Overview
EN ISO 5809:1994 is an internationally recognized standard developed by the International Organization for Standardization (ISO) and adopted by CEN. It specifies a precise method for the determination of sulphated ash content in starches and their derived products. The procedure involves incinerating a test portion of the product in the presence of sulphuric acid at a controlled temperature of 525 ± 25 °C. The resulting residue, called sulphated ash, is expressed as a percentage by mass either on the product as received or on a dry basis.
This standard is essential for quality control and chemical analysis in industries handling starch-based materials, ensuring consistency, safety, and compliance with regulatory requirements.
Key Topics
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Scope and Application
The method applies to starches and starch-derived products, providing a reliable measure of their inorganic residue following incineration.
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Principle
Sulphuric acid facilitates the conversion of volatile chlorides into non-volatile sulphates during incineration, preventing losses and ensuring accurate ash content measurement.
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Reagents and Apparatus
- Sulphuric acid solution and hydrochloric acid solution of specified concentrations
- Incineration dish made of platinum or inert material
- Electric furnace with precise temperature control
- Analytical balance, desiccator, water bath, and other laboratory apparatus
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Procedure
- Careful preparation and cleaning of the incineration dish
- Mixing and preparation of the test sample, including dissolution or melting if necessary
- Addition of sulphuric acid and controlled incineration until carbon residue disappears
- Cooling, weighing, and calculation of sulphated ash content
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Calculation and Expression of Results
The sulphated ash content is calculated as a percentage by mass, using established formulae that take into account sample mass, moisture content, and residue mass. Results are reported to two decimal places with guidelines for repeatability and reproducibility to ensure accuracy.
Applications
EN ISO 5809:1994 is widely utilized in:
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Food Industry
Monitoring and controlling the quality of starches used as food ingredients and additives.
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Pharmaceutical Industry
Ensuring purity and consistency of starch excipients in medications.
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Chemical and Bioproducts Manufacturing
Assessing the inorganic content in starch-derived chemicals, syrups, and bio-based materials.
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Quality Control Laboratories
Routine analysis to comply with regulatory standards and product specifications.
By accurately quantifying sulphated ash, manufacturers can maintain product quality, optimize production processes, and verify compliance with international quality standards.
Related Standards
- ISO 1666 – Determination of moisture content in starches by drying methods
- ISO 1741 – Loss in mass on drying for dextrose
- ISO 1742 – Determination of dry matter in glucose syrups via vacuum oven method
- ISO 1743 – Refractive index method for dry matter in glucose syrups
These related standards complement EN ISO 5809 by providing comprehensive testing protocols for starch and derivative products, covering moisture and dry matter analysis crucial for accurate sulphated ash determination.
Keywords: EN ISO 5809, sulphated ash determination, starch analysis, incineration method, sulphuric acid, starch quality control, starch derivatives, CEN standard, analytical method, inorganic residue, food industry testing, pharmaceutical starch analysis, moisture content in starch, chemical analysis standards.