GB/T 19719-2005 PDF in English
GB/T 19719-2005 (GB/T19719-2005, GBT 19719-2005, GBT19719-2005)
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Jewellery -- Determination of the release of nickel -- Method of spectrometry
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GB/T 19719-2005: PDF in English (GBT 19719-2005) GB/T 19719-2005
GB
ICS 39. 060
Y 88
NATIONAL STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
Jewellery - Determination of the Release of
Nickel - Method of Spectrometry
ISSUED ON. MARCH 23, 2005
IMPLEMENTED ON. SEPTEMBER 1, 2005
Jointly Issued by. General Administration of Quality Supervision, Inspection
and Quarantine of the People's Republic of China;
Standardization Administration Committee of the People's
Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Principle ... 4
4 Reagents ... 4
5 Apparatus ... 5
6 Samples ... 6
7 Procedure ... 7
8 Calculations... 8
9 Test Report ... 9
Appendix A ... 10
Appendix B ... 12
Appendix C ... 14
Appendix D ... 15
Appendix E ... 16
Appendix F... 17
Foreword
This Standard is modified in relation to European Standard EN 1811.1998 "Reference Test
Method for Release of Nickel from Products Intended to Come into Direct and Prolonged
Contact with the Skin" (English edition).
In order to be convenient for application, this Standard makes the following editorial changes.
a) "This European Standard" was changed into "this Standard";
b) The comma "," served as decimal point is replaced by the decimal point ".";
c) "cm3" is replaced by "mL";
d) The Foreword of the international standard was deleted;
e) Add Appendix E (Informative) for guidance.
Appendixes A, B, C, D, E and F of this Standard are informative.
This Standard was proposed by China National Light Industry Council.
This standard shall be under the jurisdiction of National Technical Committee on Jewellery of
Standardization Administration of China (SAC/TC 256).
Drafting organizations of this Standard. National Jewellery Quality Supervision and
Inspection Center, National Center of Quality Supervision & Inspection on Gold-Silver
Products (Nanjing), and National Center of Quality Supervision & Inspection on Gold-Silver
Products (Shanghai).
Chief drafting staffs of this Standard. Li Wujun, Wang Donghui, Fang Mingxu, Fan Jifang, Li
Yukun, and Li Suqing.
Jewellery - Determination of the Release of
Nickel - Method of Spectrometry
1 Scope
This Standard specifies a method for simulating the release of nickel from jewellery, in order
to determine whether the item releases nickel at a rate greater than 0.5 μg/(cm2·week).
This Standard is applicable to the determination of the release of nickel from jewellery, as
well as the products intended to come into direct and prolonged contact with the skin (see
4.3.2 of GB 11887-2002).
2 Normative References
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this Standard. For dated references, subsequent amendments to, or
revisions of, any of these publications do not apply. However, parties to agreements based on
this Standard are encouraged to investigate the possibility of applying the most recent editions
of the normative documents indicated below. For undated references, the latest edition of the
normative document referred to applies.
GB 11887-2002 Jewellery — Fineness of Precious Metal Alloys and Designation (ISO
9202.1991, NEQ)
3 Principle
The item to be tested for nickel release is placed in an artificial sweat test solution for one
week. The concentration of dissolved nickel in the solution is determined by atomic
absorption spectrometry, inductively-coupled plasma spectrometry or other appropriate
analytical method. The nickel release is expressed in micrograms per square centimetre per
week [μg/(cm2·week)].
4 Reagents
Except where indicated, all reagents, distilled water or deionized water or equivalent shall be
of recognized analytical pure grade.
4.1 Sodium chloride.
water (7.1.1). Before use, ensure that the pH of the test solution is in the range 6.40 to 6.60.
Use the test solution within 3 h of preparation.
7.2 Release procedure
7.2.1 Place the sample, suspended by its holder, in the test vessel (5.4). Add an amount of
test solution corresponding to approximately 1 mL per cm2 sample area. The suspended
sample shall be totally immersed. However, it is not essential to immerse areas which are
completely protected by wax or lacquer. The minimum volume of test solution added shall be
0.5 mL irrespective of the surface area. Note the sample area and the amount of the test
solution used. Close the vessel with a tight lid in order to prevent evaporation of the test
solution. Leave the vessel undisturbed in a thermostatically-controlled water-bath or oven (5.3)
at (30 ± 2) ℃ for 168 h without agitation. After 1 week, remove the sample from the test
solution and rinse it with a small quantity of deionized water, adding the rinsings to the test
solution. Quantitatively transfer the test solution to an appropriately-sized volumetric flask
washed with acid. The choice of volumetric flask size should take into account the sensitivity
of the instrumentation used for the nickel determination (see 5.2.2). In order to prevent
redeposition of dissolved nickel, add dilute nitric acid (4.8) and deionized water to the test
solution to achieve a concentration of about 1 % nitric acid when the flask is made up to
volume (V ml). The minimum final volume to which the test solution may be diluted is 2 mL.
7.3 Determination of nickel
Determine the nickel content of the test solution using an analytical spectrometer (see 5.2).
7.4 Number of replicates
Whenever possible, the determination shall be carried out on at least two identical samples.
7.5 Blank tests
Duplicate blank tests shall be carried out at the same time as the testing of the sample.
Identical vessels and holders shall be used and the test procedure is identical except that no
sample is placed in the vessels. Identical amounts of test solution, rinsing water and dilute
nitric acid shall be used.
8 Calculations
8.1 Nickel release
The nickel release of a sample, d, expressed in micrograms per square centimetre per week
[μg/(cm2·week)], is given by the equation.
1 2( )
V c cd
(1)
Appendix C
(Informative)
Identification and Determination of Sample Area; and Coating of
Non-significant Areas
C.1 Identification and determination of sample area
When identifying the sample area, account should be taken of the elasticity of the skin and of
the manner in which items come into contact with the skin. Where articles appear to be made
from uniform materials, consideration should be given to testing the whole surface (whether
or not it is all in direct and prolonged contact with the skin) since errors may be introduced by
the stopping-off process. For articles made from round wire (diameter < 3 mm) joined
together, such as neck-chains or bracelets, the calculation of surface area should use the
projected areas of all significant surfaces, unless the wire passes through the skin when the
true surface is appropriate. Articles made from square, rectangular, oval, etc. sections or round
wire (diameter ≥ 3 mm) can be assumed to depress the skin around the article to a depth of 2
mm. Equally, if the surface of the part of the article in contact with the skin contains
indentations or depressions ≥ 2 mm, their projected areas should be included in the sample
area. The surface area of articles made essentially from sheet material, such as watch-cases,
some medallions and lockets, can be assumed to be that area projected by all parts within 2
mm of the uncompressed skin-contact surface. The designer of an article may be able to
advise on its surface area, especially when computer-aided design has been used.
Autocatalytic coating techniques may be applied to measure the surface area.
C.2 Coating of non-significant areas
A number of stopping-off lacquers used in the electroplating industry have been suggested.
The important points in their selection and use are.
— effective, preferably in a single coat, in preventing access of the artificial sweat to the
non-significant surface;
— application using a brush...
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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