ASTM D7637-10 rus PDF

Full title and description

Standard Test Method for Determination of Glycerin Assay by Titration (Sodium Meta Periodate) — ASTM D7637-10. This method describes a titrimetric procedure in which glycerin (glycerol) is oxidized by sodium metaperiodate in strong acidic medium; the resulting formic acid is measured by titration to determine glycerin content in glycerin or glycerin/water mixtures greater than 75% (m/m).

Abstract

ASTM D7637-10 specifies a cold oxidation/titration assay for quantitative determination of glycerin (glycerol) using sodium metaperiodate oxidation and back-titration of produced formic acid. The method notes common interferences (compounds with adjacent polyhydroxyl groups such as sugars or glycols) and gives procedural details for reagents, apparatus, and endpoint determination (pH 8.1 ± 0.1). The test is intended for neat glycerin or glycerin/water mixes above 75% by mass.

General information

• Status: Active (current ASTM standard / maintained).
• Publication date: Originally approved 2010 (designation D7637-10); subsequently reapproved/revised in later editorial actions (editions/confirmations in 2015, 2021 and further document activity recorded).
• Publisher: ASTM International.
• ICS / categories: 71.080.60 (Alcohols. Ethers).
• Edition / version: Designation D7637-10 (base year 2010); available as reapproved/revised editorial versions (2015, 2021 and later actions noted).
• Number of pages: 4 pages (concise test method).

Scope

This test method provides a quantitative titrimetric procedure for determining glycerin content in glycerin or glycerin/water mixtures having glycerin >75% (m/m). The method is based on oxidation of glycerol by sodium metaperiodate in acidic solution and measurement of the produced formic acid by titration with standard sodium hydroxide to a specified pH endpoint. The standard includes reagent specifications, apparatus requirements, procedure steps, and notes on interferences and safety.

Key topics and requirements

• Principle: Cold oxidation of glycerol with sodium metaperiodate to produce formic acid; formic acid quantified by titration to pH 8.1 ± 0.1.
• Applicability: Neat glycerin and glycerin/water mixtures with glycerin content greater than 75% (m/m).
• Reagents and solutions: Specification and preparation of sodium metaperiodate reagent, acid medium, potassium iodide, starch indicator solution, and standardized NaOH titrant.
• Apparatus: Type A calibrated burettes, pH meter or suitable endpoint detection, and light-protected storage for certain reagents.
• Precision and validation: Interlaboratory study / research report performed to establish method precision (ASTM RR:D15-1027).
• Limitations and interferences: Substances with adjacent di- or polyhydroxyl groups (e.g., sugars, polyols) can produce interfering formic acid; samples must be free of such interfering species for accurate glycerin assay.
• Safety: The method involves strong acids and oxidizing reagents; users must follow appropriate laboratory safety, waste disposal, and regulatory requirements.

Typical use and users

Common users include quality control and analytical laboratories in chemical manufacturing, glycerin producers and distributors, antifreeze/engine-coolant formulators, biodiesel producers (in contexts where glycerin content needs quantification), and laboratories performing incoming material or product release testing. The method serves routine assay needs where a titrimetric approach is preferred or where instrumental methods are not available.

Related standards

Closely related ASTM methods and standards include other glycerin and related assays (for example, methods addressing fatty acid/ester content in glycerin and chromatographic determination of free/total glycerin in biodiesel). Examples: ASTM D7638 (fatty acids and esters in glycerin, titrimetric) and ASTM D7591 (free and total glycerin in biodiesel by anion exchange chromatography). These documents are maintained by relevant ASTM subcommittees and may be used together depending on the sample matrix and analytical needs.

Keywords

glycerin; glycerol; glycerine; titration; sodium metaperiodate; assay; titrimetric method; antifreeze; engine coolant; quality control.

FAQ

Q: What is this standard?

A: ASTM D7637-10 is a standard test method that describes a titrimetric assay for determining the glycerin (glycerol) content of glycerin or glycerin/water mixtures by oxidizing glycerol with sodium metaperiodate and measuring the produced formic acid.

Q: What does it cover?

A: It covers reagent and apparatus specifications, the oxidation/titration procedure, endpoint definition (pH 8.1 ± 0.1), precautions about interferences (e.g., sugars or polyols), and requirements for result expression (percentage mass of glycerin). The method applies to samples with glycerin content >75% (m/m).

Q: Who typically uses it?

A: Analytical and QC laboratories in chemical and glycerin production, formulators of antifreeze and engine coolants, biodiesel and bio-based product labs (when relevant), and any laboratory needing a robust titrimetric glycerin assay.

Q: Is it current or superseded?

A: The core designation is D7637-10 (2010). The document has been subject to reapproval and editorial revisions (document history shows confirmations/revisions in subsequent years). Users should confirm the most current revision/confirmatory designation before purchase or use. ASTM is the publisher and maintains the official revision history.

Q: Is it part of a series?

A: Yes — it is part of a family of ASTM D15 series standards dealing with chemical properties and analytical methods for fuels, lubricants, and related products; related glycerin- and biodiesel-related test methods are maintained in the same general program and by relevant subcommittees.

Q: What are the key keywords?

A: Glycerin, glycerol, titration, sodium metaperiodate, assay, titrimetric method, antifreeze, engine coolant, quality control.