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Iron, steel and alloy -- Determination of manganese content -- Flame atomic absorption spectrometric method
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Methods for chemical analysis of iron, steel and alloy--The flame atomic absorption spectrometric method for the determination of manganese content
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GB/T 223.64-2008: Iron, steel and alloy -- Determination of manganese content -- Flame atomic absorption spectrometric method
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Iron, steel and alloy. Determination of manganese content. Flame atomic absorption spectrometric method
ICS 77.080.01
H11
National Standards of People's Republic of China
GB/T 223.64-2008/ISO 10700..1994
Replacing GB/T 223.64-1988
Steel and alloy - Determination of manganese content
Flame atomic absorption spectrometry
(ISO 10700..1994, IDT)
2008-05-13 released
2008-11-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
China National Standardization Administration released
Foreword
This part of GB/T 223 is equivalent to ISO 10700..1994 "Determination of manganese content of steel flame atomic absorption spectrometry."
For ease of use, this section made the following editorial changes.
a) Replace the word "international standard" with "this part";
b) Use "." instead of "," as the decimal point
c) Delete the preface to the International Standard.
This section instead of GB/T 223.64-1988, compared with the main changes made to the following.
--- Determination range from 0.1% ~ 2.0% adjusted to 0.002% ~ 2.0%;
--- The amount of sample is adjusted from 0.5000g to 1.0g;
--- Sample processing according to different samples by adding different acids into a unified by hydrochloric acid, nitric acid dissolved, perchloric acid smoke;
--- From a unified calibration curve to a piecemeal calibration curve.
This part of the Appendix A normative appendix, Appendix B and Appendix C are informative appendices.
This part is proposed by China Iron and Steel Association.
This part of the National Standardization Technical Committee Iron and Steel centralized.
This section mainly drafted by. Wuhan Iron and Steel (Group) Company.
The main drafters of this section. Li Xiaojie, Shen Ke, Shang Hui, Zhou Daqing.
This part of the standard replaces the previous editions are.
--- GB/T 223.64-1988.
GB/T 223.64-2008/ISO 10700..1994
Steel and alloy - Determination of manganese content
Flame atomic absorption spectrometry
Warning. Personnel using this section should have practical experience in formal laboratory work. This section does not indicate all possible security issues. Make
It is the user's responsibility to take appropriate safety and health measures and to ensure compliance with the requirements of the relevant state laws and regulations.
1 Scope
This section GB/T 223 specifies the determination of manganese content in steel by flame atomic absorption spectrometry.
This section applies to the mass fraction of 0.002% ~ 2.0% determination of manganese content.
2 Normative references
The following documents contain provisions that, through reference in this section, become the provisions of this part of GB/T 223. Any reference to the date of the citation
All subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to be reached under this section
The parties to the agreement study whether the latest versions of these documents are available. For undated references, the latest version applies to this book
section.
ISO 377-2. 1989 Selection and preparation of test specimens for sample and forged steels - Part 2. Samples for determination of chemical composition
ISO 385-1. 1984 Laboratory glassware burets - Part 1. Basic requirements
Laboratory glassware single standard pipette
ISO 5725. 1986 Precision of measurement methods - Repeatability and reproducibility of standard measurement methods are determined by interlaboratory tests
ISO 1042. 1983 Laboratory glassware single standard line volumetric flask
ISO 3696. 1987 Analysis of laboratory water specifications and test methods
3 principle
Sample with hydrochloric acid and nitric acid decomposition, plus perchloric acid evaporated to take white smoke. The solution is injected into the air - acetylene flame, with a hollow cathode lamp made of manganese
Light source, Atomic absorption spectrometer at 279.5nm, atomic absorption spectrometry.
4 reagent
Unless otherwise indicated in the analysis, only certified analytical reagents and secondary water specified in ISO 3696 are used.
4.1 Pure iron, manganese-free or known residual manganese content.
4.2 Hydrochloric acid, p approximately 1.19 g/mL.
4.3 hydrofluoric acid, p about 1.15 g/mL.
4.4 nitric acid, p about 1.40 g/mL.
4.5 perchloric acid, ρ about 1.54g/mL.
Note 1. Perchloric acid with a density of 1.67 g/mL, 100 mL of perchloric acid with a density of 1.54 g/mL and 79 mL with a density of 1.67 g/mL
Perchloric acid quite.
4.6 The bottom liquid. Weigh 10.00g pure iron (4.1), accurate to 0.01g, placed in a 1000mL beaker, add.200mL hydrochloric acid (4.2),
Cover the beaker with a watch glass and heat at low temperature until the pure iron decomposes, then add 50 mL of nitric acid (4.4) to oxidize. Add 150 mL perchloric acid
(4.5), high temperature heating, until the concentration of white perchloric acid smoke. Continue to smoke 15min, control the temperature of white perchloric acid smoke in the beaker wall shape
Into a stable return. Cool, add 300mL water, low temperature heat to dissolve salts. Quantitatively transferred to 1000mL single standard line volumetric flask, water
Dilute to the mark and mix well. 1mL The bottom liquid contains 0.010g of iron.
GB/T 223.64-2008/ISO 10700..1994
4.7 manganese standard solution
4.7.1 Manganese stock solution, equivalent to 1.00g manganese per liter. Weigh 1.000g pure manganese metal [purity ≥ 99.9% (mass fraction)], accurate to
0.1mg, placed in 250mL beaker, add 40mL hydrochloric acid (4.2), cover the surface of the dish, low temperature heating until the manganese completely decomposed. Cool, will
Quantitative solution into the 1000mL single-standard line volumetric flask, diluted with water to the mark, mix. This standard solution 1mL contains 1.00mg manganese.
4.7.2 manganese standard solution, equivalent to 0.0200g per liter of manganese. Pipette 20.0mL stock solution (4.7.1) in 1000mL single standard line capacity
Bottle, diluted with water to the mark, mix well. Prepared before use. This standard solution 1mL contains 0.0200mg manganese.
5 instruments
All glass feelers shall comply with Class A of ISO 385-1, ISO 648 or ISO 1042.
5.1 Atomic Absorption Spectrometer with Manganese Hollow Cathode Lamps, Supplied Air - The acetylene gas should be pure enough not to contain water, oil, and manganese to mention
For the stable and clear lean flame.
After optimization of the atomic absorption spectrometer according to 7.3.5, the detection limit and characteristic concentration should be consistent with the parameters provided by the instrument manufacturer, and satisfy
Indicators in 5.1.1 to 5.1.3.
The apparatus should also meet the additional performance requirements given in 5.1.4.
5.1.1 Minimum precision (see Appendix A.1)
With the highest concentration of the calibration solution, absorbance measured 10 times, calculate the standard deviation of this standard deviation shall not exceed this solution absorbance level
1.5% of the mean.
Measure the absorbance 10 times with the lowest calibration solution (not a zero calibration solution) and calculate its standard deviation, which should not exceed
The highest concentration of 0.5% of the average absorbance of the calibration solution.
5.1.2 detection limit (see Appendix A.2)
The detection limit is defined as the standard deviation of the 10 absorbance measurements of the analyte element in the solution slightly above the zero calibration solution
2 times.
The detection limit of manganese should be less than 0.02 μg/mL in a solution similar to the matrix of the final sample solution.
5.1.3 Calibration curve linearity (see Appendix A.3)
When measured in the same manner, the slope of the upper 20% of the calibration curve (expressed as the change in absorbance) is proportional to the lower 20% conc.
The slope of the degree of the ratio of the value should not be less than 0.7.
For instruments calibrated automatically with two or more standard samples, the absorbance readings obtained should be used prior to analysis to
Find the linear calibration curve.
5.1.4 characteristic concentration (see Appendix A.4)
In solutions consistent with the final sample solution matrix, the characteristic concentration of manganese should be less than 0.1 μg/mL.
5.2 Auxiliary devices
It is recommended to use tape recorders or digital reading devices to evaluate the indicators in 5.1.1 to 5.1.3 and make further measurements.
The scale can be magnified until the observed noise is greater than the reading error, and absorbance below 0.1 is recommended. If you have to use the scale to put
Large, but can not read the magnification, available in the following ways to get the magnification. respectively, with and without the use of scale amplification
The appropriate amount of solution absorbance, calculate the ratio of the signal measured.
6 sample preparation
Prepare samples according to ISO 377-2 or appropriate national standards.
7 Analysis steps
WARNING. In the presence of ammonia, nitrous acid fumes, or organic matter, it may cause an explosion when exposed to perchloric acid fumes. All evaporations must be made at a suitable time
Perchloric acid fume hood.
Make sure to flush the sprinkler system and drain system after using perchloric acid.
GB/T 223.64-2008/ISO 10700..1994
7.1 Sample volume
Weigh about 1.0g sample, accurate to 0.001g.
7.2 blank test
Follow the same procedure with a blank test run, using the same amount of reagent and the amount of pure iron (4.1) used
the same.
7.3 Determination
7.3.1 Preparation of test solution
The sample (7.1) placed in 250mL beaker, add 20mL hydrochloric acid (4.2), cover the watch glass, low temperature heating dissolved until the reaction was stopped.
Add 5mL nitric acid (4.4) boil 1min, drive away the nitrogen oxides, add 15mL perchloric acid (4.5), without covering the surface of the dish heated at high temperature until
smoke. Then cover the watch glass to continue heating, heating temperature should make perchloric acid smoke in the beaker wall to maintain a steady reflux, continue heating until
Perchloric acid smoke can not be seen in the beaker.
Hydrochloric acid and nitric acid is not easy to dissolve the sample, add 15mL perchloric acid before the addition of 2mL hydrofluoric acid (4.3), continue with the above operation
get on.
7.3.2 solution treatment
7.3.2.1 Manganese content (mass fraction) below 0.10%
Cooling, adding 25mL of water, slightly soluble salts, cooled again, quantitatively transferred to 250mL single standard line volumetric flask, diluted with water until engraved
Degree, mix well. Filter with medium speed filter paper, filter out the residue or precipitate, after discarding the first part, the filtrate collected in a clean dry beaker.
This filtrate is the determination of manganese content (mass fraction) below 0.10% of the test solution.
7.3.2.2 Manganese content (mass fraction) 0.10% ~ 0.40%
Pipette 50.0mL filtrate (7.3.2.1) in.200mL single-labeled volumetric flask, diluted with water to the mark, and mix.
7.3.2.3 Manganese content (mass fraction) at 0.40% ~ 2.0%
Pipette 10.0mL filtrate (7.3.2.1) in.200mL single-labeled volumetric flask, diluted with water to the mark, and mix.
7.3.3 Preparation of calibration solution
7.3.3.1 Manganese content (mass fraction) below 0.10%
40.0mL bottom solution (4.6) were added to eight 100mL single-labeled volumetric flask, with a burette or pipette according to Table 1 was added to the phase
The volume of manganese standard solution (4.7.2), diluted with water to the mark, mix well.
Table 1 manganese content below 0.10% of the calibration solution
Manganese standard solution (4.7.2) Volume/mL Manganese mass/mg Equivalent to the manganese content (mass fraction) /%
0a
0.4
2.0
4.0
8.0
12.0
16.0
20.0
0.008
0.04
0.08
0.16
0.24
0.32
0.40
0.002
0.010
0.020
0.040
0.060
0.080
0.100
a Zero calibration solution.
7.3.3.2 Manganese content (mass fraction) is 0.10% ~ 0.40%
The 10.0mL bottom solution (4.6) were added to six 100mL single-labeled volumetric flask, with a burette or pipette according to Table 2 added phase
The volume of manganese standard solution (4.7.2), diluted with water to the mark, mix well.
GB/T 223.64-2008/ISO 10700..1994
Table 2 manganese content of 0.10% ~ 0.40% of the calibration solution
Manganese standard solution (4.7.2) Volume/mL Mass of manganese/mg Equivalent to manganese in sample /%
0a
4.0
8.0
12.0
16.0
20.0
0.08
0.16
0.24
0.32
0.40
0.080
0.16
0.24
0.32
0.40
a Zero calibration solution.
7.3.3.3 Manganese content (mass fraction) is 0.40% ~ 2.0%
The 2.0mL bottom solution (4.6) were added to six 100mL single-labeled volumetric flask, with a burette or pipette according to Table 3 added phase
The volume of manganese standard solution (4.7.2), diluted with water to the mark, mix well.
Table 3 manganese content of 0.40% ~ 2.0% calibration solution
Manganese standard solution (4.7.2) Volume/mL Mass of manganese/mg Equivalent to manganese in sample /%
0a
4.0
8.0
12.0
16.0
20.0
0.08
0.16
0.24
0.32
0.40
0.40
0.80
1.20
1.60
2.00
a Zero calibration solution.
7.3.4 Atomic absorption spectrometer adjustment
The adjustment of the instrument is shown in Table 4.
Table 4 Instrument Adjustment
Feature characteristics
Type of lamp
wavelength
flame
Lamp current
bandwidth
Manganese hollow cathode lamp
279.5 nm
Air-acetylene lean flame with maximum manganese response
Follow the manufacturer's recommendations
Follow the manufacturer's recommendations
Warning. In strict accordance with the manufacturer's recommendations, in particular, should pay attention to the following safety points.
犪) acetylene is explosive, should always pay attention to use;
犫) Wear colored glasses to protect the operator's eyes from UV radiation damage;
犮) The burner should be kept clean and free from salt. Plugging of the burner may result in tempering;
7.3.5 Atomic Absorption Device Optimization
Prepare the instrument according to the manufacturer's instructions.
Adjust lamp current, wavelength, gas flow, ignite flame, spray water until device shows steady state.
Adjust the absorbance to zero with water.
Select a buffer setting or integration time to keep the instrument signal sufficiently stable to meet the specifications in 5.1.1 through 5.1.3.
The flame is adjusted to lean burn, the combustion head height is adjusted to 10mm below the optical path alternately sprayed into the highest concentration calibration solution and zero school
GB/T 223.64-2008/ISO 10700..1994
Quasi-solution (see Table 1 to Table 3). Adjust gas flow and head position (horizontal, vertical and rotation) until absorbance between calibration solutions
The maximum difference is reached.
Check the spectrometer to set the spectrometer to the exact position where the wavelength is required.
Evaluation 5.1.1 to 5.1.3 indicators, and additional features required 5.1.4, to ensure that the instrument is suitable for the determination of manganese.
7.3.6 Spectral measurement
Set the scale ratio, so that the highest concentration of the calibration solution absorbance near full scale, according to the concentration of the order of increasing spray into the calibration solution, repeat
Perform the measurement until the specified accuracy is reached, indicating that the instrument has reached a steady state. Select two calibration solutions, one slightly lower than the test solution
Absorbance, and the other slightly higher than the absorbance of the test solution, according to the concentration in increasing order, and then in descending order of injection calibration solution, test solution sandwiched in the middle
Measurement, each measured relative to water absorbance. Measure all calibration solutions within the calibration range in ascending and descending order, including zero calibration
Quasi-solution, and finally the calibration solution ascending and descending average absorbance for the calibration curve.
It should be noted that these steps do not apply to automatic atomic absorption spectrometry using only two calibration solutions, in which case it is not advisable
Two "sandwich" solutions are used to plot the calibration curve, but should be alternated with the test solution.
In bulk sample determination process, after some time on the calibration solution spray, if the results show that due to blockage and lead to lower accuracy,
The burner should be cleaned.
The average absorbance of each calibration solution is obtained.
Get the average absorbance of the test solution and the blank solution.
7.4 Calibration curve drawing
For each measurement and the range of manganese to be tested, a new calibration curve is required.
Usually zero calibration solution absorbance is very low, but if there is a significant absorption, you need to calculate according to equation (1) zero calibration solution of manganese
concentration.
ρMn, z = ρMn, cl ×
Az
AMn, cl-Az
(1)
Where.
ρMn, cl --- added to the first calibration solution manganese concentration in micrograms per milliliter (μg/mL);
Az --- zero calibration solution absorbance;
AMn, cl --- absorbance of the first calibration solution.
Add the calculated ρ value to each calibration concentration to pass the calibration curve through the origin of the coordinates.
Absorbance of two adjacent calibration solutions on the calibration curve. If the reading deviates from the curve and does not exceed the allowable precision index, read the test solution
The value is acceptable.
8 results indicated
8.1 Calculation method
The absorbance of the test solution and the blank test solution is converted to the manganese content using a calibration curve (7.4) in μg/mL.
According to formula (2) calculate the manganese content Mn, expressed in mass fraction (%).
Mn =
(ΡMn, 1-ρMn, 0) × 250
106 ×
(ΡMn, 1-ρMn, 0) × 25D
(2)
Where.
ρMn, 0 --- blank test solution (7.2) in the manganese concentration in micrograms per milliliter (μg/mL);
ρMn, 1 --- manganese concentration of the test solution (7.4) obtained from the calibration curve, in micrograms per milliliter (μg/mL);
GB/T 223.64-2008/ISO 10700..1994
D --- dilution factor.
D = 1 for manganese content (mass fraction) less than 0.10%;
D = 4 for manganese content (mass fraction) of 0.10% to 0.40%;
D = 20 for manganese content (mass fraction) of 0.40% ~ 2.0%.
8.2 Precision
This part of the precision test to 10 levels in 20 laboratories, each laboratory for each level of manganese content was determined three times (see
Note 2 and Note 3).
The samples used are listed in Table B in Appendix B. 1.
According to ISO 5725, the results obtained are statistically processed.
Table 5, the data diagram from Appendix C. 1 is given.
Table 5 Precision data
Reproducibility limit
R RW
0.002
0.005
0.010
0.020
0.050
0.100
0.20
0.50
1.00
2.00
0.00029
0.00052
0.00081
0.0013
0.0023
0.0036
0.0056
0.010
0.016
0.024
0.00062
0.0012
0.0018
0.0029
0.0053
0.0084
0.013
0.024
0.038
0.061
0.00030
0.00059
0.00099
0.0017
0.0033
0.0055
0.0092
0.0018
0.030
0.051
NOTE 2 The two determinations of the three determinations are carried out under the repeatability conditions specified in ISO 5725, ie by the same instructor, using the same instrument, the same
Test conditions, the same calibration, measured in the shortest possible time.
Note 3. The third determination by the Note 1 Noteworthy staff, using the same instrument, at different times (different days), with a new calibration.
The results obtained, calculate the reproducibility limit (RW) in the laboratory.
9 test report
The test report should include the following.
a) Identification of materials, laboratory and analysis date;
b) to comply with the provisions of this section;
c) analysis results and their representation;
d) the anomalies observed in the assay;
e) Actions or optional actions that may have an impact on the analysis but are not covered by this section.
GB/T 223.64-2008/ISO 10700..1994
Appendix A.
(Normative)
Instrument index measurement steps
To establish a standard method for the analysis of flame atomic absorption spectrometry, the working group should determine the values of the instrumental indicators based on the inter-laboratory measurements.
A. 1 Determination of the lowest precision
The standard deviations 狊 A and 狊 B of the measured values of the calibration solutions for the highest and lowest concentrations are given by Eqs. (A.1) and (A.2) respectively.
狊 A = Σ
狊 B = Σ
The minimum accuracies of the highest and lowest calibration solutions are 狊 A × 100/AA and 狊 B × 100/AB, respectively.
A solution of 2 parts identical to the matrix of the sample solution was prepared, however, the concentrations of the measured elements were the following known concentrations.
- ρ'Mn (μg/mL) solution resulting absorbance A 'is about 0.01;
--- Matrix blank solution absorbance A0.
Measure ρ'Mn solution and blank solution 10 times, each reading time is about 10s, should use a sufficiently large scale, so that you can clearly see
To signal fluctuations. The absorbance average A 'and A0 were obtained.
Calculate the standard deviation using the formula (A.3) 狊 A '.
狊 A '= Σ
Where.
From (A.4) to calculate the detection limit ρMn, min (犽 usually take 2).
ρMn, min =
ρ'Mn × 狊 A '× 犽
A'-A0
(A.4)
A. 3 calibration curve linear criterion
Prior to any alignment of the plotted calibration curve (see Figure A.1), a net absorbance value of 20% above the calibration concentration range
AA, and the net absorbance AB of 20% at the bottom of the calibration concentration range, calculate AA/AB, which must not be less than 0.7.
A. 4 Determination of characteristic concentration ρM-like, 犽
Prepare 1 part of the same solution as the matrix of the sample solution. However, the concentration of the element to be measured is the following known concentration.
The absorbance A produced by ρMn (μg/mL) solution is about 0.1.
Without expanding the scale, measure the ρMn solution with a blank solution to obtain the absorbances A and A0, respectively, and calculate the characteristic from equation (A.5)
Concentration ρMn, 犽.
GB/T 223.64-2008/ISO 10700..1994
ρMn, 犽 =
ρMn × 0.0044
A-A0
(A.5)
Figure A. 1
GB/T 223.64-2008/ISO 10700..1994
Appendix B
(Informative)
International cooperation test additional information
In 1987 and.1991, the international cooperation test results of eight steel samples and two iron samples from 20 laboratories in 9 countries
Get Table 5.
The test results are reported in ISO /T C17/SC1N910, January.1992. Pictorial precision data in Appendix C.
The samples used are listed in Table B. 1.
Table B. 1 laboratory test results
Sample
Manganese content (mass fraction) /% precision data
Approved value
Measured value Repeatability Value Reproducibility value
JSS003-1 (high purity iron)
ECRM097-1 (high purity iron)
ECRM285-1 (18Ni, 5Mo, 9Co steel)
ECRM114-1 (4Si steel)
ECRM090-1 (1C, 0.2V steel)
JSS608-8 (4Cr, 1V, 9Co, 17W steel)
ECRM081-1 (non-alloy steel)
ECRM051-1 (0.1S steel)
ECRM227-1 (10Ni, 18Cr, 0.2Mo steel)
ECRM126-1 (0.3Cr, 0.1V steel)
0.0018
0.0064
0.013
0.0655
0.226
0.33
0.605
1.18
1.535
1.817
0.00182
0.00690
0.0122
0.0664
0.225
0.331
0.606
1.190
1.546
1.808
0.00185
0.00684
0.0122
0.0664
0.226
0.311
0.608
1.191
1.544
1.805
0.00072
0.00061
0.00048
0.00140
0.0043
0.0068
0.0093
0.0204
0.0338
0.0341
0.00106
0.00126
0.00154
0.00361
0.0147
0.0181
0.0270
0.0491
0.0506
0.0768
0.00047
0.00079
0.00079
0.00268
0.0094
0.0117
0.0150
0.0491
0.0469
0.0622
Mn, 1. Average of data measured on the same day.
Mn, 2. The average of the data measured on different days.
GB/T 223.64-2008/ISO 10700..1994
Appendix C
(Informative appendix)
Precision data illustration
lgRW = 0.7420lgMn, 2-1.5195
lgR = 0.66171lgMn, 1-1.4157
Where.
Mn, 1 --- the average value of the manganese content (mass fraction) obtained on the same day,%;
Mn, 2 --- The average of manganese content (mass fraction) obtained from different days,%.
GB/T 223.64-2008/ISO 10700..1994
......
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