ISO 4939:2016

INTERNATIONAL ISO
STANDARD 4939
Second edition
2016-02-01
Steel — Determination of
nickel — Dimethylglyoxime
spectrophotometric method
Aciers — Détermination du nickel — Méthode spectrophotométrique
à la diméthylglyoxime
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
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ii © ISO 2016 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Principle . 1
4 Reagents . 1
5 Apparatus . 2
6 Sampling . 2
7 Procedure. 2
7.1 Test portion . 2
7.2 Blank test . 2
7.3 Determination . 2
7.3.1 Preparation of the test solution . 2
7.3.2 Colour development . . 3
7.3.3 Preparation of the compensating solution . 3
7.3.4 Spectrophotometric measurement . 3
7.4 Establishment of the calibration curve . 3
7.4.1 Preparation of the calibration solutions . 3
7.4.2 Spectrophotometric measurement . 4
7.4.3 Calibration curves . 4
8 Expression of results . 4
9 Precision . 5
9.1 General . 5
9.2 Repeatability . 5
9.3 Reproducibility . 5
10 Test report . 5
Annex A (informative) Additional information on the international interlaboratory test.7
Annex B (informative) Graphical representation of precision data . 8
Bibliography . 9
Foreword
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different types of ISO documents should be noted. This document was drafted in accordance with the
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Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.
The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 1, Methods of
determination of chemical compound.
This second edition cancels and replaces the first edition (ISO 4939:1984), which has been
technically revised. In particular, the specification of plotting of the calibration graphs shown in
7.4.3 has been corrected.
iv © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 4939:2016(E)
Steel — Determination of nickel — Dimethylglyoxime
spectrophotometric method
1 Scope
This International Standard specifies a spectrophotometric method for the determination of nickel in
steel using dimethylglyoxime.
The method is applicable to the determination of nickel mass fractions in the range of 0,10 % and 2,0 %.
Cobalt, copper and manganese can cause interferences (see 7.3.2).
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.
ISO 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical
composition
3 Principle
Dissolution of a test portion in hydrochloric, nitric and perchloric acids.
Formation of a coloured complex of nickel(lll) with dimethylglyoxime in ammoniacal solution containing
iodine and potassium iodide.
Spectrophotometric measurement at a wavelength of about 535 nm.
4 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only
grade 2 water as specified in ISO 3696.
4.1 Acid mixture.
Mix two volumes of hydrochloric acid, ρ approximately 1,19 g/ml, one volume of nitric acid, ρ
approximately 1,40 g/ml and two volumes of water.
4.2 Perchloric acid, ρ approximately 1,54 g/ml.
WARNING — Perchloric acid vapour might cause explosions in the presence of ammonia, nitrous
fumes or organic material in general.
Perchloric acid, ρ approximately 1,67 g/ml, may also be used. 100 ml of perchloric acid, ρ approximately
1,54 g/ml is equivalent to 79 ml of perchloric acid, ρ approximately 1,67 g/ml.
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