Thermo Fisher Scientific has developed a high-performance anion-exchange chromatography with pulsed amperometric detection method, based on AOAC Official Method 2011.18, to determine free and bound myo-inositol in infant formula and adult nutritionals.
Application Note (AN) 1083: Determination of Myo-Inositol (Free and Bound as Phosphatidylinositol) in Infant Formula and Adult Nutritionals demonstrates a column-switching technique used to remove strongly retained carbohydrates in the sample, thereby reducing run time.
Pulsed amperometric detection with a gold on polytetrafluoroethylene disposable electrode offers high sensitivity while eliminating the need for sample derivatization and electrode polishing.
For the determination of bound myo-inositol, AN 1083 compares the results obtained using a silica solid-phase extraction (SPE)column as described in AOAC Official Method 2011.18 to using a polymeric reversed-phase sample pretreatment cartridge, the Thermo Scientific™ Dionex™ OnGuard™ II RP cartridge.
The results demonstrate that the pretreatment cartridge produces higher content and provides improved recoveries of bound myo-inositol in the samples.
The pretreatment cartridge also reduces sample preparation time and eliminates the hazardous chemicals associated with use of the silica SPE column.