Quantification Limit

Estimate concentration LOQ from calibration slope, blank noise, and a supplied S/N criterion.

Description

A quantification-limit estimate converts a signal-to-noise requirement into concentration through a calibration slope.

A quantification-limit estimate converts a signal-to-noise requirement into concentration through a calibration slope. Units follow the noise and slope basis supplied.^[1]

Estimate concentration LOQ from calibration slope, blank noise, and a supplied S/N criterion.

When to use Quantification Limit

Use this tool to estimate concentration LOQ from calibration slope, blank noise, and a supplied S/N criterion.

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 Quantification Limit 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 blankNoiseStdDev, signalSlopePerUmol, quantificationSnr using the field table and calculation rules, then run the tool.
Read limitUmol. 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
blankNoiseStdDev	Blank noise std dev	number	Required
signalSlopePerUmol	Signal slope per umol	number	Required
quantificationSnr	Quantification snr	number	Required

Enter strictly positive noise standard deviation, signal slope per µmol and S/N criterion. Return the corresponding limit in µmol.

limitUmol=noiseStdDev×quantificationSnr/signalSlopePerUmol

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

Output field	Meaning	Value type
limitUmol	Limit umol	number

json

{
  "input": {
    "blankNoiseStdDev": 2,
    "signalSlopePerUmol": 10,
    "quantificationSnr": 10
  },
  "output": {
    "limitUmol": 2
  }
}

Limitations and assumptions

No calibration fit, blank statistics or analytical validation is performed. This is an arithmetic estimate under the supplied linear-response model.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Detection Limit: Estimate LOD from a measured standard concentration and target signal-to-noise ratio. For a complementary task, use Baseline Noise Snr: Estimate baseline noise and signal-to-noise from a sampled segment.

References

Quantification Limit — tool.io

Similar or alternative tools

Detection Limit
Estimate LOD from a measured standard concentration and target signal-to-noise ratio.
Baseline Noise Snr
Estimate baseline noise and signal-to-noise from a sampled segment.