Detection of oxytetracycline residues in water based on surface-enhanced Raman spectroscopy

A new method using surface enhanced Raman spectroscopy (SERS) is established for rapid detection of oxytetracycline (OTC) residues in water. In this research, OTR202 and OTR103 are used as the SERS active substrate, and the adaptive iteratively reweighted penalized least squares (air-PLS) was used to subtract the fluorescence background of SERS. Then the absorption spectra of colloid and colloidal mixtures and the SERS of oxytetracycline solution are discussed. Finally, the effects of the addition amount of oxytetracycline solution and the different mixing time on SERS intensity are analyzed, and the linear regression equation is established between the concentrations of oxytetracycline residues in water (X) and the peak area of SERS at 1 332 cm-1 Y. The results show that a good linearity in the concentration range of 0.1-22.0 mg/L is obtained between the peak area at 1332 cm-1 and oxytetracycline residues in water, Y=5165.7X+4304.9, and the coefficient of determination is 0.986 9. The determination coefficient of OTC content in the prediction samples between actual value and predictive value is 0.9732, and the root mean square error (RMSE) is 1.112 2 mg/L. Recovery of oxytetracycline residues in water is 96.7%-124.5%, and the relative standard deviation is between 1.209 8% and 4.787 4% (n=5). This method could meet the detection requirements of oxytetracycline residues in water, and it provides a good foundation for the rapid detection of oxytetracycline residues in water on spot. ©, 2015, Board of Optronics Lasers. All right reserved.