The Processes and Mechanism of Antimony Sequestered by Red Blood Cells and Its Metabolic Conjugation with Hemoglobin in Rats.

•Mechanism of Sb accumulated in RBCs was explored by in vitro and in vivo studies.•Parent form of Sb had notable affinity with RBCs but negligible affinity with Hb.•In vivo studies demonstrated that most of Sb metabolites were integrated into Hb.•Liver metabolism played a potential role influencing Sb’s partitioning in blood.•Nano-HPLC–MS/MS suggested Sb(CH3)2O2H conjugated with Hb (α chain, Cys104/Cys111).