Zinc dust pigments for paints - Specifications and test methods (ISO 3549:1995)

This International Standard specifies the requirements and the corresponding methods of test for zinc dust pigments suitable for use in protective coatings.

Zinkstaub-Pigmente für Beschichtungsstoffe - Anforderungen und Prüfverfahren (ISO 3549:1995)

Diese Internationale Norm legt Anforderungen und die entsprechenden Prüfverfahren für Zinkstaub-Pigmente fest, die zur Verwendung in Korrosionsschutzbeschichtungen geeignet sind.

Pigments a base de poussiere de zinc pour peintures - Spécifications et méthodes d'essai (ISO 3549:1995)

Cinkovi pigmenti v prahu za barve - Specifikacije in preskusne metode (ISO 3549:1995)

General Information

Status
Published
Publication Date
31-Dec-2002
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Jan-2003
Due Date
01-Jan-2003
Completion Date
01-Jan-2003

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SLOVENSKI STANDARD
SIST EN ISO 3549:2003
01-januar-2003
Cinkovi pigmenti v prahu za barve - Specifikacije in preskusne metode (ISO
3549:1995)
Zinc dust pigments for paints - Specifications and test methods (ISO 3549:1995)

Zinkstaub-Pigmente für Beschichtungsstoffe - Anforderungen und Prüfverfahren (ISO

3549:1995)
Pigments a base de poussiere de zinc pour peintures - Spécifications et méthodes
d'essai (ISO 3549:1995)
Ta slovenski standard je istoveten z: EN ISO 3549:2002
ICS:
87.060.10 Pigmenti in polnila Pigments and extenders
SIST EN ISO 3549:2003 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 3549:2003
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SIST EN ISO 3549:2003
EUROPEAN STANDARD
EN ISO 3549
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2002
ICS 87.060.10
English version
Zinc dust pigments for paints - Specifications and test methods
(ISO 3549:1995)

Pigments à base de poussière de zinc pour peintures - Zinkstaub-Pigmente für Beschichtungsstoffe -

Spécifications et méthodes d'essai (ISO 3549:1995) Anforderungen und Prüfverfahren (ISO 3549:1995)

This European Standard was approved by CEN on 21 July 2002.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national

standards may be obtained on application to the Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation

under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official

versions.

CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,

Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3549:2002 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 3549:2003
EN ISO 3549:2002 (E)
Foreword

The text of ISO 3549:1995 has been prepared by Technical Committee ISO/TC 35 "Paints and varnishes” of the

International Organization for Standardization (ISO) and has been taken over as EN ISO 3549:2002 by Technical

Committee CEN/TC 298 "Pigments and extenders", the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an identical text or

by endorsement, at the latest by March 2003, and conflicting national standards shall be withdrawn at the latest by

March 2003.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following

countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,

France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,

Sweden, Switzerland and the United Kingdom.
Endorsement notice

The text of the International Standard ISO 3549:1995 has been approved by CEN as a European Standard without

any modifications.

NOTE Normative references to International Standards are listed in annex ZA (normative).

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SIST EN ISO 3549:2003
EN ISO 3549:2002 (E)
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications

This European Standard incorporates by dated or undated reference, provisions from other publications. These

normative references are cited at the appropriate places in the text and the publications are listed hereafter. For

dated references, subsequent amendments to or revisions of any of these publications apply to this European

Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the

publication referred to applies (including amendments).

NOTE Where an International Publication has been modified by common modifications, indicated by (mod.), the relevant EN/HD

applies.
Publication Year EN/HD Year
Title
ISO 594-1 1986 Conical fittings with a 6% (Luer) taper for EN 20594-1 1993
syringes, needles and certain other
medical equipment - Part 1: General
requirements
ISO 3696 1987 Water for analytical laboratory use - EN ISO 3696 1995
Specification and test methods
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SIST EN ISO 3549:2003
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SIST EN ISO 3549:2003
INTERNATIONAL
STANDARD
Second edition
19951 l-l 5
Zinc dust Pigments for paints -
Specifications and test methods
Pigments 2 base de poussi&e de zinc pour peintures - Spkifications
et m6 thodes d ‘essai
Reference number
ISO 3549: 1995(E)
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SIST EN ISO 3549:2003
Foreword
ISO (the International Organization for Standardization) is a worldwide fed-
eration of national Standards bodies (ISO member bodies). The work of
preparing International Standards is normally carried out through ISO tech-
nical committees. Esch 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 collabo-
rates closely with the International Electrotechnical Commission (IEC) on
all matters of electrotechnical Standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 3549 was prepared by Technical Committee
ISO/TC 35, Paints and varnishes, Subcommittee SC 2, Pigments and
extenders.
This second edition cancels and replaces the first edition (ISO 3549:1976),
which has been technically revised.
0 ISO 1995

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced

or utilized in any form or by any means, electronie or mechanical, including photocopying and

microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-l 21 1G eneve 20 l Switzerland
Printed in Switzerland
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SIST EN ISO 3549:2003
ISO 3549:1995(E)
INTERNATIONAL STANDARD o ISO
Zinc dust Pigments for paints - Specifications and test
methods
NOTE 1 Zinc dust Pigments for paints may vary in their
1 Scope
metallic zinc content, Chemical purity, particle shape, par-
title size distribution, mean and maximum diameter, etc.
This International Standard specifies the requirements
These variations are all likely to have an influence on the
and corresponding test methods for zinc dust pig-
zinc dust behaviour in paints with regard to Parameters
ments suitable for use in protective coatings.
such as dispersibility, fineness of grind, reactivity, electrical
conductivity and packing properties.
2 Normative references
The following Standards contain provisions which,
4 Required characteristics and tolerantes
through reference in this text, constitute provisions of
this International Standard. At the time of publication,
4.1 For zinc dust Pigments complying with this In-
the editions indicated were valid. All Standards are
ternational Standard, the essential requirements are
subject to revision, and Parties to agreements based
specified in tables 1 and 2.
on this International Standard are encouraged to in-
vestigate the possibility of applying the most recent
editions of the Standards indicated below. Members

of IEC and ISO maintain registers of currently valid Table 1 - Composition of zinc dust Pigment

International Standards.
Test
Characteristic Unit Requirement
method
ISO 565:1990, Test sieves - Metal wire cloth, perfo- I I
rated metal plate and electroformed sheet - Nominal
Total zinc %(dm) min. 98 See clause 7
sizes of openings.
content
/ I
ISO 594-1 :1986, Conical fittings with a 6 % (Luer)
Metallic zinc % (dm) min. 94 See clause 8
taper for syringes, needles and certain other medical
content
I I
Part 1: General requiremen ts.
equipmen t -
% (dm) max. 02 See clause 9
Lead (Pb)
content
ISO 842: 1984, Raw materials for paints and varnishes
I /
- Sampling.
Cadmium (Cd) % (dm) max. 0,l See clause 9
content
I I
ISO 3696: 1987, Water for analytical labora tory use -

Specifica tion and tes t me thods. Iron (Fe) content % (dm) max. 0,05 See clause 9

Arsenic (As) % (m/m) max. 0,000 5 See clause 10
content
3 Definition
Chloride (Cl) % (dm) max. 0,005 See clause 11
content)
l I
For the purposes of this International Standard, the
Matter insoluble % (dm) max. 0,05 See clause 12
following definition applies.
in acid
I I
NOTE - If the zinc Oxide content is required, this tan be calcu-
3.1 zinc dust Pigment: A fine grey powder of es-
lated by multiplying the differente between the total zinc con-
sentially spheroidal particles, mainly consisting of
tent and the metallic zinc content by 1,244 7.
metallic zinc.
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SIST EN ISO 3549:2003
ISO 3549: 1995(E) 0 ISO

Table 2 - Residue on sieve The air inlet is connected to a jet rotating at 20 r/min

to 25 r/min and consists of a slot-shaped nozzle

Nominal size of sieve Residue on located beneath and very close to the sieve (see

Test
sieve
aperture
figure 1). When the jet rotates, it blows air continu-
method
ously through the sieve, preventing the powder par-
% (dm)
#Jm
ticles from settling. The air is extracted through the
125 1 max. 0,Ol 1
outlet, drawing the finer particles through the sieve.
The flow of air is controlled by adjusting a slot at the
1 maxO,l. 1 Seeclause6
outlet.
max.5
I I I
The vacuum obtained shall be 1 250 Pa or better.
6.2.3 Timer (for example a stopwatch), recording to
4.2 Requirements for other physical properties
the nearest 1 s or better. lt may be equipped with a
(surface area, particle size distribution, etc.) and the
switch for stopping the motor of the sieve apparatus
choice of reference Pigment to which these proper-
(6.2.2).
ties refer shall be the subject of agreement between
the interested Parties.
6.2.4 Analytical balance, capable of weighing at
least 50 g to the nearest 1 mg.
43 The reference Pigment shall also comply with
the requirements given in tables 1 and 2.
6.2.5 Mallet, of light construction, with a plastic
head, suitable for tapping the apparatus to dislodge
powder adhering to the lid and sieve.
5 Sampling
6.2.6 Clean brush.
Take a representative Sample of the product to be
tested, as described in ISO 842.
6.2.7 Stainless-steel boat.
WARNING - The sample shall on no account be
dried before testing, and any Portion of the sample
6.3 Checking and cleaning the sieve
not used shall not be returned to the Sample con-
tainer after having been manipulated.
Check that the sieve is clean and undamaged and is
not blocked by material used in a previous determin-
ation. A magnifying glass of sufficient magnification is
recommended to aid this inspection.
6 Determination of residue on sieve
If cleaning of the sieve is necessary, an ultrasonic
6.1 Principle
System is recommended for this purpose. lt is also
possible to clean the sieve by turning it upside down
A suitable test Portion of the Sample is passed
on a clean sheet of Paper and tapping vigorously to
through an air-jet sieve apparatus having sieves with
eliminate any residual particles.
nominal mesh apertures of 45 um, 90 um and
125 um. The residue on each of these sieves is de-
termined.
6.4 Procedure
Carry out the determination in duplicate.
6.2 Apparatus
6.4.1 Weigh, to the nearest 0,Ol g, a test Portion of

6.2.1 Sieves, circular, with a sieving area of diameter approximately 50 g (172~).

200 mm and with nominal mesh apertures of 45 um,
90 um and 125 um, complying with ISO 565. A trans-
6.4.2 Secure the 45 um sieve (6.2.1) in Position in
parent lid shall be provided to cover the sieve during
the sieve apparatus (6.2.2) and transfer the test
use.
Portion to the sieve.

6.2.2 Air-jet sieve apparatus (see figure l), consist- 6.4.3 Cover the sieve with the transparent lid, switch

ing of a cylindrical casing which contains a sieve (see on the extractor fan and sieve apparatus (6.2.2) and

6.2.1). The base of the casing has an outlet (to which tap the lid and the sieve lightly from time to time with

an extractor fan is connected) and an air inlet to per- the mallet (6.2.5) to distribute the material and dis-

mit the injection of air. lodge adhering particles.
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SIST EN ISO 3549:2003
0 ISO
Sieve
Adjustable slot
Casing
To extractor fan
- Manometer
Figure 1 - Air-jet sieve apparatus
6.4.4 After 120 s, switch off the apparatus and re-
is the mass, in grams, of the steel boat;
move the transparent lid and sieve. Recover the sieve

residue by turning the sieve upside down on a clean is the mass, in grams, of the boat and the

sheet of Paper and tapping vigorously to ensure that sieve residue.
all particles are recovered.
If the two results (duplicates) for each sieve differ by
more than one tenth of the maximum limit for that
6.4.5 Weigh the stainless-steel boat (6.2.7) to the
sieve in table 2, repeat the procedure.
nearest 1 mg (mI). Transfer the sieve residue to it and
reweigh to the nearest 1 mg (Q).
Calculate the mean of two valid results (replicates)
and report the result to three decimal places for the
6.4.6 Repeat the operations described in 6.4.1 to
125 um sieve, two decimal places for the 90 um sieve
6.4.5 with the 90 um sieve and then with the 125 um
and one decimal place for the 45 um sieve.
sieve on fresh 50 g portions of the Sample.
6.5 Expression of results 7 Determination of total zinc content
Calculate the residue on each sieve, R, expressed as a 7.1 Principle
percentage by mass, using the equation
The zinc is titrated against EDTA Solution.
&-m,)
R= XI00
7.2 Reagents
where
During the analysis, use only reagents of recognized
analytical grade and only water of at least grade 3
is the mass, in grams, of the test Portion;
purity as defined in ISO 3696.
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SIST EN ISO 3549:2003
ISO 3549: 1995(E) 0 ISO

7.2.1 Hydrochlorit acid, concentrated, approxi- in grams, of zi nc fo Irming a comp lex with 1 ml of

mately 38 % (dm), p = 1 ,19 g/mI. EDTA Solution), using the equation
m. x 50
7.22 Hydrochlorit acid, diluted 1 + 4.
p(Zn) =
500 x v. =10 x vo
Dilute 200 ml of concentrated hydrochloric acid (7.2.1)
to 1 litre with water.
is the mass, in grams, of zinc metal used;
7.2.3 Sulfuric acid, diluted 1 + 1.
is the volume, in millilitres, of EDTA Solution
Slowly add, whilst cooling, 1 part by volume of con-
used for the titration.
centrated sulfuric acid [approximately 96 % (dm),
p = 1,84 g/mI] to 1 part by volume of water.
Carry out the titration three times and calculate the
mean value of the zinc equivalent p(Zn), in grams
Per
approximately
7.2.4 Nitrit acid, concentrated,
millilitre.
68 % (dm), p= 1,42 ghl.
7.2.8 Xylenol orange, lg/l indicator Solution of the
7.2.5 Ammonia solution, approximately 25 % (dm),
sodium salt in water.
p= 0,81 g/mI.
7.2.6 Buffer solution. 7.2.9 Bromothymol blue, 1 g/l indicator Solution in
96 % (VW) ethanol.
Dissolve 200 g of hydroxylammonium chloride
(NH,OH.HCI) in approximately 300 ml of water. Dis-
solve 28 g of sodium hydroxide in approximately
300 ml of water. Combine the two solutions, cool and
7.3 Procedure
dilute to 1 litre with water.
7.3.1 Test Portion
7.2.7 (Ethylenedinitrilo)tetraacetic acid (EDTA), di-
sodium salt dihydrate, Standard volumetric Solution.
Weigh, to the nearest 1 mg, 1,5 g of the Sample (m,)
into a 250 ml beaker.
7.2.7.1 Preparation
7.3.2 Determination
Weigh, to the nearest 1 mg, about 20 g of disodium
EDTA dihydrate, dissolve in water and make up to
Carry out the determination in duplicate.
1 litre. Store in a polyethylene bottle.
Dissolve the test Portion in 20 ml of concentrated
7.2.7.2 Standardkation
hydrochloric acid (7.2.1) and add 1 ml or 2 ml of nitric
acid (7.2.4) to ensure that any lead present is dis-
Weigh, to the nearest 1 mg, approximately 1,5 g of
solved. Add 5 ml of sulfuric acid (7.2.3) and evaporate
99,99 % pure zinc metal (mass mo) into a 250 ml
until dense white fumes appear. Cool, then add
beaker. Dissolve in 20 ml of hydrochloric acid (7.2.1)
100 ml of water, boil for a short time and allow to
and add 1 ml or 2 ml of nitric acid (7.2.4). After com-
stand until the following day.
plete dissolution, transfer quantitatively into a 500 ml
volumetric flask, make up to the mark with water and
Filter the Solution through a sintered-glass or silica
mix thoroughly.
filter crucible (P40 porosity); wash the beaker and the
crucible, collecting the filtrate in a 500 ml one-mark

Pipette 50 ml of the zinc Solution into a 500 ml conical volumetric flask. Make the Solution up to the mark

flask. Add 200 ml of water and 3 drops of bromo- and mix thoroug hly.
thymol blue indicator (7.2.9), followed by ammonia

Solution (7.2.5), drop by drop, until the colour changes Pipette 50 ml of the Solution into a 500 ml conical

to blue. Then add dilute hydrochloric acid (7.2.2) until flask. Add 200 ml of water and 3 drops of bromo-

the yellow colour returns. Finally add 20 ml of buffer thymol blue indicator (7.2.9), followed by ammonia

Solution (7.2.6) and 3 drops of xylenol orange indicator Solution (7.2.5), drop by drop, until the colour changes

(7.2.8) and titrate with EDTA Solution (7.2.7.1) until the to blue. Then add dilute hydrochloric acid (7.2.2) until

red colour changes to pale yellow. the yellow colour returns. Finally add 20 ml of buffer

Solution (7.2.6) and 3 drops of xylenol orange indicator
(7.2.8) and titrate with EDTA Solution (7.2.7) until the
Calculate the zinc equivalent of the EDTA Solution,

p(Zn), expressed in grams per millilitre (i.e. the mass, red colour changes to pale yellow.

---------------------- Page: 12 ----------------------
SIST EN ISO 3549:2003
0 ISO
8.2.5 Iron(lll) sulfate, saturated Solution.
7.4 Expression of results
Dissolve, as far as possible, 330 g of iron(lll) sulfate
Calculate the total zinc content, w(Zn),, expressed as a
[Fe2(SO&] in 1 litre of cold water. Heat until dis-
percentage by mass, using the equation
Solution is complete. Allow to cool to room tempera-
ture, then filter.
1000 x y x p(Zn)
w(Zn), =
8.2.6 Potassium permanganate, Standard volu-
where
metric Solution, c(KMnOJ = 0,06 mol/l.
is the mass, in grams, of the test Portion;
m-l
8.2.6.1 Preparation
p(Zn) is the zinc equivalent, in grams per millilitre,
Weigh 20 g of potassium permanganate (KMn04) into
of the EDTA Solution;
a 3-litre or 4-litre flask and add 2 litres of water. Boil
for 1 h, allow to cool and allow to stand until the fol-
is the volume, in millilitres, of EDTA Solution
lowing day.
used.
Decant through a filter of glass wool or a sintered-
If the two results (duplicates) differ by
glass filter of pore size 0,5 um into a 2 000 ml one-
0,5 % repeat the procedure.
hhd,
mark volumetric flask, make up to the mark with
water and mix weil. Transfer to a brown-glass bottle
Calculate the mean of two valid results (replicates)
fitted with a glass stopper.
and report the result to one decimal place.
8.2.6.2 Standardization
8 Determination of metallic zinc content
Weigh, to the nearest 1 mg, 0,72 g of sodium oxalate
(which has been dried for 1 h at 105 “C) into a 500 ml
8.1 Principle
conical flask. Dissolve in approximately 200 ml of
dilute sulfuric acid (8.2.3).
Iron(lll) sulfate solution and, as a catalyst, copper(ll)
sulfate Solution are added to a test Portion of the zinc
Heat to boiling and titrate with the potassium per-
dust Pigment. The zinc is dissolved as zinc sulfate and
manganate Solution (8.2.6.1) until a pink colour just
the resulting iron(ll) sulfate is titrated against pot-
appears.
assium permanganate Solution.
Calculate the concentration of the potassium per-
manganate Solution, c(KMnO,), expressed in moles
8.2 Reagents and materials
per litre, usi 1g the equation
During the analysis, use only reagents of recognized
2 x m.
analytical grade and only water of at least grade 3 -
c(KMnO,) x 1000
purity as defined in ISO 3696. 5 x vo x Mox
where
8.2.1 Nitrogen, commercial grade, in a cylinder.
is the mass, in grams, of sodium oxalate
8.2.2 Orthophosphoric acid, approximately 85 % used;
(m/m), p = 1,71 g/mI.
is the volume, in millilitres, of potassium per-
manganate Solution used for the titration;
8.2.3 Sulfuric acid, diluted 1 + 19.
is the molar mass, in grams per mole, of so-
Mox
Slowly add, whilst cooling, 1 part by volume of con-
dium oxalate (Mo, = 134,OO g/mol).
centrated sulfuric acid [approximately 96 % (mlm),
p = 1,84 g/mI] to 19 Parts by volume of water.
Carry out the titration three times and calculate the
mean value of the concentration of the potassium
permanganate Solution, C, in moles per litre.
8.2.4 Copper(ll) sulfate, Solution.
Carry out this standardization before using the sol-
Dissolve 200 g of copper(ll) sulfate pentahydrate
(CuSo4*5H20) in 1 litre of water. ution.
---------------------- Page: 13 ----------------------
SIST EN ISO 3549:2003
0 ISO
8.3 Procedure is the volume, in millilitres, of potassium per-
manganate Solution used in the determi-
nation;
Carry out the determination in duplicate and as rapidly as
possible. Ensure that the flask is kept stoppered as much
is the volume, in millilitres, of potassium per-
as possible.
manganate Solution used in the blank test;
8.3.1 Test Portion
Mz, is the molar mass, in grams per mole, of zinc
Zn = 65,37 g/moI).
Take a dry 750 ml conical flask and fill it with nitrogen
(8.2.1). Stopper the flask carefully with a rubber bung.
If the two results (duplicates) differ by more than
Weigh, to the nearest 0,l mg, about 0,4 g of the
0,5 % (m/m), repeat the procedure.
Sample and quickly wash it into the flask with 4 ml or
5 ml of water from a water jet. Immediately replace
Calculate the mean of two valid results (replicates)
the rubber bung. Prevent the formation of agglomer-
and report the result to one decimal place.
ates as far as possible by shaking regularly.
8.3.2 Determination
9 Determination of lead, Cadmium and
iron content
Add to the flask 10 ml of copper(ll) sulfate Solution
(8.2.4) and Shake vigorously for about 1 min to pre-
vent the formation of agglomerates. Then, using a
9.1 Principle
pipette, wash down the neck of the flask to remove
any metallic particles with 50 ml of iron(lll) sulfate
A test Solution is aspirated into an acetylene/air flame
Solution (8.2.5) which has previously been deoxygen-
in an atomic absorption spectrometer and the absorp-
ated by passing through it a stream of nitrogen (8.2.1)
tion is measured at selected spectral emission lines of
for 10 min.
hollow-cathode lamps or discharge lamps.
Allow to stand, shaking frequently, until dissolution is
complete. This takes 15 min to 30 min.
9.2 Reagents and materials
When dissolution is complete, add 20 ml of ortho-
During the analysis, use only reagents of recognized
phosphoric acid (8.2.2) and 200 ml of dilute sulfuric
analytical grade and only water of at least grade 3
acid (8.2.3) and titrate immediately with potassium
purity as defined in ISO 3696.
permanganate Solution (8.2.6) until a faint pink colour
is obtained (volume of potassium permanganate sol-
ution used: V,).
9.2.1 Nitrit acid, concentrated, approximately 68 %
(mm), p= 1,42 g/mI.
Carry out a blank test, omitting the test Portion
(volume of potassium permanganate Solution used:
9.2.2 Meta lit lead, 99,99 % (m/m) minimum purity.
v,).
lit Cadmium, 99,99 % (m/m) minimum
9.2.3 Meta
purity.
8.4 Expression of results
9.2.4 Meta Ilic iron, 99,99 % (m/m) minimum purity.
Calculate the metallic zinc content, w(Zn),, expressed
as a percentage by mass, using the equation
9.2.5 Metallic zinc, 99,999 9 % (mlm) minimum purity.
5(v,-V2)xCxMz,x100
w(Zn), =
2 ml x 1000
9.2.6 Lead, Cadmium and iron, Standard stock
Solution containing 1 g of each metal per litre.
(vj - v-2) x F
=16,34 x
Weigh, to the nearest 0,l mg, 1 g of Cadmium (9.2.3)
and 1 g of iron (9.2.4) into a 500 ml beaker. Dissolve
the metals in approximately 20 ml of concentrated
where
nitric acid (9.2.1), with heating, after covering with a
watch glass. After complete dissolution, add approxi-

c is the mean concentration, in moles per litre, mately 40 ml of water. Weigh, to the nearest 0,l mg,

of the potassium permanganate Solution; 1 g of lead (9.2.2) and introduce it into the beaker.

Heat again for a few minutes and, after complete
dissolution, heat to boiling and allow to boil gently for
is the mass, in grams, of the test Portion;
---------------------- Page: 14 ----------------------
SIST EN ISO 3549:2003
0 ISO ISO 3549: 1995(E)
about 5 min. Allow to cool to room temperature and
9.3 Apparatus
transfer quantitatively to a 1 000 ml one-mark volu-
metric flask. Make up to the mark with water and mix
Ordinary laboratory apparatus and glassware, toget her
weil.
with the following:
1 ml of this sta ndard stock Solution contains 1 mg
mium and iro n.
each of lead, cad 9.3.1 Flame atomic absorption spectrometer,
fitted with hollow-cathode lamps or an electrodeless
discharge lamp for lead, Cadmium and iron, and with a
9.2.7 Lead, Cadmium and iron, Standard Solution
nebulizer-burner fed with acetylene and air.
containing 50 mg of each metal per litre.
By means of a pipette, transfer 25 ml of the Solution
9.3.2 Polyethylene bottles, 500 ml, with double
obtained as described in 9.2.6 into a 500 ml one-mark
closure.
volumetric flask, make up to the mark with water and
mix weil.
9.4 Procedure
1 ml of this Standard Solution contains 50 ug each of
lead, Cadmium and iron.
9.4.1 Test Portion
9.2.8 Lead, Cadmium and iron, calibration solutions.
Determination in the range 0,000 1 % to 0,Ol %:
weigh, to the nearest 1 mg, 10 g of the Sample.
These d ilute solutions shall not be used after storage
of more than one mon th.
Determination in the range 0,Ol % to 1 %: weigh, to
the nearest 1 mg, 1 g of the Sample.
9.2.8.1 For calibration in the range 0,000 1 % to
0,Ol %
9.4.2 Preparation of test solutions
Weigh, to the nearest 10 mg, 10 g of zinc (9.2.5) into
each of five 300 ml beakers and, by means of pi-
9.4.2.1 For determination in the range 0,000 1 % to
pettes, add respectively 0 ml, 2 ml, 6 ml, 10 ml and
0,Ol %
20 ml of the Standard Solution (9.2.7). Dissolve in
approximately 50 ml of concentrated nitric acid (9.2.1)
Place the 10 g test Portion in a 300 ml beaker and add
and cover the beakers with watch glasses. After
approximately 20 ml of water and approximately 50 ml
complete dissolution, heat to boiling, then allow to
of concentrated nitric acid (9.2.1). Allow to dissolve
cool to room temperature, and transfer quantitatively
slowly after covering the beaker with a watch glass.
to IOO-ml one-mark volumetric flasks. Make up to the
After complete dissolution, heat to boiling, then allow
mark with water, mix well and transfer to poly-
to cool to room temperature and transfer quantita-
ethylene bottles, which are then hermetically closed
tively to a 100 ml one-mark volumetric flask. Make up
for storage.
to the mark with water, mix weil and transfer to a
polyethylene bottle, which is then hermetically sealed
These five calibration solutions contain, respectively,
when closed.
0 mg, 1 mg, 3 mg, 5 mg and 10 mg of lead, Cadmium
and iron per litre.
9.4.2.2 For determination in the range 0,Ol % to
0,l %
9.2.8.2 For calibration in the range 0,Ol % to 1 %
Place the 1 g test Portion in a 300 ml beaker and
Pipette respectively 0 ml, 2 ml, 6 ml, 10 ml and 20 ml of
add approximately 10 ml of water and approximately
the Standard Solution (9.2.7) into five 100 ml one-mark
10 ml of concentrated nitric acid (9.2.1), covering the
volumetric flasks. Add approximately 10 ml of concen-
beaker with a watch glass. Continue as described in
trated nitric acid (9.2.1) to each and make up to the mark
9.4.2.1.
with water, mix weil and transfer to polyethylene bottles,
which are then hermetically closed for storage.
9.4.2.3 For determination in the range 0,l % to 1 %
These five calibration solutions contain, respectively,
0 mg, 1 mg, 3 mg, 5 mg and 10 mg of lead, Cadmium
Proceed as in 9.4.2.2, but add approximately 50 ml of
and iron per litre.
water and approximately 100 ml of concentrated nitric
acid (92.1) to a 300 ml beaker, and transfer to a

9.2.9 Acetylene, commercial grade, in a cylinder. 1 000 ml one-mark volumetric flask.

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SIST EN ISO 3549:2003
0 ISO
ISO 3549: 1995(E)
9.5.3 Calculate the content w of the element to be
9.4.3 Determination
determined (lead, Cadmium or iron), expr
...

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