EN 725-1:2007

Advanced technical ceramics - Methods of test for ceramic powders - Part 1: Determination of impurities in alumina

This Part of EN 725 specifies one fusion and one acid dissolution method for the determination of elements of sodium, potassium, iron, silicon, calcium and magnesium present as impurities in alumina using atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP) spectroscopy. For each element present as impurities, the methods are applicable to the following ranges, calculated as oxides :
-   Sodium oxide:      20 ppm to 6000 ppm
-   Potassium oxide:      20 ppm to 100 ppm
-   Ferric oxide:      20 ppm to 300 ppm
-   Silica:         50 ppm to 2000 ppm
-   Calcium oxide:      20 ppm to 700 ppm
-   Magnesium oxide:                   5 ppm to 1000 ppm

Hochleistungskeramik - Prüfverfahren für keramische Pulver - Teil 1: Bestimmung von Verunreinigungen in Aluminiumoxidpulver

Dieser Teil von EN 725 legt ein Schmelz- und ein Säureaufschlussverfahren für die Bestimmung der Elemen¬te Natrium, Kalium, Eisen, Silicium, Calcium und Magnesium als Verunreinigungen in Aluminiumoxid mit Hilfe der Atomabsorptionsspektrometrie (AAS) oder der Atomemissionsspektrometrie mit induktiv gekoppeltem Plasma (ICP) fest. Bei jedem als Verunreinigung vorliegenden Element sind die Verfahren auf folgende Konzentrationsbereiche der oxidischen Verunreinigungen anwendbar:
   Natriumoxid:   von 20 ppm bis 6 000 ppm
   Kaliumoxid:   von 20 ppm bis 100 ppm
   Eisentrioxid:   von 20 ppm bis 300 ppm
   Siliciumdioxid:   von 50 ppm bis 2 000 ppm
   Calciumoxid:   von 20 ppm bis 700 ppm
   Magnesiumoxid:   von 5 ppm bis 1 000 ppm

Céramiques techniques avancées - Méthodes d'essai des poudres céramiques - Partie 1 : Détermination des impuretés dans l'alumine

La présente partie de l’EN 725 spécifie une méthode de fusion et une méthode par attaque acide permettant le dosage d’éléments de sodium, potassium, fer, silicium, calcium et magnésium présents en tant qu’impuretés dans l’alumine, par spectrométrie d’absorption atomique (SAA) ou par spectrométrie d’émission avec plasma à couplage induit par haute fréquence (ICP). Pour chaque élément présent sous forme d’impureté, les méthodes s’appliquent aux gammes de concentrations suivantes, le calcul portant sur les oxydes :
   Oxyde de sodium :   20 ppm à 6000 ppm ;
   Oxyde de potassium :   20 ppm à 100 ppm ;
   Oxyde ferrique :   20 ppm à 300 ppm ;
   Oxyde de silicium :   50 ppm à 2000 ppm ;
   Oxyde de calcium :   20 ppm à 700 ppm ;
   Oxyde de magnésium :   5 ppm à 1000 ppm.

Sodobna tehnična keramika - Preskusne metode za keramične praške - 1. del: Ugotavljanje nečistoč v aluminijevem oksidu

General Information

• Status: Published
• Publication Date: 11-Sep-2007
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: CEN/TC 184 - Advanced technical ceramics
• Drafting Committee: CEN/TC 184/WG 2 - Methods of test for ceramic powders
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 01-Apr-2025
• Completion Date: 14-Apr-2025
• Mandate: M/BC/CEN/90/4 - Request concerning the realisation of a standardization programme in the field of advanced technical ceramics
• Ref Project: SIST EN 725-1:2008 - Advanced technical ceramics - Methods of test for ceramic powders - Part 1: Determination of impurities in alumina

Relations

• Replaces: EN 725-1:1997 - Advanced technical ceramics - Methods of test for ceramic powders - Part 1: Determination of impurities in alumina
• Effective Date: 22-Dec-2008

Overview

EN 725-1:2007 - Advanced technical ceramics: Methods of test for ceramic powders - Part 1: Determination of impurities in alumina - is a CEN standard that specifies laboratory procedures to quantify common impurity elements in alumina (Al2O3). The document defines two decomposition routes (a fusion method and an acid dissolution method) and analytical determination by atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP). It is intended for quality control, material specification and analytical laboratories working with ceramic powders.

Key topics and technical requirements

• Scope of analysis: determination of sodium, potassium, iron, silicon, calcium and magnesium impurities expressed as oxides, with specified applicable concentration ranges:
  • Sodium oxide (Na2O): 20 ppm to 6000 ppm
  • Potassium oxide (K2O): 20 ppm to 100 ppm
  • Ferric oxide (Fe2O3): 20 ppm to 300 ppm
  • Silica (SiO2): 50 ppm to 2000 ppm
  • Calcium oxide (CaO): 20 ppm to 700 ppm
  • Magnesium oxide (MgO): 5 ppm to 1000 ppm
• Two decomposition methods:
  • Fusion with lithium metaborate (LiBO2) in platinum/platinum‑gold crucibles and subsequent nitric acid dissolution.
  • Acid dissolution using a sulphuric acid–phosphoric acid mixture (note: the acid dissolution method is not applicable for silicon determination).
• Sample and reagents:
  • Typical test sample mass ≈ 1 g; high‑purity reagents (≥ 99.99%) and water conforming to EN ISO 3696.
  • Apparatus includes platinum crucibles, muffle furnace (≈ 1 150 °C), hot plate with magnetic stirrer, and AAS/ICP instrumentation.
• Calibration and measurement:
  • Matrix‑matched calibration using decomposed pure alumina spiked with standard solutions.
  • Recommended analytical wavelengths for AAS/ICP are given (e.g., Na 589.0 nm, K 766.5/769.9 nm, Ca 422.7/393.3 nm, Fe 248.3/259.9 nm, Si 251.6 nm, Mg 285.2/279.5 nm).
  • Results reported as oxide concentrations in ppm; blank subtraction and repeat measurements are required.
• Quality and reporting:
  • Reporting requirements follow EN ISO/IEC 17025 - include method used (AAS or ICP), calibration, equipment, deviations, repeatability/reproducibility, and test data.

Applications and users

• Who uses EN 725-1:2007:
  • Analytical and contract testing laboratories performing alumina impurity analysis.
  • Ceramic manufacturers and materials suppliers for quality control of advanced technical ceramics.
  • R&D teams optimizing sintering, electrical or mechanical properties where trace impurities affect performance.
  • Procurement and compliance personnel specifying raw‑material acceptance criteria.
• Practical benefits:
  • Standardized, traceable test procedures for consistent impurity measurement across suppliers and labs.
  • Data to support process control, failure analysis, and certification of alumina powders for high‑performance ceramic components.

Related standards

• EN 725 series (other parts cover barium titanate, oxygen analysis, particle size, bulk density, etc.).
• Normative references within EN 725-1: EN ISO 3696 (water for analytical use) and EN ISO/IEC 17025 (laboratory competence).

Keywords: EN 725-1:2007, alumina impurities, advanced technical ceramics, AAS, ICP spectroscopy, fusion method, acid dissolution, ceramic powders testing, ppm.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2008
1DGRPHãþD
SIST EN 725-1:2000
6RGREQDWHKQLþQDNHUDPLND3UHVNXVQHPHWRGH]DNHUDPLþQHSUDãNHGHO
8JRWDYOMDQMHQHþLVWRþYDOXPLQLMHYHPRNVLGX
Advanced technical ceramics - Methods of test for ceramic powders - Part 1:
Determination of impurities in alumina
Hochleistungskeramik - Prüfverfahren für keramische Pulver - Teil 1: Bestimmung von
Verunreinigungen in Aluminiumoxidpulver
Céramiques techniques avancées - Méthodes d'essai pour poudres céramiques - Partie
1: Détermination des impuretés dans l'alumine
Ta slovenski standard je istoveten z: EN 725-1:2007
ICS:
81.060.30
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 725-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2007
ICS 81.060.30 Supersedes EN 725-1:1997
English Version
Advanced technical ceramics - Methods of test for ceramic
powders - Part 1: Determination of impurities in alumina
Céramiques techniques avancées - Méthodes d'essai des Hochleistungskeramik - Prüfverfahren für keramische
poudres céramiques - Partie 1 : Dosage des impuretés Pulver - Teil 1: Bestimmung von Verunreinigungen in
dans l'alumine Aluminiumoxidpulver
This European Standard was approved by CEN on 11 August 2007.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 725-1:2007: E
worldwide for CEN national Members.

Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Principle.4
4 Reagents.4
4.1 General.4
4.2 Reagents for fusion .4
4.3 Sulphuric acid-phosphoric acid mixture for acid dissolution .5
4.4 Reagents for calibration.5
5 Apparatus .5
6 Test sample .5
7 Decomposition of the test sample .6
7.1 General.6
7.2 Fusion .6
7.3 Acid dissolution.6
8 Calibration graph .6
8.1 General.6
8.2 Fusion .6
8.3 Acid dissolution.7
8.4 Drawing the calibration curve .7
9 Adjustment of the apparatus.7
9.1 Atomic absorption spectrometer .7
9.2 Inductively coupled plasma spectrometer.8
10 Measurements.8
11 Expression of the results.8
12 Test report .9
Annex A (informative) Repeatability and reproducibility .10
Bibliography .11

Foreword
This document (EN 725-1:2007) has been prepared by Technical Committee CEN/TC 184 “Advanced
technical ceramics”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by March 2008, and conflicting national standards shall be withdrawn at
the latest by March 2008.
This document supersedes EN 725-1:1997.
EN 725 Advanced technical ceramics — Methods of test for ceramic powders was prepared in parts as
follows:
Part 1: Determination of impurities in alumina
Part 2: Determination of impurities in barium titanate
Part 3: Determination of the oxygen content of non-oxides by thermal extraction with a carrier gas
Part 4: Determination of oxygen content in aluminium nitride by XRF analysis
Part 5 Determination of particle size distribution
Part 6: Determination of the specific surface area [withdrawn]
Part 7: Determination of the absolute density [withdrawn]
Part 8: Determination of tapped bulk density
Part 9: Determination of un-tapped bulk density
Part 10: Determination of compaction properties
Part 11: Determination of densification on natural sintering
Part 12: Chemical analysis of zirconia
Parts 6 and 7 of the series were superseded in 2005 by EN ISO 18757 and EN ISO 18753 respectively.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and United Kingdom.
1 Scope
This Part of EN 725 specifies one fusion and one acid dissolution method for the determination of elements of
sodium, potassium, iron, silicon, calcium and magnesium present as impurities in alumina using atomic
absorption spectroscopy (AAS) or inductively coupled plasma (ICP) spectroscopy. For each element present
as impurities, the methods are applicable to the following ranges, calculated as oxides :
 Sodium oxide: 20 ppm to 6000 ppm
 Potassium oxide: 20 ppm to 100 ppm
 Ferric oxide:  20 ppm to 300 ppm
 Silica:  50 ppm to 2000 ppm
 Calcium oxide: 20 ppm to 700 ppm
 Magnesium oxide: 5 ppm to 1000 ppm
2 Normative references
The following referenced documents are indispensable for the application 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.
EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987)
EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC
17025:2005)
3 Principle
A test sample is decomposed by using either a fusion method or an acid dissolution method.
NOTE The acid dissolution method cannot be used for the determination of silicon.
The solution is transferred to a volumetric flask and diluted to a known volume, and the elements are
determined by AAS or ICP.
4 Reagents
4.1 General
During the analysis, use only reagents and calibration solutions of at least 99,99 % purity and water
conforming to EN ISO 3696,
...