Determination of lead in feeds - Atomic absorption spectrometry
1 Scope
This standard describes the flame atomic absorption spectrometry and graphite furnace atomic absorption spectrometry for the determination of lead in feeds.
This standard is applicable to the determination of lead in formula feed, concentrated feed, additive premix, concentrate supplement and feedstuff.
If the sampling amount is 5g and the constant volume is 50mL, the limit of quantitation for flame atomic absorption spectrometry is 2mg/kg. If the sampling amount is 1g and the constant volume is 10mL, the limit of quantitation for graphite furnace atomic absorption spectrometry is 100μg/kg.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 602 Chemical reagent - Preparations of standard solutions for impurity
GB/T 6682 Water for analytical laboratory use - Specification and test methods
GB 6819-2004 Dissolved acetylene
GB/T 14699.1 Animal feeding stuffs - Sampling
GB/T 20195 Animal feeding stuffs－Preparation of test samples
3 Principle
After dry ashing, acid dissolution or wet digestion of the test sample, lead is dissolved out, and the absorbance value is determined by an atomic absorption spectrometer at 283.3nm, and compared with the standard curve for quantification.
4 Reagents or materials
Warning: All kinds of strong acids shall be carefully handled, and shall be diluted and taken in a fume cupboard.
Unless otherwise specified, reagents used in the analysis shall be of recognized analysis pure grade. All the reagents and solutions used in the test shall be prepared according to GB/T 602.
4.1 Water: Grade I water specified in GB/T 6682.
4.2 Nitric acid: guaranteed reagent.
4.3 Perchloric acid: guaranteed reagent.
4.4 Hydrofluoric acid.
4.5 Hydrochloric acid solution (0.6mol/L): take 5mL of hydrochloric acid, dilute it with water to 100mL, and mix well.
4.6 Hydrochloric acid solution (6mol/L): take 50mL of hydrochloric acid, dilute it with water to 100mL, and mix well.
4.7 Nitric acid solution (0.5mol/L): take 3.6mL of nitric acid, dilute it with water to 100mL, and mix well.
Foreword i
1 Scope
2 Normative references
3 Principle
4 Reagents or materials
5 Instruments and apparatus
6 Sample
7 Test steps
