直接进样电热蒸发-原子荧光光谱法快速测定蒸馏酒中镉

为了快速低成本测定蒸馏酒中痕量重金属镉,利用钨丝电热蒸发器作为直接进样装置,与原子荧光光谱仪原子化器直接连接,构建了用于蒸馏酒中镉测定的直接进样原子荧光光谱检测系统(W-coil ETV-AFS),并对工作气体的气氛和流速、灰化和蒸发电压、样品承载量等参数进行了优化,建立了蒸馏酒中镉的直接进样快速检测方法。在最优条件下,Cd的检出限(LOD)为0.06μg/L(进样量为50μL),在0.5~100μg/L线性范围内回归系数(R²)为0.997;在5μg/L水平下,9个典型蒸馏酒样品的加标回收率在86.0%~116%,相对标准偏差RSD≤8.0%(n=3)。可以直接导入样品,无需复杂的前处理过程,具有良好的灵敏度、准确度和精密度,非常适合蒸馏酒中痕量镉的快速测定。

Rapid determination of cadmium in distilled liquor by direct sampling W-coil electrothermal vaporization-atomic fluorescence spectrometry

In order to quickly and cheaply determine trace cadmium in distilled liquor samples,a new direct sampling W-coil electrothermal vaporization-atomic fluorescence spectrometer(W-coil ETV-AFS)was developed by combining a tungsten coil electrothermal vaporizer with the atomizer of AFS.The instrumental parameters such as working gas atmosphere and flow rate,ashing and vaporization voltage,sample size.are optimized,then a direct sampling method for rapid determination of cadmium in distilled liquor is established.Under the optimal conditions,the limit of detection(LOD)of Cd is 0.06μg/L(sample size is 50μL),and the regression coefficient(R²)is 0.997 in the linear range of 0.5-100μg/L.At the level of 5μg/L,the recoveries of 9 typical distilled liquor samples are in the range of 98.0%-116%with RSD≤8.0%(n=3).This proposed method fulfills direct sampling analysis of Cd in liquor samples regardless of complicated sample pretreatment process,and is thereby characterized with favorable sensitivity,accuracy and precision,which is very suitable for the rapid determination of trace cadmium in distilled liquor to protect food safety.