GB/T 30902-2014 PDF in English
GB/T 30902-2014 (GB/T30902-2014, GBT 30902-2014, GBT30902-2014)
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Name of Chinese Standard | Status |
| GB/T 30902-2014 | English | 225 |
Add to Cart
|
0-9 seconds. Auto-delivery.
|
Inorganic chemicals for industrial use -- Determination of impurity element -- Inductively coupled plasma optical emission spectrometry (ICP-OES)
| Valid |
Standards related to (historical): GB/T 30902-2014
PDF Preview
GB/T 30902-2014: PDF in English (GBT 30902-2014) GB/T 30902-2014
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.060.01
G 10
Inorganic chemicals for industrial use - Determination of
impurity element - Inductively coupled plasma optical
emission spectrometry (ICP-OES)
ISSUED ON: JULY 08, 2014
IMPLEMENTED ON: DECEMBER 01, 2014
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Principle ... 6
5 Reagents ... 6
6 Instruments and apparatuses ... 7
7 Procedure ... 7
8 Precision ... 11
9 Recovery ... 11
Appendix A (Informative) Preparation of multi-element standard solutions ... 12
Appendix B (Informative) Wavelength of analysis spectral lines of elements to be
measured ... 13
Appendix C (Informative) Determination method of detection limit ... 15
Inorganic chemicals for industrial use - Determination of
impurity element - Inductively coupled plasma optical
emission spectrometry (ICP-OES)
Warning: Some of the reagents used in this test method are toxic or corrosive, so
be careful when operating! If it splashes on the skin, rinse it with water
immediately, and in serious cases, treat it immediately; high-pressure argon gas
cylinders are used in this test method and shall be operated according to the safety
operation regulations of high-pressure cylinders; after igniting the plasma, the
torch chamber door shall not be opened to prevent high-frequency radiation from
harming the body; pay attention to safe use of electricity.
1 Scope
This Standard specifies the principle, reagents, instruments, apparatuses, analysis steps,
precision, and recovery rate for the determination of metallic and non-metallic impurity
elements in inorganic chemicals for industrial use using inductively coupled plasma
optical emission spectrometry (ICP-OES).
This Standard applies to direct injection of liquid samples containing various impurities
in inorganic chemicals for industrial use or test solutions after removing the matrix,
using an inductively coupled plasma optical emission spectrometer for measurement.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 4470, Analytical spectroscopic methods - Flame emission, atomic absorption
and atomic fluorescence - Vocabulary
GB/T 4842, Argon
GB/T 6379.2, Accuracy (trueness and precision) of measurement methods and
results - Part 2: Basic method for the determination of repeatability and
reproducibility of a standard measurement method
GB/T 6682-2008, Water for analytical laboratory use - Specification and test
methods
The air flow between the outermost tube and the middle tube of the torch, which serves
to cool the torch and maintain the plasma.
3.7
auxiliary gas
The gas flow between the middle tube and central tube of the torch, which serves to
ignite the plasma, keep the bottom of the high-temperature ICP at a certain distance
from the central tube and the middle tube, protect the tops of the central tube and the
middle tube, especially the central tube mouth, from being melted or overheated, and
reduce the excessive deposition of salt carried by aerosols on the central tube mouth. In
addition, it also plays a role in raising the ICP and changing the plasma observation
degree.
3.8
carrier gas
The gas flow in the central tube of the torch, which serves to atomize the liquid into an
aerosol and carries the aerosol into the plasma.
3.9
washing time
The time to flush the sampling system with sample solution before exposure.
4 Principle
After the liquid sample is brought into the atomization system by the carrier gas for
atomization, it enters the axial channel of the plasma in the form of an aerosol, and is
fully evaporated, atomized, ionized and excited in the high temperature and inert gas.
The characteristic spectral lines of the emitted elements enter the spectrum detector
through the spectroscopic system, and the spectrum detector performs qualitative, semi-
quantitative, and quantitative analysis methods based on the characteristic spectrum.
5 Reagents
5.1 Unless other requirements are specified, the reagents used refer to reagents of
analytical grade or above. Inorganic acids, such as hydrochloric acid, nitric acid,
perchloric acid, hydrofluoric acid, are commonly used in sample processing. They shall
be checked before use to ensure that they do not contain the metal elements to be
measured.
5.2 Laboratory water shall meet the specifications for water of grade 2 or above in GB/T
6682-2008.
5.3 Standard stock solution: The standard stock solution of each analytical element shall
be prepared according to the regulations in HG/T 3696.2. Alternatively, mixed solutions
and single standard solutions of certified series of national standard materials with
corresponding concentrations can be used, and diluted to the required concentration.
See Appendix A for the preparation of multi-element group standard solutions.
6 Instruments and apparatuses
Inductively coupled plasma atomic emission spectrometer: consisting of a sampling
system, an excitation light source, an optical system, a detection system and a data
processing system.
7 Procedure
7.1 Selection of measurement conditions
7.1.1 Analysis spectral line of elements to be measured
Refer to Appendix B for the wavelength of the analysis spectral line of elements to be
measured.
7.1.2 Incident power
Select the optimal power according to the characteristics of the sample to be tested and
the instrument conditions. The general range is 0.8 kW ~ 1.6 kW.
7.1.3 Observation height
The distance from the upper end of the induction coil to the measuring axis, which is
generally 14 mm ~ 18 mm. When measuring a single element, the optical observation
height of the element to be measured shall be selected; when measuring multiple
elements, a moderate observation height shall be selected.
7.1.4 Solution lifting rate
The solution lifting rate is generally 0.6 mL/min ~ 2 mL/min.
7.1.5 Gas flow
Determine the optimal flow rate of each gas according to the torch and analysis
requirements. The argon gas used shall comply with the requirements of GB/T 4842.
7.1.6 Analysis time
7.3.2.3 Microwave digestion method
Under the action of microwave (generally in the frequency of 2 450 MHz) and under
closed pressure conditions, after the mixture of sample and acid absorbs microwave
heat, the boiling point of the inorganic acid increases, and then the oxidation reaction
activity increases, causing the surface layer of the sample to agitate and rupture,
constantly producing new sample surfaces that are in contact with the acid solvent until
the sample is completely digested and then undergo acid treatment.
7.3.2.4 Alkali metal fusion method
Use various alkali metal solvents, such as lithium metaborate, lithium tetraborate,
sodium carbonate, sodium hydroxide, sodium peroxide, corresponding potassium salts
and alkali metal fluorides (especially potassium bifluoride), to mix with the sample and
melt at high temperature.
7.3.2.5 Separation and preconcentration methods
The separation process can remove possible matrix effects and interference, achieve
preconcentration, and reduce the quantitation-limit. The main methods include solvent
extraction, ion exchange, and co-precipitation/adsorption.
7.3.3 Liquid solution requirements
After the sample is processed, adjust the volume to an appropriate volume according to
the content of the element to be measured, and make the sample solution.
The sampling volume is determined based on the mass concentration of the element to
be measured in the sample and the detection limit of the method; the mass concentration
of the element to be measured in the sample solution shall be at least three times the
detection limit of the element. See Appendix C for the determination method of
detection limit.
7.4 Determination
7.4.1 Qualitative analysis
Based on three or more sensitive lines of the element to be measured in the spectrum,
qualitatively determine whether the element to be measured is present. Generally, there
are two qualitative methods: comparative spectral line method and semi-automatic
qualitative analysis.
7.4.2 Semi-quantitative analysis
The approximate content of the element to be measured in the sample can be measured,
and semi-quantitative analysis results can be obtained using the software provided by
the ICP-OES instrument. Generally, there are two semi-quantitative analysis methods:
partial calibration method and persistence curve method.
7.4.3 Quantitative analysis
7.4.3.1 Standard curve method
According to the provisions of the product standard, prepare a sample solution, a blank
test solution and three or more standard series solutions of different concentrations (all
shall be prepared in the same matrix, generally using 1% ~ 5% dilute nitric acid as the
medium); under the specified instrument conditions, measure the corresponding
emission intensity values, respectively. Draw a standard curve with the mass
concentration of the standard solution (μg/mL) as the abscissa and the corresponding
emission intensity value as the ordinate. Find the mass concentration of the element to
be measured in the sample solution on the standard curve, and then calculate the content
of the element to be measured in the sample.
7.4.3.2 Internal standard calibration standard curve method
This method uses one element as a reference point to calibrate the measurement of
another element or multiple elements. Add internal standard (ISTD) elements of the
same concentration (generally using 1% ~ 5% dilute nitric acid as the medium) to the
standard solution, sample solution and blank test solution of the element to be measured;
under the specified instrument conditions, respectively measure the emission intensity
values of corresponding concentrations. Taking the ratio of the emission intensity value
of the standard solution of the element to be measured and the emission intensity value
of the internal standard element as the ordinate, and the corresponding mass
concentration (μg/mL) as the abscissa, draw the internal standard calibration standard
curve and calculate the regression equation. Using the ratio of the emission intensity
value of the element to be measured and the emission intensity value of the internal
standard element in the test solution, after subtracting the reagent blank, find the mass
concentration of the element to be measured in the sample solution from the internal
standard calibration standard curve, and then calculate the content of the element to be
measured in the sample.
7.4.3.3 Standard addition method
Prepare the test solution and blank test solution according to the provisions for the
element to be measured in the product standard. Use a pipette to pipette 5 portions of
test solution of the same volume and place them in 5 volumetric flasks of the same
volume. Except for the first volumetric flask, use a pipette to pipette proportioned
standard solutions of the element to be measured into the other 4 volumetric flasks
(usually using 1% ~ 5% dilute nitric acid as the medium); dilute to the mark respectively;
shake well. Under the specified instrument conditions, use the blank test solution for
zero setting, and respectively measure the corresponding emission intensity values.
Taking the mass concentration (μg/mL) of the added standard solution as the abscissa
and the corresponding emission intensity value as the ordinate, draw a working curve;
extend the curve in the opposite direction and intersect the horizontal axis. The distance
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
|