ISO 19043:2023

INTERNATIONAL ISO
STANDARD 19043
Second edition
2023-05
Natural rubber latex concentrate —
Determination of total phosphate
content by spectrophotometric
method
Concentré de latex de caoutchouc naturel — Détermination de la
teneur totale en phosphate par méthode spectrophotométrique
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 1
6 Reagents . 2
7 Procedure .2
7.1 General . 2
7.2 Determination of total solids content . 2
7.3 Preparation of standard phosphate solutions . 2
7.4 Determination of phosphate content . 3
8 Expression of results . 3
9 Precision data .4
10 Test report . 4
Annex A (informative) Precision data . 5
Bibliography . 7
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products,
Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry.
This second edition cancels and replaces the first edition (ISO 19043:2015), which has been technically
revised.
The main changes are as follows:
— the CAS numbers of the chemicals have been added;
— in 6.4, the requirement for potassium dihydrogen phosphate (stock solution) has been changed to
include both the commercially available standard solution and the prepared one;
— in 7.1, "The difference between two readings” has been changed into "The difference between the
results of duplicate determinations";
— in Clause 8, “Report the result as the mean of the duplicate determinations" has been added;
— in Annex A, the precision data have been updated by the results of an ITP evaluated in accordance
with ISO 19983.
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.
iv
INTERNATIONAL STANDARD ISO 19043:2023(E)
Natural rubber latex concentrate — Determination of total
phosphate content by spectrophotometric method
WARNING — Persons using this document should be familiar with normal laboratory practice.
This document 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.
1 Scope
This document specifies a method for the determination of total phosphate content of natural rubber
latex concentrate. This method is not necessarily suitable for latex from natural sources other than the
Hevea brasiliensis.
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 124, Latex, rubber — Determination of total solids content
ISO 648, Laboratory glassware — Single-volume pipettes
3 Terms and definitions
No terms and definitio
...