GB/T 7979-2020_English: PDF (GB/T7979-2020)
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Pulp--Determination of dichloromethane soluble matter
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| GB/T 7979-2005 | English | 90 |
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Pulps -- Determination of dichloromethane soluble matter
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| GB/T 7979-1987 | English | 199 |
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Pulps--Determination of dichloromethane soluble matter
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| Standard ID | GB/T 7979-2020 (GB/T7979-2020) | | Description (Translated English) | Pulp--Determination of dichloromethane soluble matter | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | Y30 | | Classification of International Standard | 85.040 | | Word Count Estimation | 6,644 | | Date of Issue | 2020-07-21 | | Date of Implementation | 2021-02-01 | | Older Standard (superseded by this standard) | GB/T 7979-2005 | | Drafting Organization | Shandong Sun Paper Co., Ltd., China Pulp and Paper Research Institute Co., Ltd. (National Paper Quality Supervision and Inspection Center), Crane Co., Ltd., Borui De Environmental Group Co., Ltd., Deqing Shuangqiao Paper Co., Ltd. | | Administrative Organization | National Paper Industry Standardization Technical Committee (SAC/TC 141) | | Proposing organization | China National Light Industry Council | | Issuing agency(ies) | State Administration for Market Regulation, National Standardization Administration | | Standard ID | GB/T 7979-2005 (GB/T7979-2005) | | Description (Translated English) | Pulps. Determination of dichloromethane soluble matter | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | Y30 | | Classification of International Standard | 85.040 | | Word Count Estimation | 6,665 | | Date of Issue | 2005-09-26 | | Date of Implementation | 2006-04-01 | | Older Standard (superseded by this standard) | GB/T 7979-1987 | | Quoted Standard | GB/T 740; GB/T 741; | | Drafting Organization | Tianjin Institute of Light Industry Paper Technology | | Administrative Organization | National Standardization Technical Committee Paper Industry | | Regulation (derived from) | Announcement of Newly Approved National Standards No. 12 of 2005 (total 86) | | Proposing organization | China Light Industry Federation | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People Republic of China, China National Standardization Administration Committee | | Summary | This standard specifies: Determination of the pulp is soluble in dichloromethane ingredient approach. This standard applies to: all kinds of chemical pulp and semi-chemical pulp. | | Standard ID | GB/T 7979-1987 (GB/T7979-1987) | | Description (Translated English) | Pulps--Determination of dichloromethane soluble matter | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | Y30 | | Classification of International Standard | 85.040 | | Word Count Estimation | 2,297 | | Date of Issue | 1987/6/26 | | Date of Implementation | 1987/12/1 | | Adopted Standard | ISO 624-1974, MOD | | Regulation (derived from) | Announcement of Newly Approved National Standards 2005 No. (No. 86 overall) 12 |
GB/T 7979-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 85.040
Y 30
Replacing GB/T 7979-2005
Pulp – Determination of Dichloromethane
Soluble Matter
ISSUED ON: JULY 21, 2020
IMPLEMENTED ON: FEBRUARY 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Principle ... 5
4 Reagents ... 6
5 Apparatus ... 6
6 Sample Preparation ... 6
7 Test Procedures ... 7
8 Calculation of Results ... 7
9 Report ... 8
Pulp – Determination of Dichloromethane
Soluble Matter
Warning - Personnel who uses this Standard shall have practical experience
working in a formal chemical laboratory. This standard does not point out all
possible safety issues. The user is responsible for taking appropriate safety and
health measures and ensuring compliance with relevant national regulations.
1 Scope
This Standard specifies the method for determining the content of dichloromethane
extracts in pulp.
This Standard is applicable to all kinds of pulps except waste pulp. When the sampling
volume is 10g, the limit of detection for this method is 0.05%.
2 Normative References
The following documents are essential to the application of this document. For the
dated documents, only the versions with the dates indicated are applicable to this
document; for the undated documents, only the latest version (including all the
amendments) is applicable to this document.
GB/T 462 Paper, Board and Pulp – Determination of Moisture in the Analysis
Specimen
GB/T 740 Pulps - Sampling for Testing
3 Principle
In the Soxhlet extractor, the pulp sample is extracted by dichloromethane. After at least
24 cycles of extraction, the solvent is evaporated, and the extraction residue is dried
at (105±2) °C, and then weighed. The ratio of the mass of the dichloromethane extract
to the absolute dry mass of the sample is the dichloromethane extract content in the
sample.
and the bulk pulp sample shall be torn into fragmented specimens. Place the sample
in a wide-mouth bottle with a ground mouth; cap the bottle; and equilibrate it in the
bottle for 24h for later use.
7 Test Procedures
7.1 Use a balance (5.4) to weigh about 10g (or 5g, accurate to 0.0001g) specimen for
parallel determination. If it is a bulk pulp specimen, wrap the specimen tightly by filter
paper extracted by dichloromethane in advance; and tie it by cotton thread extracted
by dichloromethane in advance. At the same time, determine the water content
according to the provisions of GB/T 462.
7.2 Firstly, put a small group of absorbent cotton that has been pre-extracted by
dichloromethane at the outlet of the Soxhlet extractor (5.1); and then put the specimen
into the Soxhlet extractor; and connect the flat-bottomed flask that has been dried in
the electric heating blast drying oven (5.5), and has been cooled to the constant weight
to the extractor; and then add dichloromethane equivalent to 1.5 times the volume of
the Soxhlet extractor to the flat-bottomed flask; connect to the condenser; and turn on
the cooling circulating water bath (5.3) and start the extraction.
7.3 Adjust the temperature of the constant temperature water bath (5.2) and control
the extraction cycle of dichloromethane for 8 times per hour. When the sampling
volume is 5g, use a 150mL flat-bottomed flask to extract for at least 6h, so that the total
number of extractions is at least 48. When the sampling volume is 10g, use a 250mL
flat-bottomed flask to extract at least 3h, so that the total number of extractions is at
least 24. If the return flowrate is too slow, the extraction time shall be extended
appropriately. After the extraction, the extracting solution shall be clear and free of
fibers.
7.4 After the end of extraction, lift the condenser; use a clean glass rod or medicine
spoon to take out the specimen; then reconnect the condenser to the extractor; and
recover a part of the solvent until there is only a small amount of dichloromethane at
the bottom of the bottle. Then the flat-bottomed flask is placed on a water bath to
evaporate the solvent to dryness. Put the flat-bottomed flask into an electric heating
blast drying box for drying. The drying time shall not exceed 16h. After cooling in a
desiccator for 45min, weigh it and repeat the drying until the weight is constant.
8 Calculation of Results
The extract content of the dichloromethane shall be calculated as per Formula (1); and
the results shall be expressed by a percentage.
......
GB/T 7979-2005
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 85.040
Y 30
Replacing GB/T 7979-1987
Pulps - Determination of
dichloromethane soluble matter
ISSUED ON. SEPTEMBER 26, 2005
IMPLEMENTED ON. APRIL 1, 2006
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration 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 Instruments ... 5
6 Sample preparation ... 5
7 Test procedure .. 5
8 Result representation ... 6
9 Test report ... 6
Appendix A ... 8
Foreword
This Standard is the revision to GB/T 7979-1987 “Pulps - Determination of
dichloromethane soluble matter”.
This Standard replaces GB/T 7979-1987.
Compared with GB/T 7979-1987, the main changes are as follows.
- Add the contents of the scope (see Chapter 1);
- Add the contents of normative references (see Chapter 2);
- Modify the contents of the test procedure (see Chapter 7);
- Add the contents of the test report (see Chapter 9).
Appendix A of this Standard is informative.
This Standard was proposed by China National Light Industry Council.
This Standard shall be under the jurisdiction of the National Standardization Technical
Committee of Paper-making Industry (SAC/TC141).
This Standard was drafted by Tianjin Paper-Making Technology Research Institute of Light
Industry.
Main drafters of this Standard. Nie Junhong.
This Standard replaces the previous version as follows.
- GB/T 7979-1987.
This Standard shall be responsibly interpreted by National Standardization Technical
Committee of the National Paper Industry.
Pulps - Determination of
dichloromethane soluble matter
1 Scope
This Standard specifies the method for the determination of the components which can
be dissolved in dichloromethane in pulp.
This method is applicable to various chemical pulp and semi-chemical pulp.
2 Normative references
The following documents contain the provisions which, through reference in this
Standard, become the provisions of this Standard. For the dated references, their
subsequent amendments (excluding corrections) or revisions do not apply to this
Standard. However, the parties who enter into agreement based on this Standard are
encouraged to investigate whether the latest versions of these documents are
applicable. For undated reference documents, the latest versions apply to this
Standard.
GB/T 740 Pulps - Sampling for testing (GB/T 740-2003, ISO 7213.1991, IDT)
GB/T 741 Pulps - Determination of moisture content (GB/T 741-2003, ISO 638.1989,
MOD)
3 Principle
In the Soxhlet extractor, extract the sample of the pulp with dichloromethane. After at
least 24 cycles of extraction, evaporate the solvent; and under the temperature of
105°C ± 2°C, dry and extract the residue for no more than 16 hours; and then weigh it.
Through the ratio OF mass of the dichloromethane soluble matter AND absolute-dry
mass of the sample, obtain the content of the dichloromethane soluble matter.
Warning! The dichloromethane extraction method is better than diethyl-ether
extraction method. Because, if diethyl-ether is acted as the solvent, there exists
the danger of fire or explosion.
4 Reagents
Analytical reagents shall be used in the analysis unless otherwise stated.
Dichloromethane. content is 98% ~ 100%; dry and solid matters shall be less than
5mg/L; boiling point shall be 39°C ~ 41°C.
If adopting the general commercial product, it shall be redistilled; collect the distillate
between 38°C ~ 41°C; and store it in the brown glass bottle. This distillate shall be
neutral.
Warning! Due to the toxic nature of this solvent, therefore, appropriate
ventilation shall be paid attention to.
5 Instruments
General laboratory equipment and
a) Soxhlet extractor. it is made entirely of glass; it is consisted of the ground
condenser, the ground extractor and ground flat-bottomed flask. The capacity of
the flat-bottomed flask should be 150mL; the capacity of the extractor should be
60mL ~ 120mL;
b) Drying oven. it can maintain the air temperature at 105°C ± 2°C, and it can be
properly ventilated;
c) Balance. the sensitivity is 0.0001g;
d) Constant-temperature water bath.
6 Sample preparation
Perform sampling according to GB/T 740; tear the pulp sample into the sample which
is less than 15mm × 15mm; and place the sample in the ground wild-mouth bottle for
standby application.
7 Test procedure
Weigh two-portion samples of about 10g (The accuracy is 0.0001g) to perform parallel
determination; at the same time, determine the moisture content according to GB/T
741.
Firstly, PUT a small mass of absorbent cotton which has been previously extracted
with the dichloromethane solvent INTO the drain pipe of the Soxhlet extractor; then
place the sample in the extractor; CONNECT the flat-bottomed flask which has been
dried at 105°C ± 2°C and cooled to constant weight TO the extractor; then PLACE the
dichloromethane of which the volume is equal to 1.5 times volume of the extractor IN
the flat-bottomed flask; connect the condenser and start to extract.
......
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