ISO 1388-11:1981

Overview

ISO 1388-11:1981 is an international standard specifying a test method for the detection of furfural in ethanol intended for industrial use. Developed and published by the International Organization for Standardization (ISO), this method ensures reliable and consistent identification of furfural impurities in industrial ethanol. The test principle involves treating a sample with aniline and acetic acid, where the presence of furfural leads to the formation of a characteristic red color. This standard is part 11 of the ISO 1388 series, which covers various test methods for ethanol quality and composition.

This document replaces ISO Recommendation R 1388-1970 and forms a comprehensive, technical revision aimed at improving testing accuracy for industrial ethanol products.

Key Topics

• Test Principle: Chemical reaction of furfural with aniline and acetic acid producing a red coloration.
• Sample Preparation: Testing a 10 ml portion of ethanol or an agreed volume.
• Reagents Required:
  • Aniline (freshly distilled before use)
  • Glacial acetic acid (density approx. 1.05 g/ml)
• Apparatus: Ordinary laboratory equipment including test tubes.
• Procedure:
  • Mix the ethanol test sample with aniline and acetic acid.
  • Observe color change within 3 minutes.
• Result Interpretation:
  • Red color formation: Indicates presence of furfural.
  • No color change: Indicates absence of furfural.
• Quality Requirements: Use only reagents of recognized analytical grade for testing accuracy.

Applications

ISO 1388-11:1981 is primarily used by manufacturers, quality control laboratories, and regulatory bodies involved in the production and distribution of industrial ethanol. Its applications include:

• Quality assurance of ethanol batches by detecting furfural impurities which can affect product performance and safety.
• Regulatory compliance for ethanol quality standards.
• Industrial process monitoring in sectors utilizing ethanol such as chemical manufacturing, pharmaceuticals, and solvents production.
• Research and development related to ethanol purification and quality improvement.

The test method facilitates rapid detection, contributing to efficient quality control workflows and ensuring ethanol meets required industrial standards.

Related Standards

ISO 1388-11:1981 is part of a broader series addressing analytical methods for industrial ethanol, including:

• ISO 1388-1 – General requirements for ethanol test methods.
• ISO 1388-2 – Detection of alkalinity or acidity.
• ISO 1388-3 to ISO 1388-4 – Estimation of carbonyl compounds and aldehydes by photometric and titrimetric methods.
• ISO 1388-5 – Test for ethanol miscibility with water.
• ISO 1388-7 and ISO 1388-8 – Determination of methanol content through photometric and calorimetric methods.
• ISO 1388-9 – Determination of esters content.
• ISO 1388-10 – Estimation of hydrocarbon content by distillation.
• ISO 1388-12 – Determination of permanganate time (oxidative stability).

These standards collectively provide a comprehensive framework for assessing the chemical quality and purity of industrial ethanol, supporting consistent and safe usage in various industrial applications.

Keywords: ISO 1388-11, ethanol for industrial use, detection of furfural, ethanol quality test, industrial ethanol standards, aniline acetic acid test, furfural detection method, ISO ethanol standards, analytical chemistry ethanol, ethanol impurities test