ISO 5664:1984

Overview

ISO 5664:1984 specifies an analytical method for determining ammonium content in water using distillation and titration. Developed by the International Organization for Standardization (ISO), this standard applies to raw, potable, and waste water. The method allows detection of ammonium nitrogen up to 10 mg in a test portion, making it suitable for a diverse range of water quality monitoring scenarios.

By providing a reliable procedure, ISO 5664:1984 helps laboratories and water authorities accurately measure ammonium levels, an important indicator of water quality used for regulatory compliance and environmental monitoring purposes.

Key Topics

• Scope and Applicability

  • Suitable for raw, potable, and waste waters.
  • Effective for ammonium nitrogen concentrations up to 10 mg per test portion.

• Principle of the Method

  • pH adjustment to 6.0-7.4.
  • Distillation of ammonia after addition of magnesium oxide under mildly alkaline conditions.
  • Collection of liberated ammonia in boric acid solution.
  • Titration of collected distillate with standard hydrochloric acid to determine ammonium concentration.

• Reagents and Apparatus

  • Use of analytical-grade reagents, such as ammonium-free water, hydrochloric acid, sodium hydroxide, and magnesium oxide.
  • Specialized distillation apparatus and glassware required to ensure precision.

• Interferences

  • Main interference sources include urea, volatile amines, and chloramines, which can result in higher measured values.
  • Chlorinated samples may require dechlorination with sodium thiosulfate prior to analysis.

• Sensitivity and Detection Limits

  • Detects ammonium nitrogen as low as 0.2 mg/L.
  • Suitable for samples with a wide range of ammonium levels.

Applications

• Environmental Monitoring

  • Used by regulatory bodies to assess nitrogen pollution in surface water, groundwater, and effluents.
  • Important for compliance with water quality standards and environmental protection regulations.

• Drinking Water Quality

  • Ensures potable water meets safety criteria for ammonium levels, as high ammonium can indicate contamination.

• Waste Water Analysis

  • Assists in monitoring effluent treatment processes, optimizing operations, and ensuring treated water meets discharge permit requirements.

• Industrial Process Water

  • Used in quality control and pollution prevention in various industries where water recycling and discharge are critical.

Related Standards

To comprehensively manage water quality and laboratory procedures, the following ISO standards are relevant:

• ISO 5663 - Water quality - Sampling techniques.
• ISO 3696 - Water for analytical laboratory use - Specification and test methods.
• ISO 11885 - Water quality - Determination of selected elements by inductively coupled plasma optical emission spectrometry (ICP-OES).
• ISO 7890 (series) - Water quality - Determination of nitrate.
• ISO 14911 - Water quality - Determination of dissolved anions by liquid chromatography.

These standards, alongside ISO 5664:1984, help establish consistent, reliable water analysis methodologies and ensure comparable, accurate data across laboratories and regulatory frameworks.

Keywords: ISO 5664:1984, water quality, ammonium determination, distillation, titration, standard method, potable water, waste water, environmental monitoring, laboratory analysis.