5(S)-HETE-d8 is intended for use as an internal standard for the quantification of 5-HETE by GC- or LC-MS. (±)5-HETE is formed via non-enzymatic oxidation of arachidonic acid (Item Nos. 90010 | 90010.1 | 10006607).{62113} 5(S)- and 5(R)-HETE are formed by lipoxygenase-mediated oxidation of arachidonic acid.{556,4720}