Most supplier qualification failures are not about the peptide. They are about an agreed method, a missing report or a batch number that does not match the drum label. The nine checks below are split into three groups and can be completed before any money changes hands.
Group 1: specification and method
1) Ask for the full specification with the analytical method named for each limit, not just a percentage. 2) Ask which impurities are controlled individually and which are only reported, plus the reporting threshold. 3) Agree whether a purity figure is area normalisation or an external-standard assay, and which column, gradient and integration rules apply.
Group 2: batch traceability and documents
4) Request a redacted sample COA and check that batch number, date and method fields are present. 5) Confirm which documents are available for the grade (COA, MSDS, TDS, chromatograms, elemental impurities, microbiology) and which are charged separately. 6) Check that the batch number on the COA will match the pack labels.
Group 3: scale-up and change control
7) Ask what changes between a sample lot and a repeat bulk lot: pack format, release testing and document set. 8) Ask how a specification or method change is communicated and re-validated. 9) Ask who signs the release and how a deviation is reported to the customer.
A useful test is to send the same nine questions to three suppliers. The replies differ far more in method detail than in price, and the method detail is what predicts whether your incoming-goods test will pass six months later.
Send us your qualification checklist with the product name. We will answer it line by line and list the documents we can arrange for that grade in the quotation.