Overview - ISO 20637:2015 (myo‑inositol in infant formula & adult nutritionals)
ISO 20637:2015 specifies a validated laboratory method for the determination of myo‑inositol (free, and free plus bound as phosphatidylinositol) in infant formula and adult nutritional products. The method uses liquid chromatography with column switching combined with pulsed amperometric detection (PAD) to separate and quantify myo‑inositol against external calibration standards. The standard includes sample preparation, extraction, HPLC/PAD operating conditions, calculations, and informative annexes (chromatograms and precision data).
Key technical topics and requirements
- Scope: analysis of infant formula and adult nutritionals for free and phosphatidyl‑bound myo‑inositol.
- Analytical principle: two separate sample preparations (one for free myo‑inositol; one for phosphatidylinositol followed by hydrolysis) followed by ion‑exchange chromatography with column switching and pulsed amperometry.
- Reagents and solvents: specified high‑purity chemicals (e.g., chloroform, methanol, metaphosphoric acid, hydrochloric acid) and preparation of myo‑inositol stock and calibration solutions.
- Apparatus: corrosion‑resistant HPLC system with two isocratic pumps, 6‑port switching valve, PAD with gold electrode, and recommended columns (e.g., CarboPac MA1/PA1 or equivalent).
- Sample types and prep: procedures for ready‑to‑feed liquids, dry blended powders (reconstituted), and wet blended powders with defined weighing and dilution practices.
- Quality control: external calibration curve construction, calculation procedures for free and bound myo‑inositol, and annexed precision data and example chromatograms.
- Safety: method involves hazardous solvents and high‑temperature hydrolysis; users must establish appropriate safety practices.
Practical applications and who uses this standard
- Food and beverage analytical laboratories testing infant formula and nutritionally complete adult beverages for nutritional labeling and regulatory compliance.
- Quality control (QC) teams in infant formula and clinical nutrition manufacturers ensuring formulation accuracy for myo‑inositol content.
- Regulatory bodies and testing laboratories assessing nutrient content claims and safety of infant and adult nutritional products.
- Research labs studying inositol content and bioavailability in formulated nutrition products.
Related standards and references
- Foreword notes equivalence to AOAC Official Method 2011.18 (Myo‑inositol in infant/pediatric formula and adult nutritionals).
- Developed under ISO/TC 34 (Food products) in collaboration with AOAC International.
This summary helps laboratories and product developers understand the analytical scope, required equipment (HPLC/PAD, column switching), sample workflows, and typical applications of ISO 20637:2015 for reliable determination of myo‑inositol in formulated nutrition products.