ISO TR 9769:2018 pdf free
ISO TR 9769:2018 pdf free.Steel and iron一Review of available methods of analysis
Principle of the method:
a) dissolution of a test portion in a mixture of hydrochloric, nitric and phosphoric acid and fuming with a mixture of phosphoric and perchloric acids;
b) addition of hydrofluoric acid and, if necessary, an internal reference element and dilution of the solution to known volume;
c) nebulization of the solution into an ICP-AES and measurement of the intensity of the emitted light from molybdenum, or with emitted light from the internal reference element, simultaneously.
NOTE 1 The method uses a calibration graph based on a very close matrix matching of the calibration solutions to the sample and close bracketing of the contents around the approximate concentration of molybdenum in the sample to be analysed. The concentrations of all elements in the sample have to be, therefore, approximately known. If the concentrations are not known, the sample has to be analysed by some semi-quantitative method.
NOTE 2 The advantage with this procedure is that all possible interferences from the matrix are automatically compensated, which results in high accuracy. This is most important for spectral interferences, which can be severe in very highly alloyed steels. However, all possible interferences have to be kept on a minimum level.
Therefore, it is essential that the spectrometer used meets the performance criteria specified in the method for the selected analytical lines.
Principle of the method:
a) the sample is dissolved in a hydrochloric, nitric and hydrofluoric acid mixture and fumed with a phosphoric and perchloric acid mixture; hydrofluoric acid and an internal standard element (if used) are added and the solution is diluted to known volume; the solution is filtered and nebulized into an inductively coupled plasma (ICP) and the intensity of the emitted light from each element is measured simultaneously with the light emitted from the internal standard element;
b) the method uses a calibration based on close matrix matching of the calibration solutions to the sample and close bracketing of the niobium content around the approximate concentration of niobium in the sample to be analysed; this compensates for matrix interferences and provides high accuracy, even in highly alloyed steels where spectral interferences can be severe; nonetheless, all interferences have to be kept to a minimum and it is therefore essential that the spectrometer used meets the performance criteria specified in the method for the selected analytical lines;
c) in order to accurately matrix match, it is necessary to know the concentration of all elements in the sample (to the nearest per cent); to this end, it may be necessary to carry out a preliminary analysis of the sample by some semi-quantitative method.ISO TR 9769 pdf download.
