How to select the suitable reference material.

1. Analyte of interest: a substance or compound in the test sample.
2. Testing range: the concentration range of the reference material should be similar to that of the analyte in the sample.
3. Matrix: the matrix in the reference material should be similar to that in the test sample.
4. Homogeneity: the homogeneity data of the reference material should be provided appropriately.
5. Stability: the stability data of the reference material should be provided appropriately.
6. Quantity: the quantity of the reference material is sufficient for the testing.
7. Uncertainty: the uncertainty value of the reference material and the calculation of the uncertainty are required.
8. Expired date: the expired date of the reference material is shown.