🔬 Nickel in Water
In short
Determination of nickel in water by flame atomic absorption spectrometry (FAAS) — the standard gives three methods: A (direct) and B and C (after chelation and extraction). The test is performed according to PN-ISO 8288:2002 (ISO 8288:1986); Range — method A: 0.1–10 mg/l (Table 1, depending on the instrument). The procedure comprises 8 steps; it is used for: Drinking water — nickel 20 µg/l (Journal of Laws 2026, item 748, Annex 1 Part B item 23); concentrations of this order — by methods B and C, Waste water — one of the reference methodologies for nickel (Journal of Laws 2019, item 1311, Annex 12 item 40), Brines, brackish waters and samples of unknown composition — methods B and C with extraction (clause 2).
At a glance
- Standard: PN-ISO 8288:2002 (ISO 8288:1986)
- Category: Physicochemistry
- Procedure steps: 8
- Range — method A: 0.1–10 mg/l (Table 1, depending on the instrument)
- Range — methods B and C: B: 1–200 µg/l; C: 0.5–100 µg/l at a ratio of 20 : 1 (Tables 2 and 3)
- Wavelength: 232.0 nm (Table 4)
Overview
STATUS (as of 29.10.2026). PN-ISO 8288:2002 — Polish version, published 29.03.2002, implements ISO 8288:1986 [IDT]; it replaced PN-C-04570-01:1992 and PN-C-04570-04:1992. The standard is current — no withdrawal note. ISO 8288:1986 (first edition, 13.03.1986) — no newer edition.
SCOPE (clauses 1–2, Tables 1–3). The standard covers cobalt, nickel, copper, zinc, cadmium and lead. Ranges for nickel (depending on the instrument): method A — direct determination in the flame — 0.1–10 mg/l; method B — after chelation with ammonium 1-pyrrolidinedithiocarbamate (APDC) and extraction with methyl isobutyl ketone (MIBK) — 1–200 µg/l; method C — after chelation (HMA-HMDC) and extraction with a DIPK-xylene mixture — 0.5–100 µg/l at a test portion to extraction solution ratio of 20 : 1 (lower concentrations — at a ratio of up to 50 : 1). Concentrations above the upper limits — after dilution of the sample. Method A is suitable for relatively high concentrations and the absence of interferences; for complex samples, samples of unknown composition or samples with a high content of dissolved solids (brines, brackish waters) method A is not applicable — method B or C is selected. Total metals are not determined without prior digestion (examples in Annex A); methods B and C are not applicable when the COD of the sample is greater than 500 mg/l.
INTERFERENCES AND CONTROL (7.4–7.5). Non-specific absorption is compensated by the continuous background correction of the spectrometer; without it, the non-specific absorbance is measured on a line not more than 1 nm away from the nickel line (Table 5) and subtracted from the total absorbance. The matrix effect is checked by the standard addition technique; if it occurs, method A is not applicable — the determination is repeated by method B or C or the result of the standard addition technique is adopted.
LEGAL REQUIREMENTS. Drinking water: nickel 20 µg/l (Journal of Laws 2026, item 748, Annex 1 Part B item 23); the method must be able to measure a concentration equal to the parametric value with a limit of quantification of not more than 30 % of that value and a measurement uncertainty of up to 25 % (Annex 4 Part B item 33) — such concentrations lie below the range of method A and within the ranges of methods B and C. Waste water: PN-ISO 8288 is one of the reference methodologies for nickel (atomic absorption spectroscopy with flame atomization), alongside PN-EN ISO 15586 and ICP-OES (Journal of Laws 2019, item 1311, Annex 12 item 40). Monitoring of surface water and groundwater: for indicator 4.1.23 “Nickel and its compounds” the regulation lists ICP-OES, ICP-MS and PN-EN ISO 15586 — PN-ISO 8288 is not listed there (Journal of Laws 2021, item 1576, Annex 8).
WHAT WE DO NOT GIVE HERE. The publicly available text of the standard covers method A in full and the beginning of method B (up to 14.3). The rest of method B, method C, the digestion examples (Annex A) and the precision data are described only to the extent of the sentences above. The same findings for the whole standard — in the entry “Heavy metals in water — AAS”.
Method principle
Method A (clause 3): a test portion of the acidified filtrate of the sample (or of the diluted sample) is aspirated into the flame of an atomic absorption spectrometer and the nickel concentration is determined directly from the specific absorbance — with a spectrometer with continuous background correction or after subtracting the non-specific absorbance. The radiation source is a hollow cathode lamp or an electrodeless discharge lamp; acetylene–air flame, oxidizing for nickel; nickel line 232.0 nm (Table 4). The concentration is read from the calibration graph.
Method B (clause 10): nickel forms a complex with APDC, which is extracted with MIBK at a pH of about 2.5, and nickel is determined in the organic phase in the flame. Method C uses chelation with HMA-HMDC and extraction with a DIPK-xylene mixture; the separation of the phases is faster and the chelates are more stable in the organic phase (clause 2).
Applications
- Drinking water — nickel 20 µg/l (Journal of Laws 2026, item 748, Annex 1 Part B item 23); concentrations of this order — by methods B and C
- Waste water — one of the reference methodologies for nickel (Journal of Laws 2019, item 1311, Annex 12 item 40)
- Brines, brackish waters and samples of unknown composition — methods B and C with extraction (clause 2)
Key parameters
| Parameter | Value |
|---|---|
| Range — method A | 0.1–10 mg/l (Table 1, depending on the instrument) |
| Range — methods B and C | B: 1–200 µg/l; C: 0.5–100 µg/l at a ratio of 20 : 1 (Tables 2 and 3) |
| Wavelength | 232.0 nm (Table 4) |
| Flame | acetylene–air, oxidizing (Table 4) |
| Calibration | at least four calibration solutions in nitric acid 0.03 mol/l; checking of the graph e.g. with a calibration solution every 5 samples (7.3–7.4) |
| Parametric value (drinking water) | 20 µg/l (Journal of Laws 2026, item 748, Annex 1 Part B item 23) |
Standard
- Standard number
- PN-ISO 8288:2002 (ISO 8288:1986)
- Title (PL)
- Jakość wody — Oznaczanie kobaltu, niklu, miedzi, cynku, kadmu i ołowiu — Metody atomowej spektrometrii absorpcyjnej z atomizacją w płomieniu
- Title (EN)
- Water quality — Determination of cobalt, nickel, copper, zinc, cadmium and lead — Flame atomic absorption spectrometric methods
Step-by-step procedure
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Sampling and preservation
Total nickel: immediately after collection acidify with nitric acid 1.4 g/ml to pH 1–2 (usually 2 ml of acid per litre of sample is sufficient); note the amount of acid and add the same amount to the blank. Dissolved nickel: filter the sample through a 0.45 µm membrane filter as soon as possible and acidify the filtrate immediately to pH 1–2 (6.2).
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Test portion
Into a 100 ml volumetric flask measure a volume of the acidified sample containing 0.2–1 mg of metal (upper limits — Table 1) and make up with water (7.1).
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Blank test
In parallel, by the same procedure and with the same quantities of reagents, using water instead of the test portion (7.2).
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Calibration solutions
Before each batch of determinations prepare from the standard solution at least four calibration solutions covering the range of concentrations to be determined, diluting them with nitric acid 0.03 mol/l (7.3).
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Setting up the spectrometer
According to the manufacturer’s instructions and Table 4 (232.0 nm, oxidizing flame), aspirating a nickel calibration solution; optimize the aspiration rate, the nature of the flame and the position of the beam in the flame; set the instrument to zero with water (7.4).
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Calibration and measurement
Aspirate the calibration solutions and the blank as the zero member, plot the absorbance against concentration; aspirate the test portion and measure the absorbance, rinsing the nebulizer with nitric acid 0.03 mol/l after each measurement. Checking the graph is advisable, e.g. with a calibration solution every 5 samples; without automatic background correction measure and subtract the non-specific absorbance (Table 5) (7.4).
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Matrix effect check
By the standard addition technique; if a matrix effect occurs, repeat the determination by method B or C or adopt the result of the standard addition technique (7.5).
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Calculation
Nickel concentration in the sample, mg/l = (ρt − ρb) × 100 / V, where ρt and ρb are the concentrations read from the graph for the test portion and the blank, V — volume of the acidified sample taken for the determination, ml (clause 8).
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Atomic absorption spectrometer | with a hollow cathode lamp or an electrodeless discharge lamp for nickel, a device for correcting non-specific absorbance and a nebulizer-burner for an acetylene–air flame; parameters according to the manufacturer’s instructions (clause 5) | — |
| Lamp for measuring non-specific absorbance | needed only without automatic background correction — according to Table 5 (7.4) | — |
| Sample containers | of polyethylene or borosilicate glass, cleaned with nitric acid 1.5 mol/l and rinsed with water (6.1) | — |
| Membrane filters 0.45 µm | for dissolved metals; washed with nitric acid 1.5 mol/l and water before use (6.2) | — |
| Laboratory glassware | soaked in nitric acid 1.5 mol/l and rinsed with water; 100 ml volumetric flasks (clause 5, 7.1) | — |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| Nitric acid, ρ = 1.4 g/ml | 7697-37-2 | for preserving samples and dissolving the standard metal (4.1) |
| Nitric acid, 1.5 mol/l | — | add 100 ml of acid 1.4 g/ml to 600 ml of water and dilute to 1000 ml; for washing glassware, containers and filters (4.2) |
| Nitric acid, 0.03 mol/l | — | add 1 ml of acid 1.4 g/ml to 400 ml of water and dilute to 500 ml; for diluting calibration solutions and rinsing the nebulizer after each measurement (4.3) |
| Nickel standard solution, 1.000 g/l | — | dissolve 1.000 g of pure nickel in nitric acid 1.4 g/ml with heating, transfer to a 1000 ml flask and make up with water; metal salts of accurately known composition and commercial solutions are permissible; store in polyethylene or borosilicate glass (4.4) |
| Water | — | deionized or distilled water in which a blank test shows no detectable concentration of nickel (clause 4) |
Health and safety (OHS)
- Nitric acid, MIBK, APDC and metal solutions are handled according to the safety data sheets
- Acetylene–air flame — the gas installation and the extraction hood above the burner are operated according to the spectrometer manufacturer’s instructions
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-ISO 8288:2002 (ISO 8288:1986) — “Water quality — Determination of cobalt, nickel, copper, zinc, cadmium and lead — Flame atomic absorption spectrometric methods”.
How does this method work?
Method A (clause 3): a test portion of the acidified filtrate of the sample (or of the diluted sample) is aspirated into the flame of an atomic absorption spectrometer and the nickel concentration is determined directly from the specific absorbance — with a spectrometer with continuous background correction or after subtracting the non-specific absorbance. The radiation source is a hollow cathode lamp or an electrodeless discharge lamp; acetylene–air flame, oxidizing for nickel; nickel line 232.
What is the measuring range and accuracy?
Range — method A: 0.1–10 mg/l (Table 1, depending on the instrument); Range — methods B and C: B: 1–200 µg/l; C: 0.5–100 µg/l at a ratio of 20 : 1 (Tables 2 and 3); Wavelength: 232.0 nm (Table 4); Flame: acetylene–air, oxidizing (Table 4).
How long does the test take?
The procedure comprises 8 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
Atomic absorption spectrometer, Lamp for measuring non-specific absorbance, Sample containers, Membrane filters 0.45 µm, Laboratory glassware.
Where is this test used?
Drinking water — nickel 20 µg/l (Journal of Laws 2026, item 748, Annex 1 Part B item 23); concentrations of this order — by methods B and C; Waste water — one of the reference methodologies for nickel (Journal of Laws 2019, item 1311, Annex 12 item 40); Brines, brackish waters and samples of unknown composition — methods B and C with extraction (clause 2).
What safety precautions apply?
Nitric acid, MIBK, APDC and metal solutions are handled according to the safety data sheets; Acetylene–air flame — the gas installation and the extraction hood above the burner 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-ISO 8288.