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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 24164-2009 Determination of the content of polychloriznated benzenes in dye products. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 24164-2009:
——the scope of this standard is modified (see Clause 1 hereof; Clause 1 of 2009 edition);
——the gas chromatographic method (GC-ECD) is deleted (see Clause 4 of 2009 edition);
——the principle is modified (see Clause 3 hereof; Clause 3 of 2009 edition);
——the preparation method of standard solution is modified (see Clause 6 hereof; 4.3 of 2009 edition);
——the preparation method of sample solution is modified (see Clause 7 hereof; 4.5.1 of 2009 edition);
——the chromatographic analysis conditions are modified (see 8.1 hereof; 4.5.2 of 2009 edition);
——the requirements for accuracy determination of the method are modified (see 10.3 hereof; 5.2 of 2009 edition);
——the types of chlorinated benzenes are modified (see Annex A hereof; Annex A of 2009 edition).
This standard was proposed by China Petroleum and Chemical Industry Federation.
This standard is under the jurisdiction of the National Technical Committee 134 on Dyestuff of Standardization Administration of China.
The previous edition of this standard is as follows:
——GB/T 24164-2009.
Determination of chlorinated benzenes in dye products
Warning – Persons using this standard shall be familiar with normal laboratory practice. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This standard specifies the method for determination of 12 kinds of chlorinated benzene residues in dye products by gas chromatography-mass spectrometry (GC/MS).
This standard is applicable to determination of chlorinated benzenes in various dye products.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgment of limiting values
3 Principle
In ultrasonic bath, chlorinated benzenes are extracted with dichloromethane from samples, separated and measured by gas chromatography-mass spectrometry (GC/MS), and quantified by peak area external standard method.
The types of chlorinated benzenes and the reference parameters for their determination are given in Annex A.
4 Reagents or materials
4.1 Standards of chlorinated benzenes (see Annex A).
4.2 Dichloromethane, chromatographic grade.
5 Apparatus
5.1 Gas chromatograph-mass spectrometer (GC/MS): equipped with EI source.
5.2 Chromatographic column: 50% phenylmethyl polysiloxane stationary phase, e.g., DB-17MS, 30 m×0.25 mm×0.25 μm or equivalent.
5.3 Analytical balance: with an accuracy of 0.01 mg.
5.4 Ultrasonic generator.
5.5 Extractor: tube with a stopper, 10 mL.
5.6 Centrifuge: 4 000 r/min.
5.7 Nitrogen blowing concentrator.
6 Preparation of standard solutions
6.1 Single-component standard stock solutions of chlorinated benzenes (1 000 mg/L)
According to Annex A, weigh 10 mg (accurate to 0.01 mg) of the listed standard substances respectively, dissolve them in dichloromethane, transfer them to 10 mL volumetric flasks and dilute to the scale to prepare the single-component standard stock solutions. The single-component standard stock solutions shall be stored below 4°C, protected from light, sealed and refrigerated. Volatile components, including monochlorobenzene, dichlorobenzene and trichlorobenzene, are valid for one week, while other components are valid for one month. Alternatively, certified standard solutions, single-component standard solutions of chlorinated benzenes or mixed standard solutions of chlorinated benzenes can also be purchased directly.
Foreword i
1 Scope
2 Normative references
3 Principle
4 Reagents or materials
5 Apparatus
6 Preparation of standard solutions
7 Preparation of sample solution
8 Test procedure
9 Result calculation
10 Detection limit, precision and accuracy
11 Test report
Annex A (Normative) Types of chlorinated benzenes and reference parameters for determination
Annex B (Informative) Chromatogram of chlorinated benzene standards
