1 Method Overview
After the sample is digested, lanthanum solution is added as a releasing agent. The sample is atomized in an atomic‑absorption flame, and the absorbance is measured at 422.7 nm. Within a certain concentration range, the absorbance is proportional to the calcium content, and quantification is performed by comparison with the standard series.
2 Scope of Application
This method is applicable to the determination of calcium in milk powder.
3 Reference Basis
GB 5009.92‑2016, National Food Safety Standard — Determination of Calcium in Foods
4 Instruments and Reagents
4.1 Instruments and Equipment
4.1.1 Testing Instruments
| No. | Name | Quantity | Technical Requirement | Accessories |
|---|---|---|---|---|
| 1 | Flame Atomic Absorption Spectrophotometer | 1 set | — | Calcium Hollow‑Cathode Lamp |
| 2 | Air Compressor | 1 set | Rated exhaust pressure: 0.3 MPa | — |
| 3 | Acetylene | 1 cylinder | Purity ≥99.99% | — |
