AOAC SPIFAN Nutrients ERP Method Reviews (September 7, 2019)

Reviewer 2 – Fluor-03

AOAC SPIFAN ERP Reviewer Form OMA#/Nutrient Code Fluor-03 Method Title

Determination of fluoride in infant formula and adult/nutritional formula by ion chromatography with sequentially supressed conductivity detection. Fluoride is extracted from the sample matrices by mixing with ultrapure water. The samples are mixed and analyzed directly using Inline Dialysis with a cellulose acetate membrane. The concentration of fluoride is determined from the polynomial regression of the fluoride in the standards compared to the fluoride response as peak height detected in the samples. To enable the detection of low quantities the signal to noise ratio is effectively reduced using sequential suppression. The application of a Dose-in gradient enables the column clean-up from negatively charged organics. Carry-over is minimized by an automatic thorough cleaning step of the equipment including the dialysis cell. Theresa Steurer et al. The method authors should be acknowledged for their efforts in having addressed the comments made by the ERP at the previous SPIFAN meeting. The proprietary nature of the dialysis cell and the risk of chromatographic interference on integration are of some concern Fluoride in Infant and Adult/Pediatric Nutritional Formula

Method Author

Summary of Method

Method Scope/Applicability General Comments about the method

Method Clarity

Good.