Hydride Generation-Atomic Fluorescence Spectrometric Determination of Mercury and Tin in Canned Food——with Microwave Assisted Sample Digestion

HG-AFS was applied to the simultaneous determination of tin and mercury in canned food.Effects of acidity and concentration of KBH4 solution on the hydride forming reaction,suitable conditions for the acid digestion of sample and the working condition of the instrument were studied and optimized.Mixed solution of thiourea and ascorbic aicd was used as masking agent and tartaric acid solution was used as carrying solution to eliminate interferences of some coexisting substances,especially in the determination of arsenic.Detection limits (3 S) of this method were found to be 0.005 μg·L-1 for mercury,and 0.20 μg·L-1 for arsenic.Precision of this method was tested at the concentration level of 2 μg·L-1 of mercury and 20 μg·L-1 of tin,and the values of RSD′s (n=12) found were in the ranges of 5.0%-6.5% (for Hg) and 4.0%-7.3% (for As).Results of recovery test were found in the ranges of 93.0%-101.0% for mercury and 92.5%-94.0% for arsenic.