ISO INTERNATIONAL STANDARD 22960 First edition 2008-01-15 Titanium and titanium alloys Determination of iron Molecular absorption spectrometry using 1, 10-phenanthroline Titane et alliages de titane-Dosage dufer-Spectrometrie d'absorption moléculaireparla 1,10-phenanthroline Referencenumber ISO 22960:2008(E) ii Contents Page Foreword. 1 Scope 2 Normative references 3 Principle.. 4 Reagents... 5 Apparatus 2 6 Sample.. 7 Procedure..... 8 Expressionof results. 9 ili Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies technical committees. Each member body interested in a subject for which a technical committee has been International Electrotechnical Commission (IEC)on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC 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. Sc 11, Titanium. iv Titanium and titanium alloysDetermination ofiron Molecularabsorptionspectrometryusing1,10-phenanthroline Scope This International Standard specifies a molecular absorption spectrometric method using 1, 10-phenanthroline for the determination of the mass fraction of iron in titanium and titanium alloys. The method is applicable to titanium and titanium alloys with a mass fraction of iron in the range from 0,005 % to 2,0 % Normative references 2 The following referenced documents are indispensable for the application of this document. For dated document (including any amendments) applies. Iso384:1978,Laboratoryglassware-Principlesofdesignandconstructionofvolumetricglassware Iso648:1),LaboratoryglasswareSinglevolumepipettes ISO1042:1998,Laboratoryglassware-One-markvolumetricflasks Iso 3696:1987, Water for analytical laboratory use—Specifications and test methods 3 Principle Dissolve the test portion in hydrochloric acid and hydrofluoric acid. Add nitric acid to oxidize titanium. Then add boric acid, tartaric acid, ammonium acetate and hydroxyl ammonium chloride. Add 1, 10-phenanthroline to make a 1,10-phenanthroline-iron complex. Determine the iron concentration in the test portion using a spectrophotometer. Reagents 4.1 General ISO3696 1)To be published. (Revision of ISO 648:1977) 1 4.2Hydrochloric acid (1+1) Add slowly 500 ml of hydrochloric acid ( P20 1,16 g/ml to 1,19 g/ml) to 500 ml of water. 4.3 Nitric acid (1+1) Add slowly 500 ml of nitric acid ( P20 1,42 g/ml) to 500 ml of water. 4.4 Hydrofluoric acid (1+1) Add, carefully and slowly, 100 ml of hydrofluoric acid ( P20 1,14 g/ml) to 100 ml of water. 4.5 Boric acid 4.6 Tartaric acid solution (200 g/l) 4.7 Ammoniumacetatesolution(500g/l) 4.8Hydroxyl ammonium chloride solution (100 g/l) 4.91,10-phenanthroline solution (100g/l) Dissolve 2,4 g of 1,10-phenanthrolinium chloride monohydrate in 1 000 ml of water, or dissolve 2,0 g of 1,10-phenanthroline monohydrate in 100 ml of ethanol [minimum purity 95 % (volume fraction)] and dilute to 1 000 ml with water. 4.10 Iron standard solution 4.10.1 Iron standard stock solution (0,500 mg Fe/ml) Weigh, to the nearest 0,1 mg, 0,500 g of iron metal [minimum purity 99,9 % (mass fraction)] into a 300 ml beaker, heat and decompose with 30 ml of hydrochloric acid (4.2). Add 5 ml of nitric acid (4.3) to oxidize iron and heat to evaporate nitrogen oxides. After cooling, transfer to a 1 0o0 ml volumetric flask, make up to the mark with water and mix. 4.10.2 Iron standard solution (0,050 mgFe/ml) waterandmix.Preparethis solutiononthedayofuse 5 Apparatus 5