ISO 15093:2020 pdf free

ISO 15093:2020 pdf free.Jewellery and precious metals一Determination ofhigh purity gold, platinum and palladium一Difference method using ICP-OES
The sample is weighed and dissolved in aqua regia to prepare a 10 g/l solution (higher concentration is used for fineness of and above 999,9 %]. The impurities are determined by ICP-OES (see Table A.1 for wavelengths), and the precious metal content is obtained by subtraction of the total content of impurities in the sample from 1 000 %o. For the determination of fineness of and above 999,9 %o,modifications described in Annex B shall be applied.
Add 5 ml of stock solution C (5.6) and 5 ml of stock solution D (5.7), make up with water to 50 ml,and mix thoroughly. This solution is unstable over time and should be prepared just before use, or its stability validated.
The volumes of stock solutions shall be lowered to match the concentration of impurities in the sample. It is possible to use a multiple-point calibration by adding calibration solutions with other concentrations.
Set up the instrument in accordance with the manufacturer’s instructions and choose appropriate background correction positions. A clean torch, spray chamber, and sample uptake tubes shall be used and the plasma shall be stabilized before use, following the recommendations of the instruments manufacturer.
Spray the blank and calibration solutions 1 (8.3.2) and 2 (8.3) in accordance with the defined instrument calibration procedure and then run the analytical procedure for the sample solutions. The result shall be displayed with enough decimal places to provide an accurate indication of concentrations at the detection limits of the relevant elements.
Each solution shall have a stabilization time of at least 30 s, followed by at least three integrations each for the determination of the net intensities (background-corrected).
The rinsing time between each measurement shall be sufficient to allow the signal of each impurity to come back to the baseline.
Set the concentration in the blank solution and the calibration solution, taking into account impurities introduced in the solution by the reference material (5.8) and calculate the calibration curve for each element using the net intensities obtained for the blank solution and the calibration solution.ISO 15093 pdf free download.