Microdiffusion and fluoride-specific electrode determination of fluoride in infant foods: collaborative study

Area of Science:

• Food Science
• Analytical Chemistry
• Environmental Science

Background:

• Accurate determination of fluoride (F) in infant foods is crucial for ensuring infant health and safety.
• Establishing reliable analytical methods is essential for regulatory compliance and quality control.
• Fluoride levels in infant foods can vary, necessitating precise measurement techniques.

Purpose of the Study:

• To evaluate the performance of a method for determining fluoride (F) in infant foods.
• To assess the intralaboratory and interlaboratory reproducibility of fluoride measurements.
• To provide data on the variability of fluoride content in common infant food matrices.

Main Methods:

• Twelve laboratories participated in a proficiency testing scheme.
• Analysis of 12 infant food samples (milk, pears, peas) fortified with 0.2-5 ppm F.
• Inclusion of blind duplicates to assess repeatability and reproducibility.

Main Results:

• Mean intralaboratory coefficient of variation was 7.06% for blind duplicates.
• Mean interlaboratory coefficient of variation was 21.6% for the 12 samples.
• Reproducibility standard deviation for all samples was 0.41 ppm; for blind duplicates, it was 0.32 ppm.
• Repeatability standard deviation for blind duplicates was 0.26 ppm.

Conclusions:

• The analytical method demonstrates good intralaboratory repeatability and acceptable interlaboratory reproducibility for fluoride determination in infant foods.
• The study identified one laboratory outlier, highlighting the importance of robust quality assurance measures.
• The findings support the reliability of the method for routine analysis of fluoride in infant food products.