⚗️ Manganese in water and wastewater — permanganate method, visual or spectrophotometric measurement, PN-C-04590-02

Physicochemistry PN-92/C-04590/02

Overview

WHAT THE STANDARD COVERS. The scope from the PKN catalogue card, quoted in full: "The method is used for determining manganese in water and wastewater in the concentration range: — for visual measurements 0.05÷1.0 mg/l, — for spectrophotometric measurements 0.1÷15.0 mg/l. If the manganese content is higher, the test sample should be diluted accordingly with water for general laboratory use. The dilution should not be greater than 10-fold. The method allows determination of total and dissolved manganese." The name of the method says that manganese is measured in the form of permanganate (the violet MnO₄⁻ ion); what it is oxidised with, the card does not say.

STATUS (state of the card on 28 September 2026). The card carries the heading "Withdrawn" and the row "Date of withdrawal: 18-01-2008". There is no "Superseded by" field; the "Supersedes" field: PN-C-04590-01:1975. Edition: published 19-03-1992, 3 pages, PKN technical committee KT 121 (Water Quality — Chemical Tests — Inorganic Substances), ICS 13.060.50. Note the year: under the number PN-C-04590-02 there was earlier a 1984 edition with the formaldoxime method, which in 1992 was moved to sheet 03 (PN-C-04590-03:1992, also withdrawn; a separate entry in this knowledge base) — the year in the designation decides which method is meant. Whether a standard replacing this one for manganese in water stands in the PKN catalogue today — WE HAVE NOT ESTABLISHED.

REQUIREMENT OF THE REGULATION FOR DRINKING WATER. Regulation of the Minister of Health of 22 May 2026 on the quality of water intended for human consumption (Journal of Laws 2026, item 748), in force since 24 June 2026 (it repealed the 2017 regulation, Journal of Laws 2017, item 2294): parametric value for manganese — 50 µg/l (Annex 1, Part C, Table 2, item 5). Annex 4, Part B, point 1: the method must be capable of "at least measuring concentrations equal to the parametric value with a limit of quantification (…) of 30 % or less of the relevant parametric value" (our translation), i.e. 15 µg/l for manganese, with a measurement uncertainty of 30 % of the parametric value (item 29 of the table). The same point ends with the sentence: "Where there is no analytical method meeting the minimum performance characteristics set out in the table, monitoring shall be carried out using the best available techniques not entailing excessive costs" (our translation). According to the card this method starts at 50 µg/l (visually) and at 100 µg/l (spectrophotometrically) — the spectrophotometric range alone starts above the parametric value. The regulation names no standard for manganese — it requires method performance characteristics.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17 September 2026, read on 28 September 2026). All records of number 04590 with sheet 02: 17 entries at 17 laboratories, each with the year 1992. Forms: "PN-92/C-04590/02" — 14 laboratories, "PN-92/C-04590.02" — 2 (AB 396, AB 1589), "PN-C-04590.02:1992" — 1 (AB 1310). The "Laboratories" tab searches for records BEGINNING with "PN-92/C-04590/02" and will show 14 laboratories; AB 396, AB 1310 and AB 1589 will remain outside it. All 17 record the spectrophotometric method; none records the visual measurement. Test object: water intended for human consumption — 14 laboratories, "water" alone — 3 (AB 680, AB 1158, AB 1310). Current scopes on the PCA website (read on 29 September 2026): 16 rows stand in the valid issues with the same range as in the copy, and none is suspended. For AB 396 the laboratory page in the PCA Public Information Bulletin gives "Accreditation valid until: 06-08-2026" (that date has already passed; whether the accreditation was extended — WE HAVE NOT ESTABLISHED) and has no scope file — we give its entry (0.040–5.0 mg/l) only according to the copy, without confirmation in a current scope.

THE METHOD LIMIT AND THE LABORATORIES' RANGES — A PLACE FOR A SEEMINGLY CORRECT RESULT. Card: spectrophotometric measurement from 0.1 mg/l. Sixteen of the 17 laboratories declare a lower limit: from 10 µg/l (AB 1231) and 0.010 mg/l (AB 1452), through 15 µg/l (AB 343, AB 1158, AB 1677), 20 µg/l (AB 990, AB 1310), 30 µg/l (AB 561, AB 764, AB 808, AB 901, AB 1443) and 40 µg/l (AB 396, AB 617), to 50 µg/l (AB 680, AB 868); only AB 1589 starts at 0.10 mg/l, as on the card. Upper limits: from 0.25 mg/l (AB 901, AB 990) to 15 000 µg/l (AB 1310). Where the limits below the card come from — WE HAVE NOT ESTABLISHED; the accreditation scope does not say. Against the 15 µg/l requirement: of the 14 laboratories with drinking water, four start their range at 15 µg/l or lower (AB 343, AB 1231, AB 1452, AB 1677), and ten higher, from 20 to 100 µg/l. The lower limit of the range is not the same as the laboratory’s limit of quantification, but a range starting above 15 µg/l does not show that the requirement is met — for a "below" result in a drinking-water report, ask the laboratory for its limit of quantification.

WHAT WE DO NOT GIVE. We did not have the text of the standard — PKN sells it (3 pages). We do not give the oxidant and oxidation conditions, the measuring wavelength, the sample preparation for total and dissolved manganese, the calibration curve, the formula or the precision.

Method principle

According to the card of the standard, manganese in water and wastewater is determined by the permanganate method — as coloured permanganate — by visual measurement in the range 0.05–1.0 mg/l or spectrophotometric measurement in the range 0.1–15.0 mg/l; samples of higher concentration are diluted with water, at most 10-fold. The method allows total and dissolved manganese to be determined. For drinking water the result is compared with the parametric value of 50 µg/l, and the method must have a limit of quantification of no more than 15 µg/l (Journal of Laws 2026, item 748). We DO NOT GIVE the oxidant and measuring conditions — we did not have the text of the standard.

Applications

• Total and dissolved manganese in water and wastewater — according to the card from 0.05 mg/l (visually) and from 0.1 mg/l (spectrophotometrically), up to 15.0 mg/l
• Drinking water: assessment against 50 µg/l (Journal of Laws 2026, item 748) — according to the card the method does not meet the 15 µg/l limit-of-quantification requirement; the laboratory has to demonstrate its own
• In accreditation scopes: 17 laboratories, all with spectrophotometric measurement, 14 for drinking water

Key parameters

Standard

Standard number

PN-C-04590-02:1992 (wersja polska)

Title (PL)

Woda i ścieki — Badania zawartości manganu — Oznaczanie manganu metodą nadmanganianową

Title (EN)

Water and wastewater — Tests for manganese content — Determination of manganese by the permanganate method

Step-by-step procedure

1. Status of the document and the year

   PKN card: standard withdrawn on 18-01-2008, no successor indicated (state of the card on 28 September 2026). In the report the designation is given with the year 1992 — the 1984 edition under this number is a different method.

2. Sample preparation

   It is decided whether total or dissolved manganese is determined; a sample with a concentration above the range is diluted with water, at most 10-fold.

3. Oxidation to permanganate

   Manganese is converted into coloured permanganate. Oxidant and conditions NOT GIVEN.

4. Measurement

   Visually (0.05–1.0 mg/l) or spectrophotometrically (0.1–15.0 mg/l); in accreditation scopes — spectrophotometrically only.

5. Result and assessment

   For drinking water the result is compared with 50 µg/l. A "below" result with a range starting above 15 µg/l does not show that the limit-of-quantification requirement is met — ask the laboratory.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The strong oxidants used to convert manganese into permanganate are corrosive and reactive — the safety data sheets of the reagents used apply
• TECHNICAL NOTE: the year in the designation decides the method — PN-C-04590-02:1984 is the formaldoxime method, PN-C-04590-02:1992 the permanganate method

Frequently asked questions