GB/T 39804-2021Method for determination of leachable harmful substances in wall materials (English PDF)

3.1 Electronic balance

Sensitivity is 0.1mg and 0.01g.

3.2 Burette

It meets the requirements of Grade A in GB/T 12805-2011.

3.3 Single mark volumetric flask

Meet the requirements of Class A in GB/T 12806-2011.

3.4 Single marking pipette

It meets the requirements of Grade A in GB/T 12808-2015.

4.1 Preparation of the extract

Proceed in accordance with the provisions of Appendix A.

4.3 Determination of hexavalent chromium content in the leaching solution

4.3.1 The spectrophotometry shall be carried out in accordance with the provisions of Appendix G.

4.3.2 Ion chromatography shall be carried out in accordance with the provisions of Appendix H.

4.5 Determination of the pH value of the extract

Proceed in accordance with the provisions of Appendix J.

4.6 Determination of total soluble solids content in the extract

Follow the provisions of Appendix K.

4.7 Determination of Chemical Oxygen Demand (COD) in the Leachate

Follow the provisions of Appendix L.

4.8 Determination of formaldehyde content in leachate

Proceed in accordance with the provisions of Appendix M.

4.9 The scope of application of heavy metal element detection methods

See Appendix N.

A.1 Method summary

At (23±2)°C room temperature, soak the sample in water (ground to powder), stir on a magnetic stirrer for 8h and then continue to stand for 64h, soak The effluent passes through a 0.45µm filter membrane.

A.2 Water

Meet the secondary water requirements specified in GB/T 6682-2008.

A.3 Equipment

A.3.1 Magnetic stirrer

A.3.2 Filter device, pressure filter device or vacuum filter device, the leachate that is not easy to filter can be separated by a centrifuge.

A.3.3 Filter membrane, 0.45µm

A.3.4 Desiccator, equipped with color-changing silica gel.

A.4 Sample preparation

Take a sample of no less than 4kg, crush it to less than 5mm, and divide it into quarters to obtain a 500g sample, and then grind it until all the samples pass.

Pass through an 80µm square-hole sieve, mix well, put it into a clean, dry sample bottle, store it in a desiccator (A.3.4), and set aside.

A.5 Experimental procedure

Weigh 100g sample, accurate to 0.1mg, place it in a 500mL glass beaker, add.200.0mL water (A.2), and put a Stir the magnet and seal the mouth of the beaker with a parafilm. Place the beaker on a magnetic stirrer and stir, stir at (23±2)°C room temperature for 8h, then continue Let it stand for 64h and filter through the filter device (A.3.2) to obtain the leachate. The leaching solution should complete the experiment within 24h. Do a blank experiment at the same time.

10mg/L, 25mg/L, 50mg/L standard working solution, the medium is nitric acid solution (B.3.6).

B.4.2.8 If the standard working solution has turbidity, precipitation or color change, it should be re-prepared.

B.5 Apparatus

Inductively coupled plasma emission spectrometer (ICP-OES) and its corresponding auxiliary equipment.

B.6 Analysis steps

B.6.1 Acidity adjustment of the leaching solution

Use nitric acid solution (B.3.4) to adjust the acidity of the extract to be consistent with the acidity of the standard working solution.

B.6.2 Drawing of standard working curve

Set the analysis conditions of the instrument according to the test requirements and instrument conditions, ignite the plasma, and wait for the plasma torch to stabilize, at the corresponding wavelength Next, measure the spectral intensity of each metal element in the standard working solution in B.4.2 in the order of concentration from low to high. With heavy metal content It is the abscissa and the spectral intensity is the ordinate to draw the standard working curve.

B.6.3 Determination of heavy metal elements in the leaching solution

Set the analysis conditions of the instrument according to the test requirements and instrument conditions, ignite the plasma, and wait for the plasma torch to stabilize. Selection and criteria The working solution is measured under the same instrument conditions, and the spectral intensity of each heavy metal element in the leaching solution and the blank leaching solution are measured separately.

The corresponding heavy metal element content (ci) of the leachate and the corresponding heavy metal element content (ci0) of the blank leachate are found in the curve. If in the leaching solution The content of heavy metal elements exceeds the calibration curve range, and the leaching solution needs to be properly diluted to make the acidity consistent with that before the dilution. Set, the dilution factor is F.

B.7 Result calculation

B.7.1 The content of heavy metal element i in the leaching solution is calculated according to formula (B.1). Xi=(ci-ci0)×F (B.1) Where.

Xi --- the content of heavy metal element i in the leachate, in milligrams per liter (mg/L); ci --- the content of heavy metal element i found on the standard working curve, in milligrams per liter (mg/L); ci0 --- The content of heavy metal element i in the blank leachate found on the standard working curve, in milligrams per liter (mg/L);

F ---Dilution multiple, the ratio of the volume after dilution to the aliquoted volume.

B.7.2 Take the arithmetic average of the two test results as the test result. The result obtained should be rounded according to GB/T 8170, when the result is >=1mg/L When the time, keep 1 decimal place; when the result is less than 1mg/L, keep 2 decimal places, if the entrusting party or relevant standards require otherwise, according to the required digits Amendment.

B.8 Precision

B.8.1 Repeatability

In the same laboratory, the same operator uses the same equipment, according to the same test method, and compares the same object under test in a short period of time.

The relative deviation of the two independent test results obtained by independent tests is less than 5%.

B.8.2 Reproducibility

In different laboratories, different operators use different equipment, according to the same test method, independently conduct the same test object.

The relative deviation of the two independent test results obtained by the line test is less than 10%.

It should be considered that the mass concentration of internal standard elements in the analysis solution is about 5µg/L~50µg/L.

C.4.4 Tuning solution

This solution is used for instrument tuning and quality calibration before analysis. The solution must contain enough heavy metal ions to cover the entire mass spectrum.

It is advisable to use metal elements containing (Li)Be, Mn, Co, Y, In(Tl) and Pb as the tuning solution. You can directly purchase a certified standard solution and use nitric acid.

The solution (B.3.6) is diluted. (The mass number and concentration of each metal element in the tuning solution required for the tuning of each instrument may be different. For details, please follow (Tune in the respective laboratory conditions to ensure that the instrument is in normal state)

C.5 Instruments

Inductively coupled plasma mass spectrometer (ICP-MS) and its corresponding auxiliary equipment.

Instrument working conditions. Different types of instruments have different optimal working conditions. Standard mode, collision mode, reaction cell mode, etc. should be in accordance with the instrument The operation manual of the device.

C.6 Analysis steps

C.6.1 Adjust the acidity of the leaching solution

Use nitric acid solution (B.3.4) to adjust the acidity of the extract to be consistent with the acidity of the standard working solution.

C.6.2 Instrument tuning

After igniting the plasma, the instrument needs to be warmed up and stabilized for 30 minutes. First, use the mass spectrometer to tune the sensitivity of the solution to the instrument, the oxide and the double The charge is tuned. Under the condition that the above indicators meet the requirements, the relative standard deviation of the signal intensity of the metal elements contained in the tuning solution The difference is <=5%. Then perform quality correction and resolution verification within the quality range covering heavy metal elements, such as the quality correction result and the true value The difference exceeds ±0.1amµ or the resolution of the tuning metal element signal is greater than 0.6amµ~0.8amµ at 10% peak height.

The range of the mass spectrometer should be calibrated in accordance with the requirements of the instrument manual.

C.6.3 Drawing of standard working curve

Set the analysis conditions of the instrument according to the test requirements and instrument conditions. After the instrument is stable, determine the concentration in the order from low to high. C.4.1 Medium standard working solution. The internal standard solution can be directly added to the standard working solution, or it can be automatically added by the peristaltic pump before the analysis solution is atomized.

Into. The concentration of heavy metal solution is taken as the abscissa, and the ratio of the heavy metal element signal to the internal standard signal is taken as the ordinate to establish a calibration curve.

The linearity of the standard working curve is checked by calculating the correlation coefficient, which should be greater than 0.999.

C.6.4 Determination of heavy metal elements in the leaching solution

When the sample is measured, the same amount of internal standard element standard solution as when the standard working curve is drawn should be added.

Before the measurement of each sample, flush the system with nitric acid solution (B.3.6) until the signal is reduced to the minimum, and start after the analysis signal is stable Determination. Select the same instrument conditions as the standard working solution to determine the information of each heavy metal element in the leaching solution and the blank leaching solution.

No. ratio, find the corresponding heavy metal element content (ci) of the leachate and the corresponding heavy metal element content of the blank leachate in the standard working curve (ci0). If the content of heavy metal elements in the leachate exceeds the calibration curve range, it needs to be diluted with a nitric acid solution (B.3.6) and re-measured. Dilution times The number is F.

C.7 Result calculation

C.7.1 The content of heavy metal element i in the leachate is calculated according to formula (C.1). Xi=(ci-ci0)×F (C.1) Where.

Xi --- the content of heavy metal element i in the leachate, in micrograms per liter (µg/L); ci --- the content of heavy metal element i found on the standard working curve, in micrograms per liter (µg/L); ci0 --- The content of heavy metal element i in the blank leachate found on the standard working curve, in micrograms per liter (µg/L);

F ---Dilution multiple, the ratio of the volume after dilution to the aliquoted volume.

C.7.2 Take the arithmetic average of the two test results as the test result. The result should be rounded according to GB/T 8170, when the result is >=1µg/L When the time, keep 1 decimal place; when the result is < 1µg/L, keep 2 decimal places, if the entrusting party or relevant standards require otherwise, according to the required digits Amendment.

C.8 Precision

C.8.1 Repeatability

In the same laboratory, the same operator uses the same equipment, according to the same test method, and compares the same object under test in a short period of time.

The relative deviation of the two independent test results obtained by independent tests is less than 10%.

C.8.2 Reproducibility

In different laboratories, different operators use different equipment, according to the same test method, independently conduct the same test object.

The relative deviation of the two independent test results obtained by the line test is less than 20%.