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 Carotenoids in Infant, Pediatric, and Adult Nutritionals by HPLC with UV-Visible Detection: Single-Laboratory Validation, First Action 2017.04.

This reversed-phase HPLC method uses C30 chromatography and UV-Vis spectroscopy to determine cis and trans isomers of lutein, β-carotene, and lycopene in infant, pediatric, and adult nutritionals. Samples are saponified with a mixture of potassium hydroxide, tetrahydrofuran, and methanol, and carotenoids are extracted from saponified samples with 75 + 25 hexane-methyl tertiary butyl ether (MtBE). After extraction, a portion of the organic layer is evaporated to dryness, and the residue is dissolved in 75 + 25 10% butylated hydroxytoluene in methanol-MtBE.

Determination of Biotin in Infant, Pediatric, and Adult Nutritionals by High-Performance Liquid Chromatography and Fluorescence Detection: Single-Laboratory Validation, First Action 2016.11.

A reversed-phase HPLC method with postcolumn protein conjugation and fluorescence detection for the quantitative determination of biotin in infant, pediatric, and adult nutritionals was developed and evaluated in a single-laboratory validation (SLV). Sample of appropriate size is mixed with 2% metaphosphoric acid to precipitate out the protein. The filtrate is injected onto a C18 HPLC column in which biotin and riboflavin are separated with an appropriate mobile phase.

Determination of biotin by high-performance liquid chromatography in infant formula, medical nutritional products, and vitamin premixes.

A solid-phase extraction sample preparation procedure was developed for use with a high-performance liquid chromatography (HPLC) method for biotin analysis. The HPLC method used a reversed-phase C18 column; chromatography run time was 8.5 min.