Overview
EN ISO 17180:2013 - "Animal feeding stuffs - Determination of lysine, methionine and threonine in commercial amino acid products and premixtures" - specifies a laboratory method for the quantitative determination of free (non‑protein‑bound) lysine, methionine and threonine in commercial amino‑acid products and premixtures. The method applies to materials containing roughly more than 10% mass fraction of the respective amino acid and does not distinguish between D‑ and L‑forms. The standard was prepared by ISO/TC 34 (Food products) with CEN/TC 327 and is published as EN ISO 17180:2013.
Key topics and technical requirements
- Scope: Quantitative assay of free lysine, methionine and threonine in trade amino‑acid products and feed premixtures (≈ >10%).
- Analytical principle:
- Extraction in dilute hydrochloric acid, dilution with sodium citrate buffer.
- Internal standard: norleucine.
- Separation by amino acid analyser or HPLC using a cation‑exchange column and sodium citrate‑based eluents.
- Post‑column derivatization with ninhydrin (colorimetric detection) or OPA (fluorescence detection).
- Reagents & materials: High‑purity amino acid and norleucine standards, sodium citrate buffer (pH ~2.20), 0.1 mol/L HCl for extraction, appropriate elution buffers and post‑column reagents.
- Apparatus: Cation exchange column (oven), guard column, injection system (10–100 µL), pumps for buffer delivery and post‑column reagent, detectors (UV at 440/570 nm for ninhydrin; fluorescence excitation 330 nm/emission 460 nm for OPA), membrane filters and analytical balance.
- Procedure essentials: Sample grinding (≤0.25 mm), prepare two independent extracts per sample, perform either weight or volumetric dilutions for calibration, and calculate results using internal standard normalization.
- Precision & reporting: The standard includes precision data from collaborative trials and requirements for test reporting.
Applications and who uses it
- Feed manufacturers: quality control of commercial amino‑acid products and premixtures before release.
- Analytical & testing laboratories: routine quantification of free lysine, methionine and threonine in raw materials and finished premixtures.
- Regulatory bodies and auditors: verifying label claims and compliance with feed composition requirements.
- Amino‑acid suppliers and formulators: confirming purity, concentration and batch consistency.
Practical uses include batch release testing, supplier qualification, formulation verification and troubleshooting of feed nutrient supply.
Related standards
- EN ISO 17180:2013 is the CEN‑endorsed version of ISO 17180:2013. It is intended to be used alongside general sampling and feed analysis standards (ISO/CEN methods for sampling and other compositional analyses) and the manufacturer’s instrument‑specific HPLC/AA analyser method guidance.
Keywords: EN ISO 17180:2013, lysine analysis, methionine threonine, amino acid analysis, animal feeding stuffs, HPLC, amino acid analyser, premixtures, feed quality control.