Method for detecting content of impurity elements in electronic-grade cobalt precursor

Abstract

The invention discloses a method for detecting the content of impurity elements in an electronic-grade cobalt precursor, and relates to the technical field of detection. The detection modes and detection parameters of the ICP-MS / MS instrument on different impurity elements, such as RF power, atomization gas flow velocity, plasma gas flow velocity, compensation gas flow velocity, auxiliary gas flow velocity, eight-level rod deflection voltage, energy discrimination and the like, are comprehensively adjusted, so that the serious interference of the electronic-level cobalt precursor matrix on part of impurities is effectively solved; the accuracy and sensitivity of the detection method are improved, meanwhile, the detection limit of impurity elements is effectively reduced, and the method has excellent practicability.

Description

Technical Field

[0001] The invention relates to the technical field of metal detection, and in particular to a method for detecting the content of impurity elements in an electronic-grade cobalt precursor. Background Art

[0002] The I CP-MS (inductively coupled plasma mass spectrometry) analysis method is generally used to measure metal impurities in cobalt precursors. The test mode of traditional I CP-MS analysis instruments such as Thermo Fisher i CAP RQ can complete the test of most elements in collision mode, but it cannot eliminate the polyatomic ion interference, oxide interference, double charge interference, hydride interference and isobaric interference in mass spectrometry interference, as well as the matrix effect and physical effect in non-mass spectrometry interference; for example, when testing (3,3-dimethyl-1-butyne) dicobalt hexacarbonyl (CCTBA) samples, the elements affected by Co matrix interference include Ni, Ga, Ge, As, Sn, (1H+59Co interference) 60Ni, (12C+59Co interference) 71Ga, (14N+59Co interference) 73Ge, (16O+1H+59Co interference) 76Ge, (59Co+16O interference) 75As, (59Co+59Co interference) 118Sn.

[0003] Therefore, the existing test methods still have many problems when testing the content of impurity elements in cobalt precursors. The interference of the matrix will lead to the following two problems:

[0004] (1) The impurity type analysis is not comprehensive, and the LOD values ​​of some elements are very high, which makes it impossible to determine the true value of the interfering elements in the product;

[0005] (2) The background signal of some light elements is also difficult to reduce, and the LOD value will be high. For low-concentration products, it is difficult to determine whether some light elements are detected or it is difficult to determine the true value.

[0006] However, traditional analytical methods cannot solve the problem of serious interference of the matrix on impurity elements such as metal impurities, which seriously affects the production and application of electronic chemicals with strict requirements. Summary of the invention

[0007] The purpose of the present invention is to provide a method for detecting the content of impurity elements in an electronic grade cobalt precursor to solve the following technical problems:

[0008] Solve the serious interference of the matrix on the impurity elements and reduce the LOD value of the detection method for the impurity elements in the cobalt precursor.

[0009] The purpose of the present invention can be achieved through the following technical solutions:

[0010] The present invention discloses a method for detecting the content of impurity elements in an electronic grade cobalt precursor, comprising the following steps:

[0011] S1. Prepare element standard solution and test solution 1

[0012] Standard solution: prepare a standard solution 1 containing Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ho, In, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, Rb, Re, Sc, Se, Sm, Sr, Tb, Th, Tl, Tm, U, V, Y, Yb, and Zn; prepare a standard solution 2 containing Ag, Ge, Hf, Mo, Nb, Sb, Si, Sn, Ta, Te, Ti, W, and Zr; prepare a standard solution 3 containing Au, Ir, Os, Pd, Pt, Rh, and Ru;

[0013] Solution 1 to be tested: at least 3 samples of the cobalt precursor to be tested are taken in parallel, and ultrapure concentrated nitric acid and ultrapure concentrated hydrogen peroxide are added thereto to digest them into a clear acidic solution, and then the acidic solution is diluted with ultrapure water and evenly dispersed to obtain solution 1 to be tested.

[0014] S2. Draw the standard curve and get the regression equation

[0015] The standard solution 1, the standard solution 2 and the standard solution 3 are respectively added to the three parallel test solutions 1 in step S1 to obtain at least a standard working curve solution 1 in which the concentration of each element is 180-350 ng / L, a standard working curve solution 2 in which the concentration of each element is 500-800 ng / L and a standard working curve solution 3 in which the concentration of each element is 1000-1300 ng / L. Then, an I CP-MS / MS testing instrument is used to detect at least the standard working curve solution 1, the standard working curve solution 2 and the standard working curve solution 3 to obtain a standard curve and a regression equation representing the relationship between the element concentration and the response signal value.

[0016] S3. Calculate the content of impurity elements

[0017] Prepare the test solution 2, the preparation method of which is exactly the same as that of the test solution 1, use I CP-MS / MS to detect the test solution 2, and calculate the impurity element content according to the regression equation.

[0018] Further, in step S1, the concentration of each element in the standard solution 1, the standard solution 2, and the standard solution 3 is 5-15 mg / L, preferably 10-12 mg / L. Further, the specific operation steps for preparing the test solution 1 in step S1 are: at least 3 portions of the cobalt precursor samples to be tested are taken in parallel and placed in polytetrafluoroethylene screw-mouth bottles, 2-10 mL of ultrapure concentrated nitric acid and 0.4-5 mL of ultrapure hydrogen peroxide are added to each sample in turn to digest it into a clear acidic solution, and then the acidic solution is diluted with ultrapure water to a concentration of 0.3-0.7 mg / mL of the cobalt precursor sample, and the test solution is obtained after uniform dispersion.

[0019] In a preferred embodiment, the specific operation steps for preparing the test solution 1 are as follows: at least 3 samples of the cobalt precursor to be tested are taken in parallel and placed in polytetrafluoroethylene screw bottles, each of which has a mass of 15-30 mg. 3 mL of ultrapure concentrated nitric acid and 1.5 mL of ultrapure hydrogen peroxide are added to each sample to digest it into a clear acidic solution, and then the acidic solution is diluted to 50 mL with 18.2 MΩ·cm ultrapure water, and the solution is uniformly dispersed to obtain the test solution. The blank solution is also diluted under the same conditions for testing.

[0020] In one embodiment, S2 includes: first diluting standard solution 1, standard solution 2, and standard solution 3 into standard reserve solution 1, standard reserve solution 2, and standard reserve solution 3 with each element content of 100-200 μg / L, and then adding standard reserve solution 1, standard reserve solution 2, and standard reserve solution 3 to the solution 1 to be tested in parallel in step S1, to obtain at least a standard working curve solution 1 with a concentration of 200 ng / L for each element, a standard working curve solution 2 with a concentration of 500 ng / L for each element, and a standard working curve solution 3 with a concentration of 1000 ng / L for each element.

[0021] Further, in steps S2-S3, the test parameters of the I CP-MS / MS are: when testing the impurities of Li, Na, Mg, Al, K, Ca, Cr, Fe, Mn, Ni, Co, Cu, and Ga in the cobalt precursor sample to be tested, the Cool NH3 mode is adopted, the scanning type is cascade, the RF power is 1000-1200W, the nebulizer gas flow rate is 0.8-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.8-1.0L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 15-20mm, the octapole deflection voltage is -15 to -10V, the axial acceleration is 1 to 1.5V, and the energy discrimination is -10 to -5V;

[0022] Preferably, the RF power is 1000W, the atomizing gas flow rate is 0.9L / min, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.9L / min, the auxiliary gas flow rate is 0.9L / min, the sampling depth is 18mm, the octapole deflection voltage is -10V, the axial acceleration is 1.5V, and the energy discrimination is -5V.

[0023] Further, in steps S2-S3, when Be and B impurities in the cobalt precursor sample to be tested are tested, the NoGas mode is adopted, the scanning type is single-rod, the RF power is 1400-1500W, the atomizing gas flow rate is 0.5-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.3-0.8L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 8-10mm, the octapole deflection voltage is -10 to -8V, the axial acceleration is 0-2V, and the energy discrimination is 3-5V;

[0024] Preferably, the RF power is 1500W, the atomizing gas flow rate is 0.7L / min, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.48L / min, the auxiliary gas flow rate is 0.9L / min, and the sampling depth is 9mm; the octapole deflection voltage is -8V, the axial acceleration is 0V, and the energy discrimination is 5V.

[0025] Further, in steps S2-S3, when testing Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Sn, Ce, Hf, Ta, W, Os, Re, Ir, Pt, Au, Hg, Tl, Pb, Bi, Th, U, In, Sb, and Ba in the cobalt precursor sample to be tested, the He mode is adopted, the scanning type is single-rod, the RF power is 1400-1500W, the atomizing gas flow rate is 0.5-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.3-0.8L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 8-10mm, the octapole deflection voltage is -18 to -15V, the axial acceleration is 1-3V, and the energy discrimination is 3-5V;

[0026] Preferably, the RF power is 1500W, the atomizing gas flow rate is 0.7L / min, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.48L / min, the auxiliary gas flow rate is 0.9L / min, the sampling depth is 9mm, the octapole deflection voltage is -18V, the axial acceleration is 1V, and the energy discrimination is 3V.

[0027] Further, in steps S2-S3, when testing the impurities of Ti, V, As, Y, and Zr in the cobalt precursor sample to be tested, the 02 mode is adopted, the scanning type is cascade, the RF power is 1400-1500W, the atomizing gas flow rate is 0.5-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.3-0.8L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 8-10mm, the octapole deflection voltage is -3 to -1V, the axial acceleration is 1-1.5V, and the energy discrimination is -10 to -7V;

[0028] Preferably, the RF power is 1500W, the atomizing gas flow rate is 0.7L / min, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.48L / min, the auxiliary gas flow rate is 0.9L / min, the sampling depth is 8-10mm, the octapole deflection voltage is -3V, the axial acceleration is 1.5V, and the energy discrimination is -7V.

[0029] Further, the cobalt precursor includes any one of (3,3-dimethyl-1-butyne) hexacarbonyl dicobalt (CCTBA), cyclopentadienyl cobalt dicarbonyl, dicyclopentadienyl cobalt, di(ethylcyclopentadienyl) cobalt, di(methylcyclopentadienyl) cobalt, octacarbonyl dicobalt, bis(2,2,6,6-tetramethyl-3,5-heptanedione) copper, diacetylacetonate cobalt, triacetylacetonate cobalt, and silylcyclopentadienyl cobalt dicarbonyl.

[0030] Beneficial effects of the present invention:

[0031] 1. In the detection method of the impurity element content in the electronic grade cobalt precursor of the present invention, the Cold NH3 mode is selected when analyzing light elements. This mode uses low-temperature plasma and ammonia as reaction gases. Adding NH3 gas collision in the low ionization energy plant area can effectively remove impurity interference and reduce the background value of the measured element, thereby reducing the LOD value of the element to the minimum as much as possible. For example, the problem of high LOD value of 40Ca due to the interference of 40Ar has always been difficult to solve, but in the Cold-NH3 mode, low-temperature plasma can reduce argon interference such as Ar. + ,ArH + and ArO + The formation of Ar + Ca + background interference; in order to further reduce the influence of interference, it is necessary to appropriately increase the carrier gas flow rate and auxiliary gas flow rate, reduce the RF forward power, increase the sampling depth and other conditions; and when the above parameters are set unreasonably, interference will be generated. Therefore, it is necessary to use the specific parameters in the present invention to cooperate with each other to achieve better detection effect;

[0032] 2. For the measured elements interfered by the matrix, since the false signal of the interfered elements is too high due to the too high matrix concentration, the LOD value of the measured elements is significantly higher. In the detection method of the impurity element content in the electronic grade cobalt precursor of the present invention, different collision modes, octapole deflection voltages, appropriate reaction gases, axial acceleration and energy discrimination conditions are selected by means of energy discrimination, charge transfer, proton transfer, etc., so as to selectively eliminate specific interfering ions and substrates without affecting the analyte ions, thereby improving the accuracy and sensitivity of the analysis and ensuring the accurate detection of low-concentration samples. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] The present embodiment provides a method for detecting the content of impurity elements in an electronic-grade cobalt precursor. In the present embodiment, the content of impurity elements is detected using high-purity electronic chemical CCTBA as an electronic-grade cobalt precursor. The detection method is performed in the following steps.

[0036] S1. Prepare element standard solution and test solution 1

[0037] Element standard solution: The element standard solution includes standard solution 1, standard solution 2, and standard solution 3. The preparation is as follows:

[0038] Standard solution 1 contains the elements Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ho, In, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, Rb, Re, Sc, Se, Sm, Sr, Tb, Th, Tl, Tm, U, V, Y, Yb, and Zn; the content of each element is 10 mg / mL.

[0039] Standard solution 2 contains the elements Ag, Ge, Hf, Mo, Nb, Sb, Si, Sn, Ta, Te, Ti, W, and Zr; the content of each element is 10 mg / mL.

[0040] Standard solution 3 contains the elements Au, Ir, Os, Pd, Pt, Rh, and Ru; the content of each element is 10 mg / mL.

[0041] Solution 1 to be tested: Take 3 samples of the CCTBA precursor to be tested in parallel and put them into polytetrafluoroethylene screw-mouth bottles. The mass of each sample is 20 mg. Place them on the workbench in the clean room. Add 3 mL of ultrapure concentrated nitric acid and 1.5 mL of ultrapure concentrated hydrogen peroxide to digest them into a clear acidic solution. Then dilute the acidic solution in the previous step to 50 mL with 18.2 MΩ·cm ultrapure water and disperse them evenly to obtain solution 1 to be tested. The blank solution is also diluted under the same conditions for testing.

[0042] S2. Preparation of standard stock solution

[0043] Use 18.2 MΩ·cm ultrapure water to dilute standard solution 1, standard solution 2 and standard solution 3 into standard stock solution 1, standard stock solution 2 and standard stock solution 3 with element content of 100 μg / L respectively.

[0044] S3. Draw the standard curve and get the regression equation

[0045] The standard stock solution 1, the standard stock solution 2, and the standard stock solution 3 were all added to the three parallel test solutions 1 to obtain the standard working curve solution 1 with a concentration of 200 ng / L for each element, the standard working curve solution 2 with a concentration of 500 ng / L for each element, and the standard working curve solution 3 with a concentration of 1000 ng / L for each element. Then, the standard working curve solution 1, the standard working curve solution 2, and the standard working curve solution 3 were detected using an I CP-MS / MS testing instrument to obtain the standard curve and regression equation for the relationship between the element concentration and the response signal value:

[0046] Among them, the I CP-MS / MS test parameters are as follows:

[0047] I CP-MS / MS test instrument uses Agilent 8900, the peak acquisition mode is 1 point, the number of repetitions is 3, and the number of scans / repetitions is 10;

[0048] When testing the impurities of Li, Na, Mg, Al, K, Ca, Cr, Fe, Mn, Ni, Co, Cu and Ga in the cobalt precursor to be tested, the Cool NH3 mode is adopted, the scanning type is cascade, the RF power is 1000W, the atomizing gas flow rate is 0.9L / min, the atomizing chamber temperature is 2°C, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.9L / min, the auxiliary gas flow rate is 0.9L / min, the sampling depth is 18mm, the octapole deflection voltage is -10V, the axial acceleration is 1.5V, and the energy discrimination is -5V;

[0049] When testing Be and B impurities in the cobalt precursor to be tested, the No Gas mode is used, the scanning type is single-rod, the RF power is 1500W, the atomizing gas flow rate is 0.7L / min, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.48L / min, the auxiliary gas flow rate is 0.9L / min, the sampling depth is 9mm, the octapole deflection voltage is -8V, the axial acceleration is 0V, and the energy discrimination is 5V;

[0050] When testing Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Sn, Ce, Hf, Ta, W, Os, Re, Ir, Pt, Au, Hg, Tl, Pb, Bi, Th, U, In, Sb, and Ba in the cobalt precursor to be tested, the He mode is adopted, the scanning type is single-rod, the RF power is 1500W, the atomizing gas flow rate is 0.7L / min, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.48L / min, the auxiliary gas flow rate is 0.9L / min, the sampling depth is 9mm, the octapole deflection voltage is -18V, the axial acceleration is 1V, and the energy discrimination is 3V;

[0051] When testing the impurities of Ti, V, As, Y, and Zr in the cobalt precursor to be tested, the 02 mode is adopted, the scanning type is cascade, the RF power is 1500W, the atomizing gas flow rate is 0.7L / min, the plasma gas flow rate is 15L / min, the compensation gas flow rate is 0.48L / min, the auxiliary gas flow rate is 0.9L / min, the sampling depth is 9mm, the octapole deflection voltage is -3V, the axial acceleration is 1.5V, and the energy discrimination is -7V.

[0052] The regression equations established by the standard curves obtained from the above test results are shown in Table 1. In each regression equation, y represents the response signal value of the I CP-MS / MS test instrument, and x represents the element concentration (ppt); Table 1 is as follows:

[0053] Table 1

[0054]

[0055]

[0056]

[0057] S4. Calculate the content of impurity elements

[0058] Prepare the test solution 2, and its preparation method is exactly the same as the preparation method of the test solution 1; add the test solution 2 to the I CP-MS / MS test instrument (Agilent 8900) for detection, and bring the obtained signal value into the regression equation in step S3 to calculate the impurity element content.

[0059] The light element instrument detection limit (LOD) and background equivalent concentration (BEC) of the impurity element content are listed in Table 2. Table 2 is as follows:

[0060] Table 2

[0061]

[0062]

[0063] Comparative Example 1

[0064] Compared with Example 1, the only difference is that the test instrument is replaced by Agilent 8900 with Thermo Fisher i CAPRQ, and when the impurities of Li, Na, Mg, Al, K, Ca, Cr, Fe, and Mn in the sample are tested, the CoolIns mode is adopted, the scanning type is single-rod, the RF power is 520W, the atomizing gas flow rate is 1.2L / min, the plasma gas flow rate is 14L / min, the auxiliary gas is 0.8L / min, the sampling depth is 10mm, the horizontal position of the rectangular tube is 1.24mm, the vertical position of the rectangular tube is -0.75mm, the extraction lens voltage is -200V, the focusing lens voltage is 14V, the extraction lens cathode voltage is -35V, the CCT focusing lens voltage is -20V, the CCT entrance voltage is -120V, and the CCT deflection voltage is -18V;

[0065] When testing Be, B, Ti, V, Cu, Ni, Zn, Ga, Ge, As, Sr, Nb, Zr, Mo, Rh, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Tl, Pb, Bi, Th, and U in the sample, the He mode is adopted, the scanning type is single-rod, the RF power is 1550W, the atomizing gas flow rate is 1.0L / min, the plasma gas flow rate is 14L / min, the auxiliary gas is 0.8L / min, the sampling depth is 5mm, the horizontal position of the rectangular tube is 0.44mm, the vertical position of the rectangular tube is -0.42mm, the extraction lens voltage is -188V, the focusing lens voltage is -7.5V, the extraction lens cathode voltage is 0V, the CCT focusing lens voltage is 2.5V, the CCT entrance voltage is -110V, and the CCT deflection voltage is -21V;

[0066] The other steps and conditions are exactly the same. Finally, the instrument detection limit and background equivalent concentration of the measured impurity element content are listed in Table 3. Table 3 is as follows:

[0067] Table 3

[0068] Test items Limit of Detection (LOD) Background Equivalent Concentration (BEC) unit Li 2.56 8.54 ppt Be 2.24 1.81 ppt B 86.82 346.67 ppt Na 32.19 218.80 ppt Mg 6.07 22.70 ppt Al 6.61 25.66 ppt K 35.48 24.65 ppt Ca 90.47 420.78 ppt Ti 5.04 16.08 ppt V 4.11 0.20 ppt Cr 2.10 9.29 ppt Mn 1.23 0.84 ppt Fe 9.98 75.19 ppt Ni 8.38 11.37 ppt Cu 10.86 11.33 ppt Zn 8.70 60.88 ppt As 53.61 97.48 ppt Sn 36.71 320.11 ppt

[0069] By analyzing the data in Table 3, it can be found that the LOD value of light elements tested by the Thermo Fisher i CAPRQ instrument is much higher than the LOD value of light elements tested by Agilent 8900 in Example 1. The LOD values ​​of light elements of B, Na, K, Ca, Fe, As, and Sn are even as high as tens of ppt, while the LOD values ​​of light elements tested in Example 1 are mostly below 10 ppt. This shows that the method of using the Agilent 8900 testing instrument in Example 1 can significantly improve the LOD values ​​of light elements of K, Ca, Fe, As, and Sn.

[0070] Comparative Example 2

[0071] Compared with Example 1, the only difference is that the Li, Be, B, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, N in the CCTBA sample When testing the impurities of i, Co, Cu, Zn, As, and Sn, the He mode was adopted, the scanning type was single-rod, the RF power was 1500W, the nebulizer gas flow rate was 0.7L / min, the plasma gas flow rate was 15L / min, the auxiliary gas flow rate was 0.9L / min, the sampling depth was 9mm, the octapole deflection voltage was -18V, the axial acceleration was 1V, and the energy discrimination was 3V; the other steps and conditions were exactly the same, and finally the instrument detection limit and background equivalent concentration (abbreviated as BEC, which is the concentration value calculated by substituting the instrument response signal value of the background into the standard curve equation, which reflects the signal-to-background ratio and detection ability of the instrument during the measurement process. In ICP-MS analysis, BEC can help eliminate the interference of background signals, thereby more accurately determining the element concentration in the sample) of the measured impurity element content are listed in Table 4, which is as follows:

[0072] Table 4

[0073]

[0074]

[0075] By analyzing the data in Table 4, it can be learned that the LOD values ​​of light elements in He mode are mostly above 20 ppt, and the LOD values ​​of K, Ca, Fe, As, and Sn are higher than 50 ppt, while most of the LOD values ​​of light elements tested in Example 1 are almost below 10 ppt, which shows that the method of using Cool NH3 mode, No Gas mode and O2 mode in Example 1 can significantly improve the LOD values ​​of K, Ca, Fe, As, and Sn.

[0076] Test Case

[0077] The impurity element content of the CCTBA sample was tested according to the method of Example 1 to verify the repeatability, reproducibility, linearity and recovery rate of the method. The standard curve can reflect the linear quantitative relationship between the analyzed substances of different concentrations and the instrument response value, and the correlation coefficient R value of each ion calibration curve to be measured should meet R≥0.990; repeatability and reproducibility are measured under controlled conditions, reflecting the size of the error in the measurement system, and are expressed by relative standard deviation (RSD), requiring repeatability RSD≤10% and reproducibility RSD≤10%; the recovery rate is usually used to evaluate the accuracy and reliability of the method, and the standard requires a recovery rate between 80% and 120%.

[0078] The linear correlation coefficient, repeatability, reproducibility, and recovery rate obtained by testing the CCTBA sample according to the method of Example 1 are listed in Table 5. Table 5 is as follows:

[0079] Table 5

[0080]

[0081]

[0082] Analysis of the data in Table 5 shows that the detection method in Example 1 can meet the standard requirements of linear correlation coefficient, repeatability, reproducibility, and recovery rate, which shows that the detection method in Example 1 is feasible, can reduce the detection limit of impurity elements, and achieve better detection effect.

[0083] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for detecting the content of impurity elements in an electronic grade cobalt precursor, characterized in that: The following steps are involved: S1. Prepare element standard solution and test solution 1 Standard solution: Prepare a standard solution containing Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ho, In, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, Rb, Re, Sc, Se, Sm, Sr, Tb, Th, Tl, Tm, U, V, Y, Yb, and Zn. A standard solution 2 containing Ag, Ge, Hf, Mo, Nb, Sb, Si, Sn, Ta, Te, Ti, W, and Zr elements; a standard solution 3 containing Au, Ir, Os, Pd, Pt, Rh, and Ru elements; a test solution 1: at least three samples of the cobalt precursor to be tested are taken in parallel, and ultrapure concentrated nitric acid and ultrapure concentrated hydrogen peroxide are added thereto to digest them into a clear acidic solution, and then the acidic solution is diluted with ultrapure water and evenly dispersed to obtain a test solution 1; S2. Draw the standard curve and get the regression equation Adding standard solution 1, standard solution 2, and standard solution 3 to the parallel solution 1 to be tested in step S1 at the same time, at least obtaining a standard working curve solution 1 in which each element concentration is 180-350 ng / L, a standard working curve solution 2 in which each element concentration is 500-800 ng / L, and a standard working curve solution 3 in which each element concentration is 1000-1300 ng / L, and then using an ICP-MS / MS testing instrument to detect at least the standard working curve solution 1, the standard working curve solution 2, and the standard working curve solution 3, to obtain a standard curve and a regression equation representing the relationship between the element concentration and the response signal value; S3. Calculate the content of impurity elements Prepare the test solution 2 in the same manner as the test solution 1. Use I CP-MS / MS to detect the test solution 2, and calculate the impurity element content according to the regression equation.

2. The method for detecting the content of impurity elements in an electronic grade cobalt precursor according to claim 1, characterized in that: The specific steps of preparing the test solution 1 in step S1 are: Take at least 3 samples of the cobalt precursor to be tested in parallel and put them in polytetrafluoroethylene screw-mouth bottles respectively. Add 2-10mL ultrapure concentrated nitric acid and 0.4-5mL ultrapure hydrogen peroxide to each sample to digest it into a clear acidic solution. Dilute the acidic solution with ultrapure water to a concentration of 0.3-0.7mg / mL of the cobalt precursor sample. Disperse evenly to obtain a solution to be tested.

3. The method for detecting the content of impurity elements in an electronic grade cobalt precursor according to claim 1, characterized in that: In steps S2-S3, the test parameters of I CP-MS / MS are: When testing Li, Na, Mg, Al, K, Ca, Cr, Fe, Mn, Ni, Co, Cu, and Ga impurities in the cobalt precursor sample to be tested, the Cool NH3 mode is adopted, the scanning type is cascade, the RF power is 1000-1200W, the atomizing gas flow rate is 0.8-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.8-1.0L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 15-20mm, the octapole deflection voltage is -15~-10V, the axial acceleration is 1-1.5V, and the energy discrimination is -10~-5V.

4. The method for detecting the content of impurity elements in an electronic grade cobalt precursor according to claim 1, characterized in that: In steps S2-S3, when testing the Be and B impurities in the cobalt precursor sample to be tested, the No Gas mode is adopted, the scanning type is single rod, the RF power is 1400-1500W, the atomizing gas flow rate is 0.5-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.3-0.8L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 8-10mm, the octapole deflection voltage is -10~-8V, the axial acceleration is 0-2V, and the energy discrimination is 3-5V.

5. The method for detecting the content of impurity elements in an electronic grade cobalt precursor according to claim 1, characterized in that: In steps S2-S3, when testing Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Sn, Ce, Hf, Ta, W, Os, Re, Ir, Pt, Au, Hg, Tl, Pb, Bi, Th, U, In, Sb, and Ba in the cobalt precursor sample to be tested, the He mode is adopted, the scanning type is single-rod, the RF power is 1400-1500W, the atomizing gas flow rate is 0.5-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.3-0.8L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 8-10mm, the octapole deflection voltage is -18 to -15V, the axial acceleration is 1-3V, and the energy discrimination is 3-5V.

6. The method for detecting the content of impurity elements in an electronic grade cobalt precursor according to claim 1, characterized in that: In steps S2-S3, when testing the impurities of Ti, V, As, Y, and Zr in the cobalt precursor sample to be tested, the 02 mode is adopted, the scanning type is cascade, the RF power is 1400-1500W, the atomizing gas flow rate is 0.5-1.0L / min, the plasma gas flow rate is 12-18L / min, the compensation gas flow rate is 0.3-0.8L / min, the auxiliary gas flow rate is 0.8-1.0L / min, the sampling depth is 8-10mm, the octapole deflection voltage is -3 to -1V, the axial acceleration is 1-1.5V, and the energy discrimination is -10 to -7V.

7. The method for detecting the content of impurity elements in an electronic grade cobalt precursor according to claim 1, characterized in that: The S2 comprises: first diluting the standard solution 1, the standard solution 2, and the standard solution 3 into the standard reserve solution 1, the standard reserve solution 2, and the standard reserve solution 3 in which the content of each element is 100-200 μg / L, and then adding the standard reserve solution 1, the standard reserve solution 2, and the standard reserve solution 3 into the solution 1 to be tested in parallel in step S1, so as to obtain at least the standard working curve solution 1 in which the concentration of each element is 200 ng / L, the standard working curve solution 2 in which the concentration of each element is 500 ng / L, and the standard working curve solution 3 in which the concentration of each element is 1000 ng / L.

8. The method for detecting the content of impurity elements in an electronic grade cobalt precursor according to claim 1, characterized in that: The cobalt precursor includes any one of (3,3-dimethyl-1-butyne) hexacarbonyl dicobalt, cyclopentadienyl cobalt dicarbonyl, dicyclopentadienyl cobalt, di(ethylcyclopentadienyl) cobalt, di(methylcyclopentadienyl) cobalt, octacarbonyl dicobalt, bis(2,2,6,6-tetramethyl-3,5-heptanedione) cobalt, diacetylacetonate cobalt, triacetylacetonate cobalt, and silylcyclopentadienyl cobalt dicarbonyl.

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