ASTM E1335-24 PDF

Full title and description

Standard Test Methods for Determination of Gold in Bullion by Fire Assay Cupellation Analysis (ASTM E1335-24). This standard specifies cupellation (fire assay) procedures and associated test methods for determining gold content in a range of bullion compositions using established cupellation analysis techniques.

Abstract

ASTM E1335-24 provides standardized cupellation test methods for assaying gold in bullion. It defines test methods appropriate to different gold concentration ranges, required materials and reagents, sample preparation, cupellation and proof correction practices, applicable interferences and safety considerations, and reporting conventions to ensure consistent, reproducible determination of gold content in bullion products.

General information

• Status: Active
• Publication date: 15 May 2024.
• Publisher: ASTM International.
• ICS / categories: 77.120.99 (Other non‑ferrous metals and their alloys).
• Edition / version: E1335-24 (2024 edition).
• Number of pages: 7.

Scope

These test methods cover cupellation analysis of bullion having compositions in specified gold and silver ranges and are presented as separate test methods for different concentration bands (for example: Test Method A for ~20.0%–99.0% gold, Test Method B for ~0.5%–4.0% gold, and Test Method C for ~98.9%–99.8% gold). The standard applies when total gold plus silver content of the material is high (typically 75%–100%) and provides procedural details to obtain accurate gold determinations across the stated ranges.

Key topics and requirements

• Defined test methods for distinct gold concentration ranges (A, B, C) and the applicable sample size and treatment for each range.
• Sample preparation and fusion/cupellation procedures, including selection and conditioning of cupels (e.g., bone ash, MgO) and proper use of fluxes and collectors.
• Proof correction and calculation practices to convert assay results to reported gold content.
• Limits and interferences — elements (e.g., As, Sb, Bi and others) that, when present above certain concentrations, can affect accuracy of the cupellation methods and require special consideration or alternative techniques.
• Health and safety considerations for handling litharge/lead and hot apparatus, and general laboratory safety for fire assay operations.

Typical use and users

Used by assayers and analytical laboratories performing precious‑metals assays, refineries, bullion dealers, quality control departments in minting and precious‑metals manufacturing, and regulatory or inspection bodies that require standardized gold determinations by fire assay. Users are expected to be trained in fire assay techniques and to operate in a properly equipped laboratory.

Related standards

Related ASTM methods and practices for fire assay and metal analysis (historical and companion documents), laboratory safety practices, and referenced specifications for reagents and cupel materials are commonly associated with E1335. Older revisions (for example E1335-08 and its reapproved editions) and other committee documents on assay precision and methodology provide background and supplemental guidance.

Keywords

gold assay, cupellation, fire assay, bullion, proof correction, cupels, precious metals analysis, assay method, gold in bullion

FAQ

Q: What is this standard?

A: ASTM E1335-24 is a set of standard test methods describing cupellation (fire assay) procedures for determining the gold content of bullion across defined concentration ranges.

Q: What does it cover?

A: It covers sample preparation, fusion and cupellation procedures, selection of cupels and reagents, proof correction and calculation, applicable concentration ranges for different test methods, known interferences, and safety considerations for fire assay operations.

Q: Who typically uses it?

A: Professional assayers, refinery and mint laboratories, bullion traders and manufacturers, and inspection or regulatory labs that require standardized, reproducible gold determinations by fire assay.

Q: Is it current or superseded?

A: Current — the 2024 edition (E1335-24) is the active edition published in 2024.

Q: Is it part of a series?

A: It is part of ASTM’s suite of test methods and practices for non‑ferrous metals and precious‑metals assaying developed by the appropriate ASTM committee and subcommittee; related historical and companion documents address precision statements, safety, and complementary assay techniques.

Q: What are the key keywords?

A: gold, bullion, cupellation, fire assay, assay method, precious metals, proof correction, cupel.