糊化制样X射线荧光光谱法快速检测鲜香菇中的铅、砷、镉

Rapid determination of lead,arsenic and cadmium in fresh Lentinula edodes by energy-dispersive X-ray fluorescence spectrometry with gelatinizing sample preparation

目的建立糊化制样能量色散X射线荧光(energy-dispersive X-ray fluorescence,EDXRF)光谱法快速检测鲜香菇中铅(Pb)、砷(As)和镉(Cd)的新方法。方法鲜香菇样品与稀硝酸水溶液均质糊化后,直接进行EDXRF光扫描,通过谱峰识别进行定性,以加标校正曲线进行定量。结果样品基质中待测元素谱峰无干扰,方法线性良好(r 2≥0.995);Pb、As和Cd的检出限分别为0.34、0.14和0.19 mg/kg,定量限分别为1.15、0.47和0.63 mg/kg;总体加标回收率为93.7%~105.8%,相对标准偏差为0.92%~20.60%;以食品安全限量为关注浓度,应用本方法进行合格性快速筛选,Pb、As和Cd含量在关注浓度及以上时阳性检出率为100%,在0.2 mg/kg以下时,假阳性检出率小于等于10%,符合快速检测方法的要求。结论该方法操作简单、快速和绿色无污染,可为食用菌产品的质量控制和检测提供有效的方法借鉴。

Objective To develop a new method for rapid determination of lead(Pb),arsenic(As)and cadmium(Cd)in fresh Lentinula edodes(L.edodes)by energy-dispersive X-ray fluorescence(EDXRF)spectrometry with gelatinizing sample preparation.Methods The fresh L.edodes samples were homogenized and gelatinized with the dilute nitric acid aqueous solution,and then EDXRF spectrometry scanning was carried out directly.Qualitative analysis was conducted through spectral peak recognition,and quantitative analysis was conducted through calibration curve addition.Results The characteristic EDXRF peaks measured had no interference,and the method linearity was good(r 2≥0.995).The limits of detection of Pb,As and Cd were 0.34,0.14 and 0.19 mg/kg,and the limits of quantification were 1.15,0.47 and 0.63 mg/kg,respectively.The overall recoveries were 93.7%‒105.8%,and the relative standard deviations were 0.92%‒20.60%.With the food safety limits of targets elements as the concentration of concern,this method was used to carry out the qualified fast screening.The positive detection rates of As,Pb and Cd content were 100%at the concentration of concern and above,and the false positive detection rate was less than or equal to 10%when the concentration was below 0.2 mg/kg,which met the requirements of the fast detection method.Conclusion This method is simple,fast,green and pollution-free,and can provide an effective reference for the quality control and detection of edible mushroom products.