Analytical guide
Short answer
HPLC estimates purity by separating peaks in a chromatogram. LC-MS (or MS after LC) confirms identity by measuring molecular mass. A strong peptide COA uses both: HPLC for purity, mass spectrometry to prove the main peak is the expected compound.
What HPLC proves
Reverse-phase HPLC separates the sample into peaks. The main peak area is reported as purity (e.g. ≥98%). HPLC answers how clean the sample appears chromatographically — not necessarily what the main peak is.
What LC-MS proves
Liquid chromatography coupled to mass spectrometry measures the mass of ions corresponding to the peptide. A match to the expected [M+H]+ or multiply charged envelope confirms identity. LC-MS answers whether the dominant species is the intended sequence.
Why both matter
A sample can show high HPLC purity while containing the wrong but similarly hydrophobic peptide. Identity testing closes that gap. HALO COAs are intended to include HPLC purity plus mass-spectrometry confirmation where applicable.
Red flags on COAs
Generic COAs without lot numbers, purity without identity, missing test dates, or methods that do not match the compound class (e.g. small-molecule GC for a peptide).
Direct answers
Is HPLC purity enough?
No for procurement-grade documentation. HPLC should be paired with identity confirmation such as LC-MS or MALDI-TOF.
What purity threshold is typical for research peptides?
HALO targets ≥98% main peak by HPLC on each batch, verified independently.
Where can I verify HALO COAs?
On the product page, /lab-results/, and in the COA shipped with your order.
Research use only. HALO materials and educational content are for qualified laboratory research only. Not for human or veterinary use.
