LED激发荧光光谱法快速测定玉米粉中的黄曲霉毒素B1

Rapid Detection of Aflatoxin B1 in Cornflour by LED Excited Fluorescence Spectrometry

以LED灯为激发光源,小型光纤光谱仪为检测设备,构建了LED激发的荧光光谱检测装置,并基于Hg^(2+)对黄曲霉毒素B1(AFB1)的荧光增强效应,建立了AFB1的荧光光谱快速定量分析方法。研究确定了激发波长为370 nm,荧光检测波长为443.2 nm,对Hg^(2+)与AFB1反应的pH值、溶剂配比、反应时间等条件进行优化,同时探究了方法的干扰因素。在优化条件下,AFB1-Hg^(2+)体系的荧光发射强度与AFB1的质量浓度在3~90μg/L范围内呈线性关系,相关系数r^(2)=0.996,检出限为0.913μg/L。将该方法用于两种玉米粉中AFB1的检测,其加标回收率为84.1%~107%,相对标准偏差(RSD)为1.1%~7.1%。该研究为AFB1的快速检测提供了一种新的具有较高灵敏度、精密度的快速检测方法,有望在现场快速检测中得到应用。

Aflatoxin(AFT)is a type of difuran ring toxins produced by some strains such as aspergillus flavus and aspergillus parasiticus.There are about 20 kinds of its derivatives,of which aflatoxin B1(AFB1)is the most widely distributed,most toxic,and most harmful.Therefore,extremely strict regulations have been imposed on the levels of AFB1 in various foods worldwide.At present,the existing detection methods for AFB1 require large-scale instruments or have poor reproducibility,and most of them are difficult to achieve rapid on-site detection to meet market needs.Fluorescence analysis is a common quantitative analysis method,which is simple,fast,and sensitive.A small portable fluorscence instrument can easily be fabricated by assembling small optical devices,such as light source and small optical detector,which has the potential for rapid on-site testing.In this work,a fluorescence spectral detection device was constructed with a LED lamp as the excitation light source and a small fiber-optic spectrometer as the detection equipment.Based on the fluorescence enhancement effect of Hg^(2+)on AFB1,a rapid fluorescence spectrometric method was established for the quantitative analysis of AFB1,using a Lumina fluorescence spectrophotometer at an excitation wavelength of 370 nm and an fluorescence detection wavelength of 443.2 nm.The pH value,solvent ratio,reaction time and other conditions of the reaction between Hg^(2+)and AFB1 were optimized.Meanwhile,the interference factors of this method were explored and the anti-interference ability of the method was evaluated.Under the optimized conditions,there is a linear relationship between the fluorescence emission intensity of the AFB1-Hg^(2+)system and AFB1 concentration in the range of 3-90μg/L,with a correlation coefficient(r^(2))of 0.996 and a detection limit of 0.913μg/L.The first step of this method is to extract the AFB1 in the sample by magnetic stirring method,then making the extract clarified by filtering it with glass fiber filter paper,and finally using the special AFB1 immunoaffinity column to refer to the instructions for the aspergillus flavus in the sample to be tested.AFB1 was specifically enriched and eluted with methanol,and then Hg^(2+)was added to the eluate to test the fluorescence spectrum of the sample.This method was used to detect AFB1 in two kinds of cornflours.The spiked recoveries ranged from 84.1%to 107%,with RSDs of 1.1%-7.1%.This study provides a new rapid method with high sensitivity and precision for the rapid detection of AFB1.In the future,it is expected that the detection method equipment will be assembled into a rapid detection kit,and the method is expected to be applied to the field of rapid detection.