[Determination of carbadox metabolites, quinoxaline-2-carboxylic acid and desoxycarbadox, in swine muscle and liver by liquid chromatography/mass spectrometry].
A sensitive and selective method using liquid chromatography-electrospray mass spectrometry (LC-ESI-MS) for the determination of carbadox metabolites, quinoxaline-2-carboxylic acid (QCA) and desoxycarbadox (Desoxy-CDX), in swine muscle and liver has been developed. The LC separation was performed on a Cadenza CD-C18 column (10 cm x 2 mm i.d.) with a gradient system of 0.01% acetic acid-acetonitrile as the mobile phase at a flow rate of 0.2 mL/min. Negative ionization produced the [M-H]- molecular ion of QCA. On the other hand, the positive mode produced the [M+H]+ ion of Desoxy-CDX. The calibration graphs for QCA and Desoxy-CDX were rectilinear from 0.01 to 0.5 ng with selected ion monitoring (SIM). The drugs were extracted with 0.3% metaphosphoric acid-methanol (7:3), and the extracts were cleaned up on an Oasis HLB cartridge (60 mg) and by liquid-liquid extraction. The recoveries of QCA and Desoxy-CDX from swine muscle and liver fortified at 2.5 and 5 ng/g were 70.2-86.3%, and the detection limits were 1 ng/g for both drugs.
Saitama Prefectural Institute of Public Health, 639-1, Kamiokubo, Sakura-ku, Saitama 338-0824, Japan.
Masakazu
M
Horie
Mitsunori
M
Murayama
D000818:Animals; D000890:Anti-Infective Agents / Q000032:analysis*; D002218:Carbadox / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004350:Drug Residues / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D008460:Meat / Q000032:analysis*; D011810:Quinoxalines / Q000032:analysis*; D012680:Sensitivity and Specificity; D013552:Swine
D000890:Anti-Infective Agents; D011810:Quinoxalines; D002218:Carbadox; C042218:quinoxaline-2-carboxylic acid