What are the national standard determination methods of four heavy metal elements in food? What are their characteristics?

What are the national standard determination methods of four heavy metal elements in food? What are their characteristics?

The detection methods of heavy metal elements in food include photometry, turbidimetry, point comparison, chromatography, spectrometry, electrochemical analysis, neutron activation analysis and so on. Relevant national standards have stipulated the determination methods of heavy metal elements in food. The following are the national standard detection methods for lead, cadmium, mercury and arsenic in food.

(1) The common detection methods of lead in food are: graphite furnace atomic absorption spectrometry with the detection limit of 5 μ g/kg; The detection limit of flame atomic absorption spectrometry is 0.65438 0 mg/kg; Single sweep polarography with detection limit of 0.085 mg/kg; Dithizone spectrophotometry with detection limit of 0.25 mg/kg; The detection limit of hydride generation atomic fluorescence spectrometry is 5 μ g/kg.

(2) The common detection methods of cadmium in food are: graphite furnace atomic absorption spectrometry, with the detection limit of 0.1μ g/kg; The detection limit of flame atomic absorption spectrometry is 5 μ g/kg; Spectrophotometry, the detection limit is 50 μ g/kg; The detection limit of atomic fluorescence spectrometry is 65438±0.2μg/kg/kg.

(3) The common detection methods of total mercury in food are: atomic fluorescence spectrometry with detection limit of 0.1.5 μ g/kg; Cold atomic absorption spectrometry with detection limit of 0.4 μ g/kg (pressure digestion method) or 10 μ g/kg (other digestion methods); The detection limit of dithizone spectrophotometry is 25 μ g/kg. Methylmercury is usually extracted by acid, adsorbed by sulfhydryl cotton, and then determined by gas chromatography or cold atomic absorption spectrometry.

(4) The common detection methods of total arsenic in food are: hydride generation atomic fluorescence spectrometry with detection limit of 0.01mg/kg; The detection limit of silver salt method is 0.2 mg/kg; The detection limit of arsenic spot method is 0.25 mg/kg; The detection limit of borohydride reduction spectrophotometry is 0.05 mg/kg.