[Proficiency test for determination of fluoride in drinking water]

Area of Science:

• Environmental Science
• Analytical Chemistry
• Public Health

Background:

• Accurate determination of fluoride in drinking water is crucial for public health and regulatory compliance.
• Proficiency testing programs are essential for assessing and ensuring laboratory analytical capabilities.

Purpose of the Study:

• To evaluate the analytical capacity of national laboratories for fluoride determination in drinking water.
• To assess the performance of laboratories through a nationwide proficiency testing program.

Main Methods:

• Secondary standard materials were prepared as reference for sample preparation.
• Homogeneity and stability of test samples were verified using analysis of variance (ANOVA) and linear regression.
• Laboratory results were statistically analyzed using robust methods and Z-scores.

Main Results:

• 985 laboratories participated in the proficiency testing program.
• 92.4% (910 laboratories) achieved satisfactory results for fluoride determination.
• 2.6% (26 laboratories) showed results indicating potential capacity issues, and 5.0% (49 laboratories) were outliers.

Conclusions:

• The overall capacity of national laboratories for drinking water fluoride analysis is satisfactory.
• A limited number of participating laboratories require targeted improvement to enhance their analytical performance.