Quantification of 1,3-olein-2-palmitin (OPO) and Palmitic Acid in -2 Position of Triacylglycerols in Human Milk by Liquid Chromatography Coupled with Mass Spectrometry.

This study describes the identification and quantification of fatty acids in the -2 position of triacylglycerols (TAG) and of the most abundant TAG regioisomers in human milk by liquid chromatography coupled with high-resolution mass spectrometry (HPLC-HRMS). Over 300 individual TAG species were observed and 1,3-olein-2-palmitin (OPO) was identified as the most abundant TAG regioisomer. Validation of the HPLC-HRMS method showed repeatability and intermediate reproducibility values ranging from 3.

Quantification of glycerophospholipids and sphingomyelin in human milk and infant formula by high performance liquid chromatography coupled with mass spectrometer detector.

Phospholipids and sphingomyelin have a central role in infant nutrition, phospholipid acting as a nutrient carrier of long chain polyunsaturated fatty acids and sphingomyelin having an important role in cognitive function. However, analytical methods to precisely characterize and quantify these compounds in maternal milk are needed. Phospholipids and sphingomyelin were extracted using chloroform and methanol and separated on Polaris 3 Si column 250×2.

Quantification of fatty acids in erythrocytes and plasma by fast gas chromatography.

As a result of the heterogeneous nature of lipid classes in complex biological matrices such as plasma and erythrocytes, it is imperative to have a robust and validated methodology for fatty acid quantification. The effective method presented here combines available methodology of fast gas chromatography and an improvement of the sample preparation methodology before injection into the gas chromatograph. This methodology ensures complete transesterification and quantification of total and individual fatty acids (and not only in relative amounts) by addition of internal standards.

Temporal Changes of Human Breast Milk Lipids of Chinese Mothers.

Fatty acids (FA), phospholipids (PL), and gangliosides (GD) play a central role in infant growth, immune and inflammatory responses. The aim of this study was to determine FA, PL, and GD compositional changes in human milk (HM) during lactation in a large group of Chinese lactating mothers (540 volunteers) residing in Beijing, Guangzhou, and Suzhou. HM samples were collected after full expression from one breast and while the baby was fed on the other breast.

Choline in infant formula and adult/pediatric nutritional Formula by ultra high-performance liquid chromatography/ Tandem mass spectrometry: AOAC First Action 2012.18.

The method described below is for the determination of choline in infant formula and adult/pediatric nutritional formula by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The single-laboratory validation data were submitted to the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel (ERP) for review at the AOAC INTERNATIONAL Annual Meeting held September 30 to October 3, 2012 in Las Vegas, NV. The ERP determined that the data reviewed met the standard method performance requirements set by SPIFAN, and the method was approved as AOAC Official First Action.

Vitamin C in infant formula and adult/pediatric nutritional Formula by ultra-performance liquid chromatography with Ultraviolet detection: first action 2012.22.

During the AOAC Annual Meeting held in Las Vegas, NV from September 30 to October 3, 2012, the Stakeholder Panel on Infant Formula and Adult Nutritionals convened to review single-laboratory validation data submitted for the method, Vitamin C in Adult/Pediatric Formula by Ultra-Performance Liquid Chromatography with Ultraviolet Detection. This method is a modified version of the method "HPLC-UV Determination of Total Vitamin C in a Wide Range of Fortified Food Products" previously published in Food Chem., 94, 626-631 (2006).

Determination of vitamin B12 in infant formula and adult nutritionals by liquid chromatography/UV detection with immunoaffinity extraction: First Action 2011.08.

At the "Standards Development and International Harmonization: AOAC INTERNATIONAL Mid-Year Meeting," on June 29, 2011, an Expert Review Panel agreed that the method "Determination of Vitamin B12 in Infant Formulas and Adult Nutritionals by Liquid Chromatography/UV Detection with Immunoaffinity Extraction" be adopted AOAC Official First Action status. The method is applicable for the determination of vitamin B12, which includes added cyanocobalamin and natural forms, making it applicable to both fortified and nonfortified products. Vitamin B12 is extracted from the sample in sodium acetate buffer in the presence of sodium cyanide (100 degrees C, 30 min).

Pantothenic acid (vitamin B5) in fortified foods: comparison of a novel ultra-performance liquid chromatography-tandem mass spectrometry method and a microbiological assay (AOAC Official Method 992.07).

A novel method was developed and single-laboratory validated for the determination of free pantothenic acid (vitamin B5) in a wide range of infant and adult fortified food products. The method combines simple sample preparation and chromatographic analysis using ultra-performance LC coupled to tandem MS with positive electrospray ionization. Pantothenic acid was quantified using [13C6, 15N2]-pantothenic acid as an internal standard.

Determination of vitamin B12 in food products by liquid chromatography/UV detection with immunoaffinity extraction: single-laboratory validation.

A fast and simple method to determine vitamin B12 in foods is presented. The method allows, in addition to the determination of added cyanocobalamin, the determination of natural vitamin B12 forms, making it also applicable to nonfortified products, especially those that are milk-based. Vitamin B12 is extracted in sodium acetate buffer in the presence of sodium cyanide (100 degrees C, 30 min).

Determination of vitamin B5 in human urine by high-performance liquid chromatography coupled with mass spectrometry.

In the present work, we have developed a simple and rapid liquid chromatography/mass spectrometry (LC/MS) method for the identification and quantification of vitamin B5 in human urine. Urine was spiked with vitamin B5 internal standard, hopantenic acid (HOPA), and then diluted with the LC mobile phase prior to its analysis by LC/MS. The quantification was performed in single ion monitoring mode.

Separation of water-soluble vitamins by reversed-phase high performance liquid chromatography with ultra-violet detection: application to polyvitaminated premixes.

Nine water-soluble vitamins: [thiamine (B1), ascorbic acid (C), nicotinamide (PP), pyridoxine (B6), calcium pantothenate (B5), folic acid (B9), cyanocobalamin (B12), riboflavin (B2) and biotin (B8)] were separated on a YMC-Pack Pro C18 column (250 mm x 4.6 mm, 5 microm particle size) in a single run with a gradient elution of mobile phase consisting of 0.025% trifluoroacetic acid pH 2.