Cross-section

IGF-1 LR3 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 IGF-1 LR3, with a class minimum gradient of 15 min, the method is a live explanation.

118 recordsmedian 98.28 %spec 95.0 %

Laboratory	Reports	Gradient	MS resolution	Median purity %	Published bias (pp)	Bias-adjusted	Method suitability
Janoshik	51	30min	High	98.15	+0.00	98.15	ADEQUATE
Medutest	28	25min	Unit	98.50	+0.08	98.42	ADEQUATE
PeptideMeter	17	28min	High	98.48	-0.05	98.53	ADEQUATE
VendorInvestigate	9	32min	High	97.64	-0.11	97.75	ADEQUATE
Kestrel	9	15min	Unit	98.38	+0.24	98.14	ADEQUATE
Nordanalyt	4 n=4	35min	High	97.84	+0.02	97.82	ADEQUATE

Figure. IGF-1 LR3 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.