Screening, determination and confirmation of chloramphenicol in seafood, meat and honey using ELISA, HPLC-UVD, GC-ECD, GC-MS-EI-SIM and GCMS-NCI-SIM methods

Studies on screening, determination and confirmation of chloramphenicol (CAP) in 10 kinds of matrices, including seafood, meat, honey, etc. by enzyme-linked immunosorbent assay (ELISA), high-performance liquid chromatography (HPLC) with UV detector (HPLC-UVD) and gas chromatography in combination with electronic capture detector (GC-ECD) and mass spectrometry detector (GC-MS) in both electronic ionization mode (EI) and the negative ion chemical ionization mode (NCI) with selected-ion monitoring (SIM) acquisition method (GC-MS-EI-SIM and GCMS-NCI-SIM) have been carried out. Methods have been developed for both qualitative and quantitative detection of chloramphenicol (CAP). Extraction, clean-up, derivatization and analysis procedure have been optimized. The ELISA was carried out for screening, HPLC, GC and GC-MS were applied to determine and confirm CAP residue concentration in suspect samples. The ELISA procedure was carried out on an aqueous extract of the samples. Determination and confirmation of suspect samples were performed after extraction with phosphoric buffer solution (PBS, pH = 6.88)/ethyl acetate, defatting with hexane, analyzed by HPLC or GC-ECD, GC-MS-EI, GC-MS-NCI method. Samples for GC analysis, were further clean-up with solid-phase extraction using LC-Si and LC-C18 cartridges and derivatized to form volatile derivatives by derivatization agent. These techniques are able to detect chloramphenicol residues at the level of 0.1-10 μg/kg. Overall recoveries were 75-120% with R.S.D. values at 5.4-8.1%.