Stability of LMM iron species in plasma and serum. 56Fe-detected LC-ICP-MS chromatograms of flow-through solutions from horse plasma and serum were run using conditions of Figure 1. Black lines are Horse 1, red lines are Horse 2. A, fresh plasma; B, frozen plasma; C, frozen serum; D, fresh plasma; E, frozen plasma; F, same as E but after incubating in a refrigerated glove box for 1 day and then refiltering through the 10 kDa cutoff membrane. G, same as F but after incubating for 9 days. Column conditions as in Figure 1.