Fentanyl & Norfentanyl panel:-:Pt:Ser/Plas:-
fentanyl & norfentanyl panel:-:pt:ser/plas:-
Fentanyl & Norfentanyl panel:-:To identify measures at a point in time:Serum/Plasma:-
fentanyl & norfentanyl panel:-:to identify measures at a point in time:serum/plasma:-