Application of graphitic sorbent for online microextraction of drugs in human plasma samples.
In the present work a new sorbent based on graphitized carbon (CarbonX(®) COA) was evaluated in microextraction by packed sorbent (MEPS) for extraction of lidocaine and ropivacaine from human plasma samples. The new graphitic sorbent showed high recoveries of lidocaine and ropivacaine compared to C18 sorbent. In the present study the G-MEPS (syringe packed with graphitic sorbent) was connect online with liquid chromatography tandem mass spectrometry (LC-MS/MS). In order to obtain a fast and reliable method different factors affecting MEPS performance were investigated. The extraction efficiency of the graphitic sorbent was compared with silica-based sorbents used in MEPS. The G-MEPS was also evaluated for reuse (50-100 times). The recoveries of lidocaine and ropivacaine from plasma samples were 79% and 82%; respectively. The method was validated according to FDA (Food and Drug Administration) guideline for bioanalytical method validation. Linearity was assessed in the range 5-2000nmol/L, with coefficient of determination r(2)>0,995 (n=3) for lidocaine and r(2)>0.997 (n=3) for ropivacaine. The lower limit of quantification (LLOQ) was 5nmol/L and the limit of detection (LOD) was 1nmol/L for studied analytes in plasma samples. For both analytes considered in this study the accuracy values in plasma samples were ranged from 86% to 113%. The Inter-day precisions, expressed as relative standard deviation (%RSD), at three different concentrations (QC-samples) ranged from 8% to 9% for lidocaine, and from 4% to 11% for ropivacaine.
Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm 106 91, Sweden.
Francesco
F
Iadaresta
Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm 106 91, Sweden; Universita di Salerno, Dipartimento di Scienze Farmaceutiche e Biomediche, Salerno, Italy.
Carlo
C
Crescenzi
Swedish drug agency, Uppsala, Sweden.
Ahmad
A
Amini
Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm 106 91, Sweden.
Anders
A
Colmsjö
Department of Medicine, Gävle Hospital and Centre for Research at Uppsala University/County Council of Gävleborg, Gävle, Sweden.
Hirsh
H
Koyi
Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm 106 91, Sweden. Electronic address: mohamed.abdel-rehim@aces.su.se.
Mohamed
M
Abdel-Rehim
D000577:Amides / Q000302:isolation & purification*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid; D006801:Humans; D008012:Lidocaine / Q000302:isolation & purification*; D057230:Limit of Detection; D059627:Liquid Phase Microextraction; D000077212:Ropivacaine; D053719:Tandem Mass Spectrometry; D014481:United States
D000577:Amides; D000077212:Ropivacaine; D008012:Lidocaine
Carbon X COA; Graphitic sorbent; Lidocaine; Microextraction by packed sorbent; Plasma samples; Ropivacaine