Metrology in physics, chemistry, and biology: differing perceptions

Area of Science:

• Metrology
• Physical Chemistry
• Analytical Chemistry

Background:

• Metrology in physics relies on two components: the measure (unit) and the measurand (entity measured).
• Physical and analytical chemistry traditionally apply these metrological principles using measures like molar relationships and techniques such as gravimetry.
• Basic metrology ensures measurement integrity through well-defined units and measurands.

Discussion:

• Extending metrology to complex chemical matrices, like food samples, introduces a third component: indirect measurements.
• Techniques such as Atomic Absorption Spectroscopy (AAS) for determining zinc in foods exemplify this addition.
• This transition necessitates additional steps to ensure the traceability and reliability of chemical measurements.

Key Insights:

• Chemical metrology differs from physics metrology when dealing with complex matrices.
• Indirect measurements are crucial for field assays in chemical analysis.
• Traceability in chemical metrology is becoming more complex.

Outlook:

• The field of chemical metrology is continuously evolving.
• Further development is needed to address the complexities of indirect measurements and traceability in chemical analysis.
• Ensuring the reliability of measurements in complex chemical systems remains a key focus.