ICP-MS (inductively coupled plasma-mass spectrometry) detection method for 66 elements in plasma

Abstract

The invention relates to an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) detection method for 66 elements in plasma. The detection method comprises the following steps: (1) preparing a mixed internal standard solution; (2) preparing a mixed standard curve solution; (3) drawing a standard curve of 66 elements; (4) sample pretreatment; and (5) determining the contents of 66 elements in the to-be-detected sample solution. By adopting the detection method disclosed by the invention, the contents of 66 elements in the plasma can be detected at the same time on a machine once, and the detected elements are various in types and wide in coverage; the sample injection volume is small, and the cost performance is high; the pretreatment process is rapid and simple; the standard curve is excellent; the accuracy is high; and the sample matrix matching degree is good.

Description

Technical Field

[0001] The invention belongs to the detection field, and specifically relates to an ICP-MS detection method for 66 elements in plasma. Background Art

[0002] Elements in the environment can enter the human body through the respiratory tract, digestive tract, skin and other pathways, and are closely related to human health. As the relationship between elements and diseases becomes increasingly clear and people pay close attention to health issues, the rapid and accurate determination of blood element content has become extremely important.

[0003] At present, blood element detection technologies include atomic absorption spectrometry and atomic fluorescence spectrometry, etc. However, these methods can detect a small number of elements, can only analyze 1 to 2 elements at a time, and have a slow analysis speed and serious matrix interference. Inductively coupled plasma mass spectrometry (ICP-MS) has the advantages of rapid and simultaneous determination of multiple elements, wide linear range, good accuracy, and low detection limit, and is an effective method for analyzing biological samples.

[0004] However, due to the differences in the physical and chemical properties and concentration ranges of different elements, it is difficult to combine multiple elements for simultaneous detection. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide an ICP-MS detection method for 66 elements in plasma, which can realize the simultaneous detection of the contents of 66 elements including Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Ag, Cd, Sn, Sb, Te, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Hf, Ta, W, Re, Os, Ir, Pt, Hg, Tl, Pb, Bi, Th and U in one operation, and the pretreatment process is simple and fast with high sensitivity and accuracy.

[0006] According to a first aspect of the present invention, there is provided an ICP-MS detection method for 66 elements in plasma, comprising the following steps:

[0007] (1) Sc, In and Lu are selected as internal standard substances, Au is selected as a substance for stabilizing and removing the element Hg to be measured, and four single element standard solutions, namely, a single element standard solution of Sc, a single element standard solution of In, a single element standard solution of Lu and a single element standard solution of Au, are mixed to obtain a mixed internal standard solution of Sc, In, Lu and Au;

[0008] (2) preparing a first mixed standard curve solution, a second mixed standard curve solution, a third mixed standard curve solution and a fourth mixed standard curve solution respectively, wherein the first mixed standard curve solution is a mixed standard curve solution of Li, Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb and U, the second mixed standard curve solution is a mixed standard curve solution of B, Ti, Ge, Zr, Nb, Mo, Ru, Rh, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt and Hg, the third mixed standard curve solution is a mixed standard curve solution of Br, Y, I, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Bi and Th, and the fourth mixed standard curve solution is a mixed standard curve solution of Na, Mg, P, S, K and Ca;

[0009] (3) sequentially injecting the first mixed standard curve solution, the second mixed standard curve solution, the third mixed standard curve solution, and the fourth mixed standard curve solution of step (2) into an inductively coupled plasma mass spectrometer, and simultaneously introducing the mixed internal standard solution of step (1) online to draw standard curves for 66 elements;

[0010] (4) Sample pretreatment: The gradient thawed plasma sample was diluted with nitric acid aqueous solution by direct dilution method, and then vortexed, sonicated and centrifuged in sequence to obtain the sample solution to be tested;

[0011] (5) Injecting the sample solution to be tested described in step (4) and the mixed internal standard solution described in step (1) into an inductively coupled plasma mass spectrometer to determine the contents of 66 elements, including Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Ag, Cd, Sn, Sb, Te, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Hf, Ta, W, Re, Os, Ir, Pt, Hg, Tl, Pb, Bi, Th and U in the sample solution to be tested.

[0012] Preferably, in step (1), the mixed internal standard solution is diluted with aqueous nitric acid solution so that the concentration of the four elements Sc, In, Lu and Au is 100 μg / L.

[0013] Preferably, the nitric acid aqueous solution is a mixed aqueous solution of 1% HNO3, 0.5% n-butanol and 0.01% TritonX-100.

[0014] Preferably, the preparation of the first mixed standard curve solution is specifically as follows: take 27 element standard solutions, single element standard solution of Rb, single element standard solution of Li, single element standard solution of Fe, single element standard solution of Zn and single element standard solution of Cu, the 27 elements are Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Tl, U, V and Zn, first dilute with aqueous nitric acid solution to obtain a mixed standard curve mother solution, and then dilute the mixed standard curve mother solution with aqueous nitric acid solution to obtain mixed standard curve solutions with different concentration gradients.

[0015] Preferably, the preparation of the second mixed standard curve solution is specifically as follows: take a 10-element standard solution, a 12-element standard solution, a single-element standard solution of Hg, a single-element standard solution of Os and a single-element standard solution of B, the 10 elements are Sb, Hf, Pd, Rh, Te, Au, Ir, Pt, Ru and Sn, the 12 elements are B, Ge, Mo, Nb, P, Re, S, Si, Ta, Ti, W and Zr, first dilute them with aqueous nitric acid solution to obtain a mixed standard curve mother solution, and then dilute the mixed standard curve mother solution with aqueous nitric acid solution to obtain mixed standard curve solutions with different concentration gradients.

[0016] Preferably, the third mixed standard curve solution is prepared as follows: take 16-element standard solutions, a single-element standard solution of I and a single-element standard solution of Br, the 16 elements being Bi, Ce, Dy, Er, Eu, Gd, Ho, La, Nd, Pr, Sm, Tb, Tm, Y and Yb, first dilute them with aqueous nitric acid solution to obtain a mixed standard curve mother liquor, and then dilute the mixed standard curve mother liquor with aqueous nitric acid solution to obtain mixed standard curve solutions with different concentration gradients.

[0017] Preferably, the fourth mixed standard curve solution is prepared as follows: take a single element standard solution of Na, a single element standard solution of Ma, a single element standard solution of P, a single element standard solution of S, a single element standard solution of K and a single element standard solution of Ca, first dilute them with aqueous nitric acid solution to obtain a mixed standard curve mother solution, and then dilute the mixed standard curve mother solution with aqueous nitric acid solution to obtain mixed standard curve solutions with different concentration gradients.

[0018] Preferably, the inductively coupled plasma mass spectrometer is Agilent 7700x ICP-MS.

[0019] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0020] (1) A wide range of detected elements and a wide coverage: This method takes into account the differences in physical and chemical properties and concentration distribution among different elements. By establishing four sets of standard curves, it can achieve the simultaneous detection of 66 elements in plasma. In addition to covering the common elements reported in patents, it also includes other elements such as halogen elements and rare earth elements, covering a wide range.

[0021] (2) Small injection volume and high cost-effectiveness: By adjusting parameters such as pump tube length, pump speed, pump boost time, element integration time, etc., the injection volume is optimized as much as possible while increasing the number of elements, and a small amount of biological samples is used to complete the detection of the largest amount of element groups. In actual application, the cost-effectiveness is significantly improved compared with previous technical methods;

[0022] (3) The pretreatment process is simple and fast: the plasma samples are treated by direct dilution method, which is simple and fast and reduces the possibility of sample element contamination or loss caused by complex pretreatment;

[0023] (4) Stabilization and removal of Hg: Since Hg has a strong memory effect, Au is added to the internal standard solution. By continuously injecting high concentrations of Au, it is beneficial to remove the residual Hg and enhance the accuracy of the determination.

[0024] (5) Excellent standard curve: The correlation coefficients (R) of the standard working curves of 66 elements are all greater than 0.999;

[0025] (6) High accuracy: ① According to SRM1643f trace element natural water quality control and The guidance on the elements included in the present invention provided in the instructions of Plasma Control Level I & Level II, the method used in the present invention is within the qualified range; ② The spiked recovery rates of 66 elements are basically between 80% and 120%;

[0026] (7) Good sample-matrix matching: The relative atomic mass numbers of the internal standard elements in this method cover low, medium and high relative atomic mass numbers. The three internal standard elements (Sc 45 ,In 115 He Lu 175 ) had a relatively stable internal standard recovery rate (80% to 120%), indicating that the matrix of this method was well matched with the sample matrix.

[0027] Instruction Manual

[0028] Figure 1 This is the standard curve of 66 elements.

[0029] Figure 2 This is the recovery rate of the internal standard in plasma samples. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] In some examples, the concentrations of the elements in the first mixed standard curve solution are respectively:

[0032]

[0033] In some examples, the concentrations of the elements in the second mixed standard curve solution are respectively:

[0034]

[0035] In some examples, the concentrations of the elements in the third mixed standard curve solution are respectively:

[0036]

[0037]

[0038] In some examples, the concentrations of the elements in the fourth mixed standard curve solution are respectively:

[0039] Element (mg / L) S1 S2 S3 S4 S5 Na 12.5 25 50 125 250 Mg 0.25 0.5 1 2.5 5 P 1.25 2.5 5 12.5 25 S / K 5 10 20 50 100 Ca 1 2 4 10 20

[0040] In some examples, the concentrations of Sc, In, Lu and Au in the mixed internal standard solution are all 100 μg / L.

[0041] In some examples, the nitric acid aqueous solution is a mixed aqueous solution of 1% HNO3, 0.5% n-butanol and 0.01% TritonX-100.

[0042] The following are specific embodiments

[0043] 1. Main instruments, consumables and reagents

[0044] (I) Main instruments

[0045] Agilent 7700x inductively coupled plasma mass spectrometry (ICP-MS) from the United States, ELGA brand ultrapure water meter from the United Kingdom, vortex analyzer from Scientific Industries of the United States, ultrasonic cleaner from Shanghai Kedao Ultrasonic Instrument Co., Ltd., low-speed centrifuge from Anhui Zhongke Zhongjia Scientific Instrument Co., Ltd. and low-temperature shaker from Shanghai Zhicheng.

[0046] (II) Main consumables

[0047] Table 1 Main consumables

[0048]

[0049]

[0050] (III) Main reagents

[0051] Table 2 Main reagents

[0052]

[0053]

[0054]

[0055]

[0056] II. ICP-MS detection method for 66 elements in plasma samples (I) ICP-MS instrument detection parameter settings

[0057] Table 3 Instrument detection parameter settings

[0058] ICP-MS instrument detection parameters set up RF Power 1550W RF matching voltage 2.00V Sampling Depth 7.7mm Analysis Mode He collision mode Helium flow rate 4.7mL / min Carrier gas flow rate 0.88L / min Dilution gas flow rate 0.28L / min Spray chamber temperature 2℃ Energy Discrimination 4.7V Sample uptake time and peristaltic pump speed 18s; 0.1rps Sample stabilization time and peristaltic pump speed 25s; 0.1rps Sample flushing time and peristaltic pump speed 40s; 0.3rps Repeated measurement times 3 Scan / repeat times 100

[0059] (II) 66 elements and their internal standard elements

[0060] 1.Li 7 ,Be 9 ,B 11 ,Na 23 Mg 24 ,Al 27 ,P 31 ,S 34 ,K 39 ,Ca 44 ,Ti 47 ,V 51 ,Cr 52 ,Mn 55 ,Fe 57 ,Co 59 ,Ni60 ,Cu 63 ,Zn 66 ,Ga 71 ,Ge 72 ,As 75 ,Se 78 ,Br 79 ,Rb 85 and Sr 88 , using Sc 45 As an internal standard element;

[0061] 2.Y 89 ,Zr 90 ,Nb 93 ,Mo 95 ,Ru 101 ,Rh 103 ,Ag 107 ,Cd 114 ,Sn 118 ,Sb 123 ,Te 125 ,I 127 ,Cs 133 ,Ba 137 ,La 139 ,Ce 140 and Pr 141 , use In 115 As an internal standard element;

[0062] 3.Nd 146 ,Sm 152 ,Eu 153 ,Gd 157 ,Tb 159 ,Dy 163 ,Ho 165 ,Er 166 ,Tm 169 ,Yb 172 Hf 178 Ta 181 ,W 182 ,Re 185 ,Os 189 ,Ir 193 ,Pt 195 ,Hg 202 ,Tl 205 ,Pb 208 ,Bi 209 ,Th 232 and U 238 , using Lu 175 as an internal standard element.

[0063] (III) Solution preparation

[0064] 1. Preparation of nitric acid aqueous solution:

[0065] First, pour a certain amount of ultrapure water into a 500mL volumetric flask, then accurately add 5.0mL of 67% HNO3, then add 2.5mL of n-butanol, 50μL of Triton X-100, make up to volume with ultrapure water, and shake to mix.

[0066] 2. Preparation of mixed internal standard solution:

[0067] First, 48.45 mL of nitric acid aqueous solution was added to a 50 mL centrifuge tube, and then 500 μL of Sc single element standard solution, 500 μL of In single element standard solution, 500 μL of Lu single element standard solution and 50 μL of Au single element standard solution were added in sequence and shaken to mix. The concentrations of Sc, In, Lu and Au in the mixed internal standard solution were all 100 μg / L.

[0068] 3. Preparation of mixed standard curve solution:

[0069] Table 4 Preparation method of mixed standard curve master solution

[0070]

[0071]

[0072] Table 5 Preparation method of mixed standard curve solution

[0073]

[0074] (IV) Methodological Validation

[0075] 1. Standard curve

[0076] The standard curves of 66 elements are as follows Figure 1 As shown, the R values ​​of the 66 elements are all ≥ 0.999, which ensures the reliability and accuracy of the test data.

[0077] 2. Accuracy

[0078] 2.1 Quality Control Samples

[0079] Determination process: (a) National Institute of Standards and Technology (NIST) SRM1643f trace element natural water quality control: This quality control is liquid and stored at 4°C. Accurately pipette 500μL of sample liquid into a 15mL centrifuge tube, dilute 20 times with nitric acid aqueous solution, mix well and then test on the machine; (b) German RECIPE company PlasmaControl Level I & Level Ⅱ: This quality control is a bottled freeze-dried powder, stored at 4°C according to the instructions. When in use, take it out to room temperature for 30 minutes, add 3mL of deionized water, seal it with a lid, place it on a low-temperature shaker (4°C) and shake it evenly for 8 hours to mix until it is completely dissolved into a reserve solution, freeze it at 4°C for later use, take it out to room temperature to melt, dilute it with nitric acid aqueous solution to the corresponding multiple (Level I, 20 times; Level Ⅱ, 40 times), vortex for 30 seconds, ultrasonicate for 15 minutes, centrifuge for 15 minutes, and then test it on the machine.

[0080] SRM1643f trace element natural water quality control of NIST, USA: This quality control provides the quality control range of 29 elements including Li, Be, B, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Te, Ba, Tl, Pb and Bi detected in the method of this research group. The detection method established by this research group, under the condition of normal operation of the instrument, the above 29 elements pass the SRM1643f quality control; RECIPE, Germany Plasma Control Level I & Level II: Level I and Level II of this quality control provide the quality control range of 28 elements including Li, Be, Mg, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sn, Sb, I, Ba, Pt, Hg and Tl detected in the method of this research group. When this research group established the method, the method was adjusted according to the results of Level I and Level II. Therefore, when the instrument is operating normally, the 28 elements can be detected by the method. PlasmaControl Level I & LevelⅡ quality control.

[0081] 2.2 Spike recovery

[0082] Determination process: The spike recovery experiment is used to perform quality control on elements not included in each quality control. Four mixed plasma samples are taken, one of which is used as the original plasma sample, and the other three are added with low-concentration, medium-concentration and high-concentration standard solutions as spiked plasma samples, then diluted with nitric acid aqueous solution, vortexed for 30 seconds, ultrasonicated for 15 minutes, and then centrifuged at 3000r / min for 15 minutes before detection. The low, medium and high concentration spiked recoveries of each element are calculated using the formula [spike recovery = (spike plasma sample measurement value - original plasma sample measurement value) / spiked concentration × 100%]; usually, the spiked recovery range is 80% to 120%. The spiked recovery results of this method are shown in Table 6. The low, medium and high concentration spiked recoveries of the 66 elements are all between 80% and 120%, except for the low concentration spiked recovery of Al and the high concentration spiked recovery of Ag.

[0083] Table 6 Spiked recovery

[0084]

[0085]

[0086]

[0087] 3. Internal standard recovery

[0088] The internal standard recovery rate is mainly used to determine whether the matrix of the sample matches and is stable with the matrix of the standard curve. According to the guidance of engineers and the experience of testing, the internal standard recovery rate can be kept between 70% and 130%. The internal standard recovery rate of this method in the process of testing plasma samples is shown in Figure 2 , it can be observed that: Sc 45 、In 115 、Lu 175 The internal standard recoveries of the three internal standard elements were relatively stable, ranging from 80% to 120%, indicating that this method can ensure matrix stability.

[0089] 4. Detection limit

[0090] After cleaning and maintaining the instrument, six groups of reagent blanks were measured (each group was measured 20 times) and the LOD was calculated using the formula: limit of detection (LOD) = 2 × √2 × 0.01 × relative standard deviation of background signal (RSDB) × analyte concentration (C0) / signal-to-noise ratio (SBR) of analyte concentration.

[0091] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the specification of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An ICP-MS detection method for 66 elements in plasma, characterized in that: The steps include: (1) Sc, In and Lu are selected as internal standard substances, Au is selected as a substance for stabilizing and removing the element Hg to be measured, and four single element standard solutions, namely, a single element standard solution of Sc, a single element standard solution of In, a single element standard solution of Lu and a single element standard solution of Au, are mixed to obtain a mixed internal standard solution of Sc, In, Lu and Au; (2) preparing a first mixed standard curve solution, a second mixed standard curve solution, a third mixed standard curve solution and a fourth mixed standard curve solution respectively, wherein the first mixed standard curve solution is a mixed standard curve solution of Li, Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb and U, the second mixed standard curve solution is a mixed standard curve solution of B, Ti, Ge, Zr, Nb, Mo, Ru, Rh, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt and Hg, the third mixed standard curve solution is a mixed standard curve solution of Br, Y, I, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Bi and Th, and the fourth mixed standard curve solution is a mixed standard curve solution of Na, Mg, P, S, K and Ca; (3) sequentially injecting the first mixed standard curve solution, the second mixed standard curve solution, the third mixed standard curve solution, and the fourth mixed standard curve solution of step (2) into an inductively coupled plasma mass spectrometer, and simultaneously introducing the mixed internal standard solution of step (1) online to draw standard curves for 66 elements; (4) Sample pretreatment: The gradient thawed plasma sample was diluted with nitric acid aqueous solution by direct dilution method, and then vortexed, sonicated and centrifuged in sequence to obtain the sample solution to be tested; (5) Injecting the sample solution to be tested described in step (4) and the mixed internal standard solution described in step (1) into an inductively coupled plasma mass spectrometer to determine the contents of 66 elements, including Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Ag, Cd, Sn, Sb, Te, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Hf, Ta, W, Re, Os, Ir, Pt, Hg, Tl, Pb, Bi, Th and U in the sample solution to be tested.

2. The ICP-MS detection method according to claim 1, characterized in that In step (1), the mixed internal standard solution is diluted with aqueous nitric acid solution to make the concentration of the four elements Sc, In, Lu and Au be 100 μg / L.

3. The ICP-MS detection method according to claim 2, characterized in that The nitric acid aqueous solution is a mixed aqueous solution of 1% HNO3, 0.5% n-butanol and 0.01% TritonX-100.

4. The ICP-MS detection method according to claim 1, characterized in that The preparation of the first mixed standard curve solution is specifically as follows: take 27 element standard solutions, a single element standard solution of Rb, a single element standard solution of Li, a single element standard solution of Fe, a single element standard solution of Zn and a single element standard solution of Cu, the 27 elements are Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Tl, U, V and Zn, first dilute them with aqueous nitric acid solution to obtain a mixed standard curve mother solution, and then dilute the mixed standard curve mother solution with aqueous nitric acid solution to obtain mixed standard curve solutions with different concentration gradients.

5. The ICP-MS detection method according to claim 1, characterized in that: The preparation of the second mixed standard curve solution is specifically as follows: take a 10-element standard solution, a 12-element standard solution, a single-element standard solution of Hg, a single-element standard solution of Os and a single-element standard solution of B, the 10 elements are Sb, Hf, Pd, Rh, Te, Au, Ir, Pt, Ru and Sn, the 12 elements are B, Ge, Mo, Nb, P, Re, S, Si, Ta, Ti, W and Zr, first dilute them with aqueous nitric acid solution to obtain a mixed standard curve mother solution, and then dilute the mixed standard curve mother solution with aqueous nitric acid solution to obtain mixed standard curve solutions with different concentration gradients.

6. The ICP-MS detection method according to claim 1, characterized in that: The third mixed standard curve solution is prepared specifically as follows: 16-element standard solutions, a single-element standard solution of I, and a single-element standard solution of Br are taken, wherein the 16 elements are Bi, Ce, Dy, Er, Eu, Gd, Ho, La, Nd, Pr, Sm, Tb, Tm, Y, and Yb, and the mixed standard curve mother solution is first diluted with aqueous nitric acid to obtain a mixed standard curve mother solution, and then the mixed standard curve mother solution is diluted with aqueous nitric acid to obtain mixed standard curve solutions with different concentration gradients.

7. The ICP-MS detection method according to claim 1, characterized in that: The fourth mixed standard curve solution is prepared specifically as follows: take a single element standard solution of Na, a single element standard solution of Ma, a single element standard solution of P, a single element standard solution of S, a single element standard solution of K and a single element standard solution of Ca, first dilute them with aqueous nitric acid solution to obtain a mixed standard curve mother solution, and then dilute the mixed standard curve mother solution with aqueous nitric acid solution to obtain mixed standard curve solutions with different concentration gradients.

8. The ICP-MS detection method according to claim 1, characterized in that The inductively coupled plasma mass spectrometer is Agilent 7700x ICP-MS.

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