🍎 Determination of arsenic, cadmium, mercury and lead in foodstuffs by ICP-MS — the sample is pressure-digested according to EN 13805, the solution diluted, internal standards (rhodium, lutetium) and gold stabilizing mercury added, and the elements measured on selected isotopes with correction of isobaric and polyatomic interferences; calibration with at least three solutions at the same nitric acid concentration, PN-EN 15763

Food chemistry PN-EN 15763

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN 15763:2010 (English version), in full (our translation): “A method of inductively coupled plasma mass spectrometry (ICP-MS) is specified for the determination of arsenic, cadmium, mercury and lead content in foodstuffs”. We read the text of the standard in the sample of SIST EN 15763:2010 (the text of EN 15763:2009 without changes) from the title page through the contents, foreword and Clauses 1–5 up to and including 6.5 of Clause 6; Table 2 (isotopes, detection limits, interferences) we read in a text layout that mixes the columns, so we give from it only the isotopes and instrumental detection limits. Outside the sample remain the rest of Clause 6 (measurement), Clauses 7–11 (calculation, quality control, limit of quantification, precision, test report) and Annex A (results of the collaborative test).

ACCORDING TO THE TEXT OF EN 15763:2009 (Clauses 1–5, 6.1–6.5). The standard was prepared by CEN/TC 275 “Food analysis — Horizontal methods” (secretariat DIN). Scope (1): determination of arsenic, cadmium, mercury and lead in foodstuffs by ICP-MS; the collaborative study included among others carrots, fish homogenate, mushrooms (reference material), graham flour, simulated diet E (reference material), scampi, mussel and the reference material Tort-2, with mass fractions in dry matter: arsenic 0.06–21.5 mg/kg, cadmium 0.03–28.3 mg/kg, mercury 0.04–0.56 mg/kg, lead 0.01–2.4 mg/kg. Normative reference (2): EN 13805 (pressure digestion — entry on PN-EN 13805). Principle (3): the solution after pressure digestion is nebulized, the aerosol transferred to an argon inductively coupled plasma, where it is dried, atomized and ionized; the ions pass through the sampler and skimmer cones into the mass spectrometer, are separated by mass to charge ratio and counted by a pulse-count or analogue detector. Warning: the method may involve hazardous materials and operations; safety practices are established by the user. Reagents (4): the content of elements in reagents and water must not affect the result — ultrapure water and high-purity acid (e.g. cleaned by sub-boiling distillation) are recommended, as well as facilities preventing contamination (e.g. laminar flow benches); nitric acid at least 65 % (approx. 1.4 g/ml); commercial stock solutions 1000 mg/l of As, Au, Cd, Hg, Lu, Rh and Pb, preferably in diluted nitric acid; diluted mercury solution 10 mg/l; diluted multi-element solution (example: As 20 mg/l, Cd and Pb 10 mg/l); calibration solution (example: As 100 µg/l, Cd, Hg, Pb 50 µg/l each, in a PFA or quartz vessel); internal standards — rhodium and lutetium 1000 mg/l, and gold stabilizes mercury in solution and reduces memory effects; internal standards should cover the mass range and be negligible in the samples; diluted internal standard solution (example: Au, Rh, Lu 5 mg/l each); optimizing solution for mass calibration and tuning (e.g. Y, Rh, Ce, Pb) giving 10 000–100 000 counts; blank solution — water with the same amount of acid as the calibration solutions. Apparatus (5): stability of solutions depends on the vessel material — for trace and ultra-trace levels quartz or fluoropolymers (PTFE, PFA) are recommended; glass and PVC should not be used; ICP-MS with a mass range of 5–240 amu, resolution at least 1 amu at 5 % peak height (resolution 300) and sensitivity to achieve the detection limits of Table 2; reaction or collision cells and high-resolution sector field spectrometers may be used; mass flow controller for the nebulizer gas; argon. Procedure (6.1): pressure digestion according to EN 13805, dilution with water to a known volume; the nitric acid concentration in the calibration solutions similar to that in the test solution; if hydrogen peroxide was added for the digestion, it is not added to the calibration solutions. ICP-MS (6.2): the relationship of counts to concentration is linear over several orders of magnitude — the linear range is checked regularly for each element, and with a dual detector also the cross-calibration factor; example settings (Table 1): RF power 1500 W, carrier gas 1.2 l/min, plasma gas 15 l/min, auxiliary gas 1.0 l/min, water-cooled double-pass spray chamber at 2 °C, three replicates; generally a power of 1100–1500 W; before measurements warm-up of 20–30 min, daily tuning with the optimizing solution to maximum signal at low oxide rates (e.g. < 2 %) and low rates of doubly charged ions (e.g. < 2 %); with a collision or reaction cell optimization of the cell gas flow; check of sample feed and washout times — prolonged for large concentration differences. Interferences (6.3): non-spectral — viscosity and matrix load, salt deposits on the cones (salt content of the test solution generally not more than 0.2 % by mass), partly corrected by internal standards; memory effects after high concentrations, especially of mercury — longer washout and control blank solutions; spectral — isobaric and polyatomic. Instrumental detection limits (Table 2, 3 standard deviations of the blank solution): 75As — 0.5 µg/l; 111Cd — 0.5 µg/l, 114Cd — 0.2 µg/l; 200Hg — 1 µg/l, 202Hg — 0.2 µg/l; 206Pb and 207Pb — 0.3 µg/l, 208Pb — 0.2 µg/l; 197Au, 175Lu and 103Rh — internal standards. Isobaric interferences (6.3.2) are corrected by formulas based on natural isotope abundances: 114Cd − 0.02683 × 118Sn (abundance of 114Sn 0.65 %, 118Sn 24.22 %), 75As − 3.127 × (77Se + 0.322 × 78Se) or − 3.127 × (77Se − 0.826 × 82Se); these formulas are usually included in the instrument software. Polyatomic interferences (6.3.3) originate from the plasma gas, reagents and matrix; they depend on the plasma settings (e.g. oxide ratio) and the matrix; they are corrected by mathematical factors or by measuring the effect of the interfering element, and most are resolved by a sector field spectrometer at a resolution of up to 10 000. Calibration (6.4): at least three concentrations chosen according to the expected contents and the linear range, with a nitric acid concentration similar to the samples; example: As 1, 5 and 20 µg/l, Cd, Hg, Pb 0.5, 2.5 and 10 µg/l; solutions are prepared fresh. Preparation of measuring solutions (6.5): every solution shall contain the internal standard at the same concentration; for mercury gold is added; the digest is measured after dilution — example: 2 ml of test solution + 8 ml of water + 0.1 ml of diluted internal standard solution (approx. 10 µg/l Rh); the internal standard can also be added via a separate pump channel, to approx. 50 µg/l.

STATUS (catalogue card as of 03.10.2026). The card of PN-EN 15763:2010 (English version, published 28-01-2010, 18 pages, price group J) has no “Withdrawn” header: Food, Agriculture and Forestry Sector, KT 235 Food Analysis, ICS 67.050, “Introduces: EN 15763:2009 [IDT]”; the card has no “Supersedes” field. The PKN search (term “PN-EN 15763”, 03.10.2026) shows no other editions and no Polish version. In the iTeh catalogue (read 03.10.2026) the Slovenian adoption SIST EN 15763:2010 has the status “Published”.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read 03.10.2026). The number 15763 appears in 9 records at 5 laboratories: AB 381, AB 438, AB 444, AB 545, AB 1447. In the current scopes on the PCA website (read 03.10.2026, issues from 31.10.2025 to 01.10.2026) AB 438, AB 545 and AB 1447 give “PN-EN 15763:2010”, and AB 381 and AB 444 the designation alone without year, in a flexible scope (with the object “Food E”), next to the procedure PB/PACH/41 (AB 381) or the entry “Test procedures” (AB 444). The “Laboratories” tab (“PN-EN 15763”) shows the same 5 laboratories; checked with the tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (PCA items). Fish and fish products, meat and meat products — lead (0.020–1.30) mg/kg, cadmium (0.0010–1.10) mg/kg, arsenic (0.20–13.0) mg/kg, mercury (0.004–3.0) mg/kg (AB 545); milk and dairy products — cadmium, mercury, arsenic and lead as separate items, without a range at this standard (AB 1447); foods for particular nutritional uses — lead and arsenic (0.008–5.000) mg/kg, cadmium (0.004–5.000) mg/kg (AB 438); food in a flexible scope (AB 381) and food and feed in a flexible scope (AB 444). Technique everywhere: ICP-MS. AB 438 cites the standard also for nickel (0.044–5.000) mg/kg — together with its own procedure IB-23-A-804; the standard does not cover nickel (Clause 1). AB 444 applies it also to feed, while the text speaks of foodstuffs.

WHERE A SEEMINGLY CORRECT RESULT IS EASY. At digestion and reagents: ICP-MS is very sensitive, so contaminated acid, water or vessels of glass or PVC give a raised result already in the blank (4.1, 5.1). For mercury: without gold in the solution mercury is unstable and “remembered” by the system — after a sample with a high content the next one comes out too high; hence longer washout and control blank solutions (4.7, 6.3.1). At measurement of cadmium and arsenic: 114Sn overlaps 114Cd, ArCl+ and other polyatomic ions overlap 75As — without the formulas of Table 3 or a collision cell, food with a high tin or chloride content gives seemingly raised cadmium or arsenic (6.3.2, 6.3.3, Table 2). At the matrix: a salt content above approx. 0.2 % deposits on the cones and changes the sensitivity — the internal standard corrects this only partly (6.3.1). At calibration: the standard requires the nitric acid concentration in the calibration solutions to be similar to that in the test solution (6.1, 6.4). At the result: the ranges of the collaborative study (e.g. mercury up to 0.56 mg/kg, lead up to 2.4 mg/kg dry matter) are narrower than the upper limits of some accreditation ranges (e.g. mercury up to 3.0 mg/kg at AB 545, lead up to 5.000 mg/kg at AB 438) — the precision of Clause 10, which we did not read, relates to the matrices and levels of the study.

WHAT WE DO NOT GIVE. We did not read the rest of Clause 6, Clauses 7–11 and Annex A, so we do not give the calculation, quality control requirements, limits of quantification of the method, precision data or the content of the test report. Pressure digestion is described by EN 13805 — we do not repeat it here. We do not give maximum levels of these elements in food, because we did not read the texts of regulations for this entry.

Method principle

The solution of a food sample after pressure digestion is nebulized into an argon inductively coupled plasma, where the elements are atomized and ionized; the ions are separated by the mass spectrometer according to mass to charge ratio, and the number of counts on the selected isotope is proportional to the concentration. Internal standards (Rh, Lu) added at the same concentration to all solutions correct sensitivity changes caused by the matrix, gold stabilizes mercury, and overlaps of isotopes and polyatomic ions are corrected by formulas or a collision cell.

Applications

• Foodstuffs — arsenic, cadmium, mercury and lead; collaborative study: vegetables, fish, mushrooms, flour, seafood, mixed diet (Clause 1)
• Control of metal content in fish, meat, milk and foods for particular nutritional uses — in the accreditation scopes of 5 laboratories at PCA
• Feed and nickel — only as an extension used by individual laboratories, outside the scope of the text of the standard

Key parameters

Standard

Standard number

PN-EN 15763:2010

Title (PL)

Artykuły żywnościowe — Oznaczanie pierwiastków śladowych — Oznaczanie zawartości arsenu, kadmu, rtęci i ołowiu metodą spektrometrii mas z plazmą wzbudzoną indukcyjnie (ICP-MS) po mineralizacji ciśnieniowej

Title (EN)

Foodstuffs — Determination of trace elements — Determination of arsenic, cadmium, mercury and lead in foodstuffs by inductively coupled plasma mass spectrometry (ICP-MS) after pressure digestion

Step-by-step procedure

1. Digestion

   Pressure digestion according to EN 13805; dilute with water to a known volume. PN-EN 15763:2010 current (PKN catalogue card as of 03.10.2026).

2. Tuning of the ICP-MS

   Warm-up 20–30 min; optimizing solution — maximum signal, oxides and doubly charged ions e.g. < 2 %; with a collision cell optimization of the gas; feed and washout times.

3. Calibration

   At least three fresh solutions (e.g. As 1–20 µg/l, Cd, Hg, Pb 0.5–10 µg/l) at the same acid concentration as the samples; check of linearity.

4. Measuring solutions

   The same internal standard (Rh, Lu) in every solution and gold for mercury; e.g. 2 ml of test solution + 8 ml of water + 0.1 ml of internal standards.

5. Measurement and corrections

   Isotopes of Table 2, isobaric correction formulas of Table 3, control of the mercury memory effect with blank solutions. Calculation (Clause 7) outside the sample read.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The method may involve hazardous materials, operations and equipment — safety practices are established by the user (warning in Clause 3)
• Concentrated nitric acid is corrosive; solutions of arsenic, cadmium, mercury and lead are highly toxic
• ICP plasma: high voltage, UV radiation and hot gases — according to the instrument manufacturer’s instructions

Frequently asked questions