GB/T 30903-2014 PDF English
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Inorganic chemicals for industrial use - Determination of impurity element - Inductively coupled plasma mass spectrometry (ICP-MS)
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GB/T 30903-2014: PDF in English (GBT 30903-2014) GB/T 30903-2014
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 mass
spectrometry (ICP-MS)
ISSUED ON. JULY 08, 2014
IMPLEMENTED ON. DECEMBER 01, 2014
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
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, devices... 6
7 Analysis steps... 7
8 Precision... 11
9 Recovery rate... 11
Annex A (normative) Quartz sub-boiling distillation unit... 13
Annex B (normative) Detection limit determination method... 14
Inorganic chemicals for industrial use - Determination of
impurity element - Inductively coupled plasma mass
spectrometry (ICP-MS)
WARNING -- Some of the reagents used in this test method are toxic or corrosive.
Be careful when operating! If splashed on the skin, rinse with water immediately,
and seek medical treatment immediately in severe cases. This test method uses
high-pressure argon cylinders, which shall be operated in accordance with the safe
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, equipment, analytical
procedures, precision and recovery rate for the determination of metallic and non-
metallic impurity elements in inorganic chemical products by inductively coupled
plasma mass spectrometry (ICP-MS).
This Standard is applicable to liquid samples containing multiple metal and non-metal
impurity elements in inorganic chemical products or direct sampling after removing the
matrix. Determination is carried out using inductively coupled plasma mass
spectrometry (ICP-MS).
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, Measurement methods and results -- Accuracy (trueness and precision)
-- Part 2.Determine the standard methods of measurement repeatability and
reproducibility of the basic method
photons from passing through.
3.9 collision/reaction cell
A multipole cavity installed in front of a quadrupole mass spectrometer.
Collision/reaction gas is introduced into the cavity to cause collision and reaction of
ions focused by the multipole, thereby eliminating mass spectrum interference.
3.10 quadrupole mass spectrometer
A mass analyzer that separates ions according to their mass-to-charge ratio (m/z) by
applying a radio frequency voltage and a direct current voltage to a counter electrode.
4 Principle
The specimen solution is introduced into the atomization system by the carrier gas
(argon) for atomization, and then enters the plasma center in the form of aerosol. It is
de-solvated, vaporized, dissociated and ionized in high temperature and inert
atmosphere, and converted into positive ions with positive charge. It enters the mass
spectrometer through the ion collection system. The mass spectrometer separates
according to the mass-to-charge ratio. The ion signal is received by the electron
multiplier. After amplification, it is detected. According to the intensity of the element
mass spectrum peak, each element is qualitatively or quantitatively analyzed.
5 Reagents
5.1 Chemical reagents shall be of high purity and purified (such as quartz sub-boiling
distillation equipment, see Annex A). Common inorganic acids include nitric acid
(HNO3), hydrochloric acid (HCl), hydrofluoric acid (HF), perchloric acid (HClO4),
sulfuric acid (H2SO4), and aqua regia (1HNO3 +3HCl).
5.2 The water used in the experiment shall have a resistivity of no less than 18.2 MΩ·cm.
5.3 Standard solutions shall use certified standard substances.
6 Instruments, devices
Inductively coupled plasma mass spectrometer. consists of an injection system, torch
and plasma, ion lens system, vacuum system, mass analyzer, detector and data
processing system.
7 Analysis steps
7.1 Selection of measurement conditions
7.1.1 Incident power
Select the best 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.
7.1.2 Gas and its flow
According to the torch and analysis requirements, determine the optimal flow rate of
each gas. The argon gas used meets the requirements of GB/T 4842.The general purity
is not less than 99.999%.
7.1.3 Solution lifting rate
The solution lifting rate is generally 0.1 mL/min~1 mL/min.
7.2 Interference and elimination
Interferences in inductively coupled plasma mass spectrometry can be roughly divided
into two categories. One is mass spectrometry interference, which mainly includes
oxide ion interference, divalent ion interference, polyatomic ion interference and
isobaric interference. The other is non-mass spectrometry interference, which mainly
includes matrix effect, physical effect and other interferences. Interference elimination
methods include optimizing instrument parameters, internal standard correction method,
interference equation correction, collision reaction cell technology, dilution correction,
standard addition method, etc.
7.3 Sample processing
7.3.1 Laboratory equipment
7.3.1.1 For general micro and trace analysis, attention shall be paid to the overall
cleanliness of the laboratory. When ultra-trace or high-demand analysis is performed,
an ultra-clean laboratory is generally required.
7.3.1.2 The containers used for solid digestion are generally made of
polytetrafluoroethylene (PTFE) or fluoroplastics (PFA), tetrafluoroethylene with
perfluorinated alkyl side chains. The containers for holding specimen solutions are
generally made of polytetrafluoroethylene (PTFE) or fluoroplastics (PFA),
tetrafluoroethylene with perfluorinated alkyl side chains, or low-density polyethylene
(LDPE) or high-density polyethylene (HDPE) or polypropylene (PP) materials.
7.3.1.3 Before use, the container shall generally be soaked in 20%~30% nitric acid
solution for several hours. After rinsing with ultrapure water, place it in an electric
is shown in Annex B.
The specimen solution measured on ICP-MS shall meet the following basic
requirements.
a) The total dissolved solids (TDS) in the solution is < 0.2%;
b) The content of organic matter in the solution cannot be too high, otherwise it will
cause serious matrix effects and carbon particles after the combustion of organic
matter will be deposited and block the cone mouth, resulting in reduced sensitivity
and stability. If the content of organic matter is high, an organic oxygenation
channel, an organic-resistant injection system and a platinum cone shall be
equipped;
c) The concentration of the element to be tested in the solution cannot be too high.
Generally, the element content in solid samples is required to be no more than
0.01%; and the liquid sample is required to be no more than 0.000 1% (preferably
no more than 0.00001%);
d) The solution must maintain a certain acidity to prevent precipitation after the
metal elements are hydrolyzed. Generally, a certain concentration (1%~5%) of
nitric acid is used as the medium;
e) Unless otherwise specified, the solution shall not contain high-boiling-point
sulfuric acid and phosphoric acid media to avoid damage to the sampling cone
and the skimmer cone, and to avoid polyatomic ion interference caused by S and
P;
f) The solution shall not contain hydrofluoric acid, otherwise it will damage the
quartz glass nebulizer, spray chamber and interface, unless a hydrofluoric acid-
resistant system injection device and platinum cone are used;
g) The sample shall be thoroughly digested and shall not be turbid. It is best to filter
through a 0.45 μm or 0.22 μm microporous membrane or centrifuge to obtain the
clear liquid for testing.
7.4 Determination
7.4.1 Qualitative analysis
In ICP-MS analysis, mass spectral information (i.e., mass spectrum) over the entire
mass range can be obtained through a fast full-spectrum mass spectrometer scanner.
7.4.2 Semi-quantitative analysis
The approximate content of the element to be measured in the sample can be measured.
The semi-quantitative analysis results can be obtained using the software provided by
the ICP-MS instrument. Specific steps. Determine the mixed standard solution of low,
medium and high mass elements (generally 5 ~ 8 elements are required). According to
the data such as the ionization degree and isotope abundance of the elements in the
periodic table, the mass number-sensitivity response curve is obtained. The sensitivity
of each element of the instrument used is corrected using this curve. The sensitivity
information is stored. Then the unknown sample is measured. The concentration of all
elements in the unknown sample can be calculated based on the response curve, thereby
obtaining the semi-quantitative analysis results of the sample. Generally, the semi-
quantitative analysis error of ICP-MS can be controlled between ± (30%~50%). Before
using the standard addition method for quantitative analysis, the size of the standard
addition amount can be pre-determined by using the semi-quantitative analysis method
of ICP-MS to improve the accuracy of the standard addition method.
7.4.3 Quantitative analysis
7.4.3.1 Standard curve method
According to the provisions of the product standard for the elements to be tested,
prepare the specimen solution, blank test solution and three or more standard series
solutions containing different concentrations of the elements to be tested (all shall be
prepared in the same matrix. Generally, 1%~5% dilute nitric acid is used as the medium).
Under the specified instrument conditions, measure the response intensity values of the
corresponding concentrations, respectively. Draw a standard curve with the mass
concentration (ng/mL) of the standard solution as the horizontal axis and the
corresponding response intensity value as the vertical axis. Calculate the regression
equation. The correlation coefficient shall not be less than 0.99.Find the mass
concentration of the element to be tested in the specimen solution from the standard
curve. Then calculate the content of the element to be tested 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 determination of
another element or multiple elements. Add the same concentration of internal standard
(ISTD) element to the standard solution of the element to be measured, the specimen
solution and the blank test solution (generally using 1%~5% dilute nitric acid as the
medium). Under the specified instrument conditions, measure the response intensity
values of the corresponding concentrations, respectively. Draw the internal standard
correction standard curve with the ratio of the response intensity value of the standard
solution of the element to be measured to the response intensity value of the internal
standard element as the ordinate and the corresponding mass concentration (ng/mL) as
the abscissa. Calculate the regression equation. Use the ratio of the response intensity
value of the element to be measured in the test solution to the response intensity value
of the internal standard element. After deducting the reagent blank, find out the mass
concentration of the element to be measured in the specimen solution from the internal
standard correction standard curve. Then calculate the content of the element to be
measured in the sample.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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