ISO/DTS 4189

Magnesium and magnesium alloys - Determination of sodium - Inductively coupled plasma optical emission spectrometric method

Titre manque

General Information

• Status: Not Published
• ICS: 77.120.20 - Magnesium and magnesium alloys
• Technical Committee: ISO/TC 79/SC 5 - Magnesium and alloys of cast or wrought magnesium
• Drafting Committee: ISO/TC 79/SC 5/WG 4 - Analysis of magnesium and magnesium alloys
• Current Stage: 5098 - Project deleted
• Start Date: 02-Nov-2023
• Completion Date: 13-Dec-2025

Overview

ISO/DTS 4189 presents a standardized inductively coupled plasma optical emission spectrometric (ICP-OES) method for the precise determination of sodium content in magnesium and its alloys. This international standard is essential for quality control and material certification, particularly due to sodium’s significant impact on the mechanical properties of magnesium alloys. The standard outlines procedures for sample preparation, analysis, calibration, and data interpretation to ensure accurate measurement of sodium concentrations ranging from 0.0002% to 0.05% by mass.

Key Topics

• Scope and Purpose
  The method specifically targets the detection of sodium in magnesium materials, addressing concentrations at trace levels to prevent quality degradation caused by sodium-induced hot brittleness.

• Analytical Principle
  The test involves dissolving the magnesium sample in nitric and hydrochloric acids, followed by nebulizing the resulting solution into an ICP-OES spectrometer. Sodium content is quantified by measuring the emission intensity at specific wavelengths and comparing it to magnesium-based calibration curves.

• Reagents and Materials

  • High-purity magnesium (≥ 99.99%) free of sodium
  • Sodium chloride for standard solutions
  • Nitric and hydrochloric acids of defined concentrations
  • Grade 2 water conforming to ISO 3696

• Instrumentation and Setup
  Use of calibrated ICP-OES equipment optimized for sodium detection, focusing on wavelengths around 588.995 nm and 589.592 nm for optimal sensitivity with minimal interference. Compliance criteria include detection limits ≤ 0.03 mg/L and calibration correlation coefficients ≥ 0.999.

• Sample Preparation and Calibration
  Samples are cleaned to eliminate surface contaminants and prepared as drillings or chips no thicker than 1 mm. Calibration curves are constructed using standard sodium solutions diluted with pure magnesium matrices to simulate sample composition accurately.

• Data Analysis and Reporting
  Sodium concentrations are calculated from emission intensity data using established calibration curves, with precision assessments provided. Detailed test reports include sample preparation details, calibration parameters, raw and computed data, and measurement uncertainties.

Applications

• Quality Control in Magnesium Production
  Ensuring sodium levels remain within strict limits to prevent hot brittleness during manufacturing processes like forging and rolling.

• Material Certification for Aerospace and Automotive Industries
  Compliance with material standards demanding low sodium contents to guarantee mechanical performance and reliability.

• Research and Development
  Precise quantification of sodium for alloy design and evaluation of impurity effects on physical properties.

• Regulatory Compliance
  Supporting traceability and adherence to international standards such as ISO 8287 regarding sodium content thresholds in magnesium alloys.

Related Standards

• ISO 8287:2021 – Specification for chemical composition limits of magnesium alloys including sodium content thresholds.
• ISO 3696 – Water quality requirements for analytical laboratory use, ensuring reagent purity.
• ISO 648 – Specifications for laboratory single-volume pipettes for accurate volumetric measurement.
• ISO 1042 – Standards for one-mark volumetric flasks used in sample and reagent preparation.

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This method provides a robust, internationally recognized approach for the determination of sodium in magnesium materials, critical for maintaining mechanical integrity and performance in industrial applications. By adhering to ISO/DTS 4189, laboratories ensure consistency, accuracy, and traceability in elemental analysis, supporting global trade and manufacturing quality assurance.

Standards Content (Sample)

ISO/TC 79/SC 5
Date:2023-05
ISO/TC 79/SC 5
Secretariat: SAC
Date: 2023-07-17
Magnesium and magnesium alloys -- — Determination of sodium -
-— Inductively coupled plasma optical emission spectrometric
method
Magnésiumetalliages de magnésium - Détermination du sodium - Méthode par
spectrométried'émissionatomique avec source à plasma induit
FDIS stage
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this
publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical,
including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can
be requested from either ISO at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
E-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
Contents
Foreword . vi
Introduction .vi i
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 1
6 Apparatus . 2
7 Sampling and sample preparation . 3
8 Procedure . 3
8.1 General . 3
8.2 Test portion . 3
8.3 Determination . 3
8.3.1 Preparation of the test solution . 3
8.3.2 Preparation of the calibration solutions . 3
8.4 Adjustment of the apparatus . 4
8.5 Measurement of the calibration solutions . 4
8.6 Calibration curve . 4
8.7 Measurements of the test solution . 4
9 Expression of results . 4
9.1 Method of calculation . 4
9.2 Precision . 5
10 Test report . 5
Annex A (normative) Limit of detection . 6
Annex B (informative) Information on the precision test . 8
Annex C (informative) Graphical representation of precision data . 9
Bibliography . 12

Foreword iii
Introduction iv
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 Principle 1
iv
5 Reagents 1
6 Apparatus 2
7 Sampling and sample preparation 3
8 Procedure 3
8.1 General 3
8.2 Test portion 3
8.3 Determination 4
8.4 Adjustment of the apparatus 4
8.5 Measurement of the calibration solutions 5
8.6 Calibration curve 5
8.7 Measurements of the test solution 5
9 Expression of results 5
9.1 Method of calculation 5
9.2 Precision 5
10 Test report 6
Annex A  (normative) Detection limit 7
Annex B (informative) Information on the precision test 8
Annex C (informative) Graphical representation of precision data 9
Bibliography 错误！未定义书签。0
Foreword
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This document was prepared by Technical Committee ISO/TC 79, Light metals and their alloys,
Subcommittee SC 5, Magnesium and alloys of cast or wrought magnesium.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at
www.iso.org/members.htmlwww.iso.org/members.html.
vi
Introduction
Magnesium and magnesium alloys are one kind of light metallic materials and show several advantageous
properties such as low density, high specific stiffness and strength, good damping capacity, castability,
weldability and machinability, etc. Sodium is, as one of the hazardous impurities leading to, creates hot
brittleness of magnesium and magnesium alloys, thereby producing crackcracks during forging and
rolling,. Sodium content should be controlled and monitored in order to check if its content remains at
trace level. In ISO 8287:2021, sodium contents are specified to be less than 0,001 % or less than 0,01 %.

Magnesium and magnesium alloys -- — Determination of sodium --
— Inductively coupled plasma optical emission spectrometric
method
1 Scope
This document specifies an inductively coupled plasma atomic emission spectrometric method (ICP-OES)
for the determination of sodium contents between 0,00 2002 % (mass fraction) and 0,050 % (mass
fraction) in magnesium and magnesium alloys.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3696, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminologicalterminology databases for use in standardization at the following
addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obphttps://www.iso.org/obp
— — IEC Electropedia: available at http://www.electropedia.org/https://www.electropedia.org/
4 Principle
After dissolution of a test portion with nitric acid and hydrochloric acid, the solution is nebulized into an
inductively coupled plasma optical emission spectrometry (ICP-OES)spectrometer and the intensity of
the sodium emitted light from sodium is measured. The concentrations of sodium in the test solutions
are derived from magnesium -based calibration curves.
5 Reagents
During the analysis, use only reagents of recognized analytical grade and only grade 2 water as specified
in ISO 3696, or water of equivalent purity.
5.1 Pure magnesium, purity ≥99,99 % (mass fraction), free from sodium.
5.2 Sodium chloride, purity ≥99,99 % (mass fraction).
5.3 Hydrochloric acid, ρ about 1,19g19 g/ml.
5.4 Nitric acid, ρ about 1,42 g/ml.
5.5 Hydrochloric acid solution 1 + 1.
Add 500 ml of hydrochloric acid (5.3)(5.3) to 500 ml of water and mix.
5.6 Nitric acid solution 1 + 1.
Add 500 ml of nitric acid (5.4)(5.4) to 500 ml of water and mix.
5.7 Sodium standard solution (1 g / /l)).
Weigh, to the nearest 1 mg, 2,543 0 g of sodium chloride (5.2)(5.2) previously calcined at a temperature
between 500 °C and 600 °C to constant mass, and transfer into a 500 ml glass beaker.
Add 60 ml of water and, if necessary, heat gently to complete the dissolution.
Allow to coo
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