Determination of chloramphenicol, thiamphenicol and florfenicol in milk and honey using modified QuEChERS extraction coupled with polymeric monolith-based capillary liquid chromatography tandem mass spectrometry

• First reported monolithic capillary LC-MS/MS to analyze amphenicol antibiotics in food.
• Minor matrix effect and good recoveries were obtained by a modified QuEChERS method.
• LMA-MAA-EDMA column offered good stability and repeatability for routine LC analysis.
• Developed QuEChERS-capillary LC-MS/MS revealed good sensitivity (0.02–0.045 ng g−1).

A poly(lauryl methacrylate-co-methacrylic acid-co-ethylene glycol dimethacrylate) [LMA-MAA-EDMA] monolithic column was used to simultaneously determine amphenicol antibiotics (chloramphenicol/CAP, thiamphenicol/TAP, and florfenicol/FF) in milk and honey samples by capillary liquid chromatography tandem mass spectrometry (LC-MS/MS). QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was optimized for sample pretreatment. Good linearity (0.1−15 ng g−1) and extraction recoveries (95.8−100.2% and 95.6−99.3% for milk and honey samples, respectively; n=3) with minor matrix effect (≦5% ion suppression) were obtained. Limits of detection were estimated at 0.02−0.045 ng g−1. Good intra-day/inter-day precision (0.2−9.1%/0.3−8.7%) and accuracy (90.5−110.0%/93.4−109.3%) were achieved. With more than 200 analyses of real samples, no noticeable carry-over and deterioration of separation efficiency were observed using the monolithic column. The applicability of the developed QuEChERS-capillary LC-MS/MS method was demonstrated by determining the occurrence of CAP, TAP, and FF in various milk and honey samples.

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