Simultaneous determination of fluoroquinolone antibiotic residues in milk sample by solid-phase extraction-liquid chromatography-tandem mass spectrometry.
A simple, sensitive, and reliable high-performance liquid chromatographic (HPLC) method coupled with tandem mass spectrometry via electrospray ionization (ESI) source (LC-MS/MS) has been developed and validated for the simultaneous determination of five fluoroquinolone residues in milk. The studied fluoroquinolones were norfloxacin, ciprofloxacin, ofloxacin, enrofloxacin, and rufloxacin. The method involved a single solid-phase extraction (SPE) on C(18) followed by the analysis of all fluoroquinolones in a single chromatographic run using LC-ESI-MS/MS. Lomefloxacin was employed as the internal standard (IS). The limit of quantification (LOQ) was 0.5 ng/g in milk, much lower than the maximum residue limit (MRL) of 100 ng/g of enrofloxacin established by the Ministry of Agriculture of China. Standard curves were linear (r > 0.99) over the concentration range of 0.5-200 ng/g with good accuracy and precision. The method has been successfully applied to the analysis of 22 different brands of cow's milk on the Chinese market.
Key Laboratory of Research of Traditional Chinese Medicine and New Drug, Southern Medical University, Guangzhou, China. tqf18@live.cn
Qingfa
Q
Tang
Tongtong
T
Yang
Xiaomei
X
Tan
Jiabo
J
Luo
D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002417:Cattle; D002681:China; D002853:Chromatography, Liquid / Q000379:methods*; D004350:Drug Residues / Q000737:chemistry*; D024841:Fluoroquinolones / Q000737:chemistry*; D008892:Milk / Q000737:chemistry*; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones