Cross-section

Liraglutide 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 Liraglutide, with a class minimum gradient of 25 min, the method is a live explanation.

88 recordsmedian 99.00 %spec 97.5 %

Laboratory	Reports	Gradient	MS resolution	Median purity %	Published bias (pp)	Bias-adjusted	Method suitability
Janoshik	40	30min	High	98.81	+0.00	98.81	ADEQUATE
Medutest	14	25min	Unit	99.44	+0.08	99.36	ADEQUATE
Nordanalyt	11	35min	High	98.67	+0.02	98.65	ADEQUATE
PeptideMeter	10	28min	High	98.73	-0.05	98.78	ADEQUATE
VendorInvestigate	7 n=7	32min	High	98.48	-0.11	98.59	ADEQUATE
Kestrel	6 n=6	15min	Unit	99.46	+0.24	99.22	BELOW CLASS MINIMUM

Figure. Liraglutide 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.