Analysis of ethyl glucuronide in human serum by capillary electrophoresis with sample self-stacking and indirect detection.
Ethyl glucuronide (EtG), a metabolite of ethanol, is a marker of recent alcohol consumption. In the past few years, its analysis in body fluids has attracted considerable attention because it closes a gap between short time and long time alcohol markers such as ethanol and carbohydrate-deficient transferrin, respectively. The capillary zone electrophoresis (CZE) analysis of EtG in model mixtures and human serum is reported using uncoated and coated fused-silica capillaries together with acidic buffers in the pH range between 3.2 and 4.4 and indirect detection. In these approaches, separation of EtG from endogenous macro- and microcomponents (anionic serum components of high and low concentration, respectively) is based upon transient isotachophoretic stacking referred to as sample self-stacking. The selection of a favorable bufferco-ion and pH is shown to be crucial for optimized sensitivity. Abuffercomposed of 10 mM nicotinic acid and epsilon-aminocaproic acid (pH 4.3) is demonstrated to provide a detection limit for EtG in serum of 0.1 microg/ml, a value that is relevant for clinical and forensic purposes.
Krivánková
L
L
Department of Clinical Pharmacology, University of Bern, Murtenstrasse 35, CH-3010 Bern, Switzerland.
Caslavska
J
J
Malásková
H
H
Gebauer
P
P
Thormann
W
W
D002021:Buffers; D004573:Electrolytes; D019075:Electrophoresis, Capillary / Q000379:methods*; D005965:Glucuronates / Q000097:blood* / Q000302:isolation & purification; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008333:Mandelic Acids; D009525:Niacin; D012680:Sensitivity and Specificity
D002021:Buffers; D004573:Electrolytes; D005965:Glucuronates; D008333:Mandelic Acids; C093924:ethyl glucuronide; D009525:Niacin; C037938:mandelic acid