FTIR regions relevant to the selected context. Presets do not alter the chemical identity of the sample and do not identify a material automatically.

Carbon nanotubes and related carbon nanomaterials
Graphene and graphene oxide
Metal oxide nanoparticles
Quantum dots and surface ligands
Nanocomposites
Polymers and plastics
Ceramics and glasses
Biomaterials
Catalysts and surface species
Coatings and films
Pharmaceutical analysis
Environmental samples
Food and biochemical samples
Forensic and unknown organic samples

For example, a metal-oxide preset emphasizes low-wavenumber metal-oxygen regions together with hydroxyl, adsorbed water and common surface-anion bands, whereas a polymer preset emphasizes C-H, carbonyl, aromatic and C-O/C-N regions. The preset changes interpretation priority, not the uploaded spectrum itself.

Curated FTIR Reference Database

The built-in reference database provides approximate group-frequency ranges together with vibration type, typical qualitative intensity, functional-group category and interpretive notes. Users can search the database by assignment or functional-group terms and filter the displayed entries.

Exact FTIR positions can shift because of bonding environment, conjugation, hydrogen bonding, molecular symmetry, crystal phase, adsorption state, concentration and measurement conditions. Reference ranges should therefore be used as guidance rather than fixed universal peak positions.

Interactive Spectrum Visualization

The FTIR chart supports pan, zoom in, zoom out and reset controls so users can inspect both the full spectrum and crowded regions in more detail. Detected or manually selected bands can be visualized on the spectrum, and the processed chart can be exported as a PNG image.

For scientific reporting, preserve the raw spectrum separately from any smoothed or baseline-corrected version. Processing choices should be documented when they materially affect the appearance or interpretation of bands.

How to Use the ChemFitX FTIR Analysis Tool

Upload an FTIR spectrum in CSV, TSV, TXT, XY, DAT, ASC, XLSX or XLS format.
Confirm the wavenumber and signal data are loaded correctly.
Leave Spectrum Type on Auto-detect or manually choose Transmittance (%T) or Absorbance when the signal type is known.
Inspect the raw spectrum before applying any processing.
If needed, choose a smoothing method and a conservative window size, then apply smoothing.
If baseline drift is present, choose an appropriate baseline method or draw manual baseline points and apply the correction.
Optionally select a material/application preset to focus interpretation on relevant spectral regions.
Set peak-detection sensitivity and minimum separation, then run Detect Peaks.
Compare the detected peak markers with the visible FTIR bands. Use Insert Peak only when a meaningful band has clearly been missed.
Review the peak table, tentative assignment, functional-group category, alternative matches, prominence and match score.
Search the curated FTIR reference database when additional context for a wavenumber region is needed.
Export the spectrum or analysis results as PNG, CSV, JSON, Excel or a text report.

Interpreting the Main FTIR Results

Wavenumber

Wavenumber in cm⁻¹ identifies the spectral position of the detected band. Interpretation should consider the instrument resolution, sample environment and whether the apparent band is isolated or overlapped.

Signal value

The signal value is taken from the current processed spectrum. Its numerical meaning depends on whether the dataset represents absorbance or transmittance.

Peak prominence

Prominence describes how strongly a detected band stands out relative to its local spectral neighborhood in the platform’s detection workflow. It is useful for ranking candidate features but is not a substitute for quantitative concentration analysis.

Tentative assignment

The tentative assignment is the reference-range match ranked highest by the implemented interpretation rules. It should be evaluated together with alternative assignments and companion bands.

Preset match

When a preset is active, a peak can be flagged as relevant to a preset focus region. This indicates contextual relevance only; it does not establish that the sample belongs to that material class.

Exporting FTIR Analysis Results

CSV

CSV export provides a portable tabular record of the processed spectrum and detected peak information, including assignment-related fields where available.

JSON

JSON export stores the processed spectrum, detected peaks, selected peaks, processing choices, manual baseline points and active preset in a structured format suitable for programmatic reuse.

Excel

Excel export includes a spectrum worksheet and, when peaks are available, a peak-assignment worksheet containing wavenumber, signal, prominence, tentative assignment, functional group, match score, alternatives, preset relevance and whether the peak was detected automatically or inserted manually.

Text report

The report generator creates a plain-text FTIR analysis summary containing the analysis date, number of data points, signal type, wavenumber range, processing parameters, active preset and detected peak assignments.

PNG chart

The spectrum chart can be exported as a PNG image for records, presentations or figure preparation.

Data Privacy and Browser-Based Processing

The FTIR spectrum is read and processed locally in the browser by this application. The analysis code does not upload the spectroscopy file to ChemFitX servers.

Users should still follow their laboratory or institution’s policies for confidential data, unpublished spectra, shared computers, downloaded reports and browser storage.

Scientific Scope and Limitations

The platform supports FTIR data processing and interpretation; it is not a replacement for a validated spectral library search against known reference compounds.
Functional-group assignments are tentative reference-range matches, not definitive compound identification.
The assignment match score is a ranking metric and should not be interpreted as a probability of identity.
The fingerprint region contains many overlapping, sample-dependent bands and generally requires broader spectral context.
A single FTIR band should rarely be used alone to claim a functional group or material identity.
Smoothing can suppress weak bands or change apparent shapes when applied too strongly.
Baseline correction can distort the spectrum if the chosen baseline does not represent the real background.
Peak detection depends on signal quality, spectral sampling, resolution, processing choices, sensitivity and minimum separation.
Manual peak insertion is user-directed and should be supported by a visually meaningful spectral feature.
Analysis presets re-rank and filter interpretation context; they are not material-identification models.
Database ranges are approximate and can shift with chemical environment, hydrogen bonding, phase, morphology and measurement conditions.
Transmittance and absorbance data require different peak-direction handling; verify the signal type whenever possible.
Peak prominence is not a quantitative concentration measurement.
The platform does not replace instrument-specific preprocessing, ATR correction, atmospheric correction, quantitative calibration or chemometric validation when those procedures are required.
Results intended for publication should be checked against raw spectra, appropriate literature and, when possible, reference spectra or complementary characterization.

Frequently Asked Questions

What is the ChemFitX FTIR Spectral Analysis Platform?

It is a browser-based workflow for importing FTIR spectra, applying optional smoothing and baseline correction, detecting bands, comparing wavenumbers with curated reference ranges, using context presets and exporting results.

Which FTIR file formats are supported?

The platform accepts CSV, TSV, TXT, XY, DAT, ASC, XLSX and XLS files.

Can the platform analyze both transmittance and absorbance spectra?

Yes. Spectrum type can be auto-detected or selected manually. Transmittance minima are treated appropriately during peak detection while the plotted trace remains in the uploaded scale.

Does ChemFitX automatically identify compounds from FTIR?

No. It provides tentative functional-group and vibration matches from curated reference ranges. Definitive compound identification generally requires reference spectra, companion bands and broader chemical context.

What does the FTIR match score mean?

It ranks agreement between a detected band and the platform’s reference-range and context logic. It is not a probability that the assignment or compound identity is correct.

Can I smooth my FTIR spectrum?

Yes. The platform includes Savitzky-Golay, moving-average, Gaussian, Whittaker, LOWESS, median, Butterworth, Wiener, bilateral and exponential smoothing options.

Which baseline-correction methods are available?

Options include manual baseline drawing, ModPoly, IModPoly, rolling ball, asymmetric least squares, polynomial, rubber band, top-hat, SNIP, linear, spline and smart/automatic baseline correction.

How are FTIR peaks detected?

The platform uses a conservative multi-scale approach that evaluates peak prominence across more than one smoothing scale and applies duplicate suppression with a user-adjustable minimum separation.

Can I add a peak manually?

Yes. If a meaningful visible band is missed by automatic detection, the Insert Peak tool allows it to be added manually.

What are FTIR analysis presets?

Presets provide interpretation context for classes such as carbon materials, graphene oxide, metal oxides, polymers, catalysts, biomaterials, pharmaceuticals and environmental samples. They re-rank relevant assignments and focus the table on important FTIR regions.

Do presets change my spectrum?

No. They can change selected processing settings and interpretation priorities, but they do not chemically identify the sample or silently alter its identity.

Can I search the FTIR reference database?

Yes. The curated database can be searched by assignment or functional-group terms and filtered by functional-group category.

Can I export the processed FTIR spectrum?

Yes. Analysis results can be exported to CSV, JSON and Excel, the chart can be exported as PNG, and a plain-text report can be generated.

Are my FTIR data uploaded to ChemFitX?

For this application, the uploaded spectrum is read and analyzed locally in your browser and is not uploaded to ChemFitX servers by the analysis code.

Should I use the processed spectrum for publication without checking the raw data?

No. Processing should be documented and the processed spectrum should be checked against the raw data to ensure smoothing or baseline correction has not created or removed important features.

Scientific References

Griffiths, P. R.; de Haseth, J. A. Fourier Transform Infrared Spectrometry. Wiley.
Stuart, B. Infrared Spectroscopy: Fundamentals and Applications. Wiley.
Coates, J. Interpretation of Infrared Spectra, A Practical Approach. In Encyclopedia of Analytical Chemistry. Wiley.
Savitzky, A.; Golay, M. J. E. Smoothing and Differentiation of Data by Simplified Least Squares Procedures. Analytical Chemistry.
Eilers, P. H. C.; Boelens, H. F. M. Baseline Correction with Asymmetric Least Squares Smoothing.