🧪 Aluminium in Water
In short
Determination of aluminium in water and waste water by two atomic absorption spectrometric methods: with atomization in a nitrous oxide–acetylene flame in the range 5–100 mg/l and with electrothermal atomization in a graphite furnace in the range 10–100 µg/l with a 20 µl portion. The test is performed according to PN-EN ISO 12020:2002; Range — flame method: 5–100 mg/l; higher after dilution (1.1). The procedure comprises 5 steps; it is used for: Drinking water — aluminium 200 µg/l, indicator parameter (Journal of Laws 2026, item 748, Annex 1 Part C Table 2 item 3), especially when treatment uses aluminium chemicals (Annex 3), Monitoring of surface water and groundwater — indicator 3.6.11 “Aluminium” (Journal of Laws 2021, item 1576, Annex 8), Waters and waste waters — 10–100 µg/l by the graphite furnace method (1.2).
At a glance
- Standard: PN-EN ISO 12020:2002
- Category: Physicochemistry
- Procedure steps: 5
- Range — flame method: 5–100 mg/l; higher after dilution (1.1)
- Range — graphite furnace: 10–100 µg/l with a 20 µl portion (1.2)
- Flame: nitrous oxide–acetylene (clause 2)
Overview
STATUS (as of 29.10.2026). PN-EN ISO 12020:2002 — Polish version, published 21.03.2002, implements EN ISO 12020:2000 and ISO 12020:1997 [IDT]. The standard is current — no withdrawal note. ISO 12020:1997 (first edition, 27.02.1997) — no newer edition.
INTRODUCTION AND SCOPE (introduction, clause 1). Aluminium may be present in water in ionic or complex form, dissolved or finely dispersed; even with the digestion described in 2.5.3, silicates and oxidic aluminium compounds may not be covered quantitatively. Flame method (clause 2) — 5–100 mg/l; higher concentrations after dilution, and careful evaporation of the sample acidified with nitric acid extends the range downwards as long as no precipitation occurs; with a sufficiently large linear range of the instrument, concentrations below 5 mg/l can be determined, otherwise — by the graphite furnace method. Total aluminium is determined after digestion according to 2.5.3. Graphite furnace method (clause 3) — 10–100 µg/l in waters and waste waters with a 20 µl portion; the range is shifted upwards by dilution of the sample or by a smaller portion.
INTERFERENCES — FLAME METHOD (2.1). Ions can interfere when the following concentrations are exceeded: sulfate, chloride, phosphate, sodium, potassium, magnesium, calcium, iron, nickel, cobalt and lead — 10 000 mg/l, cadmium — 3 000 mg/l (the list in the available text breaks off at lead).
LEGAL REQUIREMENTS. Drinking water: aluminium 200 µg/l — an indicator parameter (Journal of Laws 2026, item 748, Annex 1 Part C Table 2 item 3); measurement uncertainty 25 % (Annex 4 Part B item 24); Annex 3 adds aluminium to the group A parameters when aluminium compounds are used as water treatment chemicals. Waste water: the reference methodologies for aluminium are PN-EN ISO 15586 (AAS with flameless atomization) and PN-EN ISO 11885 (ICP-OES) — PN-EN ISO 12020 is not listed there (Journal of Laws 2019, item 1311, Annex 12 item 28). Monitoring of surface water and groundwater: PN-EN ISO 12020 is the AAS methodology with flame atomization for indicator 3.6.11 “Aluminium”, alongside ICP-OES, ICP-MS and PN-EN ISO 15586 (Journal of Laws 2021, item 1576, Annex 8).
WHAT WE DO NOT GIVE HERE. The publicly available text of the standard ends with 2.1. We do not give the reagents, apparatus, digestion (2.5.3), the procedure of either method, the furnace programme or the data from the interlaboratory trial (informative Annex A). The aluminium line of 309.3 nm is given according to EPA Method 200.9 (second source, a different document).
Method principle
Flame method (clause 2): the sample is introduced into the nitrous oxide–acetylene flame of an atomic absorption spectrometer and the atomic absorption of aluminium is measured. Graphite furnace method (clause 3): a 20 µl portion is atomized electrothermally in a graphite furnace. The procedure of both methods — outside the available text of the standard.
In EPA Method 200.9 (second source, a different document; graphite furnace), the aluminium line is 309.3 nm, and example pyrolysis and atomization temperatures are 1700 °C and 2600 °C, the actual temperatures depending on the instrument and being determined individually.
Applications
- Drinking water — aluminium 200 µg/l, indicator parameter (Journal of Laws 2026, item 748, Annex 1 Part C Table 2 item 3), especially when treatment uses aluminium chemicals (Annex 3)
- Monitoring of surface water and groundwater — indicator 3.6.11 “Aluminium” (Journal of Laws 2021, item 1576, Annex 8)
- Waters and waste waters — 10–100 µg/l by the graphite furnace method (1.2)
- Waters with concentrations of 5–100 mg/l — flame method (1.1)
Key parameters
| Parameter | Value |
|---|---|
| Range — flame method | 5–100 mg/l; higher after dilution (1.1) |
| Range — graphite furnace | 10–100 µg/l with a 20 µl portion (1.2) |
| Flame | nitrous oxide–acetylene (clause 2) |
| Total aluminium | after digestion according to 2.5.3; silicates and oxidic aluminium compounds may not be covered quantitatively (clause 1) |
| Wavelength | 309.3 nm (EPA 200.9 — outside the available text of the standard) |
| Parametric value (drinking water) | 200 µg/l (Journal of Laws 2026, item 748, Annex 1 Part C Table 2 item 3) |
Standard
- Standard number
- PN-EN ISO 12020:2002
- Title (PL)
- Jakość wody — Oznaczanie glinu — Metody atomowej spektrometrii absorpcyjnej
- Title (EN)
- Water quality — Determination of aluminium — Atomic absorption spectrometric methods
Step-by-step procedure
-
Choice of method
5–100 mg/l — flame method; 10–100 µg/l — graphite furnace method; higher concentrations — after dilution, in the furnace also by a smaller portion (clause 1).
-
Total aluminium
Digest the sample according to 2.5.3; silicates and oxidic aluminium compounds may not be covered quantitatively (clause 1, introduction).
-
Low concentrations in the flame method
Carefully evaporate the sample acidified with nitric acid, as long as no precipitation occurs (1.1).
-
Interferences
For the flame method check the concentrations of interfering ions: 10 000 mg/l (among others sulfate, chloride, phosphate, sodium, potassium, magnesium, calcium, iron, nickel, cobalt, lead), cadmium 3 000 mg/l (2.1).
-
Measurement
According to clause 2 (nitrous oxide–acetylene flame) or clause 3 (graphite furnace) of the standard — procedure outside the available text.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Atomic absorption spectrometer with a nitrous oxide–acetylene burner | flame method (clause 2); detailed requirements — outside the available text | — |
| Atomic absorption spectrometer with graphite furnace | method with electrothermal atomization, 20 µl portion (clause 3); detailed requirements — outside the available text | — |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| Nitric acid | — | for acidifying samples (1.1); concentrations and the other reagents — outside the available text |
| Aluminium standard solutions and digestion reagents | — | according to clauses 2 and 3 of the standard (2.5.3 — digestion) — outside the available text |
Health and safety (OHS)
- Acids and standard solutions are handled according to the safety data sheets
- The nitrous oxide–acetylene flame and the gas installation are operated according to the spectrometer manufacturer’s instructions
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN ISO 12020:2002 — “Water quality — Determination of aluminium — Atomic absorption spectrometric methods”.
How does this method work?
Flame method (clause 2): the sample is introduced into the nitrous oxide–acetylene flame of an atomic absorption spectrometer and the atomic absorption of aluminium is measured. Graphite furnace method (clause 3): a 20 µl portion is atomized electrothermally in a graphite furnace.
What is the measuring range and accuracy?
Range — flame method: 5–100 mg/l; higher after dilution (1.1); Range — graphite furnace: 10–100 µg/l with a 20 µl portion (1.2); Flame: nitrous oxide–acetylene (clause 2); Total aluminium: after digestion according to 2.5.3; silicates and oxidic aluminium compounds may not be covered quantitatively (clause 1).
How long does the test take?
The procedure comprises 5 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
Atomic absorption spectrometer with a nitrous oxide–acetylene burner, Atomic absorption spectrometer with graphite furnace.
Where is this test used?
Drinking water — aluminium 200 µg/l, indicator parameter (Journal of Laws 2026, item 748, Annex 1 Part C Table 2 item 3), especially when treatment uses aluminium chemicals (Annex 3); Monitoring of surface water and groundwater — indicator 3.6.11 “Aluminium” (Journal of Laws 2021, item 1576, Annex 8); Waters and waste waters — 10–100 µg/l by the graphite furnace method (1.2); Waters with concentrations of 5–100 mg/l — flame method (1.1).
What safety precautions apply?
Acids and standard solutions are handled according to the safety data sheets; The nitrous oxide–acetylene flame and the gas installation are operated according to the spectrometer manufacturer’s instructions.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN ISO 12020.