Copper and copper alloys - Determination of phosphorus content - Spectrophotometric method

This Technical Specification specifies a molybdovanadate spectrophotometric method for the determination of phosphorus in copper and copper alloys in the form of castings or unwrought or wrought products. The method is applicable to products having phosphorus mass fractions between 0,001 % and 0,5 %.

Kupfer und Kupferlegierungen - Bestimmung des Phosphorgehaltes - Spektrophotometrisches Verfahren

Diese Technische Spezifikation legt ein spektrophotometrisches Verfahren mit Molybdatovanadat für die Bestimmung des Phosphorgehaltes in Kupfer und Kupferlegierungen fest, die als Gussstücke oder als plastisch oder nicht plastisch geformte Produkte vorliegen.
Das Verfahren ist geeignet für Produkte mit Phosphor-Massenanteilen zwischen 0,001 % und 0,5 %.

Cuivre et alliages de cuivre - Détermination du phosphore - Méthode spectrophotométrique

La présente Spécification technique définit une méthode spectrophotométrique au molybdovanadate pour le dosage du phosphore dans le cuivre et les alliages de cuivre sous forme de produits moulés ou de produits corroyés ou non.
Cette méthode s'applique aux produits présentant des fractions massiques en phosphore comprises entre 0,001 % et 0,5 %.

Baker in bakrove zlitine - Določevanje fosforja - Spektrofotometrična metoda

General Information

Status
Published
Public Enquiry End Date
08-Feb-2015
Publication Date
28-May-2015
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
26-May-2015
Due Date
31-Jul-2015
Completion Date
29-May-2015

Relations

Buy Standard

Technical specification
kTS FprCEN/TS 15656:2015
English language
13 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day
Technical specification
TS CEN/TS 15656:2015
English language
13 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
kSIST-TS FprCEN/TS 15656:2015
01-januar-2015
%DNHULQEDNURYH]OLWLQH'RORþHYDQMHIRVIRUMD6SHNWURIRWRPHWULþQDPHWRGD
Copper and copper alloys - Determination of phosphorus content - Spectrophotometric
method
Kupfer und Kupferlegierungen - Bestimmung des Phosphorgehaltes -
Spektrophotometrisches Verfahren
Cuivre et alliages de cuivre - Détermination du phosphore - Méthode
spectrophotométrique
Ta slovenski standard je istoveten z: FprCEN/TS 15656
ICS:
77.120.30 Baker in bakrove zlitine Copper and copper alloys
kSIST-TS FprCEN/TS 15656:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

kSIST-TS FprCEN/TS 15656:2015

---------------------- Page: 2 ----------------------

kSIST-TS FprCEN/TS 15656:2015

TECHNICAL SPECIFICATION
FINAL DRAFT
FprCEN/TS 15656
SPÉCIFICATION TECHNIQUE

TECHNISCHE SPEZIFIKATION

October 2014
ICS 77.120.30 Will supersede CEN/TS 15656:2009
English Version
Copper and copper alloys - Determination of phosphorus content
- Spectrophotometric method
Cuivre et alliages de cuivre - Détermination du phosphore - Kupfer und Kupferlegierungen - Bestimmung des
Méthode spectrophotométrique Phosphorgehaltes - Spektrophotometrisches Verfahren


This draft Technical Specification is submitted to CEN members for formal vote. It has been drawn up by the Technical Committee CEN/TC
133.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a Technical Specification. It is distributed for review and comments. It is subject to change without notice
and shall not be referred to as a Technical Specification.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprCEN/TS 15656:2014 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

kSIST-TS FprCEN/TS 15656:2015
FprCEN/TS 15656:2014 (E)
Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Principle .4
4 Reagents .4
5 Apparatus .6
6 Sampling .6
7 Procedure .6
8 Expression of results . 11
9 Precision . 11
10 Test report . 11
Bibliography . 13

2

---------------------- Page: 4 ----------------------

kSIST-TS FprCEN/TS 15656:2015
FprCEN/TS 15656:2014 (E)
Foreword
This document (FprCEN/TS 15656:2014) has been prepared by Technical Committee CEN/TC 133 “Copper
and copper alloys”, the secretariat of which is held by DIN.
This document is currently submitted to the Formal Vote.
This document will supersede CEN/TS 15656:2009.
Within its programme of work, Technical Committee CEN/TC 133 requested CEN/TC 133/WG 10 "Methods of
analysis" to prepare the revision of the following document:
— CEN/TS 15656:2009, Copper and copper alloys — Determination of phosphorus content —
Spectrophotometric method.
In comparison with CEN/TS 15656:2009 only editorial modifications have been made.
3

---------------------- Page: 5 ----------------------

kSIST-TS FprCEN/TS 15656:2015
FprCEN/TS 15656:2014 (E)
1 Scope
This Technical Specification specifies a molybdovanadate spectrophotometric method for the determination of
phosphorus in copper and copper alloys in the form of castings or unwrought or wrought products.
The method is applicable to products having phosphorus mass fractions between 0,001 % and 0,5 %.
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 1811-1, Copper and copper alloys — Selection and preparation of samples for chemical analysis —
Part 1: Sampling of cast unwrought products
ISO 1811-2, Copper and copper alloys — Selection and preparation of samples for chemical analysis —
Part 2: Sampling of wrought products and castings
3 Principle
Dissolution of a test portion in nitric acid. Elimination of interfering elements by fuming with perchloric,
hydrofluoric and hydrobromic acids. Decomposition of insoluble phosphates by fusion with sodium carbonate.
For concentrations below 0,01 % mass fraction, extraction of phosphorus as phosphomolybdic acid and
spectrophotometric determination as molybdenum blue; for concentrations between 0,005 % and 0,05 %
mass fraction, extraction and spectrophotometric determination as phosphovanadomolybdic acid.
4 Reagents
During the analysis, use only reagents of recognized analytical grade and only distilled water or water of
equivalent purity.
4.1 Nitric acid, HNO (ρ = 1,40 g/ml)
3
4.2 Nitric acid solution, 1 + 1
Add 500 ml of nitric acid (4.1) to 500 ml of water.
4.3 Hydrofluoric acid, HF (ρ = 1,13 g/ml)
4.4 Perchloric acid, HClO (ρ = 1,67 g/ml)
4
4.5 Hydrobromic acid, HBr (ρ = 1,50 g/ml)
4.6 Isobutanol
4.7 Sodium carbonate, Na CO
2 3
4.8 Methanol
4.9 Methyl isobutyl ketone
4.10 Ammonium molybdate solution, 50 g/l
4

---------------------- Page: 6 ----------------------

kSIST-TS FprCEN/TS 15656:2015
FprCEN/TS 15656:2014 (E)
Dissolve 50 g of ammonium molybdate tetrahydrate [(NH ) Mo O • 4H O] in 250 ml of water. Add a
4 6 7 24 2
solution of 115 ml of the perchloric acid (4.4) and 500 ml of water at room temperature. Dilute to 1 000 ml with
water.
After prolonged storage, a white precipitate may form. While this residue will not affect the analysis, care
should be taken to prevent its contamination of the aliquot used in the analysis.
Immediately before use, the aliquot used in the analysis should be purified by shaking with 10 ml of the
isobutanol (4.6).
4.11 Ammonium molybdate solution, 150 g/l
Dissolve 150 g of ammonium molybdate tetrahydrate [(NH ) Mo O • 4H O] in 1 000 ml of water.
4 6 7 24 2
4.12 Hydrochloric acid, HCl (ρ = 1,19 g/l)
4.13 Tin(II) chloride solution, 400 g/l
Dissolve 10 g of tin(II) chloride dihydrate (SnCl • 2H O) in 25 ml of hydrochloric acid (4.12). Prepare this
2 2
solution fresh before use.
4.14 Sulphuric acid, H SO (ρ = 1,84 g/l)
2 4
4.15 Sulphuric acid solution, 10 mol/l
To 100 ml of water add 56 ml of sulphuric acid (4.14) while cooling.
4.16 Tin(II) chloride solution, 2 g/l
Dilute 1 ml of the tin(II) chloride stock solution (4.13) with 10 ml of sulphuric acid solution (4.15) and make up
to 200 ml with water.
Prepare this solution fresh before use.
4.17 Ammonium vanadate solution, 2,5 g/l
Dissolve 2,5 g of ammonium vanadate (NH VO ) in 1 000 ml of water.
4 3
4.18 Citric acid solution, 500 g/l
Dissolve 500 g of citric acid (C H O ) in 1 000 ml of water.
6 8 7
4.19 Phosphorus stock solution, 100 mg/l
Dissolve 0,439 3 g of potassium dihydrogen orthophosphate (KH PO ), freshly dried at 105 °C, with water
2 4
into a 1 000 ml one-mark volumetric flask, dilute to the mark and mix well.
1 ml of this stock solution contains 0,1 mg of phosphorus.
4.20 Phosphorus standard solution, 10 mg/l
Transfer 20 ml of the phosphorus stock solution (4.19) into a 200 ml one-mark volumetric flask, dilute to the
mark with water and mix well.
1 ml of this standard solution contains 0,01 mg of phosphorus.
5

---------------------- Page: 7 ----------------------

kSIST-TS FprCEN/TS 15656:2015
FprCEN/TS 15656:2014 (E)
5 Apparatus
All vessels shall be free of contamination by phosphorus. Cleaning with hot hydrochloric acid (4.12), is
recommended.
5.1 PTFE beakers, capacity 100 ml
5.2 Spectrophotometer, fitted with cells of optical path lengths 1 cm and 4 cm
6 Sampling
Sampling shall be carried out in accordance with ISO 1811-1 or ISO 1811-2, as appropriate.
Test samples shall be in the form of fine drillings, chips or millings with a maximum thickness of 0,5 mm.
7 Procedure
7.1 Preparation of the test portion solution
7.1.1 Test portion
Weigh (1 ± 0,001) g of the test sample.
7.1.2 Test portion solution
7.1.2.1 Dissolve the test portion (7.1.1) in a PTFE beaker (5.1) with 10,0 ml of nitric acid solution (4.2).
Heat gently, if necessary. To eliminate silicon, add 0,50 ml of hydrofluoric acid (4.3) and 10,0 ml of perchloric
acid (4.4) and heat until fuming begins.
7.1.2.2 Dilute the solution with 10 ml of water and add 10,0 ml of hydrobromic acid (4.5). To eliminate
interference from arsenic, antimony and tin, heat gently until fuming begins again. If tin content is > 1 % (mass
fraction), repeat the fuming step with 10,0 ml of hydrobromic acid (4.5).
7.1.2.3 Dissolve the copper bromide formed during the fuming steps by adding several millilitres of nitric
acid solution (4.2) and bring to fuming. Dilute this solution with 30 ml of water. Heat to boiling for 10 min, then
cool to room temperature. Filter the solution through a fine pored filter. Wash the filter with hot water until it is
free of acid, then dry and ignite the filter in a small platinum crucible covered with a platinum cover. The
temperature has to be increased slowly. Mix the residue with about 0,3 g of sodium carbonate and fuse.
NOTE If the test sample contains zirconium, titanium, niobium and/or tantalum, phosphorus can be found totally or
partially as insoluble phosphates. The procedure for dissolving these residues is described below.
After cooling, dissolve the melt with a small amount of water. Filter off any insoluble residue and wash with hot
water, adding the washings to the filtrate. Neutralize the combined filtrate and washings with perchloric acid
(4.4). Add the neutralized solution of the original copper-containing filtrate. The total volume should not
exceed 50 ml; if necessary, the volume should be reduced by evaporating.
7.2 Blank test
Carry out a blank test simultaneously with the determination, following the same procedure and using the
same quantities of all reagents and of pure copper as used for the determination, but omitting the test portion.
Correct the result obtained from the determination in accordance with the result for the blank.
6

---------------------- Page: 8 ----------------------

kSIST-TS FprCEN/TS 15656:2015
FprCEN/TS 15656:2014 (E)
7.3 Check test
Make a pr
...

SLOVENSKI STANDARD
SIST-TS CEN/TS 15656:2015
01-julij-2015
1DGRPHãþD
SIST-TS CEN/TS 15656:2010
%DNHULQEDNURYH]OLWLQH'RORþHYDQMHIRVIRUMD6SHNWURIRWRPHWULþQDPHWRGD
Copper and copper alloys - Determination of phosphorus content - Spectrophotometric
method
Kupfer und Kupferlegierungen - Bestimmung des Phosphorgehaltes -
Spektrophotometrisches Verfahren
Cuivre et alliages de cuivre - Détermination du phosphore - Méthode
spectrophotométrique
Ta slovenski standard je istoveten z: CEN/TS 15656:2015
ICS:
77.120.30 Baker in bakrove zlitine Copper and copper alloys
SIST-TS CEN/TS 15656:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST-TS CEN/TS 15656:2015

---------------------- Page: 2 ----------------------

SIST-TS CEN/TS 15656:2015

TECHNICAL SPECIFICATION
CEN/TS 15656

SPÉCIFICATION TECHNIQUE

TECHNISCHE SPEZIFIKATION
April 2015
ICS 77.120.30 Supersedes CEN/TS 15656:2009
English Version
Copper and copper alloys - Determination of phosphorus content
- Spectrophotometric method
Cuivre et alliages de cuivre - Détermination du phosphore - Kupfer und Kupferlegierungen - Bestimmung des
Méthode spectrophotométrique Phosphorgehaltes - Spektrophotometrisches Verfahren
This Technical Specification (CEN/TS) was approved by CEN on 24 February 2015 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15656:2015 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST-TS CEN/TS 15656:2015
CEN/TS 15656:2015 (E)
Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Principle .4
4 Reagents .4
5 Apparatus .6
6 Sampling .6
7 Procedure .6
7.1 Preparation of the test portion solution .6
7.2 Blank test .6
7.3 Check test .7
7.4 Establishment of the calibration curve .7
7.5 Determination . 10
8 Expression of results . 11
9 Precision . 11
10 Test report . 12
Bibliography . 13


2

---------------------- Page: 4 ----------------------

SIST-TS CEN/TS 15656:2015
CEN/TS 15656:2015 (E)
Foreword
This document (CEN/TS 15656:2015) has been prepared by Technical Committee CEN/TC 133 “Copper and
copper alloys”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN/TS 15656:2009.
Within its programme of work, Technical Committee CEN/TC 133 requested CEN/TC 133/WG 10 "Methods of
analysis" to prepare the revision of the following document:
CEN/TS 15656:2009, Copper and copper alloys — Determination of phosphorus content —
Spectrophotometric method.
In comparison with CEN/TS 15656:2009 only editorial modifications have been made.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

3

---------------------- Page: 5 ----------------------

SIST-TS CEN/TS 15656:2015
CEN/TS 15656:2015 (E)
1 Scope
This Technical Specification specifies a molybdovanadate spectrophotometric method for the determination of
phosphorus in copper and copper alloys in the form of castings or unwrought or wrought products.
The method is applicable to products having phosphorus mass fractions between 0,001 % and 0,5 %.
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 1811-1, Copper and copper alloys — Selection and preparation of samples for chemical analysis —
Part 1: Sampling of cast unwrought products
ISO 1811-2, Copper and copper alloys — Selection and preparation of samples for chemical analysis —
Part 2: Sampling of wrought products and castings
3 Principle
Dissolution of a test portion in nitric acid. Elimination of interfering elements by fuming with perchloric,
hydrofluoric and hydrobromic acids. Decomposition of insoluble phosphates by fusion with sodium carbonate.
For contents below 0,01 % mass fraction, extraction of phosphorus as phosphomolybdic acid and
spectrophotometric determination as molybdenum blue; for contents between 0,005 % and 0,05 % mass
fraction, extraction and spectrophotometric determination as phosphovanadomolybdic acid.
4 Reagents
During the analysis, use only reagents of recognized analytical grade and only distilled water or water of
equivalent purity.
4.1 Nitric acid, HNO (ρ = 1,40 g/ml)
3
4.2 Nitric acid solution, 1 + 1
Add 500 ml of nitric acid (4.1) to 500 ml of water.
4.3 Hydrofluoric acid, HF (ρ = 1,13 g/ml)
4.4 Perchloric acid, HClO (ρ = 1,67 g/ml)
4
4.5 Hydrobromic acid, HBr (ρ = 1,50 g/ml)
4.6 Isobutanol
4.7 Sodium carbonate, Na CO
2 3
4.8 Methanol
4.9 Methyl isobutyl ketone
4

---------------------- Page: 6 ----------------------

SIST-TS CEN/TS 15656:2015
CEN/TS 15656:2015 (E)
4.10 Ammonium molybdate solution, 50 g/l
Dissolve 50 g of ammonium molybdate tetrahydrate [(NH ) Mo O • 4H O] in 250 ml of water. Add a solution
4 6 7 24 2
of 115 ml of the perchloric acid (4.4) and 500 ml of water at room temperature. Dilute to 1 000 ml with water.
After prolonged storage, a white precipitate may form. While this residue will not affect the analysis, care
should be taken to prevent its contamination of the aliquot used in the analysis.
Immediately before use, the aliquot used in the analysis should be purified by shaking with 10 ml of the
isobutanol (4.6).
4.11 Ammonium molybdate solution, 150 g/l
Dissolve 150 g of ammonium molybdate tetrahydrate [(NH ) Mo O • 4H O] in 1 000 ml of water.
4 6 7 24 2
4.12 Hydrochloric acid, HCl (ρ = 1,19 g/l)
4.13 Tin(II) chloride solution, 400 g/l
Dissolve 10 g of tin(II) chloride dihydrate (SnCl • 2H O) in 25 ml of hydrochloric acid (4.12). Prepare this
2 2
solution fresh before use.
4.14 Sulphuric acid, H SO (ρ = 1,84 g/l)
2 4
4.15 Sulphuric acid solution, 10 mol/l
To 100 ml of water add 56 ml of sulphuric acid (4.14) while cooling.
4.16 Tin(II) chloride solution, 2 g/l
Dilute 1 ml of the tin(II) chloride stock solution (4.13) with 10 ml of sulphuric acid solution (4.15) and make up
to 200 ml with water.
Prepare this solution fresh before use.
4.17 Ammonium vanadate solution, 2,5 g/l
Dissolve 2,5 g of ammonium vanadate (NH VO ) in 1 000 ml of water.
4 3
4.18 Citric acid solution, 500 g/l
Dissolve 500 g of citric acid (C H O ) in 1 000 ml of water.
6 8 7
4.19 Phosphorus stock solution, 100 mg/l
Dissolve 0,439 3 g of potassium dihydrogen orthophosphate (KH PO ), freshly dried at 105 °C, with water into
2 4
a 1 000 ml one-mark volumetric flask, dilute to the mark with water and mix well.
1 ml of this stock solution contains 0,1 mg of phosphorus.
4.20 Phosphorus standard solution, 10 mg/l
Transfer 20 ml of the phosphorus stock solution (4.19) into a 200 ml one-mark volumetric flask, dilute to the
mark with water and mix well.
1 ml of this standard solution contains 0,01 mg of phosphorus.
5

---------------------- Page: 7 ----------------------

SIST-TS CEN/TS 15656:2015
CEN/TS 15656:2015 (E)
5 Apparatus
All vessels shall be free of contamination by phosphorus. Cleaning with hot hydrochloric acid (4.12), is
recommended.
5.1 PTFE beakers, capacity 100 ml
5.2 Spectrophotometer, fitted with cells of optical path lengths 1 cm and 4 cm
6 Sampling
Sampling shall be carried out in accordance with ISO 1811-1 or ISO 1811-2, as appropriate.
Test samples shall be in the form of fine drillings, chips or millings with a maximum thickness of 0,5 mm.
7 Procedure
7.1 Preparation of the test portion solution
7.1.1 Test portion
Weigh (1 ± 0,001) g of the test sample.
7.1.2 Test portion solution
7.1.2.1 Dissolve the test portion (7.1.1) in a PTFE beaker (5.1) with 10,0 ml of nitric acid solution (4.2).
Heat gently, if necessary. To eliminate silicon, add 0,50 ml of hydrofluoric acid (4.3) and 10,0 ml of perchloric
acid (4.4) and heat until fuming begins.
7.1.2.2 Dilute the solution with 10 ml of water and add 10,0 ml of hydrobromic acid (4.5). To eliminate
interference from arsenic, antimony and tin, heat gently until fuming begins again. If tin content is > 1 % (mass
fraction), repeat the fuming step with 10,0 ml of hydrobromic acid (4.5).
7.1.2.3 Dissolve the copper bromide formed during the fuming steps by adding several millilitres of nitric
acid solution (4.2) and bring to fuming. Dilute with 30 ml of water. Heat to boiling for 10 min, then cool to room
temperature. Filter the solution through a fine pored filter. Wash the filter with hot water until it is free of acid,
then dry and ignite the filter in a small platinum crucible covered with a platinum cover. The temperature has
to be increased slowly. Mix the residue with about 0,3 g of sodium carbonate and fuse.
NOTE If the test sample contains zirconium, titanium, niobium and/or tantalum, phosphorus can be found totally or
partially as insoluble phosphates. The procedure for dissolving these residues is described below.
After cooling, dissolve the melt with a small amount of water. Filter off any insoluble residue and wash with hot
water, add
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.