ForewordScopeNormative referencesTerms and definitionsPrincipleReagentsApparatusSamplingProcedureTest portionBlank testDeterminationDissolution of the test portionPreparation of the final test solutionGeneralAbsence of tantalumPresence of tantalumDilutionsDilution for titanium contents ≤ 1 %Dilution for titanium contents between 1 % and 5 %Colour developmentSpectrophotometric measurementEstablishment of the calibration curveCheck testExpression of resultsMethod of calculationPrecisionLaboratory testsStatistical evaluationTest reportBibliography