Determination of marbofloxacin residues in beef and pork with an enzyme-linked immunosorbent assay.
Marbofloxacin is a fluoroquinolone veterinary antibiotic. An indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of marbofloxacin using polyclonal antibody. The half-maximum inhibition concentrations (IC(50)) and limit of detection (LOD, calculated as IC(20)) of the ELISA for marbofloxacin in phosphate buffer were 4.6 and 0.6 ng/mL, respectively. The assay showed little cross-reactivity with marbofloxacin structural analogues, except for ofloxacin (148%). Matrixes from the extracts of beef and pork muscle have shown a significant influence on the ELISA. Standard curves of ELISA for marbofloxacin in the extracts of the appropriate marbofloxacin-free control muscles were used in the analysis of marbofloxacin in the animal muscles without any cleanup. The average recoveries of intra- and interassay for marbofloxacin from fortified muscle samples, at five concentrations of 10, 50, 100, 500, and 1000 ng/g, were 87-93 and 84-95%, respectively. The LOD of this assay for marbofloxacin in real muscle extracts was 0.8 ng/mL. A survey of 55 animal muscle samples purchased from local markets by the ELISA was conducted, and marbofloxacin was detected in one of them at a concentration of 22 ng/g. This positive sample was validated by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) to be 28 ng/g of marbofloxacin.
Sheng
Wei
W
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Xia
Xunfeng
X
Wei
Keyi
K
Li
Ji
J
Li
Qing X
QX
Xu
Ting
T
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D024841:Fluoroquinolones / Q000032:analysis*; D008460:Meat / Q000032:analysis*; D009132:Muscles / Q000737:chemistry; D011817:Rabbits; D012680:Sensitivity and Specificity; D013552:Swine
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; C080260:marbofloxacin