This standard specifies various methods for determination of cadmium in foods.
This standard is applicable to the determination of cadmium in various foods.
Detection limit in this method: 0.1μg/kg for graphite furnace atomization method; 5.0μg/kg for flame atomization method; 50μg/kg for colorimetric method; l.2μg/kg for atomic fluorescence method and 0~50ng/mL for linear range of standard curve.
The samples shall be incinerated or digested in acid, and then injected into the graphite furnace of atomic absorption spectrophotometer; the resonance line of 283.3nm shall be absorbed after electrothermal atomization, and its absorption value is proportional to the cadmium content within a certain concentration range, and is determined by comparing with the standard series.
3 Reagents
3.1 Nitric acid.
3.2 Sulfuric acid.
3.3 Hydogen peroxide (30%).
3.4 Barium perchlorate.
3.5 Nitric acid (1+1): take 50mL of nitric acid and add it into 50mL water slowly.
3.6 Nitric acid (0.5mol/L): take 3.2mL of nitric acid to add into 50mL water and dilute it until 100mL.
3.7 Hydrochloric acid 1+1): take 50mL of hydrochloric acid and add it into 50mL water slowly.
3.8 Ammonium phosphate solution (20g/L): weigh 2.0g of ammonium phosphate and dissolve it with water to dilute until 100mL.
3.9 Mixed acid: nitric acid+perchloric acid (4+1). Mix four shares of nitric acid and one share of perchloric acid.
3.10 Cadmium standard stock solution: weigh accurately 1.000g of cadmium metal (99.99%), dissolve it by adding 20mL of hydrochloric acid (1+1) for several times, add two drops of nitric acid, move it into a 1 000mL volumetric flask, water to the scale and mix uniformly. This solution contains 1.0mg of cadmium per milliliter.
3.11 Cadmium standard working solution: absorb 10.0mL of cadmium standard stock solution every time to 100mL volumetric flask and add nitric acid (0.5mol/L) to the scale. Dilute it like this for several times into a standard working solution of 100.0ng of cadmium per milliliter.
GB/T 5009.15-2003 The following standards are cited：
GB/T 5009.15-2003 Cited by the following standards：
