Total determination of chloramphenicol residues in foods by liquid chromatography-tandem mass spectrometry

- A LC-MS/MS method for the determination of CAP and CAPG in foods was developed.
- The enzymatic hydrolysis conditions with β-glucuronidase were optimized.
- The developed method would be useful for monitoring the illegal use of chloramphenicol in foods.

A simple and sensitive analytical method for the determination of chloramphenicol (CAP) and chloramphenicol glucuronide (CAPG) residues in foods such as livestock products, seafood, honey and royal jelly was developed. The method comprises solvent extraction with methanol, enzymatic hydrolysis with β-glucuronidase and clean-up using a hydrophilic lipophilic balanced copolymer solid phase extraction column. To determine the optimal conditions for the complete enzymatic hydrolysis of CAPG, we examined the effect of enzyme concentration and incubation time on the hydrolysis. The detection of CAP using LC-MS/MS was optimized and determined by SRM. The developed method was validated using ten food products at a spiked level of 0.5 μg/kg. The validation results show excellent recoveries (79-109%) and precision (<15%) for CAP and CAPG. The limit of quantification (S/N ≥ 10) of the developed method was 0.5 μg/kg. The proposed method would be useful for the regulatory monitoring of CAP and CAPG residues in foods.