🔵 Aluminium in water by the eriochrome cyanine R method according to PN-C-04605-02 — standard withdrawn, and a low parametric value

Physicochemistry PN-92/C-04605

Overview

STATUS (state of the PKN card on 23.09.2026). PN-C-04605-02:1992 — Polish version — is WITHDRAWN. Publication date 31-03-1992, WITHDRAWAL DATE 14-11-2012, number of pages 4, technical body KT 121 (Water Quality — Chemical Testing — Inorganic Substances), ICS 13.060.50. The card contains no "Replaced by" row.

WHAT LABORATORIES CITE (measurement on the database of scopes, reading of 23.09.2026): 26 entries at 21 laboratories across all forms of notation; 23 entries at 20 laboratories when matching by the BEGINNING of the notation in the old scheme ("PN-92/C-04605") — this is the number the "Laboratories" tab shows. Checked: this prefix does not pull in other parts of the series.

THE NEW NOTATION SCHEME FINDS ONE LABORATORY. The notation "PN-C-04605-02:1992" stands in 3 entries at 1 laboratory, whereas the old scheme "PN-92/C-04605/02" — in 17 entries, and "PN-92/C-04605.02" — in 6. Anyone searching by the new scheme finds one laboratory out of twenty-one.

THE TECHNIQUE AGREES WITH THE REAGENT. Twenty-three entries declare a spectrophotometric method, and the standard indicates the reagent in its title: eriochrome cyanine R, a dye that forms a coloured complex with aluminium. Here the name of the technique in the scopes and the description in the title of the standard do not diverge — unlike with chlorine, formaldehyde and sulphates (separate entries in this database).

MEASURING RANGES: (0.020 – 0.500) mg/l, (0.020 – 0.60) mg/l, (0.04 – 1.0) mg/l, (0.040 – 0.28) mg/l, (0.040 – 0.40) mg/l, (0.040 – 1.0) mg/l, and in one entry (0.06 – 1000) mg/l. This last upper value — 1000 mg/l of aluminium in drinking water — deviates from the others by three orders of magnitude; we do not settle whether it is a range for another matrix or a writing error, but when reading the scopes it is worth seeing it.

AGAINST WHAT THESE NUMBERS APPLY. The parametric value for aluminium (Al) in water intended for human consumption is 200 µg/l, i.e. 0.2 mg/l — item 3 of the list of indicator parameters of the regulation of the Minister of Health of 22 May 2026 (Journal of Laws 2026 item 748, in force since 24 June 2026). The same regulation requires that the method allows a concentration equal to the parametric value to be measured with a limit of quantification of 30 % of this value or less — for aluminium this is 0.06 mg/l — and that the measurement uncertainty for aluminium does not exceed 25 % of the parametric value. THE DECLARED LOWER LIMITS OF 0.020–0.040 mg/l MEET THIS REQUIREMENT; the limit of 0.06 mg/l lies exactly on the threshold.

ALUMINIUM IS ALSO A WATER TREATMENT CHEMICAL — AND THAT IS WHY IT IS MEASURED. The regulation lists aluminium (alongside iron) among the parameters that are tested "jeżeli są stosowane jako chemikalia do uzdatniania wody" [if they are used as water treatment chemicals]. Aluminium coagulants are widespread, so the determination of aluminium in treated water is a check on the effectiveness of the treatment itself, not only a test of contamination of the raw water.

MATRICES IN THE SCOPES: "Woda, Woda do spożycia przez ludzi" [water, water intended for human consumption] (7 entries), "Woda do spożycia przez ludzi" [water intended for human consumption] (6), "Woda (w tym woda na pływalniach), Woda do spożycia" [water (including swimming pool water), drinking water] (3), "Woda, woda do spożycia przez ludzi" (2). The title of the standard covers water and waste water, but in the accreditation scopes it is accompanied by water.

WHAT WE DO NOT GIVE. We did not have the text of the standard. We DO NOT GIVE the composition of the eriochrome cyanine R reagent, the buffering of the sample, the way of removing the interfering effect of fluorides and iron, or the measurement wavelength.

TWO NAMES FOR THE SAME ELEMENT (23.09.2026). In accreditation scopes, aluminium also appears under the name "aluminium" [besides the Polish "glin"] — measurement on the copy of the scopes, test name or parameter, with inflection by case: "glin" 140 laboratories / 254 entries, "aluminium" 15 / 34. When searching for laboratories, it is worth entering both names.

Method principle

Aluminium present in the sample forms a coloured complex with eriochrome cyanine R, and the colour intensity is measured spectrophotometrically against a calibration curve. The title of the standard itself indicates the reagent. WE DO NOT DESCRIBE THE DETAILS OF EXECUTION — the pH of the reaction, the composition of the buffer, the procedure in the presence of interfering substances, the wavelength: we did not have the text of the standard.

Applications

• Determination of aluminium in water intended for human consumption
• Checking the effectiveness of water treatment with aluminium coagulants
• Testing of swimming pool water, where aluminium is sometimes a residue of coagulation
• Reading an accreditation scope in which a standard withdrawn in 2012 stands next to aluminium

Key parameters

Standard

Standard number

PN-C-04605-02:1992 (wersja polska)

Title (PL)

Woda i ścieki — Badania zawartości glinu — Oznaczanie glinu metodą z eriochromocyjaniną R

Step-by-step procedure

1. Checking which document stands in the scope

   PN-C-04605-02:1992, most often written in the scopes as PN-92/C-04605/02, has been withdrawn since 14-11-2012 and has no successor indicated on the card.

2. Checking the requirements for the method

   The regulation on the quality of drinking water requires for aluminium a limit of quantification not greater than 30 % of the parametric value (0.06 mg/l) and a measurement uncertainty not greater than 25 % of this value. The range declared by the laboratory must be read against these two numbers.

3. Preparing the sample

   Prepare the sample according to the laboratory's procedure — the colour reaction depends on pH, and the result on the cleanliness of the vessels, because the concentrations determined are of the order of hundredths of a milligram per litre. We do not give the details of the standard.

4. Developing the colour

   Add the reagent with eriochrome cyanine R and wait for the time established in the procedure. Treat the standards exactly like the samples.

5. Spectrophotometric measurement

   Measure the colour intensity against a calibration curve covering the range around the parametric value of 0.2 mg/l.

6. Relating to the parametric value

   Compare with the value of 200 µg/l (0.2 mg/l) for water intended for human consumption (Journal of Laws 2026 item 748). If the water was treated with an aluminium coagulant, the result is at the same time a measure of the effectiveness of the treatment.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The standard has been withdrawn since 14-11-2012 and has no successor on the card — citing its number alone does not say where today's description of the method comes from
• The parametric value of 0.2 mg/l is low in relation to the contamination introduced by glassware and reagents — a result raised by the vessels looks the same as a true one
• A limit of quantification of 0.06 mg/l lies exactly on the permissible threshold (30 % of the parametric value); any deterioration takes the method outside the requirement of the regulation
• A range with an upper limit of 1000 mg/l for drinking water deviates from the others by three orders of magnitude — when reading the accreditation scope it is worth checking this at the source
• Searching for laboratories by the new numbering scheme finds one laboratory out of twenty-one — one must search by both schemes

Frequently asked questions