GB/T 19421-2026 Test methods of crystalline layered sodium disilicate English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS
CCS
National Standard of the People's Republic of China
GB/T 19421-2026
Test methods of crystalline layered sodium disilicate
层状结晶二硅酸钠试验方法
Issue date: 2026-03-31 Implementation date: 2026-10-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Qualitative Analysis of δ Phase Layered Crystalline Sodium Disilicate — X ray Diffractometer Method
5 Determination of Whiteness
6 Determination of pH
7 Determination of Calcium Exchange Capacity by EDTA Volumetric Method
8 Determination of Magnesium Exchange Capacity by EDTA Volumetric Method
9 Determination of Loss on Ignition by Gravimetric Method
10 Determination of Hygroscopic Moisture Content by Gravimetric Method
11 Determination of Iron(III) Oxide Content by o Phenanthroline Colorimetric Method
12 Determination of Sodium Oxide Content by Volumetric Method
13 Determination of Silicon Dioxide Content by Potassium Fluorosilicate Volumetric Method
14 Determination of Calcium Oxide Content by Atomic Absorption Spectrophotometry
15 Determination of Magnesium Oxide Content by Atomic Absorption Spectrophotometry
16 Requirements for Reporting Test Results
Annex A (Informative) X ray Diffraction Pattern of δ Phase Layered Crystalline Sodium Disilicate
Test methods for layered crystalline sodium disilicate
1 Scope
This document describes the qualitative analysis of the δ phase of layered crystalline sodium disilicate, a detergent builder, by the X ray diffractometer method, and the test methods for whiteness, pH value, calcium exchange capacity, magnesium exchange capacity, loss on ignition, hygroscopic moisture content, iron(III) oxide, sodium oxide, silicon dioxide, calcium oxide, magnesium oxide and other indicators.
This document applies to the determination of indicators for layered crystalline sodium disilicate products for use in detergents.
2 Normative References
The following documents are essential for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 6682 Water for analytical laboratory use — Specification and test methods
GB/T 9086 Standard white plates for colour and photometric measurement
GB/T 13173 Surface active agents — Detergents — Test methods
JJG 512 Verification Regulation of Whiteness Meters
QB/T 2739-2005 Common test methods for washing products — Preparation of test solutions for titration analysis (volumetric analysis)
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1 δ phase method of X ray diffractometer
A method in which a δ phase crystal, under irradiation by X rays of a given wavelength, exhibits a characteristic diffraction pattern of the δ phase of layered crystalline sodium disilicate, which is then compared with the data of the substance to be tested.
3.2 whiteness
The ratio of the radiant energy diffusely reflected by a substance relative to that of a perfect reflecting diffuser (standard white) in the visible region.
NOTE: Expressed as a percentage.
3.3 calcium exchange capacity
The capacity of the sodium ions in a product to be exchanged by calcium ions in a solution under certain conditions of temperature and alkalinity, etc.
3.4 magnesium exchange capacity
The capacity of the sodium ions in a product to be exchanged by magnesium ions in a solution under certain conditions of temperature and alkalinity, etc.
3.5 loss on ignition
The percentage decrease in mass of a sample after ignition at high temperature.
3.6 hygroscopic moisture
The mass fraction of the difference in mass of a sample before and after drying in an oven at a certain temperature, relative to the mass of the sample before drying.
4 Qualitative Analysis of δ Phase Layered Crystalline Sodium Disilicate — X ray Diffractometer Method
4.1 Principle
Any crystalline substance has specific structural parameters. Under irradiation by X rays of a given wavelength, it exhibits a characteristic polycrystalline diffraction pattern. The diffraction pattern of each phase indicates the chemical bonding state of the elements in that phase. Based on this unique correspondence between the polycrystalline diffraction pattern and the crystalline substance, the diffraction data of the substance to be tested can be compared with the known diffraction data of various substances to perform qualitative phase analysis.
4.2 Instruments and equipment
4.2.1 X ray diffractometer.
4.2.2 Agate mortar.
4.2.3 Sample preparation device.
4.3 Procedure
4.3.1 Sample preparation
Weigh approximately 2 g of the sample and grind it in a clean, dry agate mortar to a particle size of less than 5 μm, i.e., until no grittiness is felt when rubbed between clean, dry fingers. Place the ground sample into a sample holder, fill it tightly, and lightly press to form a tablet with sufficient pressure so that the tablet does not collapse when stood on its edge.
4.3.2 Determination
Turn on the cooling system of the equipment and start the X ray diffractometer. Allow it to warm up for 30 min. Start the X ray diffractometer measurement and control system and perform a baseline calibration of the diffractometer. Under CuKα radiation, perform a scanning measurement on the sample (4.3.1) over a 2θ range of 10° to 50°.
4.3.3 Data processing
Use the data processing program to obtain the X ray diffraction pattern of the sample (see Annex A). Mark the interplanar spacing (d value) at the diffraction peak positions. Compare the obtained d values with the d values in Table 1. Diffraction lines that match the data in Table 1 are those of δ phase layered crystalline sodium disilicate; otherwise, they are from other impurity phases. When the content of δ phase layered crystalline sodium disilicate in the sample is low, some weaker spectral lines may not be displayed. The presence or absence of the δ phase layered crystalline sodium disilicate can be determined by the three main strong lines.
5 Determination of Whiteness
5.1 Instruments and equipment
5.1.1 Standard white plate
A standard white plate conforming to GB/T 9086, used to calibrate the whiteness meter.
5.1.2 Working white plate
For convenience of measurement, a white ceramic plate with a flat surface, free from scratches and cracks, may be used as a daily working white plate. The working white plate shall be self calibrated monthly against the standard white plate. The working white plate shall be stored in a desiccator protected from light. If contaminated, it shall be wiped with a flannelette or absorbent cotton soaked in absolute ethanol. It shall then be dried in an oven at 105 °C to 110 °C for 30 min, removed, cooled to room temperature in a desiccator, and calibrated against the standard white plate.
5.1.3 Whiteness meter
The optical geometry of the instrument may be any of vertical/diffuse (o/d), diffuse/vertical (d/o), 45°/vertical (45°/o) or vertical/45° (o/45°). The light source of the instrument may be a D65 or C source. The reading accuracy of the instrument shall be to one decimal place. The instrument shall comply with the requirements of Class II or above in JJG 512.
5.2 Procedure
5.2.1 Sampling
Reduce the test sample to a certain amount (not less than 200 g) for use in the determination according to the sample division method specified in GB/T 13173.
5.2.2 Sample preparation
Select an appropriate amount of sample based on the density of the sample and the volume of the sample press. Prepare sample plates with a flat surface, free from cracks and stains, according to the procedure specified in GB/T 9086. Prepare two sample plates simultaneously for each sample.
5.2.3 Calibration of the instrument
Turn on, warm up and adjust the instrument according to the instruction manual. Calibrate the instrument to a stable nominal value using the standard white plate or the working white plate.
5.2.4 Whiteness measurement
After the instrument has been calibrated and stabilised, measure and record the tristimulus values X, Y, Z and the R₄₅₇ value for each sample plate. For continuous testing, recalibrate the instrument periodically with the standard white plate or the working white plate to eliminate the effect of instrument reading drift.
5.3 Calculation of results
Standard
GB/T 19421-2026 Test methods of crystalline layered sodium disilicate (English Version)
Standard No.
GB/T 19421-2026
Status
to be valid
Language
English
File Format
PDF
Word Count
14500 words
Price(USD)
435.0
Implemented on
2026-11-1
Delivery
via email in 1~5 business day
Detail of GB/T 19421-2026
Standard No.
GB/T 19421-2026
English Name
Test methods of crystalline layered sodium disilicate
GB/T 19421-2026 Test methods of crystalline layered sodium disilicate English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS
CCS
National Standard of the People's Republic of China
GB/T 19421-2026
Test methods of crystalline layered sodium disilicate
层状结晶二硅酸钠试验方法
Issue date: 2026-03-31 Implementation date: 2026-10-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Qualitative Analysis of δ Phase Layered Crystalline Sodium Disilicate — X ray Diffractometer Method
5 Determination of Whiteness
6 Determination of pH
7 Determination of Calcium Exchange Capacity by EDTA Volumetric Method
8 Determination of Magnesium Exchange Capacity by EDTA Volumetric Method
9 Determination of Loss on Ignition by Gravimetric Method
10 Determination of Hygroscopic Moisture Content by Gravimetric Method
11 Determination of Iron(III) Oxide Content by o Phenanthroline Colorimetric Method
12 Determination of Sodium Oxide Content by Volumetric Method
13 Determination of Silicon Dioxide Content by Potassium Fluorosilicate Volumetric Method
14 Determination of Calcium Oxide Content by Atomic Absorption Spectrophotometry
15 Determination of Magnesium Oxide Content by Atomic Absorption Spectrophotometry
16 Requirements for Reporting Test Results
Annex A (Informative) X ray Diffraction Pattern of δ Phase Layered Crystalline Sodium Disilicate
Test methods for layered crystalline sodium disilicate
1 Scope
This document describes the qualitative analysis of the δ phase of layered crystalline sodium disilicate, a detergent builder, by the X ray diffractometer method, and the test methods for whiteness, pH value, calcium exchange capacity, magnesium exchange capacity, loss on ignition, hygroscopic moisture content, iron(III) oxide, sodium oxide, silicon dioxide, calcium oxide, magnesium oxide and other indicators.
This document applies to the determination of indicators for layered crystalline sodium disilicate products for use in detergents.
2 Normative References
The following documents are essential for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 6682 Water for analytical laboratory use — Specification and test methods
GB/T 9086 Standard white plates for colour and photometric measurement
GB/T 13173 Surface active agents — Detergents — Test methods
JJG 512 Verification Regulation of Whiteness Meters
QB/T 2739-2005 Common test methods for washing products — Preparation of test solutions for titration analysis (volumetric analysis)
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1 δ phase method of X ray diffractometer
A method in which a δ phase crystal, under irradiation by X rays of a given wavelength, exhibits a characteristic diffraction pattern of the δ phase of layered crystalline sodium disilicate, which is then compared with the data of the substance to be tested.
3.2 whiteness
The ratio of the radiant energy diffusely reflected by a substance relative to that of a perfect reflecting diffuser (standard white) in the visible region.
NOTE: Expressed as a percentage.
3.3 calcium exchange capacity
The capacity of the sodium ions in a product to be exchanged by calcium ions in a solution under certain conditions of temperature and alkalinity, etc.
3.4 magnesium exchange capacity
The capacity of the sodium ions in a product to be exchanged by magnesium ions in a solution under certain conditions of temperature and alkalinity, etc.
3.5 loss on ignition
The percentage decrease in mass of a sample after ignition at high temperature.
3.6 hygroscopic moisture
The mass fraction of the difference in mass of a sample before and after drying in an oven at a certain temperature, relative to the mass of the sample before drying.
4 Qualitative Analysis of δ Phase Layered Crystalline Sodium Disilicate — X ray Diffractometer Method
4.1 Principle
Any crystalline substance has specific structural parameters. Under irradiation by X rays of a given wavelength, it exhibits a characteristic polycrystalline diffraction pattern. The diffraction pattern of each phase indicates the chemical bonding state of the elements in that phase. Based on this unique correspondence between the polycrystalline diffraction pattern and the crystalline substance, the diffraction data of the substance to be tested can be compared with the known diffraction data of various substances to perform qualitative phase analysis.
4.2 Instruments and equipment
4.2.1 X ray diffractometer.
4.2.2 Agate mortar.
4.2.3 Sample preparation device.
4.3 Procedure
4.3.1 Sample preparation
Weigh approximately 2 g of the sample and grind it in a clean, dry agate mortar to a particle size of less than 5 μm, i.e., until no grittiness is felt when rubbed between clean, dry fingers. Place the ground sample into a sample holder, fill it tightly, and lightly press to form a tablet with sufficient pressure so that the tablet does not collapse when stood on its edge.
4.3.2 Determination
Turn on the cooling system of the equipment and start the X ray diffractometer. Allow it to warm up for 30 min. Start the X ray diffractometer measurement and control system and perform a baseline calibration of the diffractometer. Under CuKα radiation, perform a scanning measurement on the sample (4.3.1) over a 2θ range of 10° to 50°.
4.3.3 Data processing
Use the data processing program to obtain the X ray diffraction pattern of the sample (see Annex A). Mark the interplanar spacing (d value) at the diffraction peak positions. Compare the obtained d values with the d values in Table 1. Diffraction lines that match the data in Table 1 are those of δ phase layered crystalline sodium disilicate; otherwise, they are from other impurity phases. When the content of δ phase layered crystalline sodium disilicate in the sample is low, some weaker spectral lines may not be displayed. The presence or absence of the δ phase layered crystalline sodium disilicate can be determined by the three main strong lines.
5 Determination of Whiteness
5.1 Instruments and equipment
5.1.1 Standard white plate
A standard white plate conforming to GB/T 9086, used to calibrate the whiteness meter.
5.1.2 Working white plate
For convenience of measurement, a white ceramic plate with a flat surface, free from scratches and cracks, may be used as a daily working white plate. The working white plate shall be self calibrated monthly against the standard white plate. The working white plate shall be stored in a desiccator protected from light. If contaminated, it shall be wiped with a flannelette or absorbent cotton soaked in absolute ethanol. It shall then be dried in an oven at 105 °C to 110 °C for 30 min, removed, cooled to room temperature in a desiccator, and calibrated against the standard white plate.
5.1.3 Whiteness meter
The optical geometry of the instrument may be any of vertical/diffuse (o/d), diffuse/vertical (d/o), 45°/vertical (45°/o) or vertical/45° (o/45°). The light source of the instrument may be a D65 or C source. The reading accuracy of the instrument shall be to one decimal place. The instrument shall comply with the requirements of Class II or above in JJG 512.
5.2 Procedure
5.2.1 Sampling
Reduce the test sample to a certain amount (not less than 200 g) for use in the determination according to the sample division method specified in GB/T 13173.
5.2.2 Sample preparation
Select an appropriate amount of sample based on the density of the sample and the volume of the sample press. Prepare sample plates with a flat surface, free from cracks and stains, according to the procedure specified in GB/T 9086. Prepare two sample plates simultaneously for each sample.
5.2.3 Calibration of the instrument
Turn on, warm up and adjust the instrument according to the instruction manual. Calibrate the instrument to a stable nominal value using the standard white plate or the working white plate.
5.2.4 Whiteness measurement
After the instrument has been calibrated and stabilised, measure and record the tristimulus values X, Y, Z and the R₄₅₇ value for each sample plate. For continuous testing, recalibrate the instrument periodically with the standard white plate or the working white plate to eliminate the effect of instrument reading drift.
5.3 Calculation of results
