@WesEqualshXc It also reduces (but does not eliminate) the possibility that Nexaph is shipping multiple batches under a single batches testing, because effectively the vials being tested are randomized across all the vials they send out under a given batch ID. Its all a statistical game, but the probabilities are better with Nexaph than with many others.
I am generally a fan of Nexaph, and use them for many many things... but one thing I'm not a fan of is certain compounds (like 5-amino-1mq) Janoshik does not offer purity tests for (only mass tests) and since Nexaph exclusively uses Janoshik (for reasons I broadly agree with) I don't personally trust those tests. So I run my own. And what I can say is that at least for 5-amino-1mq not only do the third party tests I've commissioned directly via Analytic Formulations come back at excellent purity and acceptable (to me) mass (a bit overfilled, but manageable) but also are clean on sterility, heavy metals, and endotoxins.
Again, its a statistical game, so take that simply as more data points to add into the risk tolerance computation