Quality
Methods
How the samples were measured, and where the measurement stops being informative.
RP-HPLC with a linear gradient
Reversed-phase high-performance liquid chromatography separates the components of a sample by polarity. The dissolved sample runs through a column while the share of organic solvent rises. Each substance appears as its own peak in the chromatogram.
In the reports, the mobile phases are water and acetonitrile, each with 0.1% trifluoroacetic acid (TFA). The content comes from comparison with a reference chromatogram. The reports state a measurement error of ±0.05 mg.
The gradient in the report
| Time | Water + 0.1% TFA | Acetonitrile + 0.1% TFA |
|---|---|---|
| 0 min | 100% | 0% |
| 15 min | 50% | 50% |
| 30 min | 0% | 100% |
Example from report 100002515.
How to read the values
- Measured amount
- The amount of peptide in the vial, compared with the declared amount on the label.
- Purity
- The share of the target peptide among the substances captured in the chromatogram.
- Deviation
- The difference between measured and declared amount, in percent.