Quality4 min read
HPLC purity: what the percentage measures and what it does not
HPLC purity is a share of peak area in the UV signal. It leaves out water, counter-ions such as TFA, and salts. How to read the figure and the peak table.
Quality, storage and ordering, explained
Short articles on certificates of analysis, purity testing, storage and the rules for ordering. Each article lists its sources at the end.
6 articles
Quality4 min read
Identity by mass spectrometry: why a CoA needs two tests
HPLC tells you how large the main peak is. Mass spectrometry tells you whether the substance has the expected mass. What a certificate of analysis should show for each.
Ordering3 min read
Paying by bank transfer in advance: how it works
Order, take the bank details from the confirmation e-mail, use the order number as payment reference, then invoice and dispatch once the payment arrives. Plus the rules for SEPA transfers.
Quality4 min read
Reading a certificate of analysis: what each field tells you
Batch number, method, specification and result, dates and release: what a certificate of analysis (CoA) should contain and how to spot one with gaps.
Lab3 min read
Storing lyophilised peptides: cold, dry, dark, sealed
Temperature, moisture, light, warming before opening, aliquoting: how peptide manufacturers describe laboratory storage of lyophilised peptides.
Ordering5 min read
Right of withdrawal for online orders in Germany and Austria
14 days from receipt of the goods, no reason needed, refund within 14 days, exceptions: the consumer right of withdrawal under the BGB, the EU directive and the FAGG.