Kendrick Mass Defect
Convert exact mass to a caller-defined Kendrick repeat-unit basis.
Description
Kendrick scaling rescales an exact mass to a caller-defined nominal repeat-unit basis.
Kendrick scaling rescales an exact mass to a caller-defined nominal repeat-unit basis. Mass defect then measures the difference from the nearest integer scaled mass.1
Convert exact mass to a caller-defined Kendrick repeat-unit basis.
When to use Kendrick Mass Defect
Use this tool to convert exact mass to a caller-defined Kendrick repeat-unit basis.
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 Kendrick Mass Defect 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 exactMassDa, exactRepeatMassDa, nominalRepeatMassDa using the field table and calculation rules, then run the tool.
- Read kendrickMass, kendrickNominalMass, kendrickDefect. 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 |
|---|---|---|---|
| exactMassDa | Exact mass da | number | Required |
| exactRepeatMassDa | Exact repeat mass da | number | Required |
| nominalRepeatMassDa | Nominal repeat mass da | number | Required |
Enter positive masses. Snap scaled mass to its rounded integer when the difference is below 1e−12; return scaled mass, nominal Kendrick mass and signed defect.
KM=exactMass×nominalRepeat/exactRepeat; defect=round(KM)−KM Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| kendrickMass | Kendrick mass | number |
| kendrickNominalMass | Kendrick nominal mass | number |
| kendrickDefect | Kendrick defect | number |
{
"input": {
"exactMassDa": 28.0313,
"exactRepeatMassDa": 14.01565,
"nominalRepeatMassDa": 14
},
"output": {
"kendrickMass": 28,
"kendrickNominalMass": 28,
"kendrickDefect": 0
}
}Limitations and assumptions
The repeat unit is not fixed to CH2. No homologous-series detection or formula assignment is performed.
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 Nominal Mass Defect: Determine signed nominal-minus-exact molecular mass defect. For a complementary task, use Monoisotopic Formula Mass: Sum neutral monoisotopic mass from C/H/N/O/S/P atomic compositions.
References
-
Kendrick Mass Defect — tool.io
Similar or alternative tools
- Nominal Mass Defect
Determine signed nominal-minus-exact molecular mass defect.
- Monoisotopic Formula Mass
Sum neutral monoisotopic mass from C/H/N/O/S/P atomic compositions.