GB/T 20975.27-2018 English PDF (GBT20975.27-2018)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 20975.27-2018
Historical versions: GB/T 20975.27-2018
Preview True-PDF (Reload/Scroll if blank)

GB/T 20975.27-2018: Methods for chemical analysis of aluminium and aluminium alloys -- Part 27: Determination of cerium, lanthanum, scandium -- Inductively coupled plasma atomic emission spectrometry method
GB/T 20975.27-2018
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.120.10
H 12
Methods for chemical analysis of aluminium and
aluminium alloys - Part 27. Determination of cerium,
lanthanum, scandium - Inductively coupled plasma
atomic emission spectrometry method
ISSUED ON. MAY 14, 2018
IMPLEMENTED ON. FEBRUARY 1, 2019
Issued by. State Administration for Market Regulation;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 3 
1 Scope ... 6 
2 Method principle ... 6 
3 Reagents and materials ... 6 
4 Instrument ... 8 
5 Sample ... 8 
6 Analytical procedures ... 8 
7 Calculation of analytical results ... 10 
8 Precision ... 10 
9 Quality assurance and control ... 11 
10 Test report ... 12 
Foreword
GB/T 20975 “Methods for chemical analysis of aluminium and aluminium alloys”
is divided into 31 parts.
- Part 1. Determination of mercury content;
- Part 2. Determination of arsenic content;
- Part 3. Determination of copper content;
- Part 4. Determination of iron content - Orthopenanthroline photometric
method;
- Part 5. Determination of silicon content;
- Part 6. Determination of cadmium content - Flame atomic absorption
spectrometric method;
- Part 7. Determination of manganese content - Potassium periodate
spectrophotometric method;
- Part 8. Determination of zinc content;
- Part 9. Determination of lithium content - Flame atomic absorption
spectrometric method;
- Part 10. Determination of tin content;
- Part 11. Determination of lead content;
- Part 12. Determination of titanium content;
- Part 13. Determination of vanadium content - N-benzoyl-
Nphenylhydroxylamine spectrophotometric method;
- Part 14. Determination of nickel content;
- Part 15. Determination of boron content;
- Part 16. Determination of magnesium content;
- Part 17. Determination of strontium content - Flame atomic absorption
spectrometric method;
- Part 18. Determination of chromium content;
Methods for chemical analysis of aluminium and
aluminium alloys - Part 27. Determination of cerium,
lanthanum, scandium - Inductively coupled plasma
atomic emission spectrometry method
1 Scope
This Part of GB/T 20975 specifies the method for determination of cerium,
lanthanum, scandium content in aluminium and aluminium alloys.
This Part is applicable to the determination of cerium, lanthanum, and scandium
content in aluminium and aluminium alloys. The aluminium in aluminium and
aluminium alloys interferes with the determination of cerium, lanthanum, and
scandium. The same amount of aluminium is added to the working curve to
eliminate the interference. Cerium, lanthanum, and scandium do not interfere
with each other, and other coexisting elements do not interfere with the
determination. Measurement range. cerium. 0.005%~0.90%; lanthanum.
0.005%~0.50%; scandium. 0.0002%~0.50%.
2 Method principle
After the sample is dissolved, in dilute hydrochloric acid medium, using
inductively coupled plasma atomic emission spectrometer (ICP-AES), the
content of cerium, lanthanum, and scandium elements is determined. By matrix
matching method, the influence of the matrix on the measurement results is
corrected.
3 Reagents and materials
Unless otherwise stated, in the analysis, only Grade 2 water is used.
3.1 Hydrogen peroxide (ρ=1.10 g/mL).
3.2 Hydrochloric acid (ρ=1.19 g/mL), analytically pure.
3.3 Nitric acid (ρ=1.42 g/mL), analytically pure.
3.4 Argon (>99.99%).
3.5 Hydrochloric acid (1+1).
3.6 Sodium hydroxide (200 g/L).
3.7 Aluminium [w(Al)≥99.99%], before use, dip-rinse with a small amount of acid;
then WASH off the acid with water, RINSE 2~3 times with absolute ethyl alcohol,
and air dry.
3.8 Aluminium matrix solution (20 mg/mL). WEIGH 10.00 g of aluminium (3.7)
into a 500 mL beaker; COVER the watch glass; and ADD a total of 300 mL of
hydrochloric acid (3.5) in portions. After the violent reaction is stopped, ADD a
few drops of hydrogen peroxide (3.1); slowly HEAT until completely dissolved;
then BOIL for a few minutes, COOL; and TRANSFER the solution to a 500 mL
volumetric flask; USE water to dilute to volume, and MIX well.
3.9 Standard stock solution of cerium (1 mg/mL). WEIGH 0.3071 g of cerium
oxide [w(CeO2)≥99.99%, pre-burned at 1000 °C for 1 h, and cooled in a
desiccator] in a 100 mL beaker; ADD 15 mL of nitric acid (3.3). PLACE for a
while and HEAT to boil; then ADD 1 mL of hydrogen peroxide (3.1); HEAT at
low temperature for 4 times~5 times until complete dissolution; HEAT to boil,
and COOL. TRANSFER to a 250 mL volumetric flask; USE water to dilute to
volume, and MIX well.
3.10 Standard stock solution of lanthanum (1 mg/mL). WEIGH 0.2932 g of
lanthanum trioxide [w(La2O3)≥99.99%, pre-burned at 1000 °C for 1 h, and
cooled in a desiccator] in a 100 mL beaker; ADD 50 mL of hydrochloric acid
(3.5); HEAT until complete dissolution, and COOL. TRANSFER to a 250 mL
volumetric flask; USE water to dilute to volume, and MIX well.
3.11 Standard stock solution of scandium (1 mg/mL). WEIGH 0.3835 g of
scandium oxide [w(Sc2O3)≥99.99%, pre-burned at 800 °C for 1 h, and cooled
in a desiccator] into a 100 mL beaker; ADD 25 mL of nitric acid (3.3); dropwise
ADD hydrogen peroxide (3.1) until completely dissolved. Then BOIL for a few
minutes, COOL; and TRANSFER to a 250 mL volumetric flask; ADD 25 mL of
nitric acid (3.3); USE water to dilute to volume, and MIX well.
3.12 Cerium standard solution. PIPETTE 10.00 mL of standard stock solution
of cerium (3.9) into a 100 mL volumetric flask; USE water to dilute to volume,
and MIX well, to obtain cerium standard solution A (100 μg/mL). By stepwise
dilution in the same manner, cerium standard solution B (10 μg/mL) can be
obtained.
3.13 Lanthanum standard solution. PIPETTE 10.00 mL of standard stock
solution of lanthanum (3.10) into a 100 mL volumetric flask; USE water to dilute
to volume, and MIX well, to obtain lanthanum standard solution A (100 μg/mL).
6.3 Blank test
WEIGH the same amount of aluminium (3.7) as the test portion; and PERFORM
a blank test along with the test portion.
6.4 Determination
6.4.1 When the silicon’s mass fraction in the sample is ≤2%, PLACE the test
portion (6.1) in a 100 mL beaker; ADD 10 mL of hydrochloric acid (3.5), and
COVER the watch glass. After the reaction is stopped, ADD a few drops of
hydrogen peroxide (3.1); slowly HEAT until completely dissolved; and then
BOIL for 3 min~5 min, COOL. TRANSFER the solution to a 100 mL volumetric
flask; USE water to dilute to volume, and MIX well. The test solution is
introduced into a plasma atomic emission spectrometer for determination.
6.4.2 When the silicon’s mass fraction in the sample is >2%, PLACE the test
portion (6.1) in a 100 mL polytetrafluoroethylene beaker; ADD 10 mL of sodium
hydroxide solution (3.6), and COVER the watch glass. After the reaction is
completed, COOL to room temperature; ADD 15 mL of hydrochloric acid (3.5),
and COOL. TRANSFER the solution to a 100 mL volumetric flask; USE water
to dilute to volume, and MIX well. The test solution is introduced into a plasma
atomic emission spectrometer for determination.
When the linear correlation coefficient of working curve is ≥0.99, according to
the relationship between the spectral intensity and the concentration, the
concentration of cerium, lanthanum, and scandium elements in the sample is
automatically given by the comp...