GB/T 19942-2019Leather and fur - Chemical tests - Determination of banned azo colorants (English PDF)

Foreword

This Standard is drafted in accordance with the rules given in GB/T 1.1-2009.

This Standard replaces GB/T 19942-2005 "Leather and fur - Chemical tests -

Determination of banned azo colourants".

Compared with GB/T 19942-2005, the main technical changes of this Standard

are as follows.

- In "Normative references", delete the year number cited to GB/T 6682; ADD

the reference to "GB/T 33392" (see Clause 2; Clause 2 of the 2005 edition);

- In "Principle" clause, delete specific test conditions; ADD the method for

determination of amine (see Clause 4; Clause 4 of the 2005 edition);

- ADD the purity requirement for methanol (see 5.2);

- ADD ethyl acetate (see 5.3);

- ADD the purity requirement and descriptive note for tert-butyl methyl ether

(see 5.4);

- ADD the requirement for the storage time after the preparation of sodium

dithionite solution (see 5.6);

- Modify the pre-heating temperature requirement for citrate buffer (see 5.11;

252 on Leather Industry of Standardization Administration of China (SAC/TC

252).

Drafting organizations of this Standard. Jiaxing Fur and Footwear Industry

Research Institute, Chongqing Testing and Certification (Group) Co., Ltd., State

Center of Supervision and Test for Leather (Zhejiang), Guangzhou Quality

Supervision and Testing Institute, Jihua 3514 Leather and Footware Co., Ltd.,

Sungoal (Dongguan) Advanced Materials Tech Co., Ltd., Saturday Co., Ltd.

Main drafters of this Standard. Jiang Sujie, Zhang Li, Shen Yun, Zhong Xihao,

Huo Jianchun, Li Xiaolong, Zeng Hao, Sun Dong, Li Li, Zhao Xiangxu.

The previous editions of the standard replaced by this Standard were released

as follows.

- GB/T 19942-2005.

Leather and fur - Chemical tests - Determination of

banned azo colorants

WARNING - The personnel using this Standard shall have practical

experience in regular laboratory work. The aromatic amines are classified

as substances known to be or suspected to be human carcinogens. This

Standard does not point out all possible safety problems. It is the

responsibility of the user to take appropriate safety and health measures

and ensure compliance with the conditions of relevant national and local

laws and regulations.

1 Scope

This Standard specifies the determination method for banned azo colorants that

can release carcinogenic aromatic amines in dyed leather and fur.

2 Normative references

The following documents are indispensable for the application of this document.

For the dated references, only the editions with the dates indicated are

applicable to this document. For the undated references, the latest edition

(including all the amendments) are applicable to this document.

GB/T 6682 Water for analytical laboratory use - Specification and test

methods (GB/T 6682-2008, ISO 3696.1987, MOD)

3 Terms and definitions

The following term and definition applies to this document.

The colorant which can cleave one or more azo groups to produce the aromatic

amines listed in Table 1.

4 Principle

PLACE the degreased sample in a closed vessel; at a certain temperature, in

a buffer of specified pH, use sodium dithionite to treat it; then extract it by liquid-

liquid extraction of kieselguhr columns. EXTRACT the aromatic amine

produced by reductive cleavage into tert-butyl methyl ether. After concentration,

use an appropriate solvent to dissolve and dilute.

5 Reagents and materials

Unless otherwise specified, the reagents used are of analytical grade; all

solutions are aqueous solutions.

6 Apparatus

Extraction column, polypropylene or glass column. Inner diameter is 25

mm~30 mm; length is 140 mm~150 mm. The end is equipped with porous

granular kieselguhr (about 20 g; lightly tap the glass column to make the

packing firm).

7 Sampling and preparation of samples

For printed and multi-color splicing samples, the various colors of leather fur

shall be considered as much as possible and tested separately. If the sample

is composed of leather and fur of different qualities, the materials of different

qualities shall be tested separately.

Leather. It shall be in accordance with the provisions of QB/T 2716.

8 Test procedure

USE a glass rod to squeeze the fiber material in the reactor as much as possible;

carefully transfer all the lysis solution to the kieselguhr extraction column (6.5);

and allow to be absorbed for 15 min.

9 Calculation and expression of results

By comparing the peak area of each aromatic amine component in the sample

solution with the standard working solution (5.12), calculate the aromatic amine

content in the sample. The calculation formula is shown in formula (1).

According to the following recognition threshold, list and report separately.

10 Method feasibility

The feasibility of the method is expressed by the recovery rate. TAKE 1.0 mL of

aromatic amine standard solution (5.12); ADD it to the reactor (6.1) containing

16 mL of preheated citrate buffer (5.11); then, perform analysis according to the

operation steps for treating samples (see 8.2 and 8.3).

11 Test report

The test report shall include the following.

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