ISO 2831:1973

Overview

ISO 2831:1973 is an internationally recognized standard issued by the International Organization for Standardization (ISO) for the determination of water-insoluble matter in sodium fluoride intended for industrial use. This method is crucial for quality control in chemical manufacturing where sodium fluoride purity affects product functionality and safety. The standard is also approved by the International Union of Pure and Applied Chemistry (IUPAC), highlighting its scientific reliability and global acceptance.

Key Topics

• Scope and Application ISO 2831:1973 specifies a precise analytical procedure designed to quantify the amount of water-insoluble matter in industrial sodium fluoride. This ensures that impurities which do not dissolve in water are accurately identified and measured.

• Test Principle The method involves dissolving a carefully weighed test portion of sodium fluoride in water, followed by vacuum filtration through a sintered glass filter crucible to separate insoluble substances. The filter is then dried in an oven at 110 ± 2 °C and weighed. This process is repeated until constant weight is achieved, allowing reliable quantification.

• Reagents and Apparatus

  • Use of distilled or equivalent purity water for the dissolution step.
  • Filter crucible with sintered glass (pore size index 16–40 µm) for effective filtration of insoluble particles.
  • An electric ventilated oven for controlled drying and weighing of residues.

• Calculation and Reporting The water-insoluble content is expressed as a percentage of the test portion by mass. Detailed documentation includes the method reference, conditions, results, and any deviations or special observations made during testing.

Applications

• Industrial Quality Control Manufacturers of sodium fluoride and downstream chemical industries use ISO 2831 to verify raw material purity. The presence of insoluble impurities can affect chemical processes, product performance, and safety.

• Regulatory Compliance Adherence to ISO 2831 supports compliance with international trade regulations and customer specifications, facilitating smooth market access.

• Research and Development Analytical laboratories employ this standard for comparative studies, formulation adjustments, or troubleshooting production inconsistencies related to impurities.

• Environmental and Safety Monitoring Detecting insoluble contaminants helps prevent equipment fouling and potential hazardous reactions, contributing to workplace safety and environmental protection.

Related Standards

• ISO Preparation of Test Samples Proper preparation and storage of sodium fluoride test samples as referenced in the standard are critical to ensuring accuracy and repeatability.

• IUPAC Analytical Methods The approval by IUPAC aligns ISO 2831 with globally trusted chemical analysis methods, promoting interoperability in scientific research and industrial practice.

• Other Sodium Fluoride Quality Standards ISO 2831 complements other standards focused on chemical composition, packaging, and handling of sodium fluoride for industrial or pharmaceutical applications.

Keywords: ISO 2831, sodium fluoride, water-insoluble matter, industrial chemicals, chemical analysis, filtration method, quality control, IUPAC approved, industrial standards, impurity determination, analytical chemistry, standard test method.