GB/T 223.88-2019 English PDF (GB/T223.88-2019)

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