ISO 30011:2025

International
Standard
ISO 30011
Second edition
Workplace air — Determination of
2025-08
metals and metalloids in airborne
particulate matter by inductively
coupled plasma mass spectrometry
Air des lieux de travail — Détermination des métaux et
métalloïdes dans les particules en suspension dans l'air par
spectrométrie de masse avec plasma à couplage inductif
Reference number
© ISO 2025
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ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
3.1 Terms related to analysis .2
3.2 Terms related to inductively coupled plasma mass spectrometry (ICP-MS) .3
4 Principle . 6
5 Requirements . 6
6 Reagents . 6
7 Laboratory apparatus . 9
8 Procedure .10
8.1 Preparation of sample solutions .10
8.2 Method development . .10
8.2.1 General .10
8.2.2 Interferences .10
8.2.3 Sample introduction system .10
8.2.4 Analytical mass .10
8.2.5 Plasma conditions . 12
8.2.6 Instrument operating parameters . 13
8.2.7 Sample introduction rate . 13
8.2.8 Sample wash-out parameters . 13
8.2.9 Minimization of wall losses and contamination . 13
8.2.10 Calibration solutions .14
8.2.11 Selection of internal standards .14
8.3 Instrument performance checks . 15
8.3.1 Visual inspection . 15
8.3.2 Performance checks and fault diagnostics. 15
8.4 Routine analysis . 15
8.4.1 Dilution of sample solutions . 15
8.4.2 Addition of internal standards . 15
8.4.3 Determination of mercury . 15
8.4.4 Setting up the instrument .16
8.4.5 Analysis .16
8.5 Estimation of detection and quantification limits .17
8.5.1 Estimation of the instrumental detection limit .17
8.5.2 Estimation of the limit of detection and the limit of quantification .17
8.6 Quality control .17
8.6.1 Blank solutions .17
8.6.2 Quality control solutions .17
8.6.3 Internal standards .18
8.6.4 External quality assessment .18
8.7 Estimation of measurement uncertainty .18
9 Expression of results .18
10 Method performance . 19
10.1 Limits of detection and limits of quantification .19
10.2 Upper limits of the analytical range .19
10.3 Bias and precision .19
10.3.1 Analytical bias .19
10.3.2 Analytical precision . . . 20
10.4 Evaluation of measurement uncertainty for this method . 20

iii
11 Test report .20
11.1 Test records . 20
11.2 Laboratory report .21
Annex A (informative) ICP-MS principles and interferences .22
Annex B (informative) Examples of instrument operating parameters .25
Annex C (informative) Guidance on maintenance of ICP-MS instrumentation .27
Annex D (informative) Recalculation of metal and metalloid in air concentrations to reference
conditions .29
Annex E (informative) Method validation data (LOD, LOQ) for ICP-MS using various substrates .30
Bibliography .33

iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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Any trade name used in this document is information given for the convenience of users and does not
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For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 2, Workplace
atmospheres.
This second edition cancels and replaces the first edition (ISO 30011:2010), which has been technically
revised.
The main changes are as follows:
— references and definitions have been updated;
— data in Tables 2 and 4 have been updated;
— a new Annex B has been added containing example instrument operating parameters for standard and
collision modes (the previous Annexes B and C have been renumbered as Annexes C and D, respectively);
— a new Annex E has been added containing substrate-specific detection and quantification data.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
Introduction
The health of workers in many industries is at risk through exposure by inhalation of toxic metals and
metalloids. Industrial hygienists and other public health professionals need to determine the effectiveness
of measures taken to control workers' exposure, and this is generally achieved by taking workplace air
measurements. This document has been published in order to make available a method for making valid
ultra-trace exposure measurements for a wide range of metals and metalloids in use in industry. It is
intended for:
— agencies concerned with health and safety at work;
— industrial hygienists and other public health professionals;
— analytical laboratories;
— industrial users of metals and metalloids and their workers.
This document specifies a method for the determination of the mass concentration of metals and metalloids
in workplace air using quadrupole inductively coupled plasma mass spectrometry (ICP-MS). For many
metals and metalloids, analysis by ICP-MS is advantageous when compared to methods such as inductively
coupled plasma atomic emission spectrometry, due to its sensitivity and the presence of fewer spectral
interferences.
The execution of the provisions of this document and the interpretation of the results obtained is assumed
to be entrusted to appropriately qualified and experienced people.

vi
International Standard ISO 30011:2025(en)
Workplace air — Determination of metals and metalloids in
airborne particulate matter by inductively coupled plasma
mass spectrometry
1 Scope
This document specifies a procedure for the use of quadrupole inductively coupled plasma mass
spectrometry (ICP-MS), including single-quadrupole instruments and tandem ICP-MS/MS, for analysing
test solutions prepared from samples of airborne particulate matter collected as specified in ISO 15202-1.
Method development, performance checks and a routine analysis method are specified in this document
NOTE 1 Other types of ICP-MS (e.g. magnetic sector) are outside of the scope of this document.
Test solutions for analysis by this document are prepared as specified in ISO 15202-2.
This document is applicable to the assessment of workplace exposure to metals and metalloids for
[10] [8]
comparison with limit values (e.g. see EN 689 and ASTM E1370 ).
This document is not applicable to the determination of elemental mercury, since mercury vapour is not
collected using the sampling method specified in ISO 15202-1.
The procedure specified in this document is suitable for the assessment of exposure against the long-term
exposure limits for most of the metals and metalloids for which occupational exposure limit values have
−1
been set, when sampling at a typical flow rate of at least 2 l min for sampling times in the range 0,25 h to
8 h and for the assessment of exposure against the short-term exposure limits, where applicable.
NOTE 2 The procedure is subject to no significant spectral interferences (see Clause A.3), provided that suitable
analytical isotopes are used. However, inadequate matrix-matching can adversely affect results.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3585, Borosilicate glass 3.3 — Properties
ISO 8655-1, Piston-operated volumetric apparatus — Part 1: Terminology, general requirements and user
recommendations
ISO 8655-2, Piston-operated volumetric apparatus — Part 2: Pipettes
ISO 8655-5, Piston-operated volumetric apparatus — Part 5: Dispensers
ISO 8655-6, Piston-operated volumetric apparatus — Part 6: Gravimetric reference measurement procedure for
the determination of volume
ISO 15202-1, Workplace air — Determination of metals and metalloids in airborne particulate matter by
inductively coupled plasma atomic emission spectrometry — Part 1: Sampling
ISO 15202-2:2020, Workplace air — Determination of metals and metalloids in airborne particulate matter by
inductively coupled plasma atomic emission spectrometry — Part 2: Sample preparation

ISO 18158, Workplace air — Terminology
ISO 20581, Workplace air — General requirements for the performance of procedures for the measurement of
chemical agents
ISO 21832:2018, Workplace air — Metals and metalloids in airborne particles — Requirements for evaluation of
measuring procedures
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 18158 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Terms related to analysis
3.1.1
blank solution
solution prepared by taking a reagent blank (3.1.6), laboratory blank or field blank through the same
procedure used for sample dissolution
Note 1 to entry: A blank solution can require undergoing further operations, such as addition of an internal standard
(3.2.9), if the sample solutions (3.1.8) are subjected to such operations in order to produce test solutions (3.1.11) that
are ready for analysis.
3.1.2
calibration blank solution
calibration solution (3.1.4) prepared without the addition of any stock standard solution (3.1.10) or working
standard solution (3.1.12)
Note 1 to entry: The concentration of the analyte(s) of interest in the calibration blank solution is taken to be zero.
[11]
[SOURCE: EN 14902:2005, 3.1.3, modified — “without addition” has been replaced with “without the
addition” and “for which the concentration of the analyte(s) of interest is considered to be zero” has been
deleted from the definition.]
3.1.3
calibration curve
plot of instrument response versus concentration of standards
[13]
[SOURCE: United States Environmental Protection Agency, Document Number EPA 540-R-04-004 ,
modified — “A” has been deleted.]
3.1.4
calibration solution
solution prepared by dilution of the stock standard solution(s) (3.1.10) or working standard solution(s)
(3.1.12), containing the analyte(s) of interest at a concentration(s) that is suitable for use in calibration of the
analytical instrument
Note 1 to entry: The matrix-matching (3.2.12) technique is normally used when preparing calibration solutions.
3.1.5
linear dynamic range
range of concentrations over which the calibration curve (3.1.3) for an analyte is linear
Note 1 to entry: The linear dynamic range extends from the detection limit to the onset of calibration curvature.

3.1.6
reagent blank
reagents used in sample dissolution (3.1.7), in the same quantities used for preparation of the blank solution
(3.1.1) and sample solutions (3.1.8)
Note 1 to entry: The reagent blank is used to assess contamination from the laboratory environment and to
characterize spectral background from the reagents used in sample preparation.
3.1.7
sample dissolution
process of obtaining a solution containing all analytes of interest from a sample, which can involve complete
dissolution of the sample
[11]
[SOURCE: EN 14902:2005, 3.1.25, modified — the definition has been structurally revised and “the
analytes” has been changed to “all analytes”.]
3.1.8
sample solution
solution prepared from a sample by the process of sample dissolution (3.1.7)
Note 1 to entry: A sample solution (3.1.8) can require undergoing further operations, e.g. dilution or addition of an
internal standard(s) (3.2.9), in order to produce a test solution (3.1.11).
[11]
[SOURCE: EN 14902:2005, 3.1.22, modified — Note 1 to entry has been replaced.]
3.1.9
spiked media blank
media blank that is spiked with a known amount of the analyte(s) of interest
3.1.10
stock standard solution
solution used for preparation of working standard solutions (3.1.11) or calibration solutions (3.1.4), containing
the analyte(s) of interest at a certified concentration(s) traceable to national standards
3.1.11
test solution
blank solution (3.1.1) or sample solution (3.1.8) that has been subjected to all operations required to bring it
into a state in which it is ready for analysis
Note 1 to entry: “Ready for analysis” includes any required dilution or addition of an internal standard (3.2.9). If a
blank solution or sample solution is not subject to any further operations before analysis, it is a test solution.
3.1.12
working standard solution
solution, prepared by dilution of the stock standard solution(s) (3.1.10), that contains the analyte(s) of interest
at a concentration(s) better suited for preparation of calibration solutions (3.1.4) than the concentration(s) of
the analyte(s) in the stock standard solution(s) (3.1.10)
[11]
[SOURCE: EN 14902:2005, 3.1.32, modified — “than the concentration(s) of the analyte(s) in the stock
standard solution(s)” has been added.]
3.2 Terms related to inductively coupled plasma mass spectrometry (ICP-MS)
3.2.1
collision cell
chamber in the ion path between mass-to-charge ratio (m/z) separation elements, or between ion source
acceleration region and the first analyser, in tandem mass spectrometry in space configurations
Note 1 to entry: See Reference [14] for a more detailed description of collision cells and their function.

3.2.2
collision reaction cell
collision cell (3.2.1) for removal of interfering ions by ion/neutral reactions in inductively coupled plasma
mass spectrometry (ICP-MS)
Note 1 to entry: Collision reaction cells make use of kinetic energy dispersion, reaction chemistry or a combination of
both, to remove interfering species. A variety of applications of collision reaction cell technology are available.
Note 2 to entry: See Reference [14] for a more detailed description of collision reaction cells and their function.
3.2.3
corrosion-resistant sample introduction system
sample introduction system that features a nebulizer (3.2.13), spray chamber (3.2.16) and ICP torch (3.2.4)
injector tube (3.2.6) that are resistant to corrosion by hydrofluoric acid (6.2.6)
3.2.4
inductively coupled plasma torch
ICP torch
device used to support and introduce a sample into an ICP discharge
Note 1 to entry: An ICP torch usually consists of three concentric tubes, the outer two usually made from quartz.
3.2.5
inductively coupled plasma
ICP
high-temperature discharge generated in flowing argon by an alternating magnetic field induced by a radio
frequency (RF) load coil that surrounds the tube carrying the gas
3.2.6
injector
injector tube
centre tube
innermost tube of an ICP torch (3.2.4), through which the sample aerosol is introduced to the plasma
Note 1 to entry: The injector is usually made of quartz, ceramic material or platinum.
3.2.7
inner argon flow
nebulizer argon flow
sample argon flow
flow of argon gas that is directed through the nebulizer (3.2.13) and carries the sample aerosol through the
injector (3.2.6) and into the plasma
−1 −1
Note 1 to entry: The inner argon flow rate is typically 0,5 l min to 2 l min .
3.2.8
intermediate argon flow
auxiliary argon flow
flow of argon gas that is contained between the intermediate and centre [injector (3.2.6)] tubes of an ICP
torch (3.2.4)
−1 −1
Note 1 to entry: The intermediate argon flow rate is typically 0 l min to 2 l min .
3.2.9
internal standard
non-analyte element, present in all solutions analysed, the signal from which is used to correct for matrix
interferences (3.2.11) or improve analytical precision
3.2.10
load coil
length of metal tubing wound around the end of an ICP torch (3.2.4) and connected to the radio frequency
(RF) generator, used to inductively couple energy from the RF generator to the plasma discharge

3.2.11
matrix interference
matrix effect
non-spectral interference
interference of a non-spectral nature caused by a difference between the matrix of the calibration solutions
(3.1.4) and test solutions (3.1.11)
3.2.12
matrix-matching
technique used to minimize the effect of matrix interferences (3.2.11) on the analytical results, involving the
preparation of calibration solutions (3.1.4) in which the concentrations of acids and other major solvents and
solutes are matched with those in the test solutions (3.1.11)
3.2.13
nebulizer
device used to create an aerosol from a liquid
3.2.14
outer argon flow
plasma argon flow
coolant argon flow
flow of argon gas that is contained between the outer and intermediate tubes of an ICP torch (3.2.4)
−1 −1
Note 1 to entry: The outer argon flow rate is typically 7 l min to 15 l min .
3.2.15
spectral interference
interference caused by a species other than the analyte of interest
Note 1 to entry: A spectral interference can be atomic, polyatomic or doubly charged ion species.
40 + 40 +
EXAMPLE 1 An atomic interference is Ar on Ca .
40 16 + 56 +
EXAMPLE 2 A polyatomic interference is Ar O on Fe .
48 2+ 24 +
EXAMPLE 3 A doubly charged ion interference is Ti on Mg (see Reference [14]).
3.2.16
spray chamber
device placed between a nebulizer (3.2.13) and an ICP torch (3.2.4) whose function is to separate out aerosol
droplets according to their size, so that only very fine droplets pass into the plasma and large droplets are
drained or pumped to waste
3.2.17
tandem ICP-MS/MS
tandem inductively coupled plasma mass spectrometry/mass spectrometry
ICP-MS system with an additional quadrupole prior to the collision reaction cell (3.2.2)
Note 1 to entry: Tandem ICP-MS/MS is also known as triple-quadrupole ICP-MS (ICP-QQQ).
Note 2 to entry: See Reference [22] for additional information regarding tandem ICP-MS/MS.
3.2.18
tuning
analysis of a solution containing a range of isotopic masses to establish ICP-MS mass-scale accuracy, mass
resolution, signal intensity and precision prior to calibration
Note 1 to entry: See Reference [14] for a more detailed description of the tuning process.

4 Principle
4.1 Airborne particles containing metals and metalloids are collected using the method specified in
ISO 15202-1.
4.2 The collected sample and the filter are then treated to dissolve the metals and metalloids of interest
using one of the sample dissolution methods specified in ISO 15202-2.
4.3 The resultant solutions are analysed for the metals and metalloids of interest using single-quadrupole
ICP-MS or tandem ICP-MS/MS.
5 Requirements
The measuring procedure as a whole (specified in ISO 15202-1, ISO 15202-2 and this document) shall
conform with applicable requirements of ISO 20581 and ISO 21832 and with any relevant national standard
that specifies performance requirements for procedures for measuring chemical agents in workplace air.
6 Reagents
6.1 Water, from a purification system that delivers ultrapure water having a resistivity greater than
0,18 MΩ·m (usually expressed by manufacturers of water purification systems as 18 MΩ·cm).
6.2 Mineral acids, concentrated. Various types of mineral acid (6.2.2 to 6.2.6) are required for the
preparation of matrix-matched calibration solutions (see 6.4.2).
−1
The concentration of the metals and metalloids of interest shall be less than 0,1 mg l .
Mineral acids of higher purity can be required in order to obtain adequate detection limits for some metals
and metalloids, e.g. beryllium.
−1
6.2.1 Nitric acid, concentrated, ρ ≈1,42 g ml , with a mass fraction of w ≈ 70 %.
HNO HNO
3 3
WARNING — Concentrated nitric acid is corrosive and oxidizing and nitric acid fumes are irritant.
Avoid exposure by contact with the skin or eyes, or by inhalation of fumes. Use suitable personal
protective equipment (including suitable gloves, face shield or safety glasses, etc.) when working
with concentrated or dilute nitric acid.
−1
6.2.2 Perchloric acid, concentrated, ρ ≈ 1,67 g ml , with a mass fraction of w ≈ 70 %.
HCIO HCIO
4 4
WARNING — Concentrated perchloric acid is corrosive and oxidizing and perchloric acid fumes are
irritant. Avoid exposure by contact with the skin or eyes, or by inhalation of fumes. Use suitable
personal protective equipment (including suitable gloves, face shield or safety glasses, etc.) when
working with concentrated or dilute perchloric acid. For safety reasons, use perchloric acid in
limited quantities.
For analysis of metals and metalloids that are subject to interference from polyatomic ions containing
chlorine, the use of perchloric acid is not recommended unless a collision reaction cell is used.
−1
6.2.3 Hydrochloric acid, concentrated, ρ ≈ 1,18 g ml , with a mass fraction of w ≈ 36 %.
HCl HCl
WARNING — Concentrated hydrochloric acid is corrosive and oxidizing and hydrochloric acid fumes are
irritant. Avoid exposure by contact with the skin or eyes, or by inhalation of fumes. Use suitable personal
protective equipment (including suitable gloves, face shield or safety glasses, etc.) when working with
concentrated or dilute hydrochloric acid. Handle open vessels containing concentrated hydrochloric
acid under a fume hood. The vapour pressure of hydrochloric acid is high; therefore, beware of pressure
build-up in stoppered flasks when preparing mixtures of hydrochloric acid and water.

For analysis of metals and metalloids that are subject to interference from polyatomic ions containing
chlorine, the use of hydrochloric acid is not recommended unless a collision reaction cell is used.
−1
6.2.4 Sulfuric acid, concentrated, ρ ≈ 1,84 g ml , with a mass fraction of w ≈ 98 %.
HSO HSO
24 24
WARNING — Concentrated sulfuric acid is corrosive and causes burns. Avoid exposure by contact
with the skin or eyes. Use suitable personal protective equipment (including suitable gloves, face
shield or safety glasses, etc.) when working with concentrated or dilute sulfuric acid. Exercise great
caution when diluting sulfuric acid with water, since this process is very exothermic. Do not add
water to sulfuric acid, since it reacts violently when mixed in this manner. Prepare mixtures by
adding sulfuric acid to water.
For analysis of metals and metalloids that are subject to interference from polyatomic ions containing sulfur,
the use of sulfuric acid is not recommended unless a collision reaction cell is used.
−1
6.2.5 Hydrofluoric acid, concentrated, ρ ≈ 1,16 g ml , with a mass fraction of w ≈ 48 %.
HF HF
WARNING — Concentrated hydrofluoric acid is very toxic in contact with the skin and if inhaled
or swallowed. It is corrosive and causes severe burns. Take extreme care when using hydrofluoric
acid. Avoid contact with the skin or eyes, or inhalation of the vapour. It is essential that suitable
personal protective equipment (including suitable gloves, face shield, etc.) is used when working
with concentrated or dilute hydrofluoric acid. Handle open vessels containing concentrated
hydrofluoric acid under a fume hood. Ensure that the nature and seriousness of hydrofluoric acid
burns is understood before commencing work with this substance. Carry hydrofluoric acid burn
cream (containing calcium gluconate) at all times while working with hydrofluoric acid and for 24 h
afterwards. Apply the cream to any contaminated skin, after washing the affected area with copious
amounts of water. Obtain medical advice immediately in case of an accident.
NOTE The burning sensation associated with many concentrated acid burns is not immediately apparent on
exposure to hydrofluoric acid and can be felt only several hours later. Relatively dilute solutions of hydrofluoric
acid can also be absorbed through the skin, with serious effects similar to those resulting from exposure to the
concentrated acid.
When using hydrofluoric acid, it is recommended that a pair of disposable gloves be worn underneath
suitable rubber gloves to provide added protection for the hands.
For analysis of metals and metalloids that are subject to interference from polyatomic ions containing
fluorine, the use of hydrofluoric acid is not recommended unless a collision reaction cell is used.
6.3 Hydrogen peroxide (H O ), with a mass fraction of w ≈ 30 %.
2 2 HO
6.4 Stock standard solutions, for the preparation of calibration solutions.
6.4.1 Use commercial single-element or multi-element standard solutions with certified concentrations
traceable to national standards to prepare calibration solutions. The range of standard solutions used shall
include all the metals and metalloids of interest at a suitable concentration. Observe the manufacturer’s
expiration date or recommended shelf life.
NOTE Commercially available stock standard solutions for metals and metalloids have nominal concentrations of
−1 −1 −1 −1
100 mg l to 10 000 mg l for single element standards and 10 mg l to 1 000 mg l for multi-element standards.
6.4.2 Alternatively, prepare stock standard solutions from high-purity metals and metalloids or their salts.
The procedure used to prepare the solutions shall be fit for purpose and the calibration of any apparatus
used shall be traceable to national standards. Store in a suitable container, e.g. a polypropylene bottle (7.5).
The shelf life of stock solutions should be evaluated (e.g. during validation of the measurement method).

6.5 Working standard solutions and calibration solutions
6.5.1 Prepare a working standard solution or solutions, if desired, to include all the metals and metalloids
of interest at suitable concentrations. Accurately pipette an appropriate volume of each single-element stock
standard solution, or of multi-element stock standard solution (6.4), into a labelled, one-mark volumetric
flask (7.1). Add an appropriate volume of a suitable mineral acid (6.2) to ensure analyte stability. Dilute
almost to the mark with water (6.1), stopper, and swirl to mix. Allow to cool to room temperature, make up
to the mark with water, stopper and mix thoroughly.
Analytes that are grouped together in working standard solutions should be chosen carefully to ensure
chemical compatibility and to avoid spectral and physical interferences. The type and volume of each acid
added should be selected carefully to ensure analyte stability.
6.5.2 From the working standard solutions, prepare a set of calibration solutions, covering the range of
−1 −1
concentrations for each of the metals and metalloids of interest, typically between 1 µg l and 100 µg l . It is
recommended that a minimum of three calibration solutions be prepared. Also, prepare a calibration blank
solution (see 3.2.2). For each set of calibration solutions, accurately pipette appropriate volumes of working
standard solution (6.5.1) or stock standard solution (6.3), into individual, labelled volumetric flasks (7.2).
Add reagents, as required (see the next two paragraphs), to match the calibration solutions with that of
the test solutions (see 8.2.10.1). Dilute almost to the mark with water (6.1), stopper and swirl to mix. Allow
to cool to room temperature, make up to the mark with water, stopper and mix thoroughly. Prepare fresh
calibration solutions daily.
The type(s) and volume(s) of reagents required to matrix-match the calibration and test solutions depend
upon the sample dissolution method used. Table 1 presents information on which acids are used in the various
sample dissolution methods specified in ISO 15202-2. However, it is also necessary to take into account the
contribution to the overall acid concentration from acids present in the stock standard solution(s) used to
prepare the calibration solutions. Isobaric and physical interferences (see A.3.3 and A.3.4) should also be
considered in preparing these solutions.
Table 1 — Reagents required to prepare matrix-matched calibration solutions
Description of dissolution Acid(s) required to prepare matrix-matched
Sample dissolution method
method calibration solutions
Leaching for soluble metal
ISO 15202-2:2020, Annex B nitric acid (6.2.2)
and metalloid compounds
ISO 15202-2:2020, Annex C Hotplate dissolution nitric acid (6.2.2) and hydrochloric acid (6.2.4)
ISO 15202-2:2020, Annex D Ultrasonic agitation nitric acid (6.2.2)
sulfuric acid (6.2.5), hydrochloric acid (6.2.4) and
ISO 15202-2:2020, Annex E Hotplate dissolution
hydrogen peroxide (6.3)
nitric acid (6.2.2), perchloric acid (6.2.3), hydrochloric
ISO 15202-2:2020, Annex F Hotplate dissolution
acid (6.2.4) and hydrogen peroxide (6.3)
nitric acid (6.2.2), hydrofluoric acid (6.2.6) and optional
ISO 15202-2:2020, G.6.1 Closed vessel microwave
hydrochloric acid (6.2.4)
nitric acid (6.2.2), perchloric acid (6.2.3), hydrofluoric
ISO 15202-2:2020, G.6.2 Closed vessel microwave
acid (6.2.6) and optional hydrochloric acid (6.2.4)
nitric acid (6.2.2), or nitric acid (6.2.2) and perchloric
ISO 15202-2:2020, G.6.3 Closed vessel microwave acid (6.2.3) – can optionally include hydrochloric acid
(6.2.4)
ISO 15202-2:2020, Annex H Hot block (95 °C) dissolution nitric acid (6.2.2) and hydrochloric acid (6.2.4)
NOTE Sample dissolution methods using sulfuric acid or perchloric acid would not typically be used for
measurements by ICP-MS.
Consideration should be given to the need to matrix-match the calibration with respect to hydrofluoric
acid (6.2.6) if the test solutions are prepared from samples collected on quartz fibre filters using a sample
dissolution method that uses hydrofluoric acid. In general, matrix-matching with hydrofluoric acid is best

avoided (see WARNING in 6.2.6), but can be necessary in cases where its action on quartz fibre filters results
in high concentrations of silicon (and possibly other elements, such as aluminium, calcium and sodium)
in the test solutions. In these cases, the calibration solutions can be prepared by addition of appropriate
volumes of working standard solution (6.5.1) or stock standard solution(s) (6.4) to unused quartz fibre
filters carried through the sample dissolution method described in the relevant annex of ISO 15202-2. Under
such circumstances, plastic volumetric labware compatible with hydrofluoric acid and a corrosion-resistant
sample introduction system have to be used.
Additional information on sample preparation can be found in References [24] and [25].
6.6 Internal standard stock solutions
6.6.1 Use a commercially available single-element standard solution or solutions. The standard solution(s)
shall include the element(s) to be used as internal standard(s) at a suitable concentration and the matrix of
the single-element standard solution(s) used for addition of internal standard(s) shall be compatible with
the metals and metalloids of interest. See 8.2.11 for selection of internal standard elements.
6.6.2 Alternatively, prepare single-element stock standard solution(s) from high purity metals or their salts.
6.7 Argon, suitable for use in ICP-MS.
7 Laboratory apparatus
Usual laboratory equipment and in particular the following.
7.1 One-mark centrifuge tubes, single-use, low density polyethylene, typically 50 ml, conforming with
the requirements of ISO 1042 class A.
7.2 One-mark volumetric flasks, conforming with the requirements of ISO 1042 class A, made of
borosilicate glass 3,3 conforming with the requirements of ISO 3585, cleaned before use by soaking in nitric
acid, diluted 1 + 9, for at least 24 h and then rinsed thoroughly with water (6.1).
NOTE Either one-mark centrifuge tubes (7.1) or one-mark volumetric flasks (7.2) can be used.
7.3 Disposable tubes, plastic, compatible with the autosampler tube racks of the ICP-MS instrument.
NOTE See 8.2.9 for guidance on the use of tubes to minimize the potential for wall losses and contamination.
7.4 Piston-operated volumetric instru
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