EN 10184:2006

Chemical analysis of ferrous materials - Determination of phosphorus in non-alloyed steels and irons - Molybdenum blue spectrophotometric method

This European Standard specifies a method for the molybdenum blue spectrophotometric determination of phosphorus in non-alloyed steels and irons.
The method is applicable to non-alloyed steels and irons with phosphorus contents from 0,005 % to 0,25 % (m/m).

Chemische Analyse von Eisenwerkstoffen - Bestimmung von Phosphor in unlegierten Stählen und Eisen - Spektralphotometrisches Verfahren über Molybdänblau

Diese Europäische Norm legt ein spektralphotometrisches Verfahren zur Bestimmung von Phosphor in unlegierten Stählen und Eisen fest.
Das Verfahren ist für Phosphoranteile zwischen 0,005 % und 0,25 % (m/m) in unlegierten Stählen und Eisen anwendbar.

Analyse chimique des matériaux sidérurgiques - Dosage du phosphore dans les aciers et fontes non alliés - Méthode par spectrophotométrie d´absorption moléculaire

La présente Norme européenne spécifie une méthode de détermination spectrophotométrique au bleu de molybdène du phosphore dans les aciers et les fontes non alliés.
La méthode est applicable aux aciers et aux fontes non alliés dont la teneur en phosphore est comprise entre 0,005 % et 0,25 % (m/m).

Kemična analiza železovih zlitin – Določevanje fosforja v malolegiranih jeklih in železovih litinah – Spektrofotometrična metoda z molibdenovim modrim

General Information

• Status: Published
• Publication Date: 14-Feb-2006
• Withdrawal Date: 30-Aug-2006
• ICS: 77.040.30 - Chemical analysis of metals
• Technical Committee: ECISS/TC 102 - Methods of chemical analysis for iron and steel
• Drafting Committee: CEN/TC 459/SC 2/WG 4 - Determination of oxygen in steel
• Current Stage: 9020 - Submission to 2 Year Review Enquiry - Review Enquiry
• Start Date: 15-Oct-2025
• Completion Date: 15-Oct-2025
• Ref Project: SIST EN 10184:2006 - Chemical analysis of ferrous materials - Determination of phosphorus in non-alloyed steels and irons - Molybdenum blue spectrophotometric method

Relations

• Replaces: EN 10184:1989 - Chemical analysis of ferrous materials - Determination of phosphorus in steels and irons - Spectrophotometric method
• Effective Date: 22-Dec-2008
• Replaces: EN 10184:1989/AC:1991 - Chemical analysis of ferrous materials - Determination of phosphorus in steels and irons - Spectrophotometric method
• Effective Date: 22-Dec-2008

Overview

EN 10184:2006 (CEN) defines a standardized molybdenum blue spectrophotometric method for the chemical analysis of phosphorus in non-alloyed steels and irons. Approved December 2005 and published February 2006, the method covers phosphorus determination in the range 0.005 % to 0.25 % (m/m). It specifies sample preparation, reagents, apparatus, analytical procedure, calibration and expression of results for reproducible laboratory measurement.

Key Topics and Requirements

• Scope: Applicable to non‑alloyed steels and irons with P content from 0.005% to 0.25%.
• Principle: Dissolve the test portion in nitric and hydrochloric acids with controlled perchloric oxidation; remove silicon/arsenic interferences; form phosphomolybdate and reduce to molybdenum blue (reduced phosphomolybdate); measure absorbance spectrophotometrically.
• Spectrophotometry: Measure absorbance at ≈680 nm (2 cm cells) or ≈825 nm (1 cm cells).
• Reagents: Analytical‑grade acids (nitric, hydrochloric, perchloric, hydrofluoric, hydrobromic), ammonium molybdate, hydrazine sulphate, sodium metabisulphite, and prepared phosphorus standard (5 mg/L).
• Sample mass: Test portion mass depends on expected P content (e.g., 1 g for very low P, 0.2–0.5 g for higher P ranges).
• Calibration & blanks: Use a six‑point calibration graph from phosphorus standards; run blank and a compensating solution in parallel; subtract compensating solution absorbance from test solution.
• Interference control: Specific steps to remove silicon (repeat HF/perchloric steps when Si > 1%) and arsenic before color development.
• Precision data: Repeatability and reproducibility values are provided (derived from multi‑laboratory trials) to assess measurement uncertainty.

Applications and Users

• Laboratories performing chemical analysis of ferrous materials, particularly:
  • Steelworks quality control and metallurgical laboratories
  • Independent testing and certification labs for raw materials and finished products
  • Research labs studying phosphorus effects on steel properties
  • Regulatory and conformity assessment bodies requiring standardized phosphorus determinations
• Use cases include verifying compliance with material specifications, process control (dephosphorization), and failure analysis where phosphorus level affects mechanical behavior.

Practical Value

• Provides a validated, reproducible spectrophotometric approach for routine phosphorus testing.
• Specifies detailed reagent preparation, digestion sequence and timing to minimize interferences and ensure comparable results across labs.
• Includes guidance on sample size selection and calibration to optimize accuracy across the stated concentration range.

Related Standards

• EN ISO 14284 - Sampling and preparation of samples for chemical composition determination (referenced by EN 10184).
• ISO 5725 series - Guidance on repeatability and reproducibility (precision assessment) used in Annex A precision data.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2006
1DGRPHãþD
SIST EN 10184:1997
SIST EN 10184:1997/AC1:1997
LUDQLKMHNOLKLQ.HPLþQDDQDOL]DåHOH]RYLK]OLWLQ±'RORþHYDQMHIRVIRUMDYPDOROHJ
åHOH]RYLKOLWLQDK±6SHNWURIRWRPHWULþQDPHWRGD]PROLEGHQRYLPPRGULP
Chemical analysis of ferrous materials - Determination of phosphorus in non-alloyed
steels and irons - Molybdenum blue spectrophotometric method
Chemische Analyse von Eisenwerkstoffen - Bestimmung von Phosphor in unlegierten
Stählen und Eisen - Spektralphotometrisches Verfahren über Molybdänblau
Analyse chimique des matériaux sidérurgiques - Dosage du phosphore dans les aciers
et fontes non alliés - Méthode par spectrophotométrie d´absorption moléculaire
Ta slovenski standard je istoveten z: EN 10184:2006
ICS:
77.040.30 Kemijska analiza kovin Chemical analysis of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 10184
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2006
ICS 77.040.30 Supersedes EN 10184:1989
English Version
Chemical analysis of ferrous materials - Determination of
phosphorus in non-alloyed steels and irons - Molybdenum blue
spectrophotometric method
Analyse chimique des matériaux sidérurgiques - Chemische Analyse von Eisenwerkstoffen - Bestimmung
Détermination du phosphore dans les aciers et fontes non von Phosphor in unlegierten Stählen und Eisen -
alliés - Méthode par spectrophotométrie au bleu de Spektralphotometrisches Verfahren über Molybdänblau
molybdène
This European Standard was approved by CEN on 30 December 2005.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, 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
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 10184:2006: E
worldwide for CEN national Members.

Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Principle.4
4 Reagents.4
5 Apparatus .6
6 Sampling.6
7 Procedure .6
8 Expression of results .8
9 Note .9
10 Test report .9
Annex A (informative) Precision data.10
Bibliography .11

Foreword
This European Standard (EN 10184:2006) has been prepared by Technical Committee ECISS/TC 20
“Methods of chemical analysis of ferrous products”, the secretariat of which is held by SIS.
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 August 2006, and conflicting national standards shall be withdrawn
at the latest by August 2006.
This European Standard supersedes EN 10184:1989.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, 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 European Standard specifies a method for the molybdenum blue spectrophotometric determination of
phosphorus in non-alloyed steels and irons.
The method is applicable to non-alloyed steels and irons with phosphorus contents from 0,005 % to 0,25 %
(m/m).
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 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical
composition (ISO 14284:1996)
3 Principle
Dissolution of a test portion in nitric and hydrochloric acids and controlled addition of perchloric acid.
Formation of the phosphomolybdate complex after removal of silicon and arsenic and reduction with
hydrazine sulphate to molybdenum blue.
Spectrophotometric measurement of the blue complex at a wavelength of 680 nm or 825 nm.
4 Reagents
4.1 General
During the analysis, unless otherwise stated, only reagents of recognized analytical grade shall be used and
only distilled water or water of equivalent purity.
Blank tests shall verify that the relevant reagents are free from phosphorus. Whenever necessary, the
results shall be corrected accordingly. Grades giving high blank values are unsuitable and should be
discarded.
4.2 Hydrochloric acid
ρ about 1,19 g/ml.
4.3 Nitric acid
ρ about 1,40 g/ml.
4.4 Perchloric acid
ρ about 1,67 g/ml.
4.5 Hydrofluoric acid
ρ about 1,13 g/ml, diluted 1 + 9.
4.6 Hydrobromic acid
ρ about 1,47 g/ml, diluted 1 + 1.
4.7 Perchloric acid
ρ about 1,67 g/ml, diluted 42 + 58.
420 ml perchloric acid (4.4) shall be carefully poured into 400 ml of water. Swirl, cool, transfer to a 1000 ml
volumetric flask. Dilute to the mark with water and mix.
4.8 Sulphuric acid
ρ about 1,84 g/ml, diluted 3 + 37.
37,5 ml sulphuric acid (ρ about 1,84 g/ml) shall be carefully poured into 300 ml water. Swirl, cool and
transfer to a 500 ml volumetric flask. Dilute to the mark with water and mix.
4.9 Sodium metabisulphite
100 g/l solution.
100 g of dry sodium metabisulphite (Na S O ) shall be dissolved in 500 ml of warm water, filter and collect
2 2 5
the filtrate in a 1000 ml volumetric flask. Cool, dilute to the mark with water and mix.
4.10 Hydrazine sulphate
1,5 g/l solution to be prepared immediately before use.
4.11 Ammonium molybdate
20 g/l solution.
Dissolve 20 g of ammonium molybdate [(NH ) Mo O 4H O] in about 100 ml of diluted sulphuric acid (4.8).
4 6 7 24 2
Dilute to around 500 ml with water. Carefully pour 300 ml of sulphuric acid (4.8) into this solution. Swirl, cool
and transfer to a 1000 ml volumetric flask. Dilute to the mark with water and mix.
4.12 Molybdate reagent
Prepare immediately before use the following mixture:
Add, in order, to a 1000 ml volumetric flask, swirling between additions:
 500 ml of water;
 250 ml of molybdate solution (4.11);
 100 ml of hydrazine sulphate solution (4.10).
Dilute to the mark with water and mix.
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