4-Fluorofentanyl/Creatinine:MRto:Pt:Urine:Qn:Confirm
4-fluorofentanyl/creatinine:mrto:pt:urine:qn:confirm
4-Fluorofentanyl/Creatinine Confirm (U) [Mass ratio]
4-fluorofentanyl/creatinine confirm (u) [mass ratio]