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This article is to study GB-T 42908-2023 Determination of organic halogen content in textile dyeing and finishing auxiliary products. The study notes have been compiled and shared in the hope that more people will benefit. If there is any infringement, please contact us in time.
1 Scope
This document describes the method for the determination of organohalogen content in textile dyeing and finishing auxiliary products.
This document is applicable to the determination of organohalogen content in various types of textile dyeing and finishing auxiliaries, including organofluorine, organochlorine, and organobromine.
2 Normative reference documents
The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, for dated referenced documents
, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.
this document.
GB/T 6682 Specifications and test methods for water used in analytical laboratories
GB/T 8170—2008 Numerical rounding rules and representation and determination of limit values
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
organic halogenorganic halogen
Halogens combined with organic compounds.
Note 1: The organic halogen compounds in this document include organic compounds of fluorine (F), chlorine (Cl), and bromine (Br) except iodine (I).
Note 2:
Under the test conditions of this document, some inorganic halogen compounds will also be determined as organic halogens if they are not removed from the test.
4 Principles
The sample is dispersed or dissolved in a nitric acid aqueous solution, and activated carbon is used to adsorb the organic halide in the solution.
The activated carbon high-temperature furnace for combustion, cracking, and gasification. The product is hydrogen halide (fluorine, chlorine). , bromine hydride) is absorbed by alkaline aqueous solution, and then ionized
Halogen ions were separated and determined by subchromatography and quantified by external standard method.
5 reagents or materials
Unless otherwise specified, only use reagents confirmed to be of analytical grade and
first-grade water specified in GB/T6682. The containers used are created before use.
It is recommended to clean with nitric acid solution (5.8) and then rinse with water.
5.1 Activated carbon: granular (0.5 mm~2.5mm). See Appendix A for purification and preparation methods.
5.2 Oxygen: purity greater than or equal to 99.995% (volume fraction).
GB/T 42908—2023
5.3 Argon gas: purity greater than or equal to 99.99% (volume fraction).
5.4 Nitric acid.
5.5 potassium hydroxide, superior grade pure.
5.6 Anhydrous sodium carbonate, superior grade pure.
5.7 Sodium bicarbonate, superior grade pure.
5.8 Nitric acid solution, 1 mol/L: Pipette 67 mL of nitric acid (5.4), add water to make the volume to 1000 mL.
5.9 Sodium nitrate solution, 0.85 g/L: Weigh 17 g of sodium nitrate and dissolve it in a small amount of water, add 1.4 mL of
nitric acid (5.4), transfer it to a 1000 mL volumetric flask
, and dilute to the mark with water. Then pipette 50 mL of this solution and dilute it with water to 1000
mL.
5.10 Organohalogen reference solution, 0.25 mg/mL: Weigh 184.4
mg of 4-fluorobenzoic acid, 110.3 mg of 4-chlorobenzoic acid, and 4-bromobenzoic acid
62.9 mg, add water to dissolve and dilute to 100 mL, to prepare organic fluorine, organic chlorine and organic bromine with a mass concentration of 0.25 mg/mL.
Reference solution. Dilute as needed when using.
Note: Stored in an airtight plastic container at 4°C, the validity period is 12 months.
5.11 Potassium hydroxide solution, 30 mmol/L: Weigh 1.68 g of potassium hydroxide (5.5), dissolve it in water and adjust the volume to 1000
mL.
5.12 Mixed solution of 3.2 mmol/L sodium carbonate and 1.0 mmol/L sodium bicarbonate: Weigh 0.3392 g
anhydrous sodium carbonate (5.6) and 0.0840g sodium bicarbonate (5.7), dissolve with water and dilute to 1000 mL.
5.13 Halogen ion mixed standard stock solution, 1 mg/mL:
Bake the reference reagents sodium fluoride, sodium chloride, and sodium bromide at 105°C for 120 min (or burn at 500°C for 30 min),
cool and place in a desiccator. Weigh the dried sodium fluoride 2.2105 g, sodium chloride 1.6485 g, and sodium bromide
1.2877g, dissolve in water and dilute to 1000 mL. The mass concentrations of F-, Cl, and Br ions in the stock solution are all 1
mg/mL. . Or purchase commercially available standard solutions.
Note: Stored in an airtight plastic container at 4°C, the validity period is 12 months.
5.14
Halogen ion mixed standard working solution: Dilute the halide ion mixed standard stock solution (5.13) with water, and prepare a suitable series of concentrated solutions as needed.
mixed standard working solution of halide ions. It is recommended that the mass concentration of F-, CI, and Br ions be in the range of 0.10 mg/L ~ 2.00
mg/L.
Note: Stored in an airtight plastic container at 4°C, the validity period is 12 months.
6 Instruments and Equipment
6.1 Ion chromatograph: equipped with conductivity detector.
6.2
High-temperature combustion device: It consists of a tube furnace, cracking tube, quartz boat and controller. The schematic diagram is shown in Figure 1, or equivalent. The tube furnace can
control the temperature within the range of 500℃~1000℃, with an error of less than 10℃.
GB/T 42908—2023
Indexing serial number description:
1- — Tube furnace;
2 - lysis tube;
3——Quartz boat;
4——Controller;
5——Air inlet;
6——Inlet.
Figure 1 Schematic diagram of high temperature combustion device
6.3 Erlenmeyer flask: 100 mL, with ground stopper.
6.4 Oscillator: The speed can be controlled at (150±5)r/min.
6.5 Filtration device: Buchner funnel lined with qualitative filter paper, inner diameter 55 mm.
Rinse with suction filtration and sodium nitrate solution (5.9) in advance.
6.6 Absorption tube: 25 mL, with ground stopper.
6.7 Analytical balance: sensitivity 0.1 mg.
6.8 pH meter: Measuring range 0~14, accurate to 0.01 pH unit.
6.9 Needle filter: 0.45 μm, organic phase or aqueous phase.
6.10 Auxiliary items: such as halogen-free gloves, tweezers, medicine spoons, polyethylene bags, etc.
7 test steps
7.1 Collection and sampling
Halogen-free gloves should be worn during sample collection, and samples should be sealed and stored in polyethylene bags or bottles. If sample analysis cannot be performed after sampling
Complete within 7 days and should be stored frozen to reduce biodegradation and reduce the loss of volatile halogen compounds.
Take at least 0.5 g of a representative sample, and weigh
no less than 2 homogeneous samples of 10 mg to 50 mg (accurate to 0.1 mg).
7.2 Activated carbon adsorption
7.2.1 Put the weighed sample into a 100 mL Erlenmeyer flask (6.3) with a ground stopper, add 50 mL
sodium nitrate solution (5.9), and adjust the pH value to less than 2 with nitric acid solution (5.8).
7.2.2 Add 50 mg activated carbon (5.1) to the Erlenmeyer flask
, cover it with a ground stopper, place it in the oscillator (6.4) and oscillate at room temperature for 12 hours. After adsorption, transfer the
solution and activated carbon to the filtration device (6.5) for filtration. Then use 25 mL
sodium nitrate solution (5.9) to wash the activated carbon particles several times. Then
put the activated carbon particles into the quartz boat and proceed with combustion and cracking according to step 7.3.
GB/T 42908—2023
7.3 Combustion cracking
7.3.1 Warm up the tube furnace in advance, adjust the oxygen flow rate to more than 160 mL/min, and ventilate for
more than 10 minutes to stabilize the instrument.
7.3.2 Connect the outlet end of the lysis tube to the absorption tube (6.6) containing 10 mL of potassium hydroxide solution (5.11).
7.3.3 Move the quartz boat filled with activated carbon particles to the dry area of the combustion tube and let it stand for
more than 5 minutes. There should be no water condensation in the low temperature area of the combustion tube.
7.3.4
Push the quartz boat into the high-temperature area of the combustion tube (set at 950°C) for full combustion and cracking. The time should not be less than 3 minutes.
7.3.5 Move the quartz boat to the low temperature area and continue to blow oxygen to cool it
for more than 2 minutes. Take out the absorption tube, filter the absorption solution through the needle filter (6.9), and wait for measurement.
7.4 Analytical methods
7.4.1 Chromatographic conditions
The best analysis conditions can be selected according to different instruments and equipment. The reference conditions for chromatographic analysis are as follows.
a) Chromatographic condition one:
● Chromatographic column: hydroxide selectivity, anion exchange column, 250 mm×4 mm (inner diameter);
● Column temperature: 30℃;
● Eluent: potassium hydroxide solution (5.11);
●Flow rate: 1.0 mL/min;
● Injection volume: 25 μL.
b) Chromatographic condition two:
● Chromatographic column: carbonate selectivity, anion exchange column, 150 mm×4 mm (inner diameter);
● Column temperature: 30℃;
● Eluent: a mixed solution of 3.2 mmol/L sodium carbonate and 1.0 mmol/L sodium bicarbonate (5.12);
●Flow rate: 0.7 mL/min;
● Injection volume: 20μL.
7.4.2 Qualitative analysis
Analyze the halide ion mixed standard working solution (5.14) and absorption solution (7.3.5) in sequence according to the analysis conditions of 7.4.1. According to F-,
The retention time of Cl or Br ions is used for characterization. The halide ion separation chromatogram of the standard working solution is shown
in Figure B.1 and Figure B.2 in Appendix B.
7.4.3 Quantitative analysis
Draw a standard working curve using the mass concentration of F-, CI or Br ions in the halide ion mixed standard working solution (5.14)
as the abscissa and the corresponding peak area as the ordinate .
According to
the chromatographic peak area of F-, Cl or Br ions in the absorption solution (7.3.5), the external standard method is used for
quantification. The response value of the target substance in the sample solution should be within the linear range of instrument detection. If the content exceeds the range of the standard working curve, it should be
Dilute the sample solution to an appropriate concentration and analyze it.
7.5 Blank test
Except that no sample is added, proceed according to steps 7.2 to 7.4.
7.6 Verification test
Take 50 mL
of appropriately diluted organohalogen reference solution (5.10) and measure the organic content of the reference solution according to steps 7.2.2 to 7.4.3.
Halogen content, recovery rate should be between 85% and 110%.
GB/T 42908—2023
8 Test data processing
8.1 Result calculation
The measurement results are expressed as the detection results of organofluorine, organochlorine or organobromine respectively.
The content of organic fluorine, organic chlorine or organic bromine in the sample is calculated as X, and the value is
expressed in milligrams per kilogram (mg/kg), calculated according to formula (1):
(1)
In the formula:
pi- The value of the mass concentration of F-, Cl or Br ions in the sample absorption solution
, in milligrams per liter (mg/L);
po —the value of the mass concentration of F-, Cl or Br ions in the blank absorption solution , in milligrams per liter (mg/L);
V—the value of the volume of the absorbed solution, in milliliters (mL);
m——The value of the sample mass, unit is grams (g);
f—dilution factor.
8.2 Result presentation
The calculation results are expressed as the arithmetic mean of two parallel measurement results, in accordance with the
rounding value comparison method in GB/T 8170-2008 4.3.3
Make the appointment to single position.
9 Determination lower limit, recovery rate and precision
9.1 Lower limit of determination
The lower limit of determination of organofluorine, organochlorine or organobromine in this document is 25.0 mg/kg.
9.2 Recovery rate
The standard recovery rates of organofluorine, organochlorine or organobromine in this document are 85% to 110%.
9.3 Precision
In the same
laboratory, the absolute difference between two independent test results obtained by the same operator using the same equipment, according to the same test method, and testing the
same not greater than these two 10% of the arithmetic mean of the measured values, whichever is greater
The premise is that the arithmetic mean of the two measured values does not exceed 5% in 10% of cases.
10 test report
The test report should at least provide the following content:
a) Sample source and description;
b) The number of this document;
c) Test conditions;
d) test results;
e) Any details that deviate from this document;
f) Test date.
GB/T 42908—2023
Appendix A
(informative)
Purification and preparation of activated carbon
A.1 Purification method
Sieve out analytically pure activated carbon with a mesh diameter of 0.2 mm to 5.0 mm, and
soak it in 1 mol/L nitric acid solution (5.8) ultrasonically for 1 hour.
Afterwards, soak for
more than 12 hours, move to the filter device (6.5), wash with water until there is no nitrate ion (use diphenylamine sulfuric acid solution to check until there is no nitrate ion)
Dark blue substance is generated), dried, heated at 450℃~500℃ for more than 3 hours under the protection of nitrogen flow
, and cooled to room temperature. in clean and without
In an indoor environment polluted by organic halogen compounds , purified activated carbon particles with a mesh diameter of 0.5 mm to 2.5 mm are screened out and put into small glass bottles with ground plugs.
Store in a glass bottle, sealed.
A.2 Blank test
Determine the blank value of activated carbon after purification according to 7.5. If it is higher than the lower limit of determination,
reprocess according to A.1.
GB/T 42908—2023
Appendix B
(informative)
Halide ion separation chromatogram
Figure B.1 shows the halide ion separation chromatogram under chromatographic condition 1.
Figure B.2 shows the halide ion separation chromatogram under chromatographic condition 2.
Retention time/min
Figure B.1 Halogen ion separation chromatogram under chromatographic condition 1
Retention time/min
Figure B.2 Halogen ion separation chromatogram under chromatographic condition 2
Further reading
More information can be found in GB-T 42908-2023 Determination of organic halogen content in textile dyeing and finishing auxiliary products. Further study