COAs, Testing & Analysis
Definitions related to Certificates of Analysis (COAs), purity testing methods, analytical instruments, and quality verification terminology used in peptide research.
- Certificate of Analysis (COA)
- A document reporting analytical results for a specific batch or lot, often including identity, purity, and test methods used.
- Lot Number
- A unique identifier assigned to a specific production batch, used for traceability and recordkeeping.
- Purity
- The percentage of the desired compound relative to impurities or byproducts in a sample.
- Identity Testing
- Analytical confirmation that a sample matches the expected compound (sequence/structure), often using MS or LC-MS.
- Impurity Profile
- The distribution and types of impurities present in a sample, sometimes reported as peaks in chromatographic analysis.
- HPLC (High-Performance Liquid Chromatography)
- An analytical technique that separates components of a mixture to evaluate purity and impurity peaks.
- UHPLC
- A higher-pressure form of liquid chromatography that can provide faster runs and improved separation resolution.
- Chromatogram
- A plot produced by chromatography showing detector response over time, where peaks represent separated compounds.
- Retention Time (RT)
- The time it takes for a compound to elute through a chromatography system; used to help identify components.
- Peak Area
- A measurement used in chromatography; larger peak area typically indicates greater relative abundance.
- Mass Spectrometry (MS)
- An analytical method used to determine molecular mass and help confirm compound identity.
- LC-MS (Liquid Chromatography–Mass Spectrometry)
- A combined technique that separates compounds by chromatography and identifies them by mass spectrometry.
- MALDI-TOF
- A mass spectrometry approach commonly used to assess molecular weight and confirm peptide identity.
- Molecular Weight (MW)
- The mass of a molecule, often used as a key identity parameter for peptide verification.
- Sequence Verification
- Analytical confirmation that a peptide matches the intended amino acid sequence (commonly inferred from MS data).
- Residual Solvents
- Solvents remaining from synthesis or processing that may be measured in quality testing.
- Endotoxin
- Bacterial lipopolysaccharide contamination that may be tested for in research materials depending on use case.
- Bioburden
- The number of viable microorganisms present in a sample prior to sterilization or filtration.
- Sterile Filtration
- Filtration (commonly through a 0.22 µm filter) used to reduce microbial contamination in solutions.
- Specification (Spec)
- A defined acceptance criterion for a test (e.g., purity ≥ a target percentage) used to evaluate pass/fail.
- Method Validation
- Demonstration that an analytical method is reliable for its intended purpose (accuracy, precision, sensitivity, etc.).
- Limit of Detection (LOD)
- The lowest amount of a compound that can be detected by a method, though not necessarily quantified accurately.
- Limit of Quantification (LOQ)
- The lowest amount of a compound that can be quantified with acceptable accuracy and precision.
- Accuracy
- How close a measured value is to the true or accepted value.
- Precision
- How consistently a method produces similar results under the same conditions.
- Repeatability
- Precision under the same operating conditions over a short time interval (same analyst, same equipment).
- Reproducibility
- Precision under varied conditions (different analysts, labs, instruments), reflecting real-world consistency.
- Third-Party Testing
- Testing performed by an independent lab to provide objective verification of results.