Analytical quality
Reference Materials and Working Standards
Reference materials and working standards: Which property is assigned to the material used as a reference?
Source editorial review:
Before interpreting the result
Which property is assigned to the material used as a reference?
- Read the certificate, batch, assigned value, uncertainty and intended use.
- Distinguish a reference material from a laboratory-prepared working standard.
- Record how traceability is transferred and preserved between them.
Reference materials and working standards
A working standard is useful because of defined characterization and use, not merely because it is called a standard. Documentation should explain assigned properties, relevant traceability and storage or validity conditions. Material suitable for checking identity may not suit content quantification; each role needs justification.
A reading case: what to check
Before accepting calibration, identify the material used and its assigned property. If a commercial batch serves as an internal reference, check characterization and maintenance. Recording only supplier and name leaves the chain incomplete. The record should make it possible to reconstruct what supports the value assigned to the standard.
What to preserve in the record
A bottle labeled standard does not document every property. Calibration must use the relevant assigned value and scope, with verifiable validity and handling.
Questions and answers
Which property is assigned to the material used as a reference?
A working standard is useful because of defined characterization and use, not merely because it is called a standard. Documentation should explain assigned properties, relevant traceability and storage or validity conditions. Material suitable for checking identity may not suit content quantification; each role needs justification.
What should the review record preserve?
A bottle labeled standard does not document every property. Calibration must use the relevant assigned value and scope, with verifiable validity and handling.