山梨酸钾的三维荧光光谱特性分析

山梨酸钾作为一种较为安全、高效的防腐剂,长期或过量摄入会对人身造成伤害,因此各国对山梨酸钾的使用量都有严格的限定.文中采用FLS 920荧光光谱仪研究了山梨酸钾溶液的三维荧光光谱,发现激发光从320 nm红移至500 nm时,先后出现两个荧光峰:485 nm和565 nm,前者强度明显大于后者,对应的激发峰分别为380 nm和470 nm.分析认为这两个荧光峰分别是由山梨酸钾分子中的共轭π键和未成键n电子受激跃迁所致,根据其在485 nm谱峰荧光强度随质量浓度(0.05 ～ 12 g/L)的非线性变化规律可以检测山梨酸钾质量浓度.进而以鲜榨苹果汁为例,研究了基于荧光光谱技术检测山梨酸钾在鲜榨苹果汁中质量浓度的可行性,为进一步检测液态食品中山梨酸钾的含量提供了实验和理论依据.

Study on Potassium Sorbate by Three-Dimensional Fluorescence Spectra

Potassium sorbate is a safe and efficient preservative,can do harm to human through over or long-term intake.But it is sometimes overcommitted by some unscrupulous merchansts driver by interests for long-term preservation.The three-dimensional fluorescence spectra of potassium sorbate solution were obtained by the FLS920 fluorescence spectrometer.Results show that the emission fluorescence peaks were 485 nm and 565 nm when the excitation wavelength redshift from 320 nm to 500 nm.Fluorescence intensity of the former was significantly larger than the latter,and excitation wavelength was 380 nm and 470 nm.Advance the fluorescence of potassium sorbate which is caused by the conjugate π key and the n unpaired electrons in the potassium sorbate molecule.The nonlinear variation of the fluorescence intensity in the different concentration of the potassium sorbate solution from 0.05 g/L to 12 g/L is found.And then,study the feasibility of fluorescence spectroscopy to detect the concentration of potassium sorbate in apple juice.This result provides experimental and theoretical supports for the detection of the content of potassium sorbate in liquid food.