Meperidine+Normeperidine:PrThr:Pt:Ser/Plas:Ord:Screen
meperidine+normeperidine:prthr:pt:ser/plas:ord:screen
Meperidine+Normeperidine [Presence] in Serum or Plasma by Screen method
meperidine+normeperidine [presence] in serum or plasma by screen method