Figure 5

Principal component analysis for untargeted metabolomic tests using cortical bone (CB) from different human skeletal elements. Score plots for metabolites extracted and measured through HF-UPLC-IM-TOF-HRMS from cortical bone of femora, humeri, and tibiae of disarticulated human osteoarchaeological remains. Data matrices were subject to data cleaning, normalized, transformed, and scaled (see Materials and Methods section). (A) Polar metabolites (HILIC, ESI negative mode), N = 27, 471 variables; (B) Polar metabolites (HILIC, ESI positive mode), N = 28, 1629 variables; (C) Less-polar/apolar metabolites (C18, ESI negative mode), N = 27, 154 variables; (D) Less- polar/apolar metabolites (C18, ESI positive mode), N = 28, 665 variables. Ellipses indicate 95% of confidence for each group. The explained variances of selected principal components are shown in brackets. Observations are coloured according to each skeletal element: femur, red; humerus, green; tibia, purple.