Determination of Common Analgesics in Serum and Urine by Liquid Chromatography/Electrochemistry

Abstract

Abstract A reverse phase LC method with amperometric electrochemical detection is described for determination of several common analgesics in blood serum and urine. The retention properties as a function of organic mobile phase modifier and pH are graphically illustrated and discussed. Electrochemical properties of the analgesics and possible internal standards are also presented. Step-gradient elution was used to facilitate simultaneous determination of analgesics with a wide range of hydrophobicities. Parallel dual-electrode detection with two glassy carbon working electrodes enables acetaminophen to be selectively determined in the same chromatographic run at +0.75 V while several other analgesics are determined at +1.15 V.