Determination of Florfenicol in Antibiotic Mixtures by Solid-Phase Extraction (SPE) and Surface-Enhanced Raman Scattering (SERS)

Florfenicol has been widely used in livestock and aquaculture to treat bacterial infections. Due to the abuse of antibiotics, florfenicol has been released into the environment. Thus, there is a need for the rapid determination of trace levels of florfenicol in the environment. To improve the sensitivity for florfenicol, solid phase extraction (SPE) was employed to enrich florfenicol from multi-residue antibiotic mixtures followed by in situ determination by surface-enhanced Raman spectroscopy (SERS). Activated carbon, C18, graphene oxide (GO), and sand were applied to concentrate florfenicol in water. Silver nanoparticles (AgNP)-coated silicon (AgNPs@Si) substrate was employed to determine florfenicol enriched on the adsorbent. The results showed that the detection limit of florfenicol in water was 2.8 × 10−9 mol/L following the adsorption and enrichment of activated carbon. Besides, activated carbon was performed to extract florfenicol from the multi-residue antibiotic mixtures, including enrofloxacin, norfloxacin, and florfenicol. The results showed that activated carbon combined with SERS specifically determined florfenicol in complex antibiotic mixtures with a detection limit of 2.8 × 10−9 mol/L. Moreover, to better understand the adsorption mechanisms, the mechanism of the interaction of florfenicol with activated carbon was investigated.