🏗️ Chemical analysis of cement — reference methods and alternative XRF and ICP-OES methods — PN-EN 196-2

Construction PN-EN 196-2

Overview

SCOPE FROM THE PKN CATALOGUE CARD, QUOTED VERBATIM (our translation): "This document specifies the methods for the chemical analysis of cement. This document describes the reference methods and, in certain cases, an alternative method which can be considered to be equivalent to the reference method. In cases of dispute, only the reference methods are used. An alternative method based on X-ray fluorescence (XRF) is described for the content of SiO₂, Al₂O₃, Fe₂O₃, CaO, MgO, SO₃, K₂O, Na₂O, TiO₂, P₂O₅, Mn₂O₃, SrO, Cl and Br. The basis of this method is fused bead samples and analytical validation using certified reference materials together with performance criteria. A method using pressed pellets of unfused samples can be considered equivalent provided that it meets the same criteria in its analytical performance. An alternative method based on inductively coupled plasma optical emission spectroscopy (ICP-OES) is described for the content of SO₃."

THE SENTENCE THAT SETTLES DISPUTES: "IN CASES OF DISPUTE, ONLY THE REFERENCE METHODS ARE USED". This is the most important sentence of the whole scope for a laboratory working with X-ray fluorescence. An XRF result is fully valid in routine work and in the conformity assessment carried out by the manufacturer, but in a dispute — a complaint, a court case, between supplier and customer — the decision rests on a determination carried out by the reference method, i.e. classical wet chemistry. A laboratory that has only XRF in its accreditation scope is not able to settle such a dispute on its own.

WHAT MAY BE TESTED BY X-RAY FLUORESCENCE. The scope lists fourteen determinations: SiO₂, Al₂O₃, Fe₂O₃, CaO, MgO, SO₃, K₂O, Na₂O, TiO₂, P₂O₅, Mn₂O₃, SrO, Cl and Br. Beyond this list the alternative method is not described in the standard — although the scope allows it to be used for other elements after appropriate calibration procedures have been carried out.

BEADS OR PELLETS — THE STANDARD SETS A CONDITION, NOT A PROHIBITION. The basis of the XRF method described is fused BEADS of the sample, together with validation on certified reference materials and performance criteria. Pressed pellets of an unfused sample can be considered equivalent, but only on condition that the analytical performance meets THE SAME criteria. The difference is practical: fusion eliminates the effects of particle size and mineralogy, pressing does not, so the burden of proving equivalence lies with the laboratory.

ICP-OES FOR ONE DETERMINATION ONLY. The alternative method based on inductively coupled plasma optical emission spectrometry applies in this standard only to the SO₃ content. This narrowing is easy to overlook: owning an ICP-OES spectrometer does not make a laboratory capable of a full chemical analysis of cement according to this standard.

AN IMPORTANT RESERVATION ON THE VALIDATION OF ALTERNATIVE METHODS. The scope states explicitly that, with appropriate calibration procedures and reference materials, the XRF and ICP-OES methods are equivalent to the reference methods, but "have not yet been validated as a reference procedure for conformity assessment and in cases of dispute". Technical equivalence and the status of a reference procedure are two different things in this standard.

OTHER METHODS — THE WAY IS OPEN ON A CONDITION. The scope permits any other methods "provided they are calibrated against the reference methods or against internationally accepted reference materials in order to demonstrate their equivalence". The standard therefore does not close the door to new techniques, but requires equivalence to the reference method to be demonstrated.

NOT ONLY CEMENT. The last part of the scope extends the application: the methods apply principally to cements, but can be applied to the CONSTITUENT MATERIALS of cement, and also to other materials for which other standards call up these methods — and it is those standards that indicate which method is to be used.

WHAT POLISH LABORATORIES DO WITH THIS STANDARD. The Laboratory of Raw Materials and Building Binders of the Łukasiewicz Research Network — ICiMB, accredited since 1998, lists PN-EN 196-2 not only for common cements and their constituents but also for BUILDING GYPSUM, GLASS and glass products, SANDS and GLASS RAW MATERIALS (glass sands, kaolins, clays, magnesites, dolomites, zirconium raw materials). This confirms in practice the sentence in the scope about applying these methods to other materials — a cement standard is sometimes the reference document for materials that have little to do with cement. It is also worth noting that this laboratory lists X-ray fluorescence separately, under its own standard PN-EN ISO 12677 (chemical analysis of refractory products by XRF, fused bead method) — so the XRF technique is sometimes accredited under a different document from PN-EN 196-2, even though the latter describes it as an alternative method. The laboratory describes its role as that of a "third party" for the purposes of cement conformity assessment.

WHAT WE DO NOT GIVE. We did not have the text of the standard. WE DO NOT GIVE: the course of any reference method, sample masses, ignition temperatures, the composition of fluxes for making beads, the performance criteria set for XRF validation, or precision values. All of this is the content of the standard.

Method principle

The chemical analysis of cement consists in determining the content of oxides and selected elements in a sample brought to the form required by the method. In the reference methods, the determination is carried out by classical analytical chemistry. In the alternative XRF method, the sample is converted into a bead by fusion (or into a pressed pellet, if the laboratory demonstrates equivalence) and the intensity of the characteristic X-radiation is measured and related to the content by calibration on certified reference materials. In the alternative ICP-OES method, provided in this standard only for SO₃, the sample solution is introduced into the plasma and the emission is measured.

Applications

• Conformity assessment of cement — chemical analysis within control testing
• Testing of cement constituents: fly ash, slag, limestone, pozzolanas
• Determination of the chloride content of cement for the durability of reinforced concrete structures
• Referee analyses in supplier–customer disputes (by reference methods only)
• Analysis of other materials for which separate standards call up the methods of PN-EN 196-2

Key parameters

Standard

Standard number

PN-EN 196-2:2026-04 (wersja angielska)

Title (PL)

Metody badania cementu — Część 2: Analiza chemiczna cementu

Title (EN)

Methods of testing cement — Part 2: Chemical analysis of cement

Step-by-step procedure

1. Establishing the purpose of the test: routine or dispute

   If the result is to serve to settle a dispute, the reference method is planned from the start. An XRF result does not settle a dispute, even if the laboratory has this method in its accreditation.

2. Checking whether the determination is covered by the alternative method

   XRF covers the fourteen listed determinations, ICP-OES only SO₃. For the other determinations the reference method remains.

3. Sample preparation

   For XRF: a bead from the fused sample or a pressed pellet, if the laboratory has demonstrated equivalence. WE DO NOT GIVE THE PREPARATION METHOD — it is in the text of the standard.

4. Calibration and validation

   Calibration on certified reference materials and demonstration that the performance criteria are met. With pellets the burden of proving equivalence lies with the laboratory.

5. Carrying out the determination

   The measurement proper by the selected method. WE DO NOT GIVE THE MEASUREMENT CONDITIONS.

6. Entry in the report

   State whether the reference method or the alternative method was used, and the sample form for XRF (bead or pellet). Without this the customer does not know whether the result is suitable for settling a dispute.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The XRF spectrometer is a source of ionising radiation — work only on a working, closed instrument, in accordance with the licence and radiation protection supervision
• Bead fusion takes place at high temperature — risk of burns, heat-resistant gloves and a face shield are required
• Cement and cement dust are irritating and strongly alkaline — respiratory and eye protection during grinding
• Classical chemistry reagents: concentrated acids and alkalis — work in a fume cupboard
• Argon for ICP-OES — asphyxiant gas, room ventilation is required

Frequently asked questions