Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
In this standard, Annex A is normative and Annex B is informative.
This standard was proposed by the China Petroleum and Chemical Industry Association.
This standard is under the jurisdiction of SAC/TC 134 Technical Committee on Dyestuff of Standardization Administration of China.
Determination of the content of polychloriznated benzenes in dye products
Warning: the personnel using this standard shall have practical experience in standard laboratory work. This standard does not purport to address all of the safety problems, 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 the determination of the content of polychloriznated benzenes (see Annex A) in dye products.
This standard is applicable to the determination of the content of polychloriznated benzenes in commercial dyes, dye products, dye intermediates and textile dyeing auxiliaries by gas chromatography-mass spectrometry (GC-MS) or gas chromatography-electron capture detector (GC-ECD).
2 Normative references
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) 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 edition of the normative documents indicated below. For undated references, the latest edition of the normative document applies.
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods (ISO 3696:1987, MOD)
GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgment of limiting values
3 Theory
Extract the polychloriznated benzenes in specimens with n-hexane in ultrasonic bath, then conduct determination of the extract by gas chromatography-mass spectrometry (GC-MS) or gas chromatography-electron capture detector (GC-ECD), and quantify it by external standard method.
4 Determination method
4.1 General requirements
Unless otherwise specified, only recognized analytically pure reagents and Grade-III water (specified in GB/T 6682-2008) shall be adopted. The inspection result shall be judged according to the rounding-off value comparison method specified in 4.3.3 of GB/T 8170-2008.
4.2 Reagents and solutions
a) n-hexane;
b) Standards of polychloriznated benzenes listed in Annex A: content (mass fraction) ≥99%.
4.3 Preparation of polychloriznated benzene standard solution
4.3.1 Single stock standard solution
Respectively weigh 0.01g (accurate to 0.0001g) of the standards of polychloriznated benzenes listed in Annex A, dissolve with n-hexane, and put the solutions into different 25mL volumetric flasks to prepare single stock standard solutions with a validity period of one year.
4.3.2 Mixed standard solution
According to the requirements of Table 1, respectively extract above single stock standard solutions into different 25mL volumetric flasks, and dilute them to constant volume with n-hexane to prepare mixed standard solutions with a validity period of three months.
Table 1 Preparation of mixed standard solution In: mL
Component Volume value of component
Single standard solution 0.10 0.20 0.50 1.00
n-hexane 24.9 24.8 24.5 24.0
4.4 Instruments
a) Gas chromatograph: equipped with a mass selective detector (MSD);
b) Gas chromatograph: equipped with an electron capture detector (GC-ECD);
c) Ultrasonic generator: with an operating frequency of 40kHz;
d) Microinjector: 10μL;
e) Extractor: made of hard glass, tubular, with ground mouth and bottle stopper, 50mL;
f) 0.45μm-PTFE film filter head;
g) Ground centrifugal tube with stopper: 10mL;
h) Centrifuge: 4,000r/min.
4.5 Determination procedures
4.5.1 Extraction
Weigh 1g (accurate to 0.0001g) of the sample into an extractor. Accurately add 10.0mL of n-hexane into the extractor, and put the extractor into an ultrasonic bath for extraction for 20min. Filter the extract into a 2mL small sample flask with a 0.45μm-PTFE film filter head for use in chromatographic analysis. If the sample is water-soluble, firstly add 2mL of water into the sample where necessary, oscillate for uniform mixing, and then add 10.0mL of n-hexane; if the sample is turbid after ultrasonic extraction, centrifuge it with centrifugal equipment for 5min, wait until it is stratified and take the supernatant for analysis.
4.5.2 Chromatographic analysis
4.5.2.1 Chromatographic analysis conditions
As the test result depends on the instrument used, it is impossible to give general parameters for the chromatographic analysis. The following parameters (see Tables 2 and 3) have been proved appropriate for the test.
Foreword I
1 Scope
2 Normative references
3 Theory
4 Determination method
5 Determination lower limit, recovery rate and precision
6 Test report
Annex A (Normative) Types of polychloriznated benzenes
Annex B (Informative) Standard samples of polychloriznated benzenes
