Magnetic Chitosan Nanocomposite Used as Cleanup Material to Detect Chloramphenicol in Milk by GC-MS

A novel method for determination of chloramphenicol in milk samples was introduced. Magnetic Fe3O4@chitosan nanocomposites were synthesized by adding chitosan to the surface of magnetic Fe3O4 using glutaraldehyde as crosslinker. Extraction with ethyl acetate, the study used the magnetic Fe3O4@CS as cleanup materials, without an additional cleanup step, to detect chloramphenicol in milk samples. To obtain maximal cleanup efficiency, several parameters were investigated including amount of magnetic materials, pH of the solution, purification time, and temperature. Under the optimal conditions ( the amount of 100 mg/g of magnetic materials, pH=5, 10 min, and 20 degrees C), the sensitivity of the proposed method had improved about tenfold than that of without magnetic materials. Moreover, the decision limits and detection capability were 0.05 and 0.11 mu g/kg, respectively, which were comparable to those measured by most methods. The rapid, simple, solvent-saving, and efficient method was proved to be robust in monitoring [D(-)-theo-2-dichloroacetamido-1-p-nitrophenyl- 1,3-propanediol] in milk samples.