whats the related substances table actually telling me

is sterility tested as part of a normal purity certificate

water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it

the retention time on this one is different from the last lot, problem

a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists

single wavelength detection can miss a co-eluting impurity that does not absorb there

a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully

thats a real table