ISO 11495:2019 pdf download

ISO 11495:2019 pdf download.Jewellery and precious metals – Determination of palladium in palladium alloys – ICP-OES method using an internal standard element
1 Scope
This document describes an analytical procedure for the determination of palladium in palladium alloys with a nominal content up to 990 %0 (parts per thousand), including alloys according to ISO 9202.
2 Normative references
There are no normative references in th is document.
3 Terms and
No terms and definitions are listed in this document.
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4 Principle
At lea st two accurately weighed samp les are dissolved in aqua regia and made up to an exact ly weighed mass. The se sample solutions are mixed with th e i nternal standard and made up to the standard measuring volume. Using ICP-OES, the palladium content of the sample solution is measured by comparison of the ratio intensities of the spectra l emission of palladium and appropriate in ternal standard [ e.g. yttrium ] line(s) with the ratios for solutions containing known masses of palladium and internal standard [ e.g. yttrium) using the bracketing method.
8.2 Calibration solutions
The sequence by bracketing needs the use of on ly two standards that shall correspond to the nearest points (low standard and high standard as used the expected palladium samp le content. It is recommended to prepare a set of at least three standards and to check their linearity. Weigh approximately 45 mg, 55 mg, 65 mg, 75 mg, 82,S mg, 87,5 mg, 92,S mg, 97,S mg an d 100 mg palladium accurately to 0,01 mg each into a gl ass beaker . Heat gently the sample in the glass beaker covered with a watch glass in a mixt u re of 100 ml HCI ( il ) and 30 ml H N03 until complete dissolution and continue to heat to expel the nitrogen oxides. Transfer the solution in a 1 000 ml flask. Add 100 g accurately to 0,01 g of the internal standard solution ( .8.J. ). Add 100 ml HCl ( .5…1 ] and make up to 1 000 ml wit h thoroughly. In the presence of certain other elements [ e.g. silver ], it can be necessary to increase the H CI concentration to a maximum of 500 ml. The acid concentration of calibration solutions and samp le solutions shall be consistent.
8 .4 Measur e ments
The data processing unit of the I CP-OES is used to establish a meas uring program in which the i ntensities of the pa ll adium emission lines and of the interna l standard element yttrium can be measured simultaneously. Set up the i nstrument in accordance with the manufacturer ’ s inst ructions and choose appropr i ate background correct ion 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 inst ruments manufacturer.