🌿 Elements in soil, treated biowaste, waste, sludge and sediment — inductively coupled plasma optical emission spectrometry (ICP-OES) in solutions after digestion with aqua regia, nitric acid or with HBF₄/HF, PN-EN ISO 22036

Environment PN-EN ISO 22036

Overview

WHAT THE STANDARD COVERS. We have a sample extract of ISO 22036:2024 (second edition, 2024-01) — from the cover to clause 6.8 (page 5): the foreword, the introduction, clauses 1–5 and part of clause 6. Scope (clause 1): determination of 64 elements (full list in clause 1) — among others aluminium, antimony, arsenic, barium, beryllium, bismuth, boron, cadmium, calcium, chromium, cobalt, copper, iron, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, phosphorus, potassium, selenium, silicon, silver, sodium, strontium, sulfur, thallium, tin, titanium, vanadium, zinc and zirconium, as well as precious metals and rare earth elements — in solutions after digestion with aqua regia, nitric acid or a mixture of hydrochloric, nitric and tetrafluoroboric or hydrofluoric acids of soil, treated biowaste, waste, sludge and sediment. The method is also suitable for other extracts and solutions (e.g. after DTPA extraction, fusion or total digestion), provided the user has verified its applicability; it has been validated for the elements in Tables A.1 (sludge), A.2 (compost) and A.3 (soil), and for other solid matrices and elements it has to be verified by the user. It is also applied to elements in solutions after digestion with aqua regia and nitric acid and in eluates of construction products (EN 17200). The standard has no normative references. Foreword: it was prepared by ISO/TC 190/SC 3 in collaboration with CEN/TC 444 (Vienna Agreement); the second edition replaced ISO 22036:2008 as a technical revision — ISO 22036:2008 was merged with EN 16170:2017, the scope was extended to treated biowaste, waste, sludge and sediment, and the digestion and extraction methods were updated. Introduction (Table 1): validation was carried out on municipal and industrial sludge, sludge from the electronics industry, from printing ink waste and sewage, on compost and composted sludge, on agricultural soil and soil amended with sludge, on fly ash and slag from incineration and on the reference materials BCR 146R, BCR 176 and ISE 859; the way of calibration depends on the extractant used.

PRINCIPLE AND INTERFERENCES (clauses 4–5). The solution is sprayed in a nebulizer, and the aerosol is transported into an inductively coupled plasma, where the solvent evaporates and the salts are atomized, ionized and excited; the element is identified by the wavelength of the emission, and its concentration — by its intensity; the measurement can be multi-element. Annex B gives example wavelengths and detection limits for one instrument (synthetic soil matrix: 500 mg/l each of Al, Ca and Fe in 30 ml of aqua regia made up to 100 ml); another instrument may give other limits. Results are checked with control charts for each element and with reference materials. Spectral interferences (line and band overlaps, continuous background, stray light) are corrected by subtracting the background measured next to the line (at an interference-free position), by choosing another line or by inter-element correction — then the analyte and the interfering element have to be measured simultaneously; spectral modelling algorithms have to be checked on samples of known composition. Non-spectral interferences: physical (viscosity, surface tension at high acid and salt contents) — dilution, matching of acid concentrations, matrix matching, a reference element; chemical — with axial viewing of the plasma the effect of easily ionized elements (alkali and alkaline earth metals) has to be corrected, e.g. with an ionization buffer (CsCl) or by radial viewing, which usually gives lower sensitivity; memory effect — rinsing between samples for a time established for each element.

REAGENTS (6.1–6.8). Water with a conductivity below 0.1 mS/m; nitric acid 65–70 %, hydrochloric acid 32–37 %, tetrafluoroboric acid 38–48 %, hydrofluoric acid 40–45 %; boric acid for masking fluorides (with a warning that contaminated boric acid may falsify the result) and its 4 % solution; single-element stock solutions of 1000 mg/l each.

STATUS (state of the cards on 30 September 2026). The card of PN-EN ISO 22036:2024-07 (English version) has no "Withdrawn" header — the standard is CURRENT: published 05-07-2024, 42 pages, price group S, Health, Environment and Medicine Sector, KT 191 for Soil Chemistry, ICS 13.080.10, "Introduces: EN ISO 22036:2024 [IDT], ISO 22036:2024 [IDT]", "Replaces: PN-EN 16170:2017-02 - English version"; the "Scope" field is a Polish translation of clause 1. The PKN search for "PN-EN ISO 22036" (30 September 2026) shows only this item. The sister method by ICP-MS is PN-EN ISO 16965:2026-03 (according to its card — the same matrices and solutions, it replaces PN-EN 16171:2017-02).

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation-scope database, data loaded up to 17 September 2026, read on 30 September 2026). All notations of number 22036: 17 entries at 10 laboratories — the same number of occurrences as in the current PCA documents. "PN-EN ISO 22036:2024-07" is written by 9 laboratories; AB 213 in both entries — "PN-EN 22036:2024-07", without the ISO element (the same in the PDF). Digestion in the same entry: PN-EN ISO 54321:2021-07 — AB 127, AB 176 (method B) and AB 1173; PN-EN 16174:2012 — AB 213 and AB 1539; five laboratories (AB 165, AB 415, AB 817, AB 1717, AB 1752) give no digestion standard in the entry. The "Laboratories" tab looks for notations that BEGIN with "PN-EN ISO 22036" and will show 9 of the 10 laboratories — checked with the tab's query on the production server labcoda.pl on 30 September 2026: 9; it will not show AB 213 (under "PN-EN 22036" — 1). Current scopes on the PCA website (read on 30 September 2026, issues from 20.05.2025 to 11.09.2026): all entries are in the issues in force, each of the 204 pairs of range limits from the copy appears in the current document and no entry is suspended.

MATERIALS, ELEMENTS AND RANGES. Sewage sludge — 7 laboratories (AB 127, AB 165, AB 176, AB 415, AB 817, AB 1173, AB 1539); waste with codes 19 08 05 (AB 127, AB 176, AB 817, AB 1539 — the latter also 19 09 03 and 19 08 02) and 17 05 04 (AB 176); soil — AB 165, AB 176, AB 1539, AB 1717; compost, biomass, stabilized material as well as soil improvers and growing media — AB 213; deposits (boiler scale) — AB 1752. The elements most often determined are cadmium, chromium, copper, nickel, lead and zinc, for sewage sludge also calcium, magnesium and phosphorus; the most elements — 29 — are held by AB 213 for compost. Mercury by ICP-OES is determined by AB 415, AB 817, AB 1173 and AB 1539, lowest from 0.050 mg/kg (AB 1539). The ranges extend from 0.05 mg/kg of cadmium (AB 213) to 650 000 mg/kg of iron in boiler scale (AB 1752).

ALONGSIDE THIS STANDARD. ICP-OES in soil, sludge, waste, compost and other solid matrices (among others ash, slag, biomass, growing media) is in the scopes of 67 laboratories, 57 of them without this standard; most often they cite PN-EN ISO 11885 (32 laboratories) — a standard for water, applied to solutions after digestion (separate Knowledge Base entries: metals by ICP according to PN-EN ISO 11885 and metals in soil by ICP). PN-EN 16170:2017, replaced by this standard (according to the PKN card), is still cited by AB 667 and AB 1249. Aqua regia extraction of trace elements from soil is described in PN-ISO 11466, and determination by ICP-MS in water — in PN-EN ISO 17294-2 (separate Knowledge Base entries).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — digestion: the standard describes only the measurement in the solution; the result depends on whether the sample was digested with aqua regia, nitric acid or with HBF₄/HF, so the report must name the digestion method — and five laboratories do not give it in the scope entry. Second — spectral interferences: according to the standard, uncorrected ones give falsely high results; for matrices rich in aluminium, calcium and iron (such as the synthetic soil matrix of Annex B or boiler scale) the background measured next to the line at an interference-free position and the inter-element correction matter. Third — axial viewing: at high contents of easily ionized elements (alkali and alkaline earth metals) the same amount of analyte gives a different signal, and for these elements themselves the calibration curve loses its linearity — the standard requires this effect to be corrected. Fourth — memory effect: after a sample with a high content of an element, the next one may give a result that is too high if the rinsing time was not established for that element. Fifth — validation range: the method was validated for sewage sludge, compost and soil; boiler scale (AB 1752) and other matrices require the user to verify its applicability.

WHAT WE DO NOT GIVE. The extract ends at clause 6.8: we do not give the apparatus (7), cleaning of glassware, instrument parameters, choice of lines, inter-element correction and stability (8.1–8.4), calibration (8.5), preparation of solutions and the course of the measurement (8.6–8.7), calculation (9), expression of results (10), performance characteristics (11), the test report (12) or annexes A–C (precision, wavelengths and detection limits, inter-element correction).

Method principle

The solution obtained from a solid sample (with aqua regia, nitric acid or a mixture with HBF₄/HF) is sprayed into an inductively coupled plasma; the excited atoms and ions emit radiation whose wavelength identifies the element, and whose intensity — after calibration — gives the concentration. Spectral interferences are corrected with the background measured next to the line, by choosing another line or by inter-element correction; non-spectral ones — by matrix matching, a reference element, an ionization buffer and rinsing. We DO NOT GIVE the calibration and the course of the measurement — the extract ends at 6.8.

Applications

• Sewage sludge and waste (e.g. code 19 08 05) — heavy metals, calcium, magnesium, phosphorus, mercury — in the scopes of 7 laboratories
• Soil and ground (AB 165, AB 176, AB 1539, AB 1717); compost, biomass, stabilized material, soil improvers and growing media (AB 213); boiler scale (AB 1752)

Key parameters

Standard

Standard number

PN-EN ISO 22036:2024-07 (wersja angielska; EN ISO 22036:2024, ISO 22036:2024 IDT)

Title (PL)

Składniki stałe środowiska — Oznaczanie zawartości pierwiastków z zastosowaniem optycznej spektrometrii emisyjnej z plazmą sprzężoną indukcyjnie (ICP-OES)

Title (EN)

Environmental solid matrices — Determination of elements using inductively coupled plasma optical emission spectrometry (ICP-OES)

Step-by-step procedure

1. Sample solution

   After digestion with aqua regia, nitric acid or a mixture with HBF₄/HF according to a separate standard (in the scopes: PN-EN ISO 54321, PN-EN 16174); the standard does not describe the digestion.

2. Choice of lines and corrections

   Interference-free lines, background measured next to the line, inter-element correction with simultaneous measurement; with axial viewing — correction of the effect of easily ionized elements.

3. Calibration and measurement

   Calibration depending on the extractant, rinsing between samples for a time established for the element; we DO NOT GIVE the course (8.5–8.7).

4. Quality control

   Control charts for each element, reference materials; we DO NOT GIVE the expression of results and performance characteristics (9–11).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Hydrofluoric and tetrafluoroboric acids are extremely hazardous (burns, absorption of fluorides through the skin) — work in a fume hood, with gloves and a face shield, with an HF burn treatment at hand
• The standard requires the tests to be carried out by trained staff, and the user establishes the health and safety practices (warning at the beginning of the standard)
• TECHNICAL NOTE: a result without the name of the digestion method (aqua regia, HNO₃, HBF₄/HF) is not comparable

Frequently asked questions