Method for Limit Test of Heavy Metals in Food Additives
1 Scope
This standard specifies the method for limit test of heavy metals in food additives.
This standard is applicable to the limit test of heavy metals in food additives.
2 Principle
In the presence of weak acid (pH 3~4), heavy metal ion in the test sample will act with hydrogen sulfide to generate a substance in brownish black, which is compared to the lead standard solution experiencing the same treatment for limit test.
3 Reagents
3.1 Nitric acid.
3.2 Sulfuric acid.
3.3 Hydrochloric acid.
3.3.1 6 mol/L hydrochloric acid: measure 50mL of hydrochloric acid and dilute it with water to 100 mL.
3.3.2 1 mol/L hydrochloric acid: measure 8.3mL of hydrochloric acid and dilute it with water to 100 mL.
GB/T 5009.74-2003 The following standards are cited：
GB/T 5009.74-2003 Cited by the following standards：
