TIC Signal Normalization

Scale a peak-area vector to a supplied total ion current.

Description

Total-ion-current scaling rescales a nonnegative area profile to a chosen aggregate total.

Total-ion-current scaling rescales a nonnegative area profile to a chosen aggregate total. It preserves relative shares within that profile.^[1]

Scale a peak-area vector to a supplied total ion current.

When to use TIC Signal Normalization

Use this tool to scale a peak-area vector to a supplied total ion current.

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 TIC Signal Normalization 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 peakAreas, targetTotal using the field table and calculation rules, then run the tool.
Read normalizedAreas, scalingFactor. 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
peakAreas	Peak areas	list of number	Required
targetTotal	Target total	number	Required

Enter a nonempty nonnegative area list with positive sum and positive target total. Return scaled areas and scaling factor.

factor=targetTotal/Σareas; normalized_i=area_i×factor

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

Output field	Meaning	Value type
normalizedAreas	Normalized areas	list of number
scalingFactor	Scaling factor	number

json

{
  "input": {
    "peakAreas": [
      10,
      20
    ],
    "targetTotal": 100
  },
  "output": {
    "normalizedAreas": [
      33.333333333333336,
      66.66666666666667
    ],
    "scalingFactor": 3.3333333333333335
  }
}

Limitations and assumptions

No peak integration or chemical response correction is performed. The target is supplied and normalization can obscure changes in absolute totals.

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 Probabilistic Quotient: Normalize a metabolite profile by median sample/reference fold quotient.

References

TIC Signal Normalization — tool.io

Similar or alternative tools

TIC Area
Integrate a total-ion chromatogram using trapezoidal area.
Probabilistic Quotient
Normalize a metabolite profile by median sample/reference fold quotient.