基于表面增强拉曼光谱的水中土霉素残留量的快速检测

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

应用表面增强拉曼光谱（SERS）检测技术,建立了一种水中土霉素（OTC,oxytetracycline）残留量的快速检测方法。实验以表面增强试剂OTR202和OTR103作为活性基底,并使用自适应迭代惩罚最小二乘法（air-PLS）扣除荧光背景;然后对所用胶体和胶体混合物的吸收光谱与OTC水溶液的SERS光谱进行了探讨;最后分析了样品的加入量和不同混合的时间对SERS信号强度的影响,建立了水中OTC残留浓度X与SERS光谱的1 332cm-1处峰面积Y之间的线性回归方程。实验结果表明,当水中的OTC浓度范围为0.1~22.0mg/L时,水中OTC残留浓度与1 332cm-1处峰面积之间呈现良好的线性关系,线性方程为Y=5 165.7 X＋4 304.9,决定系数R2为0.986 9。预测集样本OTC含量的真实值与预测值之间的R2为0.9732,均方根误差（RMSEP）为1.1122mg/L,回收率为96.7~124.5%,相对标准偏差（RSD,n=5）介于1.209 8~4.787 4%,可满足水中OTC残留量的检测,为现场快速检测水中OTC残留量奠定了良好的基础。

A new method using surface enhanced Raman spectroscopy （SERS） is established for rapid de- tection 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 colloi- dal mixtures and the SERS of oxytetracycline solution are discussed. Finally, the effects of the addition a- mount 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 1332 cm-1 Y. The results show that a good linearity in the concen- tration range of 0.1--22. 0 mg/L is obtained between the peak area at 1 332 cm-1 and oxytetracycline residues in water,Y= 5165.7X-1-4 304. 9, and the coefficient of determination is 0. 986 9. The determina- tion coefficient of OTC content in the prediction samples between actual value and predictive value is 0. 973 2, 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. 2098% and 4. 7874% （n = 5）. This method could meet the detection requirements of oxytetracycline residues in water, and it pro-vides a good foundation for the rapid detection of oxytetracycline residues in water on spot.