Method for measuring content of impurity elements in high-purity quartz by ICP-MS (inductively coupled plasma mass spectrometry)

Abstract

The invention discloses a method for measuring the content of impurity elements in high-purity quartz by ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The method is characterized by comprising the following steps: S1, drying a sample; s2, weighing a sample; s3, primary dissolution with strong acid I; s4, secondary dissolution with strong acid II; s5, cooling and constant volume; and S6, respectively testing and analyzing the standard series working solution, the sample solution and the blank solution on ICP-MS (Inductively Coupled Plasma Mass Spectrometry). According to the method, the influence of impurity elements brought in in the sample treatment process on the determination result is reduced, the harm of precipitation generated by some metal ions and chloride ions on the accuracy of the result is avoided, the inductively coupled plasma mass spectrometer is adopted for analysis in the later period, the detection limit is greatly reduced, and the accuracy of the result is improved. Therefore, the purposes of reducing the lower limit of impurity element content measurement and increasing the upper limit of the silicon dioxide content range (the applicable silicon dioxide content range of the method can be higher than 99.99%) are achieved.

Description

Technical Field

[0001] The invention relates to a method for determining the content of impurity elements in high-purity quartz by ICP-MS. Background Art

[0002] Currently, the content of impurity elements in high-purity quartz is determined using inductively coupled plasma optical emission spectrometry. The principle is to dissolve the sample in hydrofluoric acid, remove silicon, fluorine, and other elements through fuming, dissolve the residue in hydrochloric acid, and introduce the sample solution into a plasma optical emission spectrometer. Under selected optimal measurement conditions, the content of each element in the sample solution is measured. During research and practice on this method, the inventors discovered three deficiencies. First, the use of hydrochloric acid as a medium can cause precipitation of some metal ions and chloride ions, affecting the test results. Second, the method uses ultra-pure reagents, which can affect the test results. Third, the lower limit of the impurity element measurement range is high, while the upper limit of the applicable silica content range is low. This method, using an inductively coupled plasma optical emission spectrometer, makes it difficult to accurately determine trace elements. While suitable for high-purity quartz raw materials and products with silica contents ranging from 99.9% to 99.99%, it is not suitable for high-purity quartz raw materials and products with silica contents exceeding 99.99%. Summary of the Invention

[0003] To overcome the shortcomings of the above methods, the present invention provides a method for determining the content of impurity elements in high-purity quartz by ICP-MS. This method has a low determination limit and higher accuracy, which greatly compensates for the shortcomings of inductively coupled plasma optical emission spectrometry in determining the content of impurity elements in high-purity quartz.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a method for determining the content of impurity elements in high-purity quartz by ICP-MS, the method comprising the following steps:

[0005] S1: Drying the sample;

[0006] S2: weigh the sample;

[0007] S3: strong acid I primary dissolution;

[0008] S4: strong acid II secondary dissolution;

[0009] S5: cooling and constant volume;

[0010] S6: The standard series working solutions, sample solutions and blank solutions were tested and analyzed on ICP-MS respectively.

[0011] Furthermore, the drying temperature in step S1 is 105° C. to 110° C., the drying time is 3 hours, and then the sample is placed in a desiccator and naturally cooled to room temperature for testing.

[0012] Further, the specific operation of step S2 is to first weigh 1.0 g to 1.5 g of the sample, accurate to 0.0001 g. Three portions of one sample are weighed simultaneously for parallel determination; then the weighed sample is placed in a 50 mL polytetrafluoroethylene crucible, wetted with a small amount of ultrapure water, 15 mL of electronic grade hydrofluoric acid is added, covered and heated on a hot plate. The temperature is slowly increased from room temperature to 180 °C and maintained to fully dissolve the sample; finally, the sample is removed, the crucible cover and the inner wall of the crucible are rinsed with a small amount of ultrapure water, and then heated on the hot plate until dry, and removed and cooled after the acid fumes have exhausted.

[0013] Further, the specific operation steps of step S3 are to add 5 mL of electronic grade nitric acid (1+1) to the crucible, cover it and place it on the hot plate, and heat to a gentle boil for 5 minutes to fully dissolve the remaining residue.

[0014] Further, remove it from the hot plate and cool to room temperature, transfer and make up the volume to 100 mL with ultrapure water in a plastic volumetric flask, shake well, and let it stand for determination.

[0015] Further, 2 sample blanks are treated simultaneously with the samples;

[0016] The standard series working solutions are prepared as follows:

[0017] Accurately pipette 0.00 mL, 0.10 mL, 0.25 mL, 0.50 mL, 1.00 mL, and 2.00 mL of the mixed standard solution (1 μg / mL) of the elements to be measured (aluminum, barium, cobalt, chromium, copper, iron, lithium, manganese, phosphorus, titanium, vanadium, zinc, potassium, sodium) into a group of 50 mL plastic volumetric flasks respectively, dilute to the mark with nitric acid solution (2+98), shake well, and prepare standard series working solutions with concentrations of 0 ng / mL, 2 ng / mL, 5 ng / mL, 10 ng / mL, 20 ng / mL, and 40 ng / mL;

[0018] The rhodium and rhenium mixed standard working solutions are prepared as follows:

[0019] Pipette 20.00 mL of the rhodium and rhenium mixed standard solution (1 μg / mL) into a 1000 mL plastic volumetric flask, dilute to the mark with nitric acid solution (2+98), shake well. The concentration of this mixed standard working solution is 20 ng / mL and is used as the internal standard.

[0020] Analyze the standard series working solutions, sample solutions, and blank solutions on an ICP-MS respectively, and correct by the internal standard method; the rhodium and rhenium mixed standard working solutions are pumped in by an on-line three-way pump.

[0021] The beneficial effects of the present invention are as follows: electronic-grade reagents are used, and the entire process of sample pretreatment and analysis and testing is carried out in a clean room (the pretreatment is at a thousand-level, and the analysis and testing are at a ten-thousand-level), which reduces the influence of impurity elements introduced during the sample treatment process on the measurement results, avoids the harm caused by the formation of precipitates of some metal ions and chloride ions to the accuracy of the results, and later uses an inductively coupled plasma mass spectrometer for analysis, greatly reducing the detection limit, thereby achieving the goal of lowering the determination lower limit of the impurity element content and increasing the upper limit of the silica content range (the silica content range applicable to this method can be higher than 99.99%). Specific Embodiments

[0022] The determination method of the present invention includes the following steps:

[0023] S1: Dry the sample.

[0024] S2: Weigh the sample.

[0025] S3: First-stage dissolution with strong acid Ⅰ.

[0026] S4: Second-stage dissolution with strong acid Ⅱ.

[0027] S5: Cool and make up the volume.

[0028] S6: Test and analyze the standard series working solution, sample solution and blank solution on ICP-MS respectively.

[0029] Furthermore, in the step S1, the drying temperature is 105°C to 110°C, the drying duration is 3 hours, and then it is placed in a desiccator and naturally cooled to room temperature for later measurement.

[0030] Furthermore, the specific operation of the step S2 is to first weigh 1.0 g to 1.5 g of the sample, accurate to 0.0001 g. Three portions of the sample are weighed simultaneously for parallel determination; then the weighed sample is placed in a 50 mL polytetrafluoroethylene crucible, wetted with a small amount of ultrapure water, 15 mL of electronic-grade hydrofluoric acid is added, covered and heated on a hot plate, the temperature is slowly raised from room temperature to 180°C and maintained to fully dissolve the sample; finally, the sample is taken down, the crucible cover and the inner wall of the crucible are rinsed with a small amount of ultrapure water, and then heated on the hot plate until dry, and taken down and cooled after the acid fumes are exhausted.

[0031] Furthermore, the specific operation steps of the step S3 are to add 5 mL of electronic-grade nitric acid (1+1) to the crucible, cover it and place it on the hot plate, and heat it to boiling gently for 5 minutes to fully dissolve the remaining residue.

[0032] Furthermore, take it down from the hot plate and cool it to room temperature, transfer and make up the volume to 100 mL in a plastic volumetric flask with ultrapure water, shake well, and let it stand for later measurement.

[0033] Further, 2 sample blanks are processed simultaneously with the samples;

[0034] The standard series working solutions are prepared as follows:

[0035] Accurately pipette 0.00 mL, 0.10 mL, 0.25 mL, 0.50 mL, 1.00 mL, and 2.00 mL of the mixed standard solution (1 μg / mL) of the elements to be measured (aluminum, barium, cobalt, chromium, copper, iron, lithium, manganese, phosphorus, titanium, vanadium, zinc, potassium, sodium) into a group of 50 mL plastic volumetric flasks respectively, dilute to the mark with nitric acid solution (2 + 98), shake well, and prepare standard series working solutions with concentrations of 0 ng / mL, 2 ng / mL, 5 ng / mL, 10 ng / mL, 20 ng / mL, and 40 ng / mL;

[0036] The rhodium and rhenium mixed standard working solutions are prepared as follows:

[0037] Pipette 20.00 mL of the rhodium and rhenium mixed standard solution (1 μg / mL) into a 1000 mL plastic volumetric flask, dilute to the mark with nitric acid solution (2 + 98), shake well. The concentration of this mixed standard working solution is 20 ng / mL and is used as the internal standard.

[0038] Analyze the standard series working solutions, sample solutions, and blank solutions on an ICP-MS respectively, and correct by the internal standard method; the rhodium and rhenium mixed standard working solutions are pumped in by an on-line three-way pump.

[0039] The results were compared using the method of JC / T 2027-2010 Determination of impurity content in high-purity quartz - Inductively coupled plasma emission spectrometry and this method. The results show that this method has the advantage of determining the impurity element content in high-purity quartz and its products with higher purity.

[0040] The above description is only proposed as a feasible technical solution of the present invention and does not serve as a single limiting condition for its technical solution itself.

Claims

1. A method for determining the content of impurity elements in high-purity quartz by ICP-MS, characterized in that It includes the following steps: S1: Dry the sample. S2: Weigh the sample. S3: First-stage dissolution with strong acid Ⅰ. S4: Second-stage dissolution with strong acid Ⅱ. S5: Cool and make up the volume. S6: Test and analyze the standard series working solution, the sample solution and the blank solution on ICP-MS respectively.

2. The method for determining the content of impurity elements in high-purity quartz by ICP-MS according to claim 1, wherein: In step S1, the drying temperature is 105°C to 110°C, the drying duration is 3h, and then it is placed in a desiccator and naturally cooled to room temperature for further measurement.

3. The method for determining the content of impurity elements in high-purity quartz by ICP-MS according to claim 1, wherein: The specific operation of step S2 is as follows: First, weigh 1.0g to 1.5g of the sample, accurate to 0.0001g. Weigh three portions of the same sample for parallel determination. Then place the weighed sample in a 50mL polytetrafluoroethylene crucible, moisten it with a small amount of ultrapure water, add 15mL of electronic grade hydrofluoric acid, cover it and heat on a hot plate. The temperature is slowly raised from room temperature to 180°C and maintained to fully dissolve the sample. Finally, remove the sample, rinse the crucible cover and the inner wall of the crucible with a small amount of ultrapure water, and continue to heat on the hot plate until it is evaporated to dryness. After the acid fumes are exhausted, remove it and let it cool.

4. The method for determining the content of impurity elements in high-purity quartz by ICP-MS according to claim 1, characterized in that: The specific operation steps of step S3 are as follows: Add 5mL of electronic grade nitric acid (1+1) to the crucible, cover it and place it on the hot plate, heat it to a gentle boil for 5 minutes to fully dissolve the remaining residue.

5. The method for determining the content of impurity elements in high-purity quartz by ICP-MS according to claim 4, characterized in that: Remove it from the hot plate and cool it to room temperature. Transfer and make up the volume to 100mL in a plastic volumetric flask with ultrapure water, shake well, and let it stand for further measurement.

6. The method for determining the content of impurity elements in high-purity quartz by ICP-MS according to claim 1, wherein: Treat 2 sample blanks simultaneously with the sample. The standard series working solution is prepared as follows: Accurately pipette 0.00mL, 0.10mL, 0.25mL, 0.50mL, 1.00mL and 2.00mL of the mixed standard solution (1μg / mL) of the elements to be measured (aluminum, barium, cobalt, chromium, copper, iron, lithium, manganese, phosphorus, titanium, vanadium, zinc, potassium, sodium) into a group of 50mL plastic volumetric flasks respectively, dilute to the mark with nitric acid solution (2+98), shake well, and prepare standard series working solutions with concentrations of 0ng / mL, 2ng / mL, 5ng / mL, 10ng / mL, 20ng / mL, 40ng / mL. The rhodium and rhenium mixed standard working solution is prepared as follows: Pipette 20.00mL of the rhodium and rhenium mixed standard solution (1μg / mL) into a 1000mL plastic volumetric flask, dilute to the mark with nitric acid solution (2+98), shake well. The concentration of this mixed standard working solution is 20ng / mL and it is used as an internal standard. Analyze the standard series working solution, the sample solution and the blank solution on ICP-MS respectively, and correct with the internal standard method; the rhodium and rhenium mixed standard working solution is pumped in by an on-line three-way pump.