ISO 1833-28:2019

Overview

ISO 1833-28:2019 specifies a quantitative chemical analysis method for textiles comprising mixtures of chitosan fibres and other fibres, using diluted acetic acid. This international standard provides a standardized laboratory procedure to accurately determine the mass percentage of chitosan fibre content in textile blends after removing non-fibrous matter. Applicable to a wide variety of fibre mixtures, this method supports quality control, compliance verification, and product development in the textile industry.

This method applies specifically to blends of chitosan fibres with cellulose fibres (e.g., cotton, linen, viscose), protein fibres (e.g., wool, silk, cashmere), or synthetic fibres (e.g., polyester, polyamide, acrylic). By dissolving chitosan selectively with diluted acetic acid at elevated temperatures, the residue can be isolated, weighed, and used to calculate chitosan content with high precision.

Key Topics

• Quantitative Chemical Analysis: Determining mass percentage of chitosan fibres in textile mixtures through a chemical dissolution and gravimetric measurement process.
• Chitosan Fibre Definition: A fibre derived from chitin with a high degree of deacetylation (typically more than 90%), which is selectively dissolved by diluted acetic acid.
• Test Procedure: Involves treating a dry sample with diluted acetic acid at 90–95 °C while agitating, filtering the residue, washing, drying, and weighing to calculate the chitosan content.
• Reagents and Apparatus: Uses diluted acetic acid, diluted ammonia solution, conical flasks, mechanical shaker with water bath, and standard laboratory filtration and drying equipment.
• Precision and Reliability: Achieves confidence limits within ±1 percentage point at a 95% confidence level, verified by interlaboratory trials across multiple countries.
• Scope of Fibres: Applicable to mixtures including cellulose fibres (cotton, linen, ramie, viscose, modal, lyocell), protein fibres (wool, cashmere, silk), and synthetic fibres (polyester, polyamide, acrylic).

Applications

• Textile Quality Control: Ensures accurate quantification of chitosan content in fabrics and yarns, facilitating compliance with product specifications and regulatory requirements.
• Material Research and Development: Enables researchers to evaluate the composition of chitosan fibre blends and optimize formulations for functional textiles.
• Sustainability Assessment: Supports the use of natural and bio-based fibres like chitosan by providing reliable compositional data.
• Trade and Certification: Assists manufacturers and certification bodies in verifying fibre composition claims for labelling and market access.
• Interlaboratory Consistency: Provides a reproducible and standardized testing method, ensuring consistent results across different laboratories worldwide.

Related Standards

• ISO 1833-1: General principles of testing methods for quantitative chemical analysis of textiles, providing foundational protocols and terminology used by ISO 1833 series.
• ISO 2076: Specifies generic names for man-made fibres, including chitin and chitosan fibres.
• ISO 13528: Statistical methods for proficiency testing, utilized for evaluating precision and reproducibility in testing.
• ISO 5725-5: Specifies alternate methods to determine accuracy, trueness, and precision of standard measurement methods in laboratory settings.

By adhering to ISO 1833-28:2019, textile testing laboratories and manufacturers can achieve accurate, reproducible analysis of chitosan fibre blends, helping advance innovation and quality in sustainable textile products.

Keywords: ISO 1833-28, chitosan fibre analysis, quantitative chemical analysis, textiles, acetic acid method, fibre mixtures, textile testing standards, chitosan content determination, cellulose fibres, protein fibres, synthetic fibres, textile quality control.