UHPLC-MS/MS analysis of arachidonic acid and 10 of its major cytochrome P450 metabolites as free acids in rat livers: effects of hepatic ischemia.

•Arachidonic acid (AA) is metabolized by cytochrome P450 enzymes to biologically active metabolites.•P450-mediated metabolites of AA are mostly present in tissues as bound to phospholipids.•A validated assay is developed to quantitate free concentrations of AA metabolites in the liver.•The assay is applied to study the effects of hepatic ischemia on the metabolites.•Hepatic ischemia increased the free concentrations of AA and most of its metabolites in the liver.