ISO 1897-9-1977 PDF

Full title and description

Phenol, o-cresol, m-cresol, p-cresol, cresylic acid and xylenols for industrial use — Methods of test — Part 9: Determination of m-cresol content (cresylic acid only). This part specifies a laboratory test method for determining the m-cresol fraction in cresylic acid by formation of an m-cresol–urea complex and measurement of its crystallizing point; it replaces ISO Recommendation R 1911‑1971.

Abstract

The method applies to cresylic acid samples containing about 35 % to 60 % (m/m) m-cresol, with not more than 5 % phenol and not more than 35 % o-cresol. A test portion is dehydrated, treated with excess urea to form an m-cresol–urea complex, and the crystallizing point of that complex is measured in a crystallizing‑point apparatus. The m-cresol content is calculated from the measured crystallizing point together with the sample water content using a tabulated relationship provided in the standard.

General information

• Status: Withdrawn.
• Publication date: April 1977 (Edition 1, 1977-04).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 71.080.40 (Chemistry — Organic chemistry).
• Edition / version: Edition 1 (1977).
• Number of pages: 4.

Scope

This part of ISO 1897 specifies a method for determining the m-cresol content specifically in cresylic acid products within the stated compositional limits. It covers sample preparation (dehydration), preparation of an excess‑urea test portion, measurement of the crystallizing point of the resulting complex, and calculation of m-cresol percentage from that measurement and the sample water content. The procedure is intended for routine laboratory quality control and specifications for industrial cresylic acid.

Key topics and requirements

• Applicability: designed for cresylic acid samples with ~35–60 % m-cresol and limited phenol/o-cresol content.
• Sample preparation: dehydration of the test sample to remove water prior to complex formation.
• Analytical principle: formation of an m-cresol–urea complex followed by determination of its crystallizing point.
• Instrumentation: crystallizing‑point apparatus required and calibrated against the method's reference table.
• Calculation: m-cresol content calculated from the crystallizing point and the measured water content using the standard’s tabulated relation.
• Reporting: results reported as percentage (m/m) m-cresol in the cresylic acid sample.

Typical use and users

Used by chemical manufacturers, quality control and testing laboratories, raw‑material suppliers and purchasers, and regulatory or standards bodies verifying the composition of cresylic acid and related phenolic mixtures. Typical applications include product specification confirmation, incoming quality inspection, and comparative batch testing in industrial and laboratory environments.

Related standards

ISO 1897‑9:1977 is one part of the ISO 1897 series covering methods of test for phenol, cresols, cresylic acid and xylenols (other parts cover water determination, neutral oils, visual impurity tests, o‑cresol determination, crystallizing point determination, distillation characteristics, etc.). Many parts of the ISO 1897 series and related test methods from the 1970s have subsequently been withdrawn or superseded; consult current ISO catalogues for the up‑to‑date status of individual parts.

Keywords

m-cresol; cresylic acid; cresols; urea complex; crystallizing point; ISO 1897-9:1977; analytical method; withdrawn; phenolic mixtures; quality control.

FAQ

Q: What is this standard?

A: ISO 1897‑9:1977 specifies a laboratory test method for determining m‑cresol content in cresylic acid by forming an m‑cresol–urea complex and measuring its crystallizing point.

Q: What does it cover?

A: It covers sample dehydration, formation of an excess‑urea complex with m‑cresol, measurement of the complex’s crystallizing point using a crystallizing‑point apparatus, and calculation of m‑cresol content from the measured value together with water content.

Q: Who typically uses it?

A: Chemical producers, QC laboratories, materials purchasers, and standards/regulatory personnel involved with phenolic products and cresylic acid composition verification typically use this method.

Q: Is it current or superseded?

A: The standard was published in April 1977 and is listed as Withdrawn in the ISO lifecycle; the ISO record does not list a direct modern replacement for this specific part. Users seeking a current method should consult the ISO catalogue or national standards bodies for updated or alternative test methods.

Q: Is it part of a series?

A: Yes — it is Part 9 of the ISO 1897 series of test methods for phenol, cresols, cresylic acid and xylenols. Several related parts address determination of water, o‑cresol, distillation characteristics, crystallizing point (general), and other test procedures. Many parts in the series have been withdrawn; check current standards listings for each part’s status.

Q: What are the key keywords?

A: m‑cresol, cresylic acid, cresols, urea complex, crystallizing point, ISO 1897, analytical test method, withdrawn.