GB 4117-1992 Industrial dichloromethane

This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, storage and transportation of industrial dichloromethane. This standard applies to dichloromethane produced by natural gas thermal chlorination and photochlorination. This product is mainly used as a solvent and extractant. GB 4117-1992 Industrial dichloromethane GB4117-1992 standard download decompression password: www.bzxz.net

UDC661.715.21：62
National Standard of the People's Republic of China
GB 41174118--92
Methyl chloride
Methyl chloride
Methylene chloride for industrial useTrichloromethane for industrial use1992-04-24Promulgated
Implemented on 1993-02-01
National Technical Blue
National Standard of the People's Republic of China
Industrial dichloromethane
Methylene chloride for industrial use1Subject content and scope of application
GB 4117---92
Replaces GB4117-83
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, storage and transportation of industrial dichloromethane. This standard applies to dichloromethane produced by natural gas thermal chlorination and photochlorination. This product is mainly used as a solvent and extractant. Molecular formula: CH, C12
Relative molecular mass: 84.93 (according to the 1987 international relative atomic mass) 2 Reference standards
GB191 Pictorial symbols for packaging, storage and transportation
GB3143 Color determination of liquid chemical products (Hazen unit - platinum-diamond color number) GB4120.3 Determination of acidity in industrial liquid chloromethane products Titration method GB4120.5 Determination of trace water in industrial liquid chloromethane products Cloud point method GB4120.6 Industrial liquid fluorocarbons Rules for packaging, marking, storage, transportation and inspection of methane products GB6283 Determination of water content in chemical products - Karl Fischer method (general method) GB6324.2 General method for determination of dry residue after evaporation of volatile organic liquids on a water bath GB6678 General rules for sampling of chemical products
GB6680 General rules for sampling of liquid chemical products
3 Technical requirements
3.1 Liquid with clear appearance, no suspended matter and no mechanical impurities 3.2 The technical indicators of industrial dichloromethane shall meet the requirements of Table 1. Table 1
Chroma (Pt-Co), No.
Acidity (in HCI), %
Water, %
Purity, %
Evaporation residue, %
4 Test method
Superior quality
First-class quality
Qualified quality
The reagents and water used in this standard, unless otherwise specified, refer to analytical reagents and laboratory distilled water or water of equivalent purity. Approved by the State Administration of Technical Supervision on April 24, 1992 and implemented on February 1, 1993
4.1 Determination of chromaticity
The method specified in GB3143 shall be followed.
4.2 Determination of acidity
The method specified in GB4120.3 shall be followed. 4.3 Determination of moisture
GB 4117 --- 92
Perform according to the method specified in GB4120.5. If there is a dispute between the supply and demand parties, the method specified in GB6283 shall be used as the arbitration method. 4.4 Determination of purity
This method uses a mixed stationary phase of dibutyl phthalate (DBP) and polyethylene glycol 2 000 (PEG-2 000) to separate the components in difluoromethane, detects with a thermal conductivity detector, and calculates the content of dichloromethane by normalization. 4.4.1 Materials and reagents
4.4.1.1 Carrier gas: hydrogen, purity better than 99.5%. 4.4.1.2 Carrier 6201 carrier, particle size 0.20~~0.28mm. 4.4.1.3 Stationary phase: dibutyl phthalate and polyethylene glycol 2000. 4.4.1.4 Solvent: acetone. wwW.bzxz.Net
4.4.2 Instruments
4.4.2.1 Gas chromatograph: equipped with a thermal conductivity detector (using hydrogen as carrier gas, the sensitivity to benzene is better than 800mV·mL/mg). 4.4.2.2 Injector: micro-syringe.
4.4.2.3 Chromatographic column: 3m long, 3~4mm inner diameter stainless steel column. 4.4.3 Analysis steps
4.4.3.1 Stationary phase: weigh 1.0g polyethylene glycol 2000 into a 250mL beaker, use acetone as solvent, and heat it in a water bath to completely dissolve it. Then weigh 19.0g dibutyl phthalate. Mix the two. Then slowly pour 100g of 6201 carrier into the column to make it completely wet and evenly coated. After the solution evaporates, move it to an infrared lamp for drying. 4.4.3.2 Filling and loading amount of chromatographic column: plug the outlet of the chromatographic column with a little glass wool or copper mesh, then suck from the outlet, and load the stationary phase into the chromatographic column under gentle vibration. For a stainless steel column with an inner diameter of 3mm, the loading amount is about 3g/m. 4.4.3.3 Aging of chromatographic column: Pass the carrier gas and age the chromatographic column at 90-100℃ for 8h. 4.4.3.4 Typical chromatographic conditions are shown in Table 2. Table 2
Vaporization temperature, ℃
Detection temperature, ℃
Column temperature,
Carrier gas flow rate, mL/min
Bridge current, mA
Injection volume, μL
Recorder range.mV
Users can adjust the chromatographic conditions appropriately, but should obtain appropriate separation, bar
4.4.3.5 Determination: Start the instrument, and inject the sample after the chromatographic operating conditions are stable. The retention time ts and relative adjusted retention time r of each component and the chromatogram are shown in Table 3 and the figure below.
Monofluoromethane
Monochloroethane
GB4117-92
Chromatogram of each component on DBP:PEG:6201=19:1:100 column 1--Air; 2--Fluoromethane; 3-Fluoroethane, 4-1,1-Dichloroethylene; 5-Chloropropylene; 6-Difluoromethane; 7-Trifluoromethane Table 3
1,1-Difluoroethylene
Chloropropylene
Dichloromethane
Trifluoromethane
If the product is added with stabilizer methanol, extract it with distilled water for 2 to 3 times during analysis, and then dry the sample with calcium chloride before determination. 4.4.4 Calculation
4.4.4.1 Determine the peak area of ​​each component in dichloromethane and calculate the mass percentage of dichloromethane r by normalization method as follows:=
wherein; f is the relative correction factor of dichloromethane, A--the peak area of ​​dichloromethane, cm\;
f is the relative correction factor of component i;
is the peak area of ​​component i, cm2.
X(,A,)
4.4.4.2 See Table 4 for the correction factors of each component on the thermal conductivity detector. Methylene chloride
Ethylene chloride
1,1-dichloroethylene
Propylene fluoride
Difluoromethane
Trifluoromethane
4.4.5 Allowable error
GB4117-92
The difference between the results of two parallel determinations shall not exceed 0.2% for dichloromethane content, and the arithmetic mean shall be taken as the determination result. 4.5 Determination of evaporation residue
The method specified in GB6324.2 shall be followed, and the sampling volume may be increased or decreased as appropriate. 5 Inspection rules, packaging, marking, storage and transportation shall be carried out in accordance with the provisions of GB4120.6.
Evaporation residue is a random inspection item and shall be inspected once a month. Additional remarks:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the technical jurisdiction of the Beijing Institute of Chemical Industry of the Ministry of Chemical Industry. This standard was drafted by Beijing Chemical Research Institute, Sichuan Zigong Honghe Chemical Plant, and Shanghai Chlor-Alkali General Plant Electrochemical Plant. The main drafters of this standard are Wei Changjie, Li Lanqing, Yang Junqing, Liao Shengrong, and Tang Guoqiang. This standard refers to the Soviet national standard rOCT9968--86 "Technical Conditions for Industrial Difluoromethane".
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