Determination of and Total Vitamin K in Infant, Pediatric, and Adult Nutritionals by HPLC with Post Column Reduction and Fluorescence Detection: Multilaboratory Testing Study, AOAC Final Action 2015.09.

A multilaboratory study was completed with AOAC INTERNATIONAL First Action 2015.09, "Determination of and Total () Vitamin K in Infant, Pediatric, and Adult Nutritionals by HPLC with Post Column Reduction and Fluorescence Detection." Eight laboratories from six countries participated in the multilaboratory study.

Determination of Myo-Inositol in Infant, Pediatric, and Adult Formulas by Liquid Chromatography-Pulsed Amperometric Detection with Column Switching: Collaborative Study, Final Action 2011.18.

AOAC First Action Method 2011.18, Myo-Inositol (Free and Bound as Phosphatidylinositol) in Infant and Pediatric Formulas and Adult Nutritionals, was collaboratively studied. With this method free myo-inositol and phosphatidylinositol bound myo-inositol are extracted using two different sample preparation procedures, separated by ion chromatography using a combination of Dionex Carbo Pac PA1 and MA1 columns with column switching, and detected with pulsed amperometry using a gold electrode.

Determination of Vitamin B12 in Infant, Adult, and Pediatric Formulas by HPLC-UV and Column Switching: Collaborative Study, Final Action 2011.10.

AOAC First Action Method 2011.10, Vitamin B12 in Infant and Pediatric Formulas and Adult Nutritionals, was collaboratively studied. This method uses a pH 4.

Determination of Vitamin K1 in Infant, Pediatric, and Adult Nutritionals by HPLC with Fluorescence Detection: Single-Laboratory Validation, First Action 2015.09.

This normal-phase HPLC method with postcolumn reduction and fluorescence detection allows for the quantitative determination of trans vitamin K1 in infant, pediatric, and adult nutritionals. Vitamin K1 is extracted from products with iso-octane after precipitation of proteins and release of lipids with methanol. Prepared samples are injected onto a silica HPLC column where cis and trans vitamin K1 are separated with an iso-octane-isopropanol mobile phase.

Determination of vitamins A and E in infant formula and adult/pediatric nutritional formula by HPLC with UV and fluorescence detection: First Action 2012.09.

The method presented is for quantification of alpha-tocopherol (vitamin E), vitamin E acetate, vitamin A acetate, and vitamin A palmitate in infant formula and adult/pediatric nutritionals. The entire lipid fraction, including vitamins A and E, is extracted from product with iso-octane after products are mixed with methanol, which precipitates proteins and disrupts micelles freeing lipids for extraction. Vitamin A palmitate, vitamin A acetate, and vitamin E acetate are separated from alpha-tocopherol on a 3 cm silica column with a 1% methylene chloride, 0.