Peak FWHM

Interpolate chromatographic full width at half maximum.

Description

Full width at half maximum measures a sampled peak’s temporal breadth at half its absolute maximum.

Full width at half maximum measures a sampled peak’s temporal breadth at half its absolute maximum. Linear interpolation estimates crossings between adjacent samples.^[1]

Interpolate chromatographic full width at half maximum.

When to use Peak FWHM

Use this tool to interpolate chromatographic full width at half maximum.

Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.

How to use Peak FWHM and understand its results

Prepare the measured profile, formula counts, upstream model outputs or caller-defined reference criteria requested. Keep paired entries aligned and units, sample basis and preprocessing consistent.
Enter timesMinutes, intensities using the field table and calculation rules, then run the tool.
Read peakTimeMinutes, leftHalfHeightMinute, rightHalfHeightMinute, fwhmMinutes. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
timesMinutes	Times minutes	list of number	Required
intensities	Intensities	list of number	Required

Enter at least three aligned strictly increasing times and finite intensities. Require a positive maximum whose first occurrence is interior. Search outward for half-height brackets, reject unbracketed or degenerate crossings, and interpolate both crossing times. Return peak and crossing times and width.

FWHM=rightHalfTime−leftHalfTime

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
peakTimeMinutes	Peak time minutes	number
leftHalfHeightMinute	Left half height minute	number
rightHalfHeightMinute	Right half height minute	number
fwhmMinutes	Fwhm minutes	number

json

{
  "input": {
    "timesMinutes": [
      0,
      1,
      2,
      3,
      4
    ],
    "intensities": [
      0,
      5,
      10,
      5,
      0
    ]
  },
  "output": {
    "peakTimeMinutes": 2,
    "leftHalfHeightMinute": 1,
    "rightHalfHeightMinute": 3,
    "fwhmMinutes": 2
  }
}

Limitations and assumptions

Signed intensities are accepted. No baseline subtraction, fitted peak shape or separation of overlapping peaks is performed; half-height uses the uncorrected maximum.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use TIC Area: Integrate a total-ion chromatogram using trapezoidal area. For a complementary task, use Coeluting Peak Split: Allocate a co-eluting peak area using caller-provided component reference intensities.

References

Peak FWHM — tool.io

Similar or alternative tools

TIC Area
Integrate a total-ion chromatogram using trapezoidal area.
Coeluting Peak Split
Allocate a co-eluting peak area using caller-provided component reference intensities.