Determination of carbadox-related residues in swine liver by gas chromatography/mass spectrometry with ion trap detection.
The ion trap detector (ITD), in combination with a capillary gas chromatograph and under chemical ionization conditions, offers sufficient sensitivity to determine carbadox-related residues as the methyl ester derivative of quinoxaline-2-carboxylic acid at 3 micrograms/kg or higher in porcine liver. A tetradeuterated internal standard of QME effectively compensates for losses incurred during sample preparation. The method produced mean levels of 3.3 (+/- 0.5), 5.5 (+/- 0.8), and 10.1 (+/- 0.9) micrograms/kg for liver fortified at 3, 5, and 10 micrograms/kg. When applied to analysis of samples containing incurred residues of 14C-carbadox at the low microgram/kg level, results were comparable to those obtained by reverse isotope dilution analysis.
Pfizer Inc., Department of Drug Metabolism, Groton, CT 06340.
M J
MJ
Lynch
F R
FR
Mosher
R P
RP
Schneider
H G
HG
Fouda
J E
JE
Risk
D000818:Animals; D002218:Carbadox / Q000032:analysis* / Q000493:pharmacokinetics; D002250:Carbon Radioisotopes; D002855:Chromatography, Thin Layer; D003903:Deuterium; D004350:Drug Residues / Q000032:analysis* / Q000493:pharmacokinetics; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D008099:Liver / Q000737:chemistry* / Q000378:metabolism; D008832:Microchemistry / Q000379:methods; D012015:Reference Standards; D013552:Swine
D002250:Carbon Radioisotopes; D003903:Deuterium; D002218:Carbadox