XIC Mass Window

Plan an extracted-ion m/z window from target mass and ppm tolerance.

Description

An extracted-ion mass window selects a symmetric interval around a target m/z.

An extracted-ion mass window selects a symmetric interval around a target m/z. A ppm tolerance scales the absolute width with target m/z.^[1]

Plan an extracted-ion m/z window from target mass and ppm tolerance.

When to use XIC Mass Window

Use this tool to plan an extracted-ion m/z window from target mass and ppm tolerance.

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 XIC Mass Window 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 targetMz, ppmTolerance using the field table and calculation rules, then run the tool.
Read lowerMz, upperMz, absoluteToleranceMz. 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
targetMz	Target mz	number	Required
ppmTolerance	Ppm tolerance	number	Required

Enter positive target m/z and nonnegative ppm tolerance. Return absolute half-width and lower/upper bounds. Equality at zero tolerance gives identical bounds.

halfWidth=targetMz×ppmTolerance/1e6; bounds=targetMz±halfWidth

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

Output field	Meaning	Value type
lowerMz	Lower mz	number
upperMz	Upper mz	number
absoluteToleranceMz	Absolute tolerance mz	number

json

{
  "input": {
    "targetMz": 500,
    "ppmTolerance": 10
  },
  "output": {
    "lowerMz": 499.995,
    "upperMz": 500.005,
    "absoluteToleranceMz": 0.005
  }
}

Limitations and assumptions

No chromatogram extraction or peak matching is performed. Extremely large tolerances can yield a negative lower bound; the model does not enforce physical window limits.

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 Mass Accuracy PPM: Calculate signed mass error in ppm relative to theoretical m/z. For a complementary task, use Neutral Loss Matcher: Match product-ion neutral losses against caller-provided diagnostic differences.

References

XIC Mass Window — tool.io

Similar or alternative tools

Mass Accuracy PPM
Calculate signed mass error in ppm relative to theoretical m/z.
Neutral Loss Matcher
Match product-ion neutral losses against caller-provided diagnostic differences.