Overview
SIST EN ISO 11543:2002 is a European adoption of the International Standard ISO 11543:2000 published by ISO/TC 93, which focuses on starch and its derivatives. This standard specifies a precise and reliable method for determining the hydroxypropyl content in modified starch using proton Nuclear Magnetic Resonance (NMR) spectrometry. The method is applicable to granular modified starch, providing quantitative analysis essential for quality control and research in starch modification processes.
By applying proton NMR, the method allows direct measurement of the methyl protons in hydroxypropyl groups, using an internal standard for accurate quantification. This technique supports manufacturers and researchers in ensuring product consistency, regulatory compliance, and enhanced product performance.
Key Topics
- Scope and Purpose
Defines the proton NMR spectrometric technique specifically for measuring the hydroxypropyl content in granular modified starch, a critical parameter impacting starch functionality.
- Sample Preparation
Includes detailed steps for sample washing, drying, and particle size adjustment to ensure representative and interference-free measurement.
- Reagents and Equipment
Lists necessary high-purity reagents such as deuterium oxide and deuterium chloride, and specialized equipment like NMR spectrometer (minimum 60 MHz), vacuum oven, micropipettes, and analytical balance.
- Analytical Procedure
Partial hydrolysis dissolves starch in deuterium chloride solution; the proton NMR spectrum is recorded with precise parameters such as relaxation delay and spectral window for methyl group identification.
- Calculation Method
Hydroxypropyl content is calculated based on integrated peak areas of methyl protons and internal standard, adjusting for moisture content, with results reported as percentage by mass.
- Precision and Validation
Includes interlaboratory study results demonstrating the method’s repeatability and reproducibility within specified limits, ensuring outcome reliability across different operators and labs.
- Test Reporting
Specifies the detailed documentation required for full traceability and validation of test outcomes.
Applications
- Food Industry
Ensures consistent modification levels in starch-based ingredients used for thickening, stabilizing, or texturizing food products.
- Pharmaceuticals
Provides quality control for hydroxypropyl starch derivatives used as excipients in drug formulations.
- Biodegradable Materials
Supports R&D and quality assurance of starch-based bioplastics and films where precise modification degrees influence material properties.
- Chemical Industry
Monitors starch modification processes to control performance specifications in paper, textile, and adhesive production.
Applying SIST EN ISO 11543:2002 allows laboratories and manufacturers to maintain high-quality standards, regulatory compliance, and enhanced functional characteristics of hydroxypropylated starch products.
Related Standards
- ISO 1666:1996 – Determination of moisture content in starch by oven drying, essential for sample preparation in NMR analysis.
- ISO 3696:1987 – Specifications for analytical-grade water used in reagent preparation, ensuring purity for accurate spectrometric results.
- ISO 5725 Series – Guidelines on accuracy, repeatability, and reproducibility of measurement methods, referenced for the validation of this NMR technique.
These standards complement SIST EN ISO 11543:2002 by underpinning sample preparation, reagent quality, and method validation to ensure technical rigor and reliability of results.
Keywords: EN ISO 11543, hydroxypropyl content, modified starch, proton NMR spectrometry, starch analysis, starch modification, quality control, proton nuclear magnetic resonance, NMR method, starch derivatives, analytical standards.