Back to Isotope Catalog
R-11060

Cephalexin (d5)

Stable isotope standard for analytical research and method development.

Module Type
Stable Isotope Standards
Category
Drugs & TDM
CAS
2101505-56-8
Unlabeled CAS
15686-71-2
PubChem CID
45038596
Molecular Formula
C16H12D5N3O4S
Molecular Weight
352.4
AI Isotope Property & Application AnalysisShow

Isotope Summary

Labels
D5
Labeled atoms
5
Isotope positions
Confirmed in structure
Calculation reliability
High, based on explicit isotope structure

Mass & MS Parameters

Unlabeled exact mass
347.093977 Da
Labeled exact mass
352.125361 Da
Exact mass shift
5.031384 Da
Nominal mass shift
5
Ionm/zStatus
[M+H]+353.132637Theoretical
[M+Na]+375.114579Theoretical
[M+NH4]+370.159184Theoretical
[M-H]-351.118084Theoretical

Label Stability

Overall
Low risk
Calculation reliability
Medium, some information should be confirmed
  • Carbon-bound deuterium is evaluated by local chemical environment; isotope effects should still be checked experimentally.

Internal Standard Suitability

Rating
High
Chromatographic similarity
Possible isotope effect
Natural isotope overlap
Low
  • Exact mass separation is 5.031384 Da; MS channel separation should be verified in the final method.
  • The unlabeled parent mass was derived from the isotope structure because a curated parent structure was not matched.
  • Overall suitability: High.

Recommended Applications

LC-MS/MS Quantitative Internal Standard
Recommended

LC-MS/MS Quantitative Internal Standard is classified as Recommended based on isotope mapping, mass separation, and label-stability rules.

Isotope Dilution Mass Spectrometry
Recommended

Isotope Dilution Mass Spectrometry is classified as Recommended based on isotope mapping, mass separation, and label-stability rules.

GC-MS Internal Standard
Possible

GC-MS Internal Standard is classified as Possible based on isotope mapping, mass separation, and label-stability rules.

Clinical Mass Spectrometry
Possible

Clinical Mass Spectrometry is classified as Possible based on isotope mapping, mass separation, and label-stability rules.

Bioanalytical Method Development
Recommended

Bioanalytical Method Development is classified as Recommended based on isotope mapping, mass separation, and label-stability rules.

AI Interpretation

This analysis is based on isotope-aware structure data. The compound contains D5, with an exact mass shift of 5.031384 Da. Label stability is assessed as Low risk, and internal-standard suitability is High. These results support analytical method development and require experimental validation.

AI-assisted analytical guidance is intended for method-development support. Actual isotope stability, chromatographic behavior, fragmentation and MRM transitions should be experimentally validated.