🌱 Total calcium, magnesium, sodium and sulfate sulfur — extraction from fertilizers — PN-EN 15960

Physicochemistry PN-EN 15960

Overview

WHAT THIS TEST IS (clause 1 of EN 15960:2011; the same scope on the PKN card): a method for the extraction of total calcium, total magnesium and total sodium and for the extraction of total sulfur present in the form of sulfates — so that the same extract can be used for the determination of each of these components. The method is applicable to the fertilizers listed in Annex I of Regulation (EC) No 2003/2003 for which the regulation provides for a declaration of these components. Regulation (EC) No 2003/2003 is repealed with effect from 16 July 2022 (Article 51 of Regulation (EU) 2019/1009); the bibliography of the standard refers to its Annex IV, method 8.1.

PRINCIPLE (clause 4): extraction by boiling with dilute hydrochloric acid under specified conditions. The principle names magnesium, sodium and sulfur in the form of sulfates; calcium is in the scope and in 8.1.

PROCEDURE — THE WHOLE EXTRACTION (clauses 5–8): • sample according to EN 1482-2; the standard recommends grinding the laboratory sample for the sake of homogeneity; • 5 g of sample, weighed to the nearest 1 mg, into a 600 ml beaker; WHEN THE FERTILIZER CONTAINS MORE THAN 15 % SULFUR (37.5 % SO₃) AND MORE THAN 18.8 % CALCIUM (26.3 % CaO), the extraction of calcium and sulfur is carried out on a 1 g test portion; • about 400 ml of water and — carefully, in small portions when the sample contains a lot of carbonates — 50 ml of hydrochloric acid diluted 1 + 1; • bring to the boil and boil for 30 min on an electric hotplate with temperature control; cool, stirring from time to time; • transfer quantitatively to a 500 ml volumetric flask, make up with water, mix, filter through a dry filter into a dry vessel, discarding the first portion; • THE EXTRACT MUST BE PERFECTLY CLEAR; if it is not used at once, it is closed with a stopper.

THE CHAIN OF STANDARDS — WHAT IS DETERMINED IN THE EXTRACT. In accreditation scopes, the following stand next to this standard: PN-EN 16196:2013-05 "Nawozy — Manganometryczne oznaczanie wyekstrahowanego wapnia wytrąconego w postaci szczawianu" [Fertilizers — Manganometric determination of extracted calcium precipitated in the form of oxalate] (14 entries), PN-EN 16197:2013-05 "Nawozy — Oznaczanie magnezu metodą atomowej spektrometrii absorpcyjnej" [Fertilizers — Determination of magnesium by atomic absorption spectrometry] (13; according to the PKN card it concerns extracts obtained according to EN 15960 and EN 15961), PN-EN 15749:2023-01 "Nawozy — Oznaczanie zawartości siarczanów trzema różnymi metodami" [Fertilizers — Determination of sulfate content by three different methods] (12; method A — gravimetric, B — ICP-OES, C — ion chromatography) and PN-EN 15961:2017-02 — extraction of the same components soluble in WATER (14). Two entries cite PN-EN 15925:2011 — extraction of total sulfur present in various forms. Titles according to the PKN cards.

EDITIONS (state of the PKN card on 25.09.2026). PN-EN 15960:2011 — Polish version, publication 27-07-2015, 10 pages, KT 156 Fertilizers, introduces EN 15960:2011 [IDT], without the "Wycofana" [Withdrawn] header; the catalogue also has the English version. EN 15960:2011 replaced CEN/TS 15960:2009 (the specification adopted as a standard, editorial changes). At the publisher (the CEN catalogue run by iTeh, read on 25.09.2026): published 23-11-2011; stage 90.93 — decision to confirm after the systematic review (enquiry from 20-06-2023, closing 23-09-2026).

HOW ACCREDITATION SCOPES CITE THE STANDARD. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 43 entries at 16 laboratories; notation "PN-EN 15960:2011" (39), once with a space after the colon, and four fields in which a second standard was entered next to it. Methodology: total magnesium (8) and "magnez" [magnesium] (5), total calcium (7) and "wapń" [calcium] (5), sulfur (4) and total sulfur (4), total sodium (1) and other formulations; techniques: titrimetric (13), flame atomic absorption spectrometry FAAS (12), gravimetric (11), ICP-OES (3). The declared ranges are given in % CaO, % MgO, % Mg, % Na, % Na₂O, % S or % SO₃.

THE KEY OF THE "LABORATORIES" TAB: "PN-EN 15960" — 16 laboratories and 43 entries, without foreign entries.

WHAT WE DO NOT GIVE. We had the text of EN 15960:2011 made available by the publisher: the foreword, clauses 1–9 and the bibliography — the whole content of the standard. We do not describe the course of the determinations according to PN-EN 16196, PN-EN 16197 and PN-EN 15749 — we have not read their texts; we give only the titles and scopes from the PKN cards.

Method principle

Calcium, magnesium, sodium and sulfate sulfur are extracted from the fertilizer by boiling for 30 min in about 400 ml of water with 50 ml of hydrochloric acid 1 + 1; the solution is made up to 500 ml and filtered until perfectly clear. Each of the components is determined in this one extract according to separate standards.

Applications

• Fertilizers with a declaration of total calcium, magnesium, sodium and sulfate sulfur (among others calcium, magnesium and sulfate fertilizers)
• Common extract for the determinations: Ca — PN-EN 16196, Mg — PN-EN 16197, sulfates — PN-EN 15749 (titles according to the PKN cards)
• Comparison with the water-soluble form — PN-EN 15961

Key parameters

Standard

Standard number

PN-EN 15960:2011 (wersja polska z 2015 r.; w katalogu PKN także wersja angielska; wprowadza EN 15960:2011 [IDT])

Title (PL)

Nawozy — Ekstrakcja całkowitego wapnia, całkowitego magnezu, całkowitego sodu i całkowitej siarki obecnej w postaci siarczanów

Title (EN)

Fertilizers — Extraction of total calcium, total magnesium, total sodium and total sulfur in the forms of sulfates

Step-by-step procedure

1. Sample

   According to EN 1482-2; grind the laboratory sample (recommendation for the sake of homogeneity).

2. Test portion

   5 g ± 1 mg into a 600 ml beaker; at S > 15 % and Ca > 18.8 % — extraction of Ca and S from a 1 g test portion.

3. Acid

   About 400 ml of water and 50 ml of HCl 1 + 1 — in small portions when the sample contains a lot of carbonates.

4. Boiling

   Bring to the boil and keep boiling; cool, stirring from time to time.

   ⏱ Time: 30 min • 🌡 Temperature: boiling

5. Extract

   Transfer to a 500 ml flask, make up to the mark, mix, filter into a dry vessel (discard the first portion); the extract perfectly clear, close it with a stopper if it is not used at once.

6. Determinations

   Ca, Mg, Na and sulfates in the extract — according to separate standards; the test report includes, among other things, information on the repeatability limit.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Hydrochloric acid — corrosive; with samples containing carbonates, violent evolution of CO₂ and foaming — add in small portions
• Boiling the acid solution — under an extraction hood

Frequently asked questions