Determination of niacin in infant formula by solid-phase extraction/liquid chromatography: peer-verified method...

Area of Science:

• Analytical Chemistry
• Food Science
• Nutritional Analysis

Background:

• Accurate niacin determination in infant formula is crucial for nutritional assessment.
• Existing methods require validation for reliability and accuracy.
• The AOAC Peer-Verified Method (PVM) 1:2,000 offers a potential solution for standardized niacin analysis.

Purpose of the Study:

• To conduct an interlaboratory peer validation study of AOAC PVM 1:2,000 for niacin determination in infant formula.
• To assess method variability, robustness, and accuracy using a Data Quality Objectives (DQO) approach.
• To ensure the method's reliability and traceability through the use of a certified reference material.

Main Methods:

• Solid-phase extraction coupled with liquid chromatography (SPE/LC) was employed.
• A DQO approach incorporated statistical agreement, recovery, repeatability relative standard deviation (RSDr), HORRAT, interference validation, and certified reference material (CRM) analysis.
• National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1846 Infant Formula was used for accuracy assessment.

Main Results:

• The HORRAT value of 1.07 met the Horwitz "limits of acceptability" criteria.
• Niacin content determined by the originating laboratory (59.7 ± 4.0 µg/g) and the peer laboratory (56.6 ± 6.6 µg/g) showed statistical equivalence.
• Linear calibration curves and quantitative recovery were achieved, indicating method performance.

Conclusions:

• The AOAC PVM 1:2,000 is a valid and reliable method for determining niacin in infant formula.
• The integration of PVM with a CRM enhances confidence in data accuracy and traceability.
• This validated method supports accurate nutritional labeling and quality control of infant formula.