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GB/T 223.88-2019 English PDF (GBT223.88-2019)

GB/T 223.88-2019 English PDF (GBT223.88-2019)

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GB/T 223.88-2019: Iron, steel and alloy -- Determination of calcium and magnesium contents -- Inductively coupled plasma atomic emission spectrometric method

GB/T 223.88-2019
Iron, steel and alloy--Determination of calcium and magnesium contents--Inductively coupled plasma atomic emission spectrometric method ICS 77.080.01
H11
National Standards of People's Republic of China
Determination of calcium and magnesium in steel and alloys
Inductively coupled plasma atomic emission spectrometry
(ISO 13933.2014, Steelandiron-Determinationofcalciumandmagnesium-
Inductivelycoupledplasmaatomicemissionspectrometricmethod, IDT)
Published on.2019-06-04
2020-05-01 implementation
State market supervision and administration
China National Standardization Administration issued
Foreword
GB/T 223 is divided into several parts.
This part is the 88th part of GB/T 223.
This part is drafted in accordance with the rules given in GB/T 1.1-2009. This section uses the translation method equivalent to ISO 13933.2014 "Steel calcium and magnesium determination inductively coupled plasma atomic emission Spectroscopy.
The documents of our country that have a consistent correspondence with the international documents referenced in this part are as follows. ---GB/T 6682-2008 Analytical laboratory water specifications and test methods (ISO 3696.1987, MOD) ---GB/T 12806-2011 Laboratory glass instrument single standard line volumetric flask (ISO 1042.1998, MOD) ---GB/T 20066-2006 Sampling and sample preparation method for samples for determination of chemical composition of steel and iron (ISO 14284.1996, IDT)
This section has made the following editorial changes.
--- In line with the existing standard series, change the name of this part to "Inductive Coupling Isolation of Determination of Calcium and Magnesium Content in Steel and Alloys" Daughter atomic emission spectrometry.
This part was proposed by the China Iron and Steel Association.
This part is under the jurisdiction of the National Steel Standardization Technical Committee (SAC/TC183). This section drafted by. Steel Research Nak Testing Technology Co., Ltd., Baosteel Special Steel Co., Ltd., Anshan Iron and Steel Co., Ltd., Wuhan Steel Iron Co., Ltd., China Metallurgical Construction Research Institute Co., Ltd. The main drafters of this section. Luo Qianhua, Liu Zheng, Wang Yujuan, Yu Yuanjun, Yu Lujun, Lin Chunlai, Li Nannan. Determination of calcium and magnesium in steel and alloys
Inductively coupled plasma atomic emission spectrometry
1 Scope
This part of GB/T 223 specifies the determination of pure iron, cast iron, steel and superalloys by inductively coupled plasma atomic emission spectrometry. Method of calcium and magnesium content.
This section applies to the magnesium content with a mass fraction of 0.0005%~0.006% and a magnesium content of 0.0005%~0.20%. Determination.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article. Pieces. For undated references, the latest edition (including all amendments) applies to this document. ISO 385 laboratory glass instrument burette (Laboratoryglassware-Burettes) ISO 648 laboratory glass instrument single-line pipette (Laboratoryglassware-Single-volumepipettes) ISO 1042 laboratory glass instrument single line volumetric flask (Laboratoryglassware-Onemarkvolumetricflasks) ISO 3696 Analytical Laboratory Water Regulations and Test Methods (Waterforanalyticallaboratoryuse-Specification Andtestmethods)
ISO 14284 Method for sampling and sample preparation of steel and iron chemical constituents (Steelandiron-Samplingand Preparationofsamplesforthedeterminationofchemicalcomposition)
3 Principle
The sample was dissolved with a mixed acid of hydrochloric acid, nitric acid and hydrofluoric acid, and perchloric acid smoked. The salts are dissolved with hydrochloric acid and nitric acid. If necessary, join inside Label the element and dilute to a certain volume. The solution is filtered (if necessary) and atomized into an inductively coupled plasma spectrometer, measuring each The element analyzes the emission intensity of the line while measuring the emission intensity of the internal standard element line. 4 reagents
Unless otherwise stated, only analytically pure reagents identified as low levels of calcium and magnesium and secondary waters specified in ISO 3696 were used in the analysis. Or water of considerable purity.
4.1 The content of pure iron, calcium and magnesium is less than 0.5μg/g. 4.2 Hydrochloric acid, ρ about 1.19g/mL.
4.3 Hydrochloric acid, ρ approximately 1.19 g/mL, diluted to 1 1.
4.4 Hydrochloric acid, ρ approximately 1.19 g/mL, diluted to 14.
4.5 Hydrochloric acid, ρ approximately 1.19 g/mL, diluted to 1 100.
4.6 Nitric acid, ρ about 1.42g/mL.
4.7 Hydrofluoric acid, ρ about 1.15g/mL.
4.8 Perchloric acid, ρ about 1.67g/mL.
4.9 Mixed acid.
2 parts of hydrochloric acid (4.2), 1 part of nitric acid (4.6) and 3 parts of water were mixed. 4.10 Calcium standard solution.
4.10.1 Calcium stock solution, 1000mg/L.
Dry a few grams of calcium carbonate (mass fraction ≥99.9%) in an oven at 100 °C ± 5 °C for at least 1 h and cool to room in a desiccator temperature. Weigh 2.497g of dried calcium carbonate to the nearest 0.0001g, place in a 400mL beaker, add 20mL of hydrochloric acid (4.3), cover the table The dish is slowly heated until completely dissolved. After cooling to room temperature, the solution was transferred to a 1000 mL volumetric flask. Dilute to the mark with water, Mix well.
This stock solution 1 mL contains 1.000 mg of calcium.
4.10.2 Calcium standard solution A, 100 mg/L.
Transfer 10.00 mL of calcium stock solution (4.10.1) into a 100 mL volumetric flask. Add 10 mL of hydrochloric acid (4.4). Dilute to the mark with water, Mix well.
1 mL of this standard solution contained 0.100 mg of calcium.
4.10.3 Calcium standard solution B, 10 mg/L.
10.00 mL of calcium standard solution A (4.10.2) was transferred to a 100 mL volumetric flask. Add 10 mL of hydrochloric acid (4.4). Dilute with water to the moment Degree, mix.
1 mL of this standard solution contained 0.010 mg of calcium.
4.10.4 Calcium standard solution C, 1.0 mg/L.
10.00 mL of calcium standard solution B (4.10.3) was transferred to a 100 mL volumetric flask. Add 10 mL of hydrochloric acid (4.4). Dilute with water to the moment Degree, mix.
1 mL of this standard solution contained 0.001 mg of calcium.
4.11 Magnesium standard solution.
4.11.1 Magnesium stock solution, 1000mg/L.
1.000 g of pure magnesium (mass fraction ≥ 99.9%) was weighed to the nearest 0.0001 g and placed in a 250 mL beaker. Add 20mL of water, then After that, hydrochloric acid (4.3) was added dropwise under constant shaking until the reaction was stopped, and hydrochloric acid (4.3) was further added to a total volume of 20 mL. Cover the watch glass, add Heat boil for 10 min. Cool to room temperature, transfer to a 1000 mL volumetric flask, dilute to the mark with water, and mix. This stock solution 1 mL contains 1.000 mg of magnesium.
4.11.2 Magnesium standard solution A, 100mg/L.
10.00 mL of magnesium stock solution (4.11.1) was transferred to a 100 mL volumetric flask. Add 10 mL of hydrochloric acid (4.4) and dilute to the mark with water. Mix well.
1 mL of this standard solution contained 0.100 mg of magnesium.
4.11.3 Magnesium standard solution B, 10 mg/L.
10.00 mL of Magnesium Standard Solution A (4.11.2) was transferred to a 100 mL volumetric flask. Add 10mL hydrochloric acid (4.4), dilute with water until the moment Degree, mix.
1 mL of this standard solution contained 0.010 mg of magnesium.
4.11.4 Magnesium standard solution C, 1.0 mg/L.
10.00 mL of Magnesium Standard Solution B (4.11.3) was transferred to a 100 mL volumetric flask. Add 10mL hydrochloric acid (4.4), dilute with water until the moment Degree, mix.
1 mL of this standard solution contained 0.001 mg of magnesium.
4.12 钇 internal standard solution, 100mg/L.
A few grams of antimony trioxide (mass fraction ≥ 99.9%) is fired in a muffle furnace at 850 ° C ± 10 ° C for at least 40 min and in a desiccator Cool to room temperature. Weigh 0.1270g of antimony trioxide, place it in a 400mL beaker, add 10mL of hydrochloric acid (4.3), cover with a watch glass, and gently Slowly heat until completely dissolved. After cooling to room temperature, the solution was transferred to a 1000 mL volumetric flask. Dilute to the mark with water and mix. 1 mL of this standard solution contained 0.100 mg of hydrazine.
5 instruments
All capacity vessels shall comply with Class A of ISO 385, ISO 648 or ISO 1042. General laboratory equipment and the following instruments.
5.1 Inductively Coupled Plasma Atomic Emission Spectrometer
After the inductively coupled plasma atomic emission spectrometer is optimized according to 7.4, it should meet the performance index given in 5.1.2~5.1.4. See Appendix A for the method of measuring the performance of the instrument. Spectrometers can be either simultaneous or sequential. If the sequential spectrometer can be equipped with a part that simultaneously measures the internal standard line Internal standard technology can be used; otherwise, the internal standard method cannot be used. 5.1.1 Analysis line
This method does not specify a specific analysis line. Each laboratory should carefully examine the analytical lines available for the instrument used, taking into account sensitivity And interference to find the most suitable analysis line.
The recommended analytical lines and possible interference elements are listed in Table 1, and these lines have been carefully studied. The wavelength of the selected internal standard element should not interfere with the analytical line and is not disturbed by elements in the test solution. It is recommended to use Y371.03nm or 360.07nm, these two lines are not interfered by the elements.
Table 1 Recommended analysis of spectral lines and their interference elements Element wavelength/nm possible interference
Calcium 393.66 no
Magnesium 279.55 no
371.03 None
360.07 none
Other elements may also be used as internal standards, but as internal standard elements should not be present in the sample and do not interfere with the wavelength of the element being tested; likewise, in the test solution Coexisting elements should not interfere with the selected wavelength of the internal standard. The excitation condition of the internal standard element should be similar to the measured element. 5.1.2 Minimum actual resolution of the spectrum
Calculate the bandwidth of the wavelength used according to A.1, and the bandwidth should be no more than 0.030 nm. 5.1.3 Minimum short-term precision
Calculate short-term precision according to A.2. For the test solution with a concentration of 100 times to 1000 times the detection limit, the relative intensity of the absolute intensity or intensity ratio The quasi-deviation (RSD) should not exceed 1%; for a test solution with a concentration of 10 to 100 times the detection limit, the RSD should not exceed 5%. 5.1.4 Limit of Detection (LOD) and Limit of Quantification (LOQ)
The detection limits (LOD) and limit of quantitation (LOQ) of the wavelengths used are calculated according to A.3. The calculation results should be lower than the values given in Table 2. Table 2 Limit of Detection (LOD) and Limit of Quantification (LOQ)
element
wavelength
Nm
LOD
Mg/L
LOQ
Mg/L
Calcium 393.66 0.0034 0.010
Magnesium 279.55 0.0046 0.014
5.1.5 Calibration curve linear
The linearity of the calibration curve is checked by calculating the correlation coefficient, and the correlation coefficient should be not less than 0.999. 5.2 Polytetrafluoroethylene (PTFE) beakers and lids
Note. Glass beakers and lids can be used only when measuring magnesium. 5.3 Volumetric flask, volume 100mL, made of polypropylene or polyethylene terephthalate (PET). 5.4 Filter membrane, PTFE or polycarbonate membrane with a pore size of 0.22 μm and a diameter of 47 mm. 5.5 Pumping system, including suction filter bottle, suction filter funnel and vacuum suction filter. 6 Take samples
Samples are prepared according to ISO 14284 or appropriate national standards for steel and cast iron. 7 test steps
Caution - Usually, in the presence of ammonia, nitrogen oxides or organic matter, the introduction of perchloric acid fumes may cause an explosion. All glassware and plastic utensils should be washed first with hydrochloric acid (4.3) and then with water. Calcium and magnesium in glassware and plastic containers The amount can be examined by measuring the intensity of the emitted light of calcium and magnesium in the water injected into it by pickling and water washing. If calcium and magnesium are present If it is contaminated, the glassware and plastic utensils should not be used and should be replaced or re-cleaned. For each measurement, all reagents, including water, calibration solutions, and acids should be used in the same batch. 7.1 Samples
Place the sample or pure iron in a PTFE beaker, add 10 mL of hydrochloric acid (4.5), and shake slowly. Discard the hydrochloric acid solution and rinse repeatedly with water The sample was then rinsed with absolute ethanol and then with acetone. After drying, 0.50 g of the sample was weighed to the nearest 1 mg. 7.2 Blank test
0.50 g of pure iron (4.1) was weighed and tested in parallel with the sample in the same procedure using the same amount of all reagents for blank testing. 7.3 Measurement
7.3.1 Preparation of test solution
Prepare the test solution as follows.
a) Place the sample in a PTFE beaker.
b) Add 6 mL of hydrochloric acid (4.2) and 3 mL of nitric acid (4.6). Heat slowly until the reaction stops. Add 3mL of hydrofluoric acid (4.7), in Heat at about 90 ° C for 15 min.
c) Remove the cooling, add 5mL perchloric acid (4.8), and heat to evaporate to the perchloric acid white smoke. Cover with PTFE cap and continue heating Perchloric acid white smoke forms a steady reflux on the beaker wall and continues to heat until the residual solution volume is about 1 mL. Note. It is recommended to cover the beaker with a PTFE cap only on samples containing high carbon when the perchloric acid smokes, so that the free carbon is completely dissolved. d) Cool, add 10mL hydrochloric acid and nitric acid mixed acid (4.9), slowly heat to dissolve the salt. e) Cool to room temperature. The solution was transferred to a 100 mL polypropylene or polyethylene terephthalate volumetric flask (5.3). If adopted Internal standard method, add 1.0mL 钇 internal standard solution (4.12), dilute to the mark with water, and mix. If there is insoluble residue in the test solution, filter the test solution according to 7.3.2. Otherwise, the filtering step is omitted. 7.3.2 Filtration of test solution
The filter (5.4) was placed in a suction filtration system (5.5), washed several times with warm hydrochloric acid (4.4), and then washed with warm water. Filter part of the test solution (7.3.1), discard the cleaning solution and filtrate from the filter bottle. Note. Filter paper can also be used for filtration, but the operator should pay attention to the blank of calcium in the filter paper; or make the residue fully precipitate before injection, the operator should be careful to avoid blocking the fog. Chemist.
The filtrate was collected by a clean and dry suction filter bottle, and part of the test solution (7.3.1) was again filtered by the same suction filtration system, and the filtrate was collected in a suction filter bottle. The filtrate was transferred to a dry 100 mL polypropylene or polyethylene terephthalate volumetric flask (5.3). The filtrate is directly inductively coupled Plasma atomic emission spectrometry.
7.3.3 Preparation of calibration solution
Weigh 0.500g ± 0.005g of pure iron (4.1) in a series of.200mL PTFE beakers, and operate according to 7.3.1 b) ~ d). The solution was cooled to room temperature and transferred to a series of 100 mL polypropylene or polyethylene terephthalate volumetric flasks (5.3). Using an internal standard method, 1.0 mL of an internal standard solution (4.12) was added to each volumetric flask. Standard solutions of calcium and magnesium were added according to Table 3, Table 4 and/or Table 5. Dilute to the mark with water and mix. If appropriate, calibration of calcium and magnesium The liquid can be dispensed in the same volumetric flask.
Table 3 Calibration curve of calcium mass fraction between 0.0005% and 0.006% Calibration solution
Numbering
Calcium standard solution C (4.10.4)
volume of
mL
Calcium Standard Solution B (4.10.3)
volume of
mL
Calibrating calcium in solution
Concentration
Gg/mL
Calcium in the corresponding sample
Quality score
S0 0 0 0 0
SCa, 1 2.00 0 0.020 0.0004
SCa, 2 4.00 0 0.040 0.0008
SCa, 3 6.00 0 0.060 0.0012
SCa, 4 10.00 0 0.10 0.0020
SCa, 5 0 2.00 0.20 0.0040
SCa, 6 0 3.00 0.30 0.0060
Table 4 Calibration curves for magnesium mass fractions from 0.0005% to 0.010% Calibration solution
Numbering
Magnesium standard solution C (4.11.4)
volume of
mL
Magnesium Standard Solution B (4.11.3)
volume of
mL
Calibration of magnesium in solution
Concentration
Gg/mL
Magnesium in the corresponding sample
Quality score
S0 0 0 0 0
SMg,1 1.00 0 0.010 0.0002
SMg, 2 2.50 0 0.025 0.0005
SMg, 3 5.00 0 0.050 0.0010
SMg, 4 10.00 0 0.10 0.0020
SMg, 5 0 2.50 0.25 0.0050
SMg, 6 0 5.00 0.50 0.010
Table 5 Calibration curves for magnesium mass fractions from 0.010% to 0.20% Calibration solution
Numbering
Magnesium Standard Solution B (4.11.3)
volume of
mL
Magnesium Standard Solution A (4.11.2)
volume of
mL
Calibration of magnesium in solution
Concentration
Gg/mL
Magnesium in the corresponding sample
Quality score
S0 0 0 0 0
SMg,6 5.00 0 0.50 0.010
SMg, 7 10.00 0 1.00 0.020
SMg, 8 0 2.50 2.50 0.050
SMg, 9 0 5.00 5.00 0.100
SMg, 10 0 10.00 10.00 0.200
7.4 Instrument adjustment
Turn on the inductively coupled plasma atomic emission spectrometer and stabilize the instrument according to the manufacturer's instructions before measurement. Optimize the instrument according to the manufacturer's instructions.
Prepare software to measure the selected analytical line strength and calculate the mean and relative standard deviation. If an internal standard is used, software for calculating the intensity ratio of the analysis line to the internal standard line is prepared. The internal standard strength should be measured simultaneously with the analytical line strength. Check the performance of the instrument according to the requirements given in 5.1.2~5.1.5. 7.5 Measurement of calibration solution
From the lowest concentration calibration solution S0 to the highest concentration calibration solution, the absolute intensity or intensity ratio of the analytical line is measured in turn. Each calibration solution was measured 3 times and the average intensity was calculated. Subtract the average absolute or average intensity of the calibration solution S0 from the average absolute or average intensity ratio (Ici) of each calibration solution The ratio (Ic0) gives a net absolute or net intensity ratio (Icn).
7.6 Drawing of the calibration curve
With the net strength or net strength ratio of calcium or magnesium as the y-axis, the mass concentration of calcium or mag...

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