Overview
ISO 5444:1978 is an international standard that specifies a precise gravimetric method for determining the loss in mass of sodium fluorosilicate (sodium hexafluorosilicate) when heated at 105 °C. This test method is crucial for the quality control of sodium fluorosilicate used in various industrial applications. The standard emphasizes accurate measurement for mass losses equal to or exceeding 0.008% (m/m), ensuring reliable assessment through a controlled drying process conducted over six hours.
Developed by ISO Technical Committee ISO/TC 47, Chemistry, and approved by IUPAC, ISO 5444:1978 ensures global consistency in testing industrial sodium fluorosilicate. The standard provides guidelines for sample preparation, apparatus requirements, and the reporting of results, promoting safe handling due to the material’s toxicity and dust hazard.
Key Topics
- Scope: Applies to sodium fluorosilicate for industrial use, focusing on mass loss determination at 105 °C.
- Principle: Gravimetric analysis based on drying the test sample and measuring mass loss.
- Sample Preparation: Includes drying a test portion in an electric oven for 6 hours at (105 ± 1) °C.
- Apparatus:
- Electric oven regulated at 105 °C.
- Glass weighing bottle with stopper for sample containment.
- Procedure:
- Initial drying and weighing of the empty bottle with stopper.
- Weighing approx. 50 g of sample into the bottle.
- Drying the loaded bottle with sample for 6 hours, followed by cooling and precise weighing.
- Calculation of Loss in Mass: Percentage loss is calculated from the mass difference before and after drying.
- Safety: Advises precautions due to sodium hexafluorosilicate’s toxicity, including avoiding dust inhalation and use of protective gear.
Applications
- Industrial Quality Control: Ensures the moisture content and volatile impurities in sodium fluorosilicate are within acceptable limits.
- Material Consistency Verification: Provides manufacturers and users with reliable data to maintain product uniformity.
- Chemical Manufacturing: Critical for processes where sodium fluorosilicate’s purity impacts chemical reactions or product formulation.
- Regulatory Compliance: Assists industries in meeting national and international standards for chemical substances.
Related Standards
ISO 5444:1978 is part of a series of standards relevant to sodium hexafluorosilicate testing, including:
- ISO 4281 - Determination of free acidity and sodium hexafluorosilicate content.
- ISO 5440 - Molybdovanadate spectrophotometric method for phosphate content.
- ISO 5443 - 1,10-Phenanthroline spectrophotometric method for iron content.
- ISO 5915 - Sieving method for particle size distribution.
- ISO 6229 - Gravimetric method for determining free silica content.
These standards collectively cover comprehensive physical and chemical analyses essential for industrial sodium fluorosilicate quality assurance.
Keywords: ISO 5444:1978, sodium fluorosilicate, sodium hexafluorosilicate, loss in mass determination, gravimetric analysis, industrial chemical testing, drying method at 105 °C, quality control standards, chemical purity testing, industrial standards for sodium fluorosilicate.
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