Abstract: In order toaccurately detect heavy metals in milk,microwave digestion-atomic fluorescence method was used to detect heavy metal elements arsenic and mercury in milk,and its detection method was optimized by one-way and orthogonal experiments with spiked recovery as the index.The method was also validated and applied. The results showed that the optimal conditions for the determination of arsenic and mercury were 50 g/L for thiourea,15 g/L for potassium borohydride-potassium hydroxide,2.5 mL of sulfamic acid,5 mL of nitric acid, and 195 ℃ for microwave digestion.The detection limits of arsenic and mercury were 0.01 mg/kg and 0.003 mg/kg,respectively;the linear ranges of the standard curve equations were 0-10 ng/mL and 0-1 ng/mL,with the correlation coefficients of 0.997 and 0.992,respectively;the RSDs of the spiked recoveries of arsenic and mercury and the reproducibility of the detection data of the quality control samples were 0.11,0.18,3.82 and 4.29,respectively.Precision was 0.59,0.56,3.28,4.32,respectively;a quarter of arsenic and mercury spiked recovery and quality control samples were tested 48 times,the recovery rate was 98.84%,99.23%,RSD was 1.01,1.91,respectively.the deviation of the detection value of the quality control samples complied with the experimental requirements,and the RSD was 2.79-3.80.the recovery rate and the deviation of the quality control value were in accordance with the national standards.Requirements.A convenient,accurate and sensitive atomic fluorescence detection method for the simultaneous detection of arsenic and mercury has been successfully established,which lays the foundation for the supervision of food contamination by heavy metals.

Key words: atomic fluorescence, microwave digestion, milk, heavy metal elements