ISO 20635-2018 PDF

Full title and description

Infant formula and adult nutritionals — Determination of vitamin C by (ultra) high performance liquid chromatography with ultraviolet detection ((U)HPLC-UV). This International Standard specifies an (U)HPLC‑UV analytical method for quantifying vitamin C (L‑ascorbic acid) in powders, ready‑to‑feed liquids and liquid concentrates of infant formulas and adult nutritionals.

Abstract

This document specifies a method for the determination of vitamin C (L‑ascorbic acid) in all forms of infant and adult formulas using (U)HPLC‑UV. The method covers an application range with a limit of quantification of 2.5 mg/100 g up to 50 mg/100 g (expressed in the product as consumed) and distinguishes between D‑ascorbic (isoascorbic/erythorbic) acid and L‑ascorbic acid.

General information

• Status: Published (confirmed in systematic review 2023).
• Publication date: 2 July 2018 (published July 2018).
• Publisher: ISO — International Organization for Standardization.
• ICS / categories: 67.050 (Food products — general methods of analysis).
• Edition / version: Edition 1 (2018).
• Number of pages: 13.

Information above is taken from the ISO bibliographic record and confirmation review.

Scope

Specifies a validated (U)HPLC‑UV method to determine vitamin C content in infant formula and adult nutritional products (powdered, ready‑to‑feed and concentrates). The method provides performance characteristics and reporting ranges appropriate for regulatory compliance and quality control, and enables separation/quantification of L‑ascorbic acid from its stereoisomeric/related forms.

Key topics and requirements

• Applicable sample types: powdered formulas, ready‑to‑feed liquids, liquid concentrates.
• Analytical technique: (ultra) high performance liquid chromatography with ultraviolet detection ((U)HPLC‑UV).
• Measurement range and sensitivity: LOQ ~2.5 mg/100 g up to ~50 mg/100 g (product as consumed).
• Ability to distinguish L‑ascorbic acid from D‑ascorbic (isoascorbic/erythorbic) acid.
• Prescribed sample preparation, chromatographic conditions, calibration and performance/validation criteria for reproducible results.
• Intended use as a harmonized reference method for regulatory verification, inter‑laboratory studies and dispute resolution.

Key application and regulatory context were developed as part of the SPIFAN initiative to harmonize nutrient test methods for infant formula and adult nutritionals.

Typical use and users

Used by regulatory laboratories, commercial testing laboratories, manufacturers of infant formula and adult nutritionals, and conformity assessment bodies to verify vitamin C content on labels, support product development, perform quality control and resolve analytical disputes. Laboratories implementing the method must follow the specified sample handling, chromatographic and validation procedures in the standard.

Related standards

This standard is part of a group of analytical methods developed for infant formula and adult nutritionals under the SPIFAN project. Closely related documents include ISO 20636 (determination of vitamin D by LC‑MS) and other ISO/AOAC/IDF methods addressing key nutrients in formula products.

Keywords

infant formula; adult nutritionals; vitamin C; L‑ascorbic acid; erythorbic acid; isoascorbic acid; (U)HPLC‑UV; analytical method; limit of quantification; SPIFAN; Codex; method validation.

FAQ

Q: What is this standard?

A: ISO 20635:2018 is an International Standard specifying an (ultra) HPLC‑UV method for the determination of vitamin C in infant formula and adult nutritionals.

Q: What does it cover?

A: It covers sample types (powder, ready‑to‑feed, concentrates), chromatographic measurement by (U)HPLC‑UV, separation of L‑ and D‑forms of ascorbic acid, calibration, validation and reporting ranges (LOQ ≈ 2.5 mg/100 g up to 50 mg/100 g, expressed as consumed).

Q: Who typically uses it?

A: Regulatory bodies, commercial testing labs, manufacturers, and accreditation/conformity assessment organizations use the method for label verification, quality control and inter‑laboratory comparisons.

Q: Is it current or superseded?

A: ISO 20635:2018 was published in July 2018 and was reviewed and confirmed in 2023; the 2018 edition remains current (confirmed).

Q: Is it part of a series?

A: Yes — it is one of a series of standards developed under the SPIFAN initiative to provide harmonized analytical methods for priority nutrients in infant formula and adult nutritionals (for example ISO 20636 for vitamin D).

Q: What are the key keywords?

A: Infant formula, adult nutritionals, vitamin C, L‑ascorbic acid, (U)HPLC‑UV, analytical method, LOQ, SPIFAN, Codex.