“…In this study, the 4 known DPHP metabolites (oxo-MPHP, OH-MPHP, cx-MPHxP, and OH-OH-MPHP) and 3 novel tentative DPHP metabolites (oxo-MPHxP, OH-MPHxP, and cx-MPBP) were identified using UPLC-MS and a rat model. One known DPHP metabolite (MPHP) was not identified because the level of MPHP is very low in rat urine [ 10 ]. Also, MPHP was not used as exposure markers to assess human DPHP exposure levels, because of its low level in human urine [ 6 ].…”