GB/T 21198.1-2007Determination of precious metals in precious metals jewellery alloys -- Method using ICP spectrometry -- Part 1: Platinum jewellery alloys -- Determination of platinum -- Method using a solution with yttrium as internal standard element (English PDF)

Foreword

GB/T 21198 "precious metal jewelery alloys precious metal content using ICP spectrometry" is divided into six parts.

--- Part 1. Determination of platinum content platinum jewelery alloys using yttrium as internal standard;

--- Part 2. Determination of platinum content platinum alloy jewelry using platinum all trace elements and the intensity ratio method;

--- Part 3. Determination of palladium jewelery alloys using palladium content of yttrium as internal standard;

--- Part 4. Determination of 999 per mille precious metal jewelery alloys precious metal content of subtraction;

Part --- Article 5. 999 per mille silver jewelery alloys - Determination of silver content difference of subtraction;

--- Part 6. Subtraction.

This section GB/T 21198 Part 1.

The section referring to ISO/DIS11494-2. "Determination of platinum in platinum jewelery alloys for the content of yttrium as internal standard using ICP spectroscopy" 2001 Write, there are mainly ISO/DIS11494-2 the following technical differences.

--- The Normative references to international standards referenced in the file to our national standard GB 11887;

--- According to our standard requirements for the preparation of reagents specifications made provisions;

--- Due to the current international and domestic no standard for sample preparation, thus deleting the original text of Chapter 6 and Chapter 9 b).

For ease of use, this section also made the following editorial changes.

--- "This International Standard" be replaced by "this section";

"." --- With a decimal point instead of a comma as the decimal point, "";

--- With "mL" instead of "cm3";

--- Delete international standards foreword.

This part is proposed by the China National Light Industry Council.

This part of the National Standardization Technical Committee jewelry (SAC/TC256) centralized.

This section drafted by. National Jewelry Quality Supervision and Inspection Center.

1 Scope

This section GB/T 21198 specifies the yttrium as internal standard using ICP spectrometry platinum alloy jewelry platinum content approach.

This section applies to a platinum content of 850 per mille ~ 970 per mille platinum jewelery alloys.

Note. The platinum alloy may contain iridium, palladium, gold, rhodium, copper, cobalt, ruthenium, gallium, chromium, indium and tungsten. Containing these alloying elements in the determination process generally do not cause interference.

2 Normative references

The following documents contain provisions which, through reference GB/T 21198 in this section constitute provisions of this section. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

GB 11887 jewelry precious metal purity and designation of (GB 11887-2002, ISO 9202:1991, NEQ)

3 PRINCIPLE OF THE METHOD

Accurately weighed sample was dissolved in aqua regia and made accurate quality solution. The sample solution was prepared quantitatively solution aliquot, and the buffer Mixing the solution and the internal standard, calibration standard to measure the volume.

Application of ICP spectrometer, the sample solution of platinum (265.95nm, 214.42nm, 299.80nm or 306.47nm) and yttrium (371.03nm) the spectral intensity ratio of divergence compared with known mass ratio of platinum and yttrium solution, measuring the platinum content.

When the alloy containing ruthenium, rhodium, iridium, with minor changes, chromium or tungsten.

4 Reagent material

Unless otherwise indicated in the analysis using only recognized as analytical grade reagents and distilled or deionized water or equivalent purity.

4.1 Hydrochloride. mass fraction of 36% ~ 38%, rho = 1.19g/mL.

4.2 nitric acid. mass fraction of 65% ~ 68%, rho = 1.40g/mL.

4.3 pure platinum. content of at least 99.99%.

4.4 Internal standard solution. Weigh 26.8g copper dihydrate (CuCl2 · 2H2O) chloride, 7.3g sodium nitrate (NaNO3) and about 680mg Six Rivers Co-yttrium chloride (YCl3 · 6H2O) was dissolved in 200mL of water, water calibration to 1000mL.

4.5 copper. content of at least 99.99%, and does not contain platinum.

5 Instruments

Conventional laboratory instruments and equipment following

5.1 Inductively coupled plasma atomic emission spectroscopy (ICP spectrometer for short). simultaneous determination of platinum emission line 265.95nm, 214.42nm, 299.80nm or 306.47nm and yttrium internal standard emission line intensity of 371.03nm.

Spectrometry results are more satisfied with the following characteristics.