Purity-adjusted content calculator
Estimated target peptide in the vial
9.85 mg
The label does not say what it measures, so the result is a range: peptide-content labels give the upper value, powder-weight labels the lower one.
An estimate from the certificate's figures. Only an amount test measured against a reference standard reports the milligrams actually in a vial.
How this works
HPLC purity is the share of the detected peak area that belongs to the target peptide. Net peptide content is the share of the powder's weight that is peptide at all, after counter-ions such as trifluoroacetate or acetate and residual water. The two answer different questions, so a full estimate multiplies them: label amount times net peptide content times purity.
Labels rarely say whether "10 mg" means 10 mg of powder or 10 mg of peptide. If the label means peptide content, only purity reduces it. If it means powder, net peptide content applies too. When the label is silent the calculator shows the range between the two readings.
None of this replaces an amount test. Quantitation against a reference standard measures the milligrams of target peptide directly, which is what a Tested.ph record reports. See HPLC-UV and counter-ion content.
Questions
- What is a normal net peptide content?
- It depends on the peptide's charge, the counter-ion and how dry the powder is, so there is no single normal value. Published analyses of peptide reference materials show counter-ions and water taking a meaningful share of the weight. A certificate should state the figure if it reports one; do not assume it.
- Why do I get a range instead of one number?
- Because the label does not say whether its milligrams are powder or peptide. Pick the option that matches your label, or ask the seller which one they mean. The upper value assumes peptide content; the lower one applies net peptide content to a powder weight.
- Is this the amount a test would measure?
- No. This estimate only rearranges the certificate's own figures. An amount test measures the target peptide in the vial against a reference standard, which also catches vials filled below the label. That measured value is what a Tested.ph record shows.