Rapid detection of sulfamethazine and ofloxacin residues in chicken based on synchronous fluorescence spectrum

Rapid detection of sulfamethazine (SM2) and ofloxacin (OFL) residues in chicken was achieved through synchronous fluorescence technology coupled with chemometric methods. First, the three-dimensional synchronous fluorescence spectra of an SM2 standard solution, an OFL standard solution, chicken extract without antibiotics, and chicken extract containing SM2 and OFL residues were analyzed. The wavelength difference (Δλ) of SM2 and OFL were determined to be 150 nm and 210 nm, respectively. The fluorescence excitation peaks of SM2 and OFL were determined to be 292.5 nm and 295 nm, respectively, for the detection of SM2 and OFL residues in chicken. Subsequently, the effects of addition amounts of β-mercaptoethanol solution and o-phthalaldehyde solution, as well as time, on the fluorescence intensities were investigated through the single factor test. A β-mercaptoethanol solution of 300 μL, an o-phthalaldehyde solution of 25 μL and a time of 44 min were the best combination of conditions for detections. Finally, the prediction models were established by the peak height and peak area algorithms respectively. The experimental results show that the prediction model based on the peak height algorithm provides a better comprehensive evaluation than the prediction model based on the peak area algorithm. For the prediction models of SM2 and OFL residues based on the peak height algorithm, the coefficients of determination for the prediction set (RP2) are 0.897 3 and 0.997 3 for SM2 and OFL, respectively. The root mean square errors for the prediction set (RMSEP) are 6.060 5 mg/kg and 0.539 2 mg/kg, for SM2 and OFL, respectively. The recovery rates of SM2 and OFL are in the range of 76.1%-115.2% and 96.7%-110.1%, respectively, and the relative standard deviations (RSDs) are in the range of 2.7%-7.0% and 2.8%-10.0%, respectively. The proposed method is fast and simple and could achieve rapid detection of SM2 and OFL residues in chicken. © 2021, Science Press. All right reserved.