AOAC SPIFAN Stakeholder Panel Meeting Book (March 12, 2020)

Analytical Method- alternative techniques 1. Microbiological 2. Enzymatic 3. GLC 4. HPLC-UV/Fl 5. HPIC-PAD

SPIFAN selections

1.

None presented

2. None presented 3. 2 considered but not approved 1 st Action 4. None presented 5. 2 approved 1 st Action (2011.18 & 2012.12). 1 approved Final Action after MLT (2011.18)

Liquid Chromatography – Ion Exchange

Methods using high performance ion chromatography-pulsed amperometry detection (PAD). Methods use dilute acid to precipitate proteins and extract free myo-inositol. For total inositol analyses, samples are mixed with strong acid and heated for several hours at high temperatures. Sample filtrates are analyzed using a hydroxide mobile phase with anion exchange chromatography and PAD. Anion exchange with PAD detection has good sensitivity. Depending on system configuration, run times can be 30-60 min Anion exchange with a hydroxide mobile phase requires a corrosion resistant system. Ion exchange methods can be used to measure free or total myo-inositol (myo-inositol + inositol phosphates including phytate + inositol containing phospholipids) depending on how the sample is prepared.

Analysis of an infant formula using anion exchange chromatography with a sodium hydroxide mobile phase and PAD