Studies On The Detection Of Chloramphenicol And Its Sodium Succinate By Surface-enhanced Raman Scattering

Chloramphenicol and its succinate sodium are two widely used efficientbroad-spectrum antibiotics, which were commonly used to treat human being and animaldiseases and can efficiently inhibit bacteria growth, but their residues in foods bring aboutserious poisonous effect on human health. In order to timely know about their situationused in animal derived foods and to ensure the safety of consumers, it is very necessary todevelop their rapid detection method. Surface-Enhanced Raman scattering （SERS） is awidely used rapid analysis technology in recent years with quick analysis and highsensitivity, which is being extensively applied in the antibiotics. The main objective of thisstudy was to investigate the feasibility of using SERS technology for rapid detection ofchloramphenicol and its succinate sodium.The best three-dimensional molecular configurations of chloramphenicol and itssuccinate sodium was simulated and their theoretical Raman spectra were calculated byusing Density Functional Theory （DFT） and software Gaussian03. All peaks of thetheoretical and experimental Raman spectra of the two antibiotics had good match. Thevibration assignments of all peaks were identified.SERS effects of Au colloidal nanoparticles, silver colloidal nanoparticles, Au-collumncomplex substrates and Fe₃O₄@SiO₂@Au substrates were compared. Results showed thatSERS effect of Au colloidal nanoparticles was best. The structure of Au colloidalnanoparticles was characterized by Transmission Electron Microscopy （TEM） andUltraviolet Spectroscopy. SERS Results showed that Au colloidal nanoparticles substrateswith50nm in diameter exhibited better SERS effect on the two antibiotics. The influenceof detection carrier types, ratio of Au colloidal nanoparticles substrate and the volume ofthe solution to be measured and absorption time on SERS effect of the two antibiotics wasinvestigated. Optimal conditions were tinfoil paper as detection carrier, ratio of Aucolloidal nanoparticles substrate and the volume of the solution to be measured at10:14and absorption time for6min. Meantime, it is also observed that SERS effect of methanol,alcohol, formdimethylamide and water on the two antibiotics displayed significantlydifference and Water as solvent had minimal interference and better SERS effect.According to the data of theoretical, experimental and SRES spectra of the twoantibiotics, it is suggested that three characteristic peaks at1104cm^-1，1344cm^-1，1596cm^-1were used to rapid qualitative analysis of the two antibiotics or one of them existed insamples and the peak at1076cm^-1were used to the further identification index ofchloramphenicol succinate sodium. The total contents of the two antibiotics could bequantified based on the SERS spectra intensity of one of them at1344cm^-1. Standard curve（y=26.022x+153.64） was established from the data of a series of chloramphenicolconcentration and its SERS peak intensity at1344cm^-1. They exhibited good linearcorrelation （R2=0.9802）. The detection limit of the method reached0.1μg/mL in case ofwater as solvent.Two antibiotics residues in20samples including8types of animal original food wereanalyzed by SERS method established and HPLC-UV method. Detection results of the two methods had good consistence. Results showed that the SERS method had good stability,high accuracy and short analysis time and can meet the analysis requirements ofchloramphenicol and its succinate sodium residues in a great deal of animal derived foodsamples.