IEC 62321-5:2013

IEC 62321-5 ®
Edition 1.0 2013-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
HORIZONTAL STANDARD
NORME HORIZONTALE
Determination of certain substances in electrotechnical products –
Part 5: Cadmium, lead and chromium in polymers and electronics and cadmium
and lead in metals by AAS, AFS, ICP-OES and ICP-MS

Détermination de certaines substances dans les produits électrotechniques –
Partie 5: Du cadmium, du plomb et du chrome dans les polymères et les
produits électroniques, du cadmium et du plomb dans les métaux par AAS,
AFS, ICP-OES et ICP-MS
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IEC 62321-5 ®
Edition 1.0 2013-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
HORIZONTAL STANDARD
NORME HORIZONTALE
Determination of certain substances in electrotechnical products –

Part 5: Cadmium, lead and chromium in polymers and electronics and cadmium

and lead in metals by AAS, AFS, ICP-OES and ICP-MS

Détermination de certaines substances dans les produits électrotechniques –

Partie 5: Du cadmium, du plomb et du chrome dans les polymères et les

produits électroniques, du cadmium et du plomb dans les métaux par AAS,

AFS, ICP-OES et ICP-MS
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.020; 43.040.10 ISBN 978-2-83220-842-7

– 2 – 62321-5 © IEC:2013
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms, definitions and abbreviations . 8
3.1 Terms and definitions . 8
3.2 Abbreviations . 9
4 Reagents . 9
4.1 General . 9
4.2 Reagents . 9
5 Apparatus . 11
5.1 General . 11
5.2 Apparatus . 12
6 Sampling . 13
6.1 General . 13
6.2 Test portion . 13
6.2.1 Polymers . 13
6.2.2 Metals . 13
6.2.3 Electronics . 13
7 Procedure. 13
7.1 Polymers . 13
7.1.1 General . 13
7.1.2 Dry ashing method . 14
7.1.3 Acid digestion method . 15
7.1.4 Microwave digestion . 15
7.2 Metals . 16
7.2.1 General . 16
7.2.2 Common methods of sample digestion. 17
7.2.3 Samples containing Zr, Hf, Ti, Ta, Nb or W . 17
7.2.4 Samples containing Sn . 17
7.3 Electronics . 18
7.3.1 General . 18
7.3.2 Digestion with aqua regia . 18
7.3.3 Microwave digestion . 19
7.4 Preparation of reagent blank solution . 20
8 Calibration . 20
8.1 General . 20
8.2 Preparation of the calibration solution . 20
8.3 Development of the calibration curve . 20
8.4 Measurement of the sample . 21
9 Calculation . 22
10 Precision . 22
11 Quality control . 24
11.1 General . 24
11.2 Limits of detection (LOD) and limits of quantification (LOQ) . 25

62321-5 © IEC:2013 – 3 –
Annex A (informative) Practical application of determination of Cd , Pb and Cr in polymers
and electronics and Cd and Pb in metals by AAS, AFS, ICP-OES and ICP-MS . 27
Annex B (informative) Results of international interlaboratory study nos. 2 (IIS2) and
4A (IIS 4A) . 33
Bibliography . 36

Figure A.1 – Background correction . 31

Table 1 – Repeatability and reproducibility . 22
Table 2 – Acceptance criteria of items for the quality control . 24
Table 3 – Method detection limit = t × s . 26
n–1
Table A.1 – Spectral interferences for the wavelengths of Cd and Pb . 28
Table A.2 – Spectral interferences for the wavelengths of Cr . 29
Table A.3 – Examples of mass/charge (m/z) ratios . 30
Table A.4 – Examples of wavelengths for AAS . 30
Table A.5 – Examples of wavelengths for AFS . 31
Table A.6 – Program for microwave digestion of samples . 32
Table B.1 – Statistical data for AAS . 33
Table B.2 – Statistical data for AFS . 33
Table B.3 – Statistical data for ICP-OES . 34
Table B.4 – Statistical data for ICP-MS . 35

– 4 – 62321-5 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DETERMINATION OF CERTAIN SUBSTANCES
IN ELECTROTECHNICAL PRODUCTS –

Part 5: Cadmium, lead and chromium in polymers and electronics
and cadmium and lead in metals by AAS, AFS, ICP-OES and ICP-MS

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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agreement between the two organizations.
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consensus of opinion on the relevant subjects since each technical committee has representation from all
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62321-5 has been prepared by IEC technical committee 111:
Environmental standardization for electrical and electronic products and systems.
It has the status of a horizontal standard in accordance with IEC Guide 108.
The first edition of IEC 62321:2008 was a 'stand-alone' standard that included an introduction,
an overview of test methods, a mechanical sample preparation as well as various test method
clauses.
This first edition of IEC 62321-5 is a partial replacement of IEC 62321:2008, forming a
structural revision and generally replacing Clauses 8 to 10, as well as Annexes F, G and H.
Future parts in the IEC 62321 series will gradually replace the corresponding clauses from
IEC 62321:2008. Until such time as all parts are published, however, IEC 62321:2008 remains
valid for those clauses not yet re-published as a separate part.

62321-5 © IEC:2013 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
111/297/FDIS 111/307/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62321 series can be found on the IEC website under the general
title: Determination of certain substances in electrotechnical products.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – 62321-5 © IEC:2013
INTRODUCTION
The widespread use of electrotechnical products has drawn increased attention to their impact
on the environment. In many countries this has resulted in the adaptation of regulations
affecting wastes, substances and energy use of electrotechnical products.
The use of certain substances (e.g. lead (Pb), cadmium (Cd) and polybrominated diphenyl
ethers (PBDE’s)) in electrotechnical products, is a source of concern in current and proposed
regional legislation.
The purpose of the IEC 62321 series is therefore to provide test methods that will allow the
electrotechnical industry to determine the levels of certain substances of concern in
electrotechnical products on a consistent global basis.
WARNING – Persons using this International Standard should be familiar with normal
laboratory practice. This standard does not purport to address all of the safety
problems, if any, associated with its use. It is the responsibility of the user to establish
appropriate safety and health practices and to ensure compliance with any national
regulatory conditions.
62321-5 © IEC:2013 – 7 –
DETERMINATION OF CERTAIN SUBSTANCES
IN ELECTROTECHNICAL PRODUCTS –

Part 5: Cadmium, lead and chromium in polymers and electronics
and cadmium and lead in metals by AAS, AFS, ICP-OES and ICP-MS

1 Scope
This Part of IEC 62321 describes the test methods for lead, cadmium and chromium in
polymers, metals and electronics by AAS, AFS, ICP-OES and ICP-MS.
This standard specifies the determination of the levels of cadmium (Cd), lead (Pb) and
chromium (Cr) in electrotechnical products. It covers three types of matrices:
polymers/polymeric workpieces, metals and alloys and electronics.
This standard refers to the sample as the object to be processed and measured. What the
sample is or how to get to the sample is defined by the entity carrying out the tests. Further
guidance on obtaining representative samples from finished electronic products to be tested
for levels of regulated substances may be found in IEC 62321-2. It is noted that the selection
and/or determination of the sample may affect the interpretation of the test results.
This standard describes the use of four methods, namely AAS (atomic absorption
spectrometry), AFS (atomic fluorescence spectrometry), ICP-OES (inductively coupled plasma
optical emission spectrometry), and ICP-MS (inductively coupled plasma mass spectrometry)
as well as several procedures for preparing the sample solution from which the most
appropriate method of analysis can be selected by experts.
As the hexavalent-Cr analysis is sometimes difficult to determine in polymers and electronics,
this standard introduces the screening methods for chrome in polymers and electronics
except from AFS. Chromium analysis provides information about the existence of hexavalent-
Cr in materials. However, elemental analyses cannot selectively detect hexavalent-Cr; it
determines the amount of Cr in all oxidation states in the samples. If Cr amounts exceed the
hexavalent-Cr limit, testing for hexavalent-Cr should be performed.
The test procedures described in this standard are intended to provide the highest level of
accuracy and precision for concentrations of Pb, Cd and Cr that range, in the case of ICP-
OES and AAS, from 10 mg/kg for Pb, Cd and Cr, in the case of ICP-MS, from 0,1 mg/kg for
Pb and Cd in the case of AFS, the range is from 10 mg/kg for Pb and 1.5 mg/kg for Cd. The
procedures are not limited for higher concentrations.
This standard does not apply to materials containing polyfluorinated polymers because of
their stability. If sulfuric acid is used in the analytical procedure, there is a risk of losing Pb,
thus resulting in erroneously low values for this analyte. In addition, sulfuric acid and
hydrofluoric acid are not suitable for determining Cd by AFS, because it disturbs the reduction
of Cd.
Limitations and risks occur due to the solution step of the sample, e.g. precipitation of the
target or other elements may occur, in which case the residues have to be checked separately
or dissolved by another method and then combined with the test sample solution.

– 8 – 62321-5 © IEC:2013
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 62321-1, Determination of certain substances in electrotechnical products – Part 1:
Introduction and overview
IEC 62321-2, Determination of certain substances in electrotechnical products – Part 2:
Disassembly, disjointment and mechanical sample preparation
IEC 62321-3-1, Determination of certain substances in electrotechnical products – Part 3-1:
Screening – Lead, mercury, cadmium, total chromium and total bromine using X-ray
fluorescence spectrometry
ISO 3696, Water for analytical laboratory use – Specification and test methods
ISO 5961, Water quality – Determination of cadmium by atomic absorption spectrometry
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62321-1, as well as
the following, apply.
3.1.1
accuracy
closeness of agreement between a test result and an accepted reference value
3.1.2
calibration standard
substance in solid or liquid form with known and stable concentration(s) of the analyte(s) of
interest used to establish instrument response (calibration curve) with respect to analyte(s)
concentration(s)
3.1.3
calibration solution
solution used to calibrate the instrument prepared either from (a) stock solution(s) or from a
(certified) reference material
3.1.4
certified reference material
reference material, accompanied by documentation issued by an authoritative body and
providing one or more specified property values with associated uncertainties and
traceabilities using valid procedures
3.1.5
laboratory control sample
known matrix spiked with compound(s) representative of the target analytes, used to
document laboratory performance
___________
To be published.
62321-5 © IEC:2013 – 9 –
[Based on US EPA SW-846] [1]
3.1.6
reagent blank solution
prepared by adding to the solvent the same amounts of reagents as those added to the test
sample solution (same final volume)
3.1.7
test sample solution
solution prepared with the test portion of the test sample according to the appropriate
specifications such that it can be used for the envisaged measurement
3.2 Abbreviations
CCV continuing calibration verification
LCS laboratory control sample
4 Reagents
4.1 General
For the determination of elements at trace level, the reagents shall be of adequate purity. The
concentration of the analyte or interfering substances in the reagents and water shall be
negligible compared to the lowest concentration to be determined.
All reagents for ICP-MS analysis, including acids or chemicals used shall be of high-purity:
-6
trace metals shall be less than 1 × 10 % in total.
For measurements by ICP-OES and ICP-MS, the memory effect occurs in cases where high
concentrations of elements are introduced. Dilution of the sample solution is required for high
levels of each element. If the memory effect is not decreased by dilution, thorough washing of
the equipment is required.
4.2 Reagents
The following reagents are used:
a) Water: Grade 1 specified in ISO 3696 used for preparation and dilution of all sample
solutions.
b) Sulfuric acid:
1) Sulfuric acid: ρ(H SO ) = 1,84 g/ml, a mass fraction of 95 %, “trace metal” grade.
2 4
2) Sulfuric acid: dilution (1:2): dilute 1 volume of concentrated sulfuric acid (4.2 b 1)) with
2 volumes of water (4.2 a))
c) Nitric acid:
1) Nitric acid: ρ(HNO ) = 1,40 g/ml, a mass fraction of 65 %, “trace metal” grade.
2) Nitric acid, a mass fraction of 10 %, “trace metal” grade.
3) Nitric acid: 0,5 mol/l, “trace metal” grade.
4) Nitric acid: dilution (1:2): dilute 1 volume of concentrated nitric acid (4.2.c 1)) with 2
volumes of water (4.2 a))
d) Hydrochloric acid:
1) Hydrochloric acid, ρ(HCl) = 1,19 g/ml, a mass fraction of 37 %, “trace metal” grade.
___________
Figures in square brackets refer to the Bibliography.

– 10 – 62321-5 © IEC:2013
2) Hydrochloric acid: dilution (1:2): dilute 1 volume of concentrated hydrochloric acid
(4.2.d) 1)) with 2 volumes of water (4.2 a))
3) Hydrochloric acid, a mass fraction of 5 %, “trace metal” grade.
4) Hydrochloric acid, a mass fraction of 10 %, “trace metal” grade.
e) Hydrofluoric acid: ρ(HF) = 1,18 g/ml, a mass fraction of 40 %, “trace metal” grade.
f) Fluoroboric acid: HBF , a mass fraction of 50 %, “trace metal” grade.
g) Perchloric acid: ρ(HClO ) =1,67 g/ml, a mass fraction of 70 %, “trace metal” grade.
h) Phosphoric acid: ρ(H PO ) =1,69 g/ml, more than a mass fraction of 85 %, “trace metal”
3 4
grade.
i) Hydrobromic acid: ρ(HBr) = 1,48 g/ml, a mass fraction of 47 % to 49 %, “trace metal”
grade.
j) Boric acid (H BO ): 50 mg/ml, a mass fraction of 5 %, “trace metal” grade.
3 3
k) Hydrogen peroxide: ρ(H O ) = 1,10 g/ml, a mass fraction of 30 %, “trace metal” grade.
2 2
l) Mixed acid:
1) Mixed acid 1, two parts hydrochloric acid (4.2 d) 1)), one part nitric acid (4.2 c)1)) and
two parts water (4.2 a)).
2) Mixed acid 2, one part nitric acid (4.2 c) 1)) and three parts hydrofluoric acid (4.2 e)).
3) Mixed acid 3, three parts hydrochloric acid (4.2 d) 1)) and one part nitric acid (4.2 c)1)).
m) Potassium hydroxide (KOH), “trace metal” grade.
n) Potassium borohydride (KBH ), “trace metal” grade.
o) Potassium ferricyanide (K (Fe(CN) )), “trace metal” grade.
3 6
p) Oxido – reduction agent: a mass fraction of 1,5 % KBH – a mass fraction of 1 %
K (Fe(CN ) in a mass fraction of 0,2 % KOH.
3 6
Add approximately 800 ml of water (4.2 a)) to a 1 000 ml volumetric flask (5.2 e)3))
followed by the addition of 2 g potassium hydroxide (4.2 m)). Add 15 g potassium
borohydride (4.2 n)) and 10 g potassium ferricyanide (4.2 o)), stir to dissolve. Fill up to the
mark with water (4.2 a)). Prepare daily.
q) Reducing agents:
1) Reducing agent 1, a mass fraction of 3 % KBH in a mass fraction of 0,2 % KOH:
Add approximately 800 ml of water (4.2 a)) to a 1 000 ml volumetric flask (5.2 e) 3))
followed by the addition of 2 g potassium hydroxide (4.2 m)). Add 30 g of potassium
borohydride (4.2 n)), stir to dissolve. Fill up to the mark with water (4.2 a)). Prepare
daily.
2) Reducing agent 2, a mass fraction of 4 % KBH in a mass fraction of 0,8 % KOH.
Add approximately 800 ml of water (4.2 a)) to a 1 000 ml volumetric flask (5.2 e) 3)),
followed by the addition of 8 g potassium hydroxide (4.2 m)). Add 40 g of potassium
borohydride (4.2 n)), stir to dissolve. Fill up to the mark with water (4.2 a)). Prepare
daily.
r) Carrier flow:
1) Carrier flow 1, a mass fraction of 1,5 % HCl.
2) Carrier flow 2, a mass fraction of 1 % HCl.
s) Thiourea ((NH ) CS) solution, a mass fraction of 10 % . Prepare daily.
2 2
t) Masking agent:
1) Masking agent 1, a mass fraction of 5 % oxalic acid – a mass fraction of 5 %
potassium sulfocyanate (KSCN) – a mass fraction of 0,5 % o-phenanthroline (C H N )
12 8 2
solution:
Add 10 g oxalic acid, 10 g potassium sulfocyanate and 1 g o-phenanthroline to 200 ml
of water (4.2 a)). Heat at low temperature and stir to dissolve, taking care to avoid

62321-5 © IEC:2013 – 11 –
boiling of the solution. Use the solution before the solid crystallizes out. Discard the
solution when it becomes dark and prepare a fresh one.
2) Masking agent 2, a mass fraction of thiourea 10 % – ascorbic acid a mass fraction of
10 % solution.
Dissolve 10 g thiourea and 10 g ascorbic acid in 100 ml of water. Prepare daily.
u) Cobalt solution, 50 mg/l.
v) Stock solution:
1) Stock solution with 1 000 mg/l of Pb.
2) Stock solution with 1 000 mg/l of Cd.
3) Stock solution with 1 000 mg/l of Cr.
4) Stock solution with 10 000 mg/l of Fe.
5) Stock solution 10 000 mg/l of Cu.
w) Internal standard stock solution.
1) Internal standard elements that do not interfere with the target element are used for
ICP-OES and ICP-MS. Also, the presence of these internal standard elements in the
sample solution shall be at negligible levels. Sc, In, Tb, Lu, Re, Rh, Bi and Y may be
used as internal standard elements.
2) For use with ICP-OES, Sc or Y is recommended. The recommended concentration is
1 000 mg/l.
3) For use with ICP-MS, Rh is recommended. The recommended concentration is
1 000 µg/l.
The toxicity of each reagent in this method has not been precisely defined; however, each
chemical compound should be treated as a potential health hazard. From this viewpoint,
exposure to these chemicals at the lowest possible level by whatever means available is
recommended.
Preparation methods involve the use of strong acids, which are corrosive and cause burns.
Laboratory coats, gloves and safety glasses should be worn when handling acids.
Nitric acid gives off toxic fumes. Always carry out digestion in a fume cupboard, and also
when adding acid to samples because of the possibility of toxic gases being released.
The exhaust gases from the plasma should be ducted away by an efficient fume extraction
system.
Special precautionary measures should be taken when hydrofluoric acid is used, i.e. HF
antidote gel (2,5 % calcium gluconate in a water-soluble gel) for first aid treatment of HF
burns on the skin.
Analytical grade reagents may be used as an alternative except when utilizing ICP-MS
methods.
5 Apparatus
5.1 General
In general, the collection and storage of glassware are critical parts of trace analysis,
regardless of the type of sample to be analysed. Because of the sensitivity of the Pb, Cd and
Cr analysis techniques described, each individual sampling step shall be carried out with
great care. All sampling, storage and manipulation apparatus shall be metal-free. Soak all
glassware in 10 % nitric acid (4.2 c) 2)) for 24 h at room temperature, and then rinse
thoroughly with water (4.2 a)).

– 12 – 62321-5 © IEC:2013
5.2 Apparatus
The following equipment shall be used:
a) Analytical balance: capable of measuring accurately to 0,000 1 g.
b) HF-resistant sample introduction system: system in which the sample insertion section and
torch have been treated for resistance to HF.
c) Argon gas: gas with purity of over 99,99 %.
d) Acetylene gas: gas with purity of over 99,99 %.
e) Glassware: all glassware shall be cleaned with 10 % nitric acid (4.2 c) 2)) before use:
1) Kjeldahl flask: 100 ml;
2) Beakers: such as 100 ml, 200 ml, 500 ml etc.;
3) Volumetric flasks: such as 50 ml, 100 ml, 200 ml, 500 ml, 1 000 ml, etc. Where
appropriate, other types of volumetric equipment with acceptable precision and
accuracy can be used as an alternative to volumetric flasks.
4) Pipettes: such as 1 ml, 5 ml, 10 ml, 20 ml, etc.;
5) Watch glass.
f) Crucibles of platinum: such as 50 ml, 150 ml, etc.
g) Crucibles of porcelain: such as 50 ml, 150 ml, etc.
h) PTFE/PFA equipment (polytetrafluoroethylene (PTFE)/perfluoro alkoxy alkane resin (PFA):
all equipment shall be cleaned with 10 % nitric acid (4.2 c) 2)) before use:
1) Beakers: such as 100 ml, 200 ml, 500 ml etc.;
2) Covers for breakers;
3) Volumetric flasks: such as 100 ml, 200 ml, 500 ml, etc.
i) Micropipettes: such as 10 µl, 100 µl, 200 µl, 500 µl, 1 000 µl etc.
j) Containers: for storage of standard solution and calibrant.
Containers to be made of high-density polyethylene (PE-HD) or PFA bottles.
k) For determination at the ultra-trace level, containers made of perfluoro alkoxy alkane resin
(PFA) or perfluoro (ethylene-propylene) plastic (FEP) shall be used. In either case, the
user shall confirm the suitability of the container selected.
l) Electric hot plate or heated sand bath.
m) Muffle furnace: capable of being maintained at 550 °C ± 25 °C.
n) Bunsen burner or similar type of gas burner.
o) Digestion with aqua regia: digestion apparatus equipped with a time and temperature
microcontroller unit, a heating block thermostat, a set of vessels, each equipped with
reflux coolers and absorption vessels.
p) Microwave digestion system equipped with a sample holder and high-pressure
polytetrafluoroethylene/tetrafluoroethylene modified (PTFE/TFM) or perfluoro alkoxy
alkane resin/tetrafluoroethylene modified (PFA/TFM) or other vessels based on
fluorocarbon materials.
There are many safety and operational recommendations specific to the model and
manufacturer of the microwave equipment used in individual laboratories. The analyst is
required to consult the specific equipment manual, manufacturer and literature for proper
and safe operation of the microwave equipment and vessels.
q) Heat-resistant thermal insulation board.
r) Glass microfibre filter (borosilicate glass), pore size 0,45 µm and a suitable filter cup.
s) Inductively coupled plasma optical atomic emission spectrometer (ICP-OES).
t) Inductively coupled plasma mass spectrometer (ICP-MS).
u) Atomic absorption spectrometer (AAS).

62321-5 © IEC:2013 – 13 –
v) Atomic fluorescence spectrometer (AFS).
6 Sampling
6.1 General
The different test methods, which can be used as alternatives according to this International
Standard, need different amounts of sample to obtain the required quality of results. Generally
it is advisable to start with the highest amount of sample suitable for the chosen procedure.
In the case of electronics, the sample shall first be destroyed mechanically by appropriate
means (e.g. grinding, milling, mill cutting) before chemical dissolution of the powder can start.
To ensure representative sample taking at this stage, a certain particle size as a function of
the starting amount of sample is required (see IEC 62321-2).
It is recommended to analyse aqueous sample solutions directly after sample preparation. If
this is not possible, it is highly recommended to stabilize the solutions in an adequate way,
and to store the solutions no longer than 180 days at ambient temperature.
6.2 Test portion
6.2.1 Polymers
For acid digestion, weigh 400 mg of sample that has been ground, milled or cut to the nearest
0,1 mg. For the dry ashing method, or for microwave digestion method, weigh 200 mg of
sample that has been ground, milled or cut is measured to the nearest 0,1 mg.
6.2.2 Metals
Weigh 1 g of sample to the nearest 0,1 mg and is placed in a glass beaker or a PTFE/PFA
beaker (5.2 h) 1)) when using HF (4.2 e)). For AFS, the quantity of the sample measured is
0,2 g.
6.2.3 Electronics
For digestion with aqua regia, weigh 2 g of the ground sample (maximum particle size:
250 µm) to the nearest 0,1 mg level. For microwave digestion method, weigh 200 mg of
ground sample (maximum particle size: 250 µm) to the nearest 0,1 mg.
7 Procedure
7.1 Polymers
7.1.1 General
The samples are pre-cut and/or milled to an appropriate size for the method selected
according to the procedure described in Clause 6. Depending on the particular method of
preparing the test solution, sample amounts may vary, as described in detail in this clause.
The test solution may be prepared by dry ashing or by sample digestion with acids such as
nitric acid or sulfuric acid. Acid digestion can be carried out in a closed system using a
microwave digestion vessel. Depending on the presence of particular elements, the details of
the approach to digestion varies – procedures are given in this clause. Information on the
presence of these elements may have been gained from previous screening experiments
(IEC 62321-3-1). Finally, in the digestion solution obtained, Pb, Cd and Cr are determined by
ICP-OES, ICP-MS or by AAS. In the case of AFS, before determination the digestion solution
should be treated additionally for Pb and Cd.

– 14 – 62321-5 © IEC:2013
7.1.2 Dry ashing method
If the sample does not contain halogen compounds (information may be available from
previous screening experiments), the following steps shall be carried out:
a) Measure the sample into a crucible (5.2 g)) mounted in the hole in the heat-resistant
thermal insulation board (5.2 q)).
b) Heat the crucible (5.2 g)) gently with the burner (5.2 n)) in a hood for proper ventilation,
taking care that the sample does not ignite.
c) When the sample has decomposed to a charred mass, heating is gradually increased until
the volatile decomposition products have been substantially expelled and a dry
carbonaceous residue remains.
d) Transfer the crucible and its contents to the muffle furnace (5.2 m)) at 550 °C ± 25 °C with
the door left slightly open to provide sufficient air to oxidize the carbon.
e) Heating is continued until the carbon is completely oxidized and a clean ash is obtained.
f) Remove the crucible (5.2 g)) and its contents from the furnace (5.2 m)) and allow to cool
to ambient temperature. For AFS, see 7.1.2 h).
g) Add 5 ml of nitric acid (4.2 c) 1)), transfer the resulting solution to a 50 ml volumetric flask
(5.2 h) 3)) and fill with water (4.2 a)) to the mark. This is the concentrate sample solution.
Dilute the concentrate sample solution with water (4.2 a)) to the appropriate concentration
level for each measurement apparatus. If an internal standard (4.2 w)) is to be used, it
shall be added before filling. For a final volume of 50 ml, add 500 µl of internal standard
(4.2 w)) for ICP-OES and for ICP-MS (after a 1:1 000 dilution step) before filling.
h) Transfer the resulting solution to a 100 ml volumetric flask (5.2 h) 3)) and fill with water
(4.2 a)) to the mark. Pipet a 2,50 ml portion of the solution to a 100 ml beaker (5.2 e) 2)).
Place the beaker on an electric hot plate (5.2 l)). Heat at low temperature until the solution
dries completely. Rinse the inside wall of the beaker with some water (4.2 a)), add either
1,0 ml (for determining Cd) or 1,5 ml (for determining Pb) of hydrochloric acid solution (4.2
d) 2)). Heat up slightly to dissolve the salts in the beaker. Cool down the solution to room
temperature, and transfer it to a 50 ml volumetric flask (5.2 h) 3)). The solution in the
50 ml flask will be treated in the following steps respectively:
– For determination of Pb, fill with water (4.2 a)) to the mark and mix well.
– For determination of Cd, provided the sample is without impurities such as copper, iron,
zinc or nickel etc., add 1,0 ml of cobalt solution (4.2 u)) and 5,0 ml of thiourea solution
(4.2 s)) to the volumetric flask. If the sample contains those foreign-metal impurities,
then substitute 5,0 ml of thiourea solution (4.2 s) by 10,0 ml of masking agent 2 (4.2 t)
2)). Fill with water (4.2 a)) to the mark and mix well.
If the sample contains significant amounts of halogen compounds (information may be
available from previous screening experiments), the following steps shall be carried out:
i) Measure the sample into a crucible (5.2 g)).
j) Add 5 ml to 15 ml of sulfuric acid (4.2 b) 1)) and heat the crucible (5.2 g)) and its contents
slowly on a hot plate or sand bath (5.2 l)) until the plastic melts and blackens.
k) After cooling, add 5 ml of nitric acid (4.2 c) 1)) and continue heating until the plastic
degrades completely and white fumes are generated.
l) After cooling, the crucible (5.2 g)) is placed in a muffle furnace (5.2 m)) maintained at
550 °C ± 25 °C and the sample is evaporated, dried and ashed until the carbon has been
completely incinerated.
m) After ashing, add 5 ml of nitric acid (4.2 c) 1)) and transfer the resulting solution to a 50 ml
volumetric flask (5.2 e) 3)) and fill with water (4.2 a)) to the mark. The resulting solution is
the concentrate sample solution. Dilute the concentrate sample solution with water (4.2 a))
to the appropriate concentration level for each measurement apparatus. If an internal
standard is to be used, it shall be added before filling. For a final volume of 50 ml 500 µl of
internal standard (4.2 w)) for ICP-OES and ICP-MS (after a 1:1 000 dilution step) shall be
added before filling.
62321-5 © IEC:2013 – 15 –
n) Any sample residues shall be separated by a centrifuge or a filter. The residues shall be
checked by appropriate measurements (e.g. XRF
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