Cross-section

Afamelanotide by laboratory

The same compound measured by different laboratories on different gradients. Where the medians differ, the question is whether the material differed or the method did — and for Afamelanotide, with a class minimum gradient of 22 min, the method is a live explanation.

43 recordsmedian 99.06 %spec 98.0 %

Laboratory	Reports	Gradient	MS resolution	Median purity %	Published bias (pp)	Bias-adjusted	Method suitability
Janoshik	21	30min	High	99.14	+0.00	99.14	ADEQUATE
Medutest	6 n=6	25min	Unit	98.81	+0.08	98.73	ADEQUATE
PeptideMeter	5 n=5	28min	High	98.42	-0.05	98.47	ADEQUATE
Nordanalyt	5 n=5	35min	High	99.31	+0.02	99.29	ADEQUATE
VendorInvestigate	4 n=4	32min	High	99.19	-0.11	99.30	ADEQUATE
Kestrel	2 n=2	15min	Unit	99.93, 98.87	+0.24	—	BELOW CLASS MINIMUM

Figure. Afamelanotide purity by contributing laboratory. Any offset between rows has two possible sources — a real difference in the material each laboratory happened to receive, and the laboratory's own bias — and this figure cannot separate them. The paired analysis that can is on inter-lab agreement.