表面增强拉曼光谱法快速检测饮料中玫瑰红B

摘要

Rapidly screening method of man-made synthetic colorant Rhodamine B in food was established based on porous Ag fiber as surface enhanced Raman scattering(SERS)substrate. Without any sample pretreatment, silver fiber substrate synthesized with electrochemical assistance by Cyclic Voltammetry(CV) scanning at 25 mV/s was immersed in the membrane filtrated drink samples for 8 minutes without stirring.After that,the silver substrate was directly introduced for Raman analysis.The characteristic SERS spectrum peaks of Rhodamine B were attributed together with standard Raman and density functional theory(DFT)Raman spectra, followed by qualitative and quantitative analysis. The band at 1 277 cm-1was selected as the characteristic peak for quantitative determination, showing good linearity from 5×10-8to 2.5×10-6mol/L and detection limit of 5×10-9mol/L.It only takes 9 minutes for the in-situ extraction coupled with Raman test of the proposed method,which was successfully applied to fast identify of Rhodamine B in drink samples with recovery in the range of 90.4 %-92.3 % and good relative standard deviations(RSDs)less than 5.2 %.%采用多孔银丝表面增强拉曼(surface enhanced Raman scattering,SERS)基底,建立快速检测饮料中人工合成着色剂玫瑰红B的分析方法.饮料样品无需前处理,滤膜过滤后采用循环伏安法扫速25 mV/s制备的多孔银丝基底静置萃取8 min后即进行拉曼测试,结合固体标准品拉曼谱图和密度泛函理论(density functional theory,DFT)计算结果对玫瑰红B表面增强拉曼谱图中的特征峰进行了归属,以对玫瑰红B进行定性和定量测定.结果表明,1277 cm-1处的峰强度与玫瑰红B浓度的线性范围为5×10-8~2.5×10-6mol/L,检出限为5×10-9mol/L.该方法原位萃取、测试时间只需9 min,可应用于饮料样品中玫瑰红B的快速检测,回收率在90.4 %~92.3 %,相对标准偏差小于5.2 %.