ISO 6101-6:2011

Rubber — Determination of metal content by atomic absorption spectrometry — Part 6: Determination of magnesium content

ISO 6101-6:2011 specifies an atomic absorption spectrometric method for the determination of the magnesium content of natural rubber latex concentrate, raw natural rubber and products made from natural rubber.

Caoutchouc — Dosage du métal par spectrométrie d'absorption atomique — Partie 6: Dosage du magnésium

General Information

• Status: Withdrawn
• Publication Date: 08-Nov-2011
• Withdrawal Date: 08-Nov-2011
• ICS: 83.060 - Rubber
• Technical Committee: ISO/TC 45/SC 2 - Testing and analysis
• Drafting Committee: ISO/TC 45/SC 2/WG 5 - Chemical tests
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 25-Sep-2018

Relations

• Revised: ISO 6101-6:2018 - Rubber — Determination of metal content by atomic absorption spectrometry — Part 6: Determination of magnesium content
• Effective Date: 10-Dec-2016

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 6101-6
First edition
2011-11-15
Rubber — Determination of metal content
by atomic absorption spectrometry —
Part 6:
Determination of magnesium content
Caoutchouc — Dosage du métal par spectrométrie d'absorption
atomique —
Partie 6: Dosage du magnésium
Reference number
ISO 6101-6:2011(E)
ISO 2011
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ISO 6101-6:2011(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2011

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

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Published in Switzerland
ii © ISO 2011 – All rights reserved
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ISO 6101-6:2011(E)
Contents Page

Foreword ............................................................................................................................................................ iv

1 Scope ...................................................................................................................................................... 1

2 Normative references ............................................................................................................................ 1

3 Terms and definitions ........................................................................................................................... 2

4 Principle ................................................................................................................................................. 2

5 Reagents ................................................................................................................................................ 2

6 Apparatus ............................................................................................................................................... 2

7 Sampling ................................................................................................................................................ 3

8 Procedure ............................................................................................................................................... 3

8.1 Test portion ............................................................................................................................................ 3

8.2 Preparation of test solution .................................................................................................................. 3

8.3 Preparation of calibration graph .......................................................................................................... 3

8.4 Determination ........................................................................................................................................ 4

8.5 Expression of results ............................................................................................................................ 5

9 Precision ................................................................................................................................................ 6

10 Test report .............................................................................................................................................. 6

Annex A (informative) Method of standard additions ..................................................................................... 7

Annex B (informative) Precision ........................................................................................................................ 8

© ISO 2011 – All rights reserved iii
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ISO 6101-6:2011(E)
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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. 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.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 6101-6 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee

SC 2, Testing and analysis.

ISO 6101 consists of the following parts, under the general title Rubber — Determination of metal content by

atomic absorption spectrometry:
 Part 1: Determination of zinc content
 Part 2: Determination of lead content
 Part 3: Determination of copper content
 Part 4: Determination of manganese content
 Part 5: Determination of iron content
 Part 6: Determination of magnesium content
iv © ISO 2011 – All rights reserved
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INTERNATIONAL STANDARD ISO 6101-6:2011(E)
Rubber — Determination of metal content by atomic absorption
spectrometry —
Part 6:
Determination of magnesium content

WARNING — Persons using this part of ISO 6101 should be familiar with normal laboratory practice.

This part of ISO 6101 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.

IMPORTANT — Certain procedures specified in this part of ISO 6101 might involve the use or

generation of substances, or the generation of waste, that could constitute a local environmental

hazard. Reference should be made to appropriate documentation on safe handling and disposal after

use.
1 Scope

This part of ISO 6101 specifies an atomic absorption spectrometric method for the determination of the

magnesium content of natural rubber latex concentrate, raw natural rubber and products made from natural

rubber.
2 Normative references

The following referenced documents are indispensable for the application 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 123, Rubber latex —Sampling
ISO 124, Latex, rubber — Determination of total solids content
ISO 247, Rubber — Determination of ash
ISO 648:2008, Laboratory glassware — Single-volume pipettes
ISO 835:2007, Laboratory glassware — Graduated pipettes
ISO 1042:1998, Laboratory glassware — One-mark volumetric flasks
ISO 1772, Laboratory crucibles in porcelain and silica

ISO 1795, Rubber, raw natural and raw synthetic — Sampling and further preparative procedures

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ISO 6101-6:2011(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
natural rubber latex concentrate

natural rubber latex from Hevea brasiliensis, containing ammonia and/or other preservatives, and which has

been subjected to some process of concentration
3.2
raw natural rubber

natural rubber, usually in bales or packages, forming the starting material for the manufacture of rubber

articles
4 Principle

A test portion is ashed at 550 °C  25 °C, or at 950 °C  25 °C for rubber products having a high carbon black

content. The ash is dissolved in dilute nitric acid. The solution is aspirated into an atomic absorption

spectrometer and the absorption is measured at a wavelength of 285,2 nm, using a magnesium hollow-

cathode lamp as the magnesium emission source.
5 Reagents

During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only

distilled water or water of equivalent purity.
5.1 Concentrated nitric acid, density  1,41 g/cm .

5.2 Dilute nitric acid, 1,6 % (by mass), prepared by carefully pipetting 11,5 cm of concentrated nitric

acid (5.1) into a 1 000 cm one-mark volumetric flask, making up to the mark with water and mixing thoroughly.

5.3 Standard magnesium stock solution, containing 1 mg of Mg per cubic centimetre. Use a

commercially available standard magnesium solution.

5.4 Standard magnesium solution, containing 10 µg of Mg per cubic centimetre, prepared by carefully

3 3

pipetting 10 cm of standard magnesium stock solution (5.3) into a 1 000 cm one-mark volumetric flask,

making up to the mark with dilute nitric acid (5.2) and mixing thoroughly. Prepare this solution preferably on

the day of use.
6 Apparatus

6.1 Atomic absorption spectrometer, fitted with a burner fed with acetylene and air compressed to at

least 60 kPa and 300 kPa, respectively, and also fitted with a magnesium hollow-cathode lamp as the

magnesium emission source. The instrument shall be operated in accordance with the manufacturer’s

instructions for optimum performance.
6.2 Balance, accurate to 0,1 mg.

6.3 Muffle furnace, capable of being maintained at a temperature of 550 °C  25 °C or 950 °C  25 °C.

3 3 3

6.4 One-mark volumetric flasks, glass-stoppered, of capacities 50 cm , 100 cm and 1 000 cm ,

complying with the requirements of ISO 1042:1998, class A.
3 3 3 3

6.5 Volumetric pipettes, of capacities 5 cm , 10 cm , 20 cm and 50 cm , complying with the

requirements of ISO 648:2008, class A.
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ISO 6101-6:2011(E)

6.6 Graduated pipette, of capacity 1 cm , complying with the requirements of ISO 835:2007, class A.

6.7 Steam bath.
6.8 Borosilicate-glass rod, for use as a stirrer.

6.9 Crucible, of silica, porcelain or borosilicate glass, of nominal capacity 50cm , complying with the

requirements of ISO 1772.
6.10 Ashless filter paper.
7 Sampling

Carry out sampling in accordance with one of the methods specified in ISO 123 for natural rubber latex, in

accordance with ISO 1795 for raw, natural rubber and on a milled or finely cut test sample representative of

the whole sample for products made from natural rubber.
8 Procedure
8.1 Test portion

8.1.1 For natural rubber latex concentrate, take a portion of thoroughly mixed latex containing about 10 g of

total solids, make into a thin film by pouring the portion onto a glass plate, dry to constant mass as specified in

ISO 124 and cut into small pieces.

8.1.2 For raw, natural rubber, take the test portion from a test sample prepared in accordance with

ISO 1795.

8.1.3 For products made from natural rubber, take the test portion from a milled or finely cut test sample.

8.2 Preparation of test solution
8.2.1 Ashing of test portion (destruction of organic matter)

Weigh out, to the nearest 0,1 mg, a test portion of approximately 3 g. Wrap the test portion in an ashless filter

paper and place in a crucible of nominal capacity 50 cm . Heat the crucible containing the test portion over a

bunsen burner or
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