Drawing Attention to the Measurement Uncertainty Arising from Sampling in Chemical and Physicochemical Analyses: An...

Area of Science:

• Analytical Chemistry
• Measurement Science

Background:

• Measurement uncertainty is crucial in analytical chemistry.
• Traditionally, uncertainty from the analytical process is well-defined, but sampling uncertainty is often overlooked.
• Sampling uncertainty arises from uncontrolled environmental factors during sample collection.

Purpose of the Study:

• To highlight the significance of sampling uncertainty in the overall measurement uncertainty.
• To review current methodologies for assessing sampling uncertainty.
• To demonstrate the impact of sampling uncertainty on compliance assessment.

Main Methods:

• Review of literature on sampling uncertainty assessment.
• Discussion of statistical approaches: classical analysis of variance, robust analysis of variance, and range statistics.
• Analysis of recent studies correlating methods with matrices, analytes, and techniques.

Main Results:

• Sampling uncertainty is a significant, often neglected, component of total measurement uncertainty.
• Various statistical methods exist for quantifying sampling uncertainty.
• Case studies show sampling uncertainty impacts compliance assessment in chemical and physicochemical analyses.

Conclusions:

• Sampling uncertainty must be considered for a comprehensive measurement uncertainty evaluation.
• Established statistical methods can effectively quantify sampling uncertainty.
• Neglecting sampling uncertainty can lead to inaccurate compliance assessments in chemical analyses.