显微共焦拉曼光谱技术在复杂未知物测定上的应用

Application of Micro Confocal Raman Spectroscopy in the Determination of Complex Unknown Components

复杂未知物的测定一直是食品分析检测领域的热点和难点之一,拉曼光谱技术因具有快速、无损、无需样品制备等优点,在各个领域被广泛应用。本文利用显微共焦拉曼光谱技术,对葡萄糖发酵后产生的复杂未知物A和B进行检测,探讨检测未知物质的方法,拟为复杂未知物质的鉴定提出一种检测思路。结果表明,样品A和样品B在显微镜放大观测下均为粉末状固体,样品A呈现红棕色,样品B呈现灰白色。样品A和样品B均在激光激发下产生强荧光,使CCD探测器饱和,探测不到拉曼光谱信号,且样品A和样品B均不适用强激光长时间照射来消除荧光背景干扰。针对强荧光未知物质的测定,可先通过纯化样品、更换激光器波长等措施消除荧光干扰,再应用显微共焦拉曼光谱技术进行分析测定。

The determination of complex unknowns has always been one of the hotspots and difficulties in the field of analysis and detection. Raman spectroscopy is widely used in various fields because of its advantages of fast, nondestructive and no sample preparation. In this paper, micro confocal Raman spectroscopy was used to detect complex unknown substances A and B, and the method of detecting unknown substances was discussed. A detection idea was proposed for the identification of complex unknown substances. The results showed that both sample A and sample B were powdery solid under microscope magnification. Sample A was reddish brown and sample B was grayish white. The results showed that both sample A and sample B produce strong fluorescence under laser excitation, which saturated the CCD detector and could not detect the Raman spectrum signal, and sample A and sample B were not suitable for long-time irradiation of strong laser to eliminate the fluorescence background interference. For the determination of unknown substances with strong fluorescence,the fluorescence interference can be eliminated by purifying the sample or changing the laser wavelength, and then analyzed and determined by micro confocal Raman spectroscopy.