Analysis of Lidocaine and Its Major Metabolite, Monoethylglycinexylidide, in Elk Velvet Antler by Liquid Chromatography with UV Detection and Confirmation by Electrospray Ionization Tandem Mass Spectrometry

• Published in: Journal of agricultural and food chemistry 2005-04, Vol.53 (7), p.2386-2391
• Main Authors: Bagonluri, Mukasa T, Woodbury, Murray R, Reid, R. Stephen, Boison, Joe O
• Format: Article
• Language: English
• Subjects: Animals; Antlers - chemistry; Biological and medical sciences; Cervus elaphus; Chromatography, Liquid - methods; dietary supplements; drug residues; elks; food contamination; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; lidocaine; Lidocaine - analogs & derivatives; Lidocaine - analysis; Lidocaine - metabolism; liquid chromatography; Male; mass spectrometry; metabolites; Methods of analysis, processing and quality control, regulation, standards; Ruminants; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; tandem mass spectrometry; velvet antlers
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf048324k

A sensitive liquid chromatographic (LC) method with UV detection was developed for the determination of residues of lidocaine (LID) and its major metabolite, monoethylglycinexylidide (MEGX), in elk velvet antler. The drugs were extracted from alkaline velvet antler homogenates, cleaned up on a C18 solid-phase extraction cartridge, and separated on an Inertsil ODS-3 (3.0 × 250 mm, 5 μm) column using an isocratic mobile phase made up of 0.05 M phosphate buffer (pH 4.0)/acetonitrile (88:12, v/v) at a flow rate of 1.0 mL/min. The limits of quantification for LID and its major metabolite, MEGX, were 10 and 20 ng/g, respectively. The method was validated and used to measure the concentration of residues of LID and MEGX in elk velvet antlers harvested after either LID anesthesia or application of a drug-free control method (electro-anesthesia, EA). No LID or MEGX residues were detected in any of the antlers harvested after EA application. No MEGX residues were detected in any of the velvet antlers harvested after LID application, but residues of LID ranging in concentration from 68 to 4300 ng/g were detected in the three sections of the velvet antlers harvested after LID administration. LC-tandem mass spectrometry was used to confirm the presence of lidocaine detected in the velvet antlers. Keywords: Lidocaine (LID); monoethylglycinexylidide (MEGX); local anesthetic; elk velvet antler; cervids; liquid chromatography (LC); tandem mass spectrometry (LC-MS/MS)