Overview
ISO 21470:2020 specifies a validated analytical method for the simultaneous quantitative determination of total vitamins B1, B2, B3 and B6 in infant formula and related adult nutritional products. The method combines enzymatic digestion to release bound and phosphorylated vitamin forms with UHPLC–MS/MS (LC‑MS/MS) for selective, sensitive measurement. ISO 21470:2020 is published by ISO in collaboration with AOAC and is equivalent to AOAC Official Method 2015.14. Note: the method is intended only for products to which vitamins have been added.
Key topics and technical requirements
- Analytes covered: total Thiamine (B1), Riboflavin (B2), Niacin/Niacinamide (B3) and Vitamin B6 (including relevant vitamers and phosphorylated forms).
- Sample types: powdered infant formula, reconstituted powders and liquid nutritionals (procedures for powdered and liquid matrices are included).
- Sample preparation: enzymatic digestion using a mixed enzyme preparation (papain, α‑amylase) and acid phosphatase to free phosphorylated forms.
- Internal standards: use of stable‑isotope labelled internal standards added during sample preparation to correct for extraction and instrument variability.
- Chromatography and detection: injection onto UHPLC coupled to triple‑quadrupole MS/MS; monitoring of precursor→product ion transitions for each analyte and its isotope-labelled internal standard.
- Calibration and quantitation: six mixed working standards spanning ~two orders of magnitude; quantitation by least‑squares regression of analyte/internal standard response ratios.
- Quality control and performance: method includes system suitability, calibration curve requirements, precision data (repeatability and reproducibility) and recommended reagents, mobile phases and solution preparation.
Practical applications and users
ISO 21470:2020 is intended for:
- Food and beverage testing laboratories conducting routine compositional and label‑claim testing.
- Infant formula and adult nutritional product manufacturers for product development and quality control.
- Regulatory and inspection agencies verifying nutrient content and compliance.
- Third‑party contract laboratories offering vitamin analysis services.
Practical benefits include improved selectivity and throughput by measuring multiple B‑vitamins in a single LC‑MS/MS run and robust compensation for matrix effects via isotope internal standards.
Related standards
- Equivalent method: AOAC Official Method 2015.14.
- Annexes in ISO 21470 provide comparisons with several European methods (EN 14122, EN 14152, EN 14164), helping laboratories align procedures and interpret performance differences.
Keywords: ISO 21470:2020, infant formula vitamin analysis, B1 B2 B3 B6, enzymatic digestion, UHPLC-MS/MS, LC‑MS/MS, stable‑isotope internal standards, infant formula testing.