Method for rapidly detecting contents of Ca and other elements in water body based on ICP-MS (Inductively Coupled Plasma Mass Spectrometry)

Abstract

The invention belongs to the technical field of metal element retrieval, and particularly discloses a method for rapidly detecting the content of Ca and other elements in a water body based on ICP-MS. Comprising the following steps: (1) filtering and acidizing a collected water sample to obtain a to-be-detected sample solution; (2) preparing an internal standard solution by taking Sc and Y as internal standard elements; (3) detecting different Ca isotopes in the standard solution by using different detection modes of an inductively coupled plasma mass spectrometer, and screening an optimal detection mode by taking a linear correlation coefficient, RSD and a detection limit as standards; on the premise that all elements can obtain good linear correlation coefficients, 12 metal elements in a sample are detected at the same time in the screened detection mode and Ca isotope, and a detection result is obtained. When Ca and other various elements are detected, the influence of reaction gas on other elements can be reduced, the detection time can be greatly shortened, and accurate and rapid detection of 12 elements can be realized in the same mode.

Description

Technical Field

[0001] The present invention belongs to the technical field of water sample detection, and particularly relates to a method for simultaneously and quickly detecting high-background, easily interfering element Ca and other elements using ICP-MS. Background Art

[0002] Ca, Na, Mg, Co, Se, Zn, Cu, Co, Mn, and As are respectively essential macro and trace elements for the human body, playing crucial roles in human function and metabolism. However, excessive intake can also be harmful. Pb is not essential for the human body; it is a highly accumulative heavy metal that has no physiological role in the human body, yet it is widely present in nature. High levels of lead in the human body can cause serious damage to human function, such as liver and reproductive system damage and nervous system disorders. Similar to lead, bismuth is a toxic and accumulative heavy metal used in medical, reactor, and cosmetic fields, particularly in the treatment of diseases such as chronic ulcerative colitis. However, excessive amounts of bismuth in the human body can cause encephalopathy, psychosis, ataxia, and other disorders. The levels of these elements in the aquatic environment constantly impact human health, making rapid and accurate detection of their levels in aquatic environments crucial.

[0003] Currently, commonly used analytical methods for elemental content determination include atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectroscopy (ICP-OES), and inductively coupled plasma mass spectrometry (ICP-MS). However, AAS can only detect one element at a time, and due to its limited detection limit, it is difficult to accurately detect trace elements. While ICP-OES can accurately determine trace elements, its detection limit is still relatively high, making it unsuitable for trace element determination.

[0004] ICP-MS is an elemental analysis technique used to accurately measure elemental concentrations. It offers low detection limits (trace detection capability of ppt-ppq), rapid detection, simultaneous analysis of multiple elements, a wide dynamic range (linear range of nine orders of magnitude), and rapid acquisition of isotopic information. Consequently, ICP-MS has a wide range of applications, including: heavy metal detection in drinking water, seawater, food, and soil; detection of high-purity metals, high-purity materials, and ultra-trace impurities in semiconductor materials; and analysis of hair, serum, and urine samples for pharmaceutical and physiological analysis. Similar to ICP-OES, ICP-MS utilizes an argon (Ar) plasma to convert the sample into ions, which are then detected by a mass spectrometer. However, ICP-MS directly detects ions, while inductively coupled plasma optical emission spectroscopy uses a spectrometer to measure the light emitted by elements as they pass through the plasma. Although both can achieve rapid analysis of multiple elements in samples, the detection limit of inductively coupled plasma is lower than that of inductively coupled plasma emission spectroscopy. It is an effective method for trace element analysis, but it also has certain difficulties in detecting Ca, which is easily interfered with and has a high background.

[0005] ICP-MS has three detection modes: standard mode (STD), collision mode (KED), and reaction cell mode (DRC).

[0006] The STD mode only requires the universal cell to be turned off, which is the standard mode in which the ICP-MS truly operates. Most elements that are not easily interfered with can be accurately detected by the standard mode, but for Ca, which is easily interfered with and has a high background, there are serious mass spectrum interferences, background and serious mass spectrum interferences. The instrument default isotope detection in STD mode is 40 Ca does not give accurate results.

[0007] KED mode uses He as the working gas and exploits the size difference between interfering polyatomic ions and the ions of the element being measured to remove interference. He collides with the larger polyatomic ions, reducing their kinetic energy and preventing them from entering the mass spectrometer's quadrupole mass analyzer. This eliminates interference from the polyatomic ions on the element being measured. However, KED lacks selectivity for different types of interference. When large quantities of Ca and other elements are being detected in a sample, it can interfere with the detection of these other elements.

[0008] The DRC mode mainly eliminates interference by selectively reacting the analyte or interfering ion with a highly active heavy mass reaction gas. It reduces the interference of argon-based molecules, ions, and complex sample matrix molecular ions on different calcium isotopes. However, when working in the DRC mode, the gas molecular reaction gas can also react with other elements in the sample matrix, causing interference with other detection elements besides Ca. For example, methane will produce some intermediate conversion products C3H7O during the sample detection process. + ,right 59 Co and 52 Cr causes interference.

[0009] Therefore, when detecting multiple elements including Ca in a large number of samples, different modes are switched. However, the mode switching process increases the time cost of detection. For a large number of samples that need to detect Ca and other multiple elements, the detection time will be greatly increased. Therefore, it is of great significance to invent a method that can reduce the impact of reaction gas on elements other than Ca and greatly reduce the detection time. Summary of the Invention

[0010] The purpose of the present invention is to provide a method for rapid detection of Ca and other elements simultaneously under the same detection mode, which can overcome the influence of matrix effects and high background and interfering elements, and realize rapid and accurate detection of the content of multiple elements in reservoir water samples.

[0011] To achieve the above object, the present invention adopts the following technical solution: a method for quickly detecting the content of element Ca and other elements in water based on ICP-MS, comprising the following steps:

[0012] (1) Filtering and acidifying the collected water samples, tap water, and drinking water to obtain a sample solution to be tested;

[0013] (2) Using Sc as the internal standard element for Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn, and Y as the internal standard element for Ca, internal standard solutions were prepared; using a multi-element calibration standard solution containing Ca, a series of standard solutions with concentration gradients were prepared;

[0014] (3) Using an inductively coupled plasma mass spectrometer, different isotopes of Ca were detected in three modes, and the optimal detection mode and the Ca isotope of the detection mode were screened using the linear correlation coefficient and RSD as the criteria;

[0015] (4) Obtained in STD and DRC detection modes respectively 48 Ca and 40 Good linear correlation and RSD of Ca;

[0016] (5) In STD mode and this detection mode48 Good standard curves and RSDs of Ca isotopes and all other elements were obtained, and the STD detection mode of ICP-MS was selected to simultaneously detect multiple elements in water samples, including Ca, an element with high background and easy interference, in a unified mode. Compared with the mode switching detection method, the detection time was greatly reduced, which is of great significance for the large-scale detection of multiple elements including Ca.

[0017] As a further improvement of the method for rapid detection of Ca and other elements in water based on ICP-MS:

[0018] Preferably, in step (1), the collected water sample is filtered with a 0.22 μm filter membrane, HNO 3 is added to the filtrate to make the acidity of the solution reach 2%-5%, and the treated solution is used as the sample solution to be tested.

[0019] Preferably, in step (2), the internal standard solution is prepared with 2 wt% HNO3, and the concentration of the internal standard element Sc in the internal standard solution is 10 μg·L -1 , the concentration of Y is 10 μg·L -1 .

[0020] Preferably, in step (2), 2% HNO3 is used to prepare standard solutions of different concentrations, and the concentrations of the standard solutions are 0 μg·L -1 , 0.1 μg·L -1 , 0.2 μg·L -1 , 0.5 μg·L -1 , 1μg·L -1 , 2μg·L -1 , 5μg·L -1 , 10 μg·L -1 .

[0021] Preferably, the specific operation of screening out the optimal detection mode of different Ca isotopes in step (2) is as follows: using the concentration of the standard solution under different detection modes as the X-axis and the ratio of the net intensity of the standard solution and the internal standard solution as the Y-axis, plotting the standard curves of different Ca isotopes under different detection modes, obtaining linear equations respectively, and using the linear correlation coefficient, RSD and detection limit of the linear equations as standards to screen out the optimal detection mode of different Ca isotopes.

[0022] Preferably, the standards are a linear correlation coefficient close to 1, an RSD less than 3%, and a detection limit of 1.100 μg / L.

[0023] Preferably, the STD, KED and DRC detection modes of ICP-MS are used.

[0024] Preferably, Ca isotopes include Ca-40, Ca-42, Ca-43, Ca-44, Ca-46 and Ca-48.

[0025] Preferably, the best detection mode for the Ca isotope Ca-48 is the single STD detection mode, and the best detection mode for the Ca isotope Ca-40 is the single DRC detection mode. The Ca isotope Ca-48 and 11 elements Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn can all obtain good curve linear relationships and RSDs under the single STD detection mode. However, under the switching conditions of the STD and DRC modes, good linear correlation coefficients cannot be obtained for all elements. In addition, compared with the single STD mode, the detection time of the STD+DRC switching mode is greatly extended, which reduces the efficiency of ICP-MS detection.

[0026] Preferably, HNO3 is added to the filtrate to make the acidity of the solution reach 2%-5%, and the volume ratio of the filtrate to the HNO3 added to the filtrate is 20ml:(400μL-1000μL).

[0027] The beneficial effects of the present invention compared to the prior art are:

[0028] 1) The present invention provides a method for quickly detecting the content of easily interfering element Ca and other elements in water based on ICP-MS, comprising the following steps: (1) filtering and acidifying the collected water sample to obtain a sample solution to be tested; (2) using Sc as an internal standard element for Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn, and Y as an internal standard element for Ca, to prepare an internal standard solution, so as to avoid the influence of improper selection of internal standards on the detection of elements; (3) using different detection modes of an inductively coupled plasma mass spectrometer to detect different Ca isotopes in the standard solution, and screening the best detection mode based on the linear correlation coefficient, RSD and detection limit as standards; the linear correlation coefficient indicates the degree of correlation, the RSD indicates the stability of the measurement result, and the detection limit represents the detection sensitivity; on the premise that good linear correlation coefficients can be obtained for all elements, the 12 metal elements in the water sample are simultaneously detected using the screened detection mode to obtain the detection results.

[0029] 2) The internal standard method adds an internal standard element of known concentration (similar in properties to the target element but not present in the sample or at a very low content) to the sample and standard solution through the online addition method, and uses the signal ratio of the internal standard to the target element to correct instrument fluctuations, matrix interference and signal drift, thereby improving the accuracy and precision of quantitative analysis. The internal standard detection method can correct the short-term or long-term drift of the signal during the detection process, and can also correct the influence of the matrix effect of some complex samples on the detection. The selection of internal standard elements has the following criteria: 1. The element is not contained in the sample to be detected. 2. The mass number is close to that of the element to be detected. 3. The properties in the chemical solution are similar to those of the element to be detected. 4. High ionization potential Elements with high ionization potential use internal standards with high ionization potential, such as Ge as the internal standard for Se.

[0030] The present invention selects Sc and Y as internal standard elements. Sc, as an internal standard element for Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn, and Y, as an internal standard element for Ca, have a strong matrix correction effect and can correct inaccuracies in test results caused by signal drift during the detection process. Sc and Y dissolve in acidic solutions and can remain stable.

[0031] 3) The testing method of the present invention selects the optimal detection mode and isotope type under the condition that the instrument sensitivity is satisfied. Under the detection mode that satisfies other elements and obtains good correlation coefficients, the appropriate Ca isotope is selected to obtain a good curve correlation coefficient and linear equation, thereby avoiding the influence of the detection signal values of other elements due to the introduction of reaction gas / collision gas and the increase in detection time cost due to switching of detection modes. This is a very advantageous detection method when a large number of samples need to be tested for Ca and other elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The STD mode in Example 1 of the present invention detects Ca isotopes;

[0033] Figure 2 The KED mode of detecting Ca isotopes in Example 1 of the present invention;

[0034] Figure 3 The DRC mode in Example 1 of the present invention detects Ca isotopes;

[0035] Figure 4 The 12 elements are detected in the STD mode in Example 1 of the present invention;

[0036] Figure 5 The 12 elements are detected in the STD+DRC mode in Example 1 of the present invention; DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] The following description fully illustrates the specific embodiments of the present invention so that those skilled in the art can implement and reproduce them. The instruments and reagents used in the examples are as follows:

[0039] Filter device (MT-1, Yancheng Xinmingte Glass Instrument Co., Ltd.)

[0040] Pipette (1000 μL, DRAGON LAB, USA)

[0041] Ultrapure water machine (Kertone-LAB, Hunan Kertone Water Co., Ltd.)

[0042] pH meter (Sartorius, Sartorius Scientific Instruments Co., Ltd.)

[0043] Beaker (500 mL, polytetrafluoroethylene beaker)

[0044] Centrifuge tube (5 mL, ct-012-5A, selected, Beijing Lanjieke Technology Co., Ltd.)

[0045] Centrifuge tube (50 mL, ct-012-50A, selected, Beijing Lanjieke Technology Co., Ltd.)

[0046] Nitric acid (electronically pure, Jingrui, Jingrui Electronic Materials Co., Ltd.)

[0047] Pure water (resistivity 18.25 MΩ·cm, 25°C)

[0048] Inductively coupled plasma mass spectrometer NeXION 5000 (PerkinElmer)

[0049] Liquid argon: purity 99.99%

[0050] Mukti-Element Calibration Standard310μg·mL for Ca, Fe, Mn, Zn, Na, Mg, Ag, Al, As, Be, Bi, Co, Cd, Cr, Cs, Cu, Ga, In, Li, Ni, Pb, Rb, Se, Sr, Tl, U, and V elements -1 , 1% nitric acid as the substrate, Be, Ce, Fe, In, Li, Mg, Pb, U tuning solution 1 μg L -1 .

[0051] Example 1

[0052] This embodiment provides a method for quickly detecting the content of the easily interfering element Ca and other elements in a water reservoir using ICP-MS, which specifically includes the following steps:

[0053] Step 1: Preparation of sample, standard solution and internal standard solution

[0054] 1.1 Sample collection and processing:

[0055] The water sampler was rinsed with ultrapure water 3-4 times before use. The water sampler was used to collect samples at three different locations in Dongpu Reservoir. The water samples were thoroughly mixed and used as the collected samples. Tap water and residents' drinking water were collected and pH tested together.

[0056] Filter the water sample using a 0.22 μm filter membrane and a suction filtration device to reduce interference and damage to the instrument during testing caused by organic matter in the sample. Take 20 mL of the filtered sample and add 400 μL of HNO₃ to bring the solution acidity to 2%. Dispense the solution into three 5 mL centrifuge tubes to serve as three parallel controls for this water sample, preparing the samples to be tested and retaining them for future use.

[0057] 1.2 Preparation of standard solution and internal standard solution:

[0058] Prepare internal standard solution: Select Sc and Y as internal standard elements and prepare 10 μg·L -1 The internal standard solutions of Sc and Y were prepared as follows: the concentration was 1000 μg mL -1 A mixed internal standard solution (including Sc, Y, Ga, and In) was pipetted 50 μL into a 50 mL centrifuge tube. 48.5 mL of ultrapure water and 1 mL of HNO3 were then added to prepare 50 mL of a 2% HNO3 matrix with Sc and Y concentrations of 10 μg·L -1 The internal standard solution was shaken and allowed to stand for 3 min.

[0059] The preparation process of standard solution is as follows: Multi-Element Calibration Standard 3 mixed standard stock solution containing Ca, Fe, Mn, Zn, Na, Mg, Ag, Al, As, Be, Bi, Co, Cd, Cr, Cs, Cu, Ga, In, Li, Ni, Pb, Rb, Se, Sr, Tl, U, and V elements is gradually diluted with 2% HNO3 to obtain concentrations of 0 μg·L -1 , 0.1 μg·L -1 , 0.2 μg·L -1 , 0.5 μg·L -1 , 1μg·L -1 , 2μg·L -1 , 5μg·L-1 , 10 μg·L -1 A series of standard solutions with a concentration gradient.

[0060] Working curve: The concentration of the standard solution is the X axis (unit: μg·L -1 ), the test point values are 0 μg·L -1 , 0.1 μg·L -1 , 0.2 μg·L -1 , 0.5 μg·L -1 , 1μg·L -1 , 2μg·L -1 , 5μg·L -1 , 10 μg·L -1 , draw a standard curve with the ratio of the net intensity of the standard solution and the internal standard solution as the Y axis.

[0061] Step 2: Generate a working curve and select the isotopes of the element to be measured using an inductively coupled plasma mass spectrometer

[0062] 2.1 Instrument startup and tuning steps:

[0063] 1) Prepare the samples to be tested, standard solutions with different concentration gradients, and internal standard solutions according to the experimental requirements.

[0064] 2) Open the refrigeration system and gas supply system (liquid argon booster valve).

[0065] 3) Ignite and preheat the plasma for 30 minutes.

[0066] 4) After preheating, install the pump tube from inside to outside in the order of waste liquid tube, internal standard tube and sample injection tube.

[0067] 5) Place the sample injection tube and internal standard tube in a 2% HNO3 solution for 1 minute, and then place them in ultrapure water for 1 minute.

[0068] 6) After cleaning the sample injection system, tune the instrument. RF power, nebulizer flow rate, and measurement mode are key operating parameters for instrument operation. Low detection limits, low background signal intensity, and high signal-to-noise ratio are the criteria, with isotope, double charge, and sensitivity as reference indicators. Use tuning solutions to test the instrument and optimize the parameters. The optimal instrument parameters are shown in Table 1.

[0069] Table 1 Instrument parameters in STD detection mode

[0070]

[0071] 2.2 Selection of detection mode and isotope of the element to be measured and generation of working curve:

[0072] The standard mode (STD), collision mode (KED), and reaction mode (DRC) of the inductively coupled plasma mass spectrometer were used to detect several isotopes of Ca in the standard solution. The detection results are shown in Table 2.

[0073] Table 2 Comparison of main parameters of six calcium isotopes under different detection modes

[0074]

[0075]

[0076] As shown in Table 2, when the six Ca isotopes were detected in three detection modes, a better curve correlation coefficient was obtained when Ca-48 and STD modes were selected. 2 The RSD and detection limit were 0.999, and were 2.800% and 1.100 μg / L, respectively, meeting the experimental requirements. The curve correlation coefficients of other Ca isotopes in STD mode were poor. In KED mode, no good linear relationship was obtained for the six Ca isotopes. In DRC mode, Ca-40 had a better curve correlation coefficient than the other five isotopes, R 2 To achieve simultaneous detection of Ca and other elements in the same mode, the standard solution can be tested by switching between STD and STD+DRC (only Ca-40 is tested in DRC mode, while the other elements are tested in STD mode). With the goal of achieving good linearity and RSD for all elements, the optimal detection method is selected for sample testing.

[0077] Based on the detection results of Ca under three different detection modes, Ca-48 and Ca-40 were selected and detected simultaneously with other elements in the single STD mode and the STD+DRC mode, respectively. The differences between the two detection modes in curve correlation coefficient, RSD, detection limit and detection time were compared, as shown in Tables 3, 4 and 5, respectively.

[0078] Table 3 Main parameters detected in STD mode

[0079]

[0080]

[0081] As shown in Table 3, using the same internal standard concentration, standard solution, and instrument parameters, the single STD mode was used to detect each element in the sample. Good correlation coefficients were obtained for Ca, Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn, and the detection limits met the experimental requirements. The RSDs were all less than 3%, indicating good precision.

[0082] Table 4 Main parameters in STD+DRC mode

[0083] element Linear correlation coefficient Relative error Internal standard recovery Detection limit Na-23 0.955 0.870％ 98％ 0.030 Mg-24 0.897 1.200％ 98％ 0.860 Zn-66 0.999 5.800％ 98％ 2.780 Ca-40 0.985 7.300％ 100％ 1.600 Pb-208 0.999 1.000％ 98％ 1.690 Bi-209 0.999 1.500％ 98％ 0.340 Co-59 0.999 2.300％ 98％ 0.130 As-75 0.999 1.500％ 98％ 3.240 Se-82 0.999 3.000％ 98％ 0.020 Mn-55 0.999 2.000％ 98％ 0.780 Cu-63 0.999 1.500％ 98％ 0.640 Ni-60 0.996 1.300％ 98％ 0.650

[0084] As can be seen from Table 4, when the STD+DRC mode was used to detect the samples, it was found that good curve correlation coefficients could be obtained for Pb, Bi, Co, As, Se, Ni, Cu, Mn, and Ni, but the curve correlation coefficients for Na, Mg, and Zn were poor. Moreover, compared with the single STD detection mode, the RSDs of most elements were larger when the STD+DRC mode switching method was used to detect the samples. Therefore, when detecting the content of 12 elements in the sample, the single STD mode is a more effective detection method. In addition, the time required to detect 12 elements in the same sample under the two detection methods is shown in Table 5. The results show that compared with the STD+DRC mode switching detection method, the single STD detection method can save 21.480% of the detection time. Therefore, under the premise of ensuring the accuracy of the test results, it is more efficient to choose the STD mode to detect multiple elements at the same time.

[0085] Table 5 Comparison of time for detecting 12 elements using STD and STD+DRC modes

[0086] Detection Mode Ca element Detection time (S) STD Ca-48 166 STD+DRC Ca-40 212

[0087] Step 3: Test results

[0088] Based on the above experimental results, the STD mode can achieve good curve correlation coefficients, high detection sensitivity and accuracy for all 12 elements in water samples, and shortens the detection time. Therefore, the single STD mode was selected to detect the 12 elements in Dongpu Reservoir water samples. The test results are shown in Table 6.

[0089] Table 6 Experimental results

[0090]

[0091]

[0092] As shown in Table 6, according to the element concentration range for Class II reservoirs specified in the National Surface Water Environmental Quality Standard (GB 3838-2002), the concentrations of Pb, As, Se, Cr, Cu, Zn, Mn, Co, and Ni in Dongpu Reservoir, residents' drinking water, and tap water are all within the national standard range and are far below the national standard range. In addition, the concentrations of Na, Ca, and Mg are lower than those of Na (16.280 mg / L), Ca (35.760 mg / L), Mg (7.480 mg / L), and Bi (18.700 μg / L) in Jinsha River Reservoir and Na (8.200-46.200 mg / L), Ca (5.300-4000 mg / L), and Mg (1.800-8.400 mg / L) in the National Natural Drinking Water (GB8538-2008). This indicates that the water quality of Dongpu Reservoir, residents' drinking water, and tap water meets the national standard.

[0093] The present invention selects Sc and Y as internal standards, and under the condition that the instrument sensitivity is satisfied, successively uses the three detection modes of ICP-MS to detect different Ca isotope elements. It is found that Ca-48 and Ca-40 can obtain good curve correlation coefficients in STD and DRC modes respectively. In order to achieve faster detection of Ca and other elements, the STD and DRC modes are selected to detect other elements. It is found that in the STD mode, good curve correlation coefficients can be obtained, and RSD<3%, indicating good precision. However, only a few elements can obtain good linear relationships in the DRC mode. Therefore, in order to achieve simultaneous detection of 12 elements, the single STD and STD+DRC mode switching method is selected to detect all elements. It is found that the single STD mode can shorten the detection time by 21.48% relative to the STD+DRC mode switching detection method. This method is very advantageous when a large number of samples need to be detected, and can save detection time to a great extent. Therefore, the present invention can achieve the simultaneous detection of high background and easily interfering element Ca and other elements in the standard mode, and the curve correlation coefficients of the 12 elements are all above 0.999, and the RSDs are all less than 3%. However, under the STD+DRC mode detection, the curve correlation coefficients of Na and Mg are only 0.955 and 0.896, which cannot meet the experimental requirements.

[0094] Through this detection method, the contents of various elements in reservoirs, residents' drinking water and tap water were obtained, and compared with the national standard data for surface water, tap water and drinking water. It was found that the water quality of Dongpu Reservoir, residents' drinking water and tap water was far below the national standard range in terms of the concentration of elements Pb, As and Se, and the water quality was good.

[0095] Figure 1The STD mode in Example 1 of the present invention is used to detect Ca isotopes. The test process is to select STD as the detection mode and MS / MS as the scanning mode when detecting the six isotopes of Ca. No reaction gas or collision gas is introduced. The internal standard element and the standard solution are tested to obtain the standard curve equation and correlation coefficient. Figure 1 The test results show that: in STD mode, except 48 Except for Ca, no good correlation coefficients could be obtained for the other five Ca isotopes.

[0096] Figure 2 The KED mode in Example 1 of the present invention is used to detect Ca isotopes. The test process is as follows: when detecting six Ca isotopes, the detection mode is KED, the scanning mode is MS / MS, and He collision gas is introduced at a gas flow rate of 4 mL min. -1 The internal standard element and the standard solution are tested to obtain the standard curve equation and correlation coefficient. Figure 2 The test results show that in the KED mode, none of the six Ca isotopes can obtain a good correlation coefficient.

[0097] Figure 3 The DRC mode in Example 1 of the present invention is used to detect Ca isotopes. The test process is as follows: when detecting six Ca isotopes, the detection mode is DRC, the scanning mode is MS / MS, and NH3 collision gas is introduced at a gas flow rate of 1.2 mL min -1 The internal standard element and the standard solution are tested to obtain the standard curve equation and correlation coefficient. Figure 3 The test results show that except 40 Except for Ca, no good correlation coefficients could be obtained for the other five Ca isotopes.

[0098] Figure 4 The 12 elements are detected in a single STD mode in Example 1 of the present invention; the test process is as follows: the detection mode is STD, the scanning mode is MS / MS, and the internal standard element of Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn is Sc. 40 The internal standard element of Ca is first selected as Y, without introducing reaction gas and collision gas, and the internal standard element and standard solution are tested to obtain the standard curve equation and correlation coefficient. Figure 4 The test results show that in STD mode, including 48 Good correlation coefficients were obtained for all 12 Ca isotopes including Ca.

[0099] Figure 5The 12 elements are detected in the STD+DRC mode in Example 1 of the present invention; the test process is that the detection mode for Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn is STD, and the internal standard element is Sc. 40 Select DRC as the Ca detection mode, select Y as the internal standard element, select MS / MS as the scanning mode, introduce NH3 reaction gas, detect the internal standard element and standard solution, and obtain the standard curve equation and correlation coefficient. Figure 5 The test results show that in the STD+DRC mode, the 12 Ca isotopes cannot all obtain good correlation coefficients. The curve correlation coefficients of Na and Mg are only 0.955 and 0.896, which cannot meet the experimental requirements. In addition, the detection time of this detection mode is 1.215 times that of the single STD detection mode.

[0100] The terms used in this invention are descriptive and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the technical solution, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope of the appended claims. Therefore, all changes and modifications that fall within the scope of the claims or their equivalents are intended to be covered by the appended claims.

Claims

1. A method for quickly detecting the content of element Ca and other elements in water based on ICP-MS, characterized in that: The steps include: (1) Filtering and acidifying the collected water samples, tap water, and drinking water to obtain a sample solution to be tested; (2) internal standard solutions were prepared using Sc as the internal standard element for Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn, and Y as the internal standard element for Ca; Use a multi-element calibration standard solution containing Ca to prepare a series of standard solutions with concentration gradients; (3) Different detection modes of inductively coupled plasma mass spectrometry were used to detect different Ca isotopes in the standard solution, and the optimal detection mode under different Ca isotopes was screened; (4) On the premise that all elements can obtain good linear correlation coefficients, the 12 metal elements are detected simultaneously using the screened detection mode to obtain the detection results.

2. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 1, characterized in that: In step (1), the water sample is filtered through a 0.22 μm filter membrane, and HNO 3 is added to the filtrate to make the acidity of the solution reach 2%-5%. The treated solution is used as the sample solution to be tested.

3. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 1, characterized in that: In step (2), 2 wt% HNO3 was used to prepare the internal solution, and the concentration of the internal standard element Sc in the internal standard solution was 10 μg·L -1 , the concentration of Y is 10 μg·L -1 .

4. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 1, characterized in that: In step (2), 2% HNO3 was used to prepare standard solutions of different concentrations, the concentrations of which were 0 μg·L -1 , 0.1 μg·L -1 , 0.2 μg·L -1 , 0.5 μg·L -1 , 1μg·L -1 , 2μg·L -1 , 5μg·L -1 , 10 μg·L -1 .

5. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 1, characterized in that: The specific operation of screening out the best detection mode under different Ca isotopes in step (2) is as follows: with the concentration of the standard solution under different detection modes as the X-axis and the ratio of the net intensity of the standard solution and the internal standard solution as the Y-axis, the standard curves of different Ca isotopes under different detection modes are drawn, and the linear equations are obtained respectively. The linear correlation coefficient, RSD and detection limit of the linear equations are used as standards to screen out the best detection mode of different Ca isotopes.

6. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 5, characterized in that: The standards were a linear correlation coefficient close to 1, an RSD less than 3%, and a detection limit of 1.100 μg / L.

7. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 1 or 5, characterized in that: The STD, KED and DRC detection modes of ICP-MS were used.

8. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 1 or 5, characterized in that: Ca isotopes include Ca-40, Ca-42, Ca-43, Ca-44, Ca-46 and Ca-48.

9. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 1 or 5, characterized in that: The best detection mode for Ca isotope Ca-48 was screened out as the single STD detection mode. Good linear relationships and RSDs were obtained between Ca isotope Ca-48 and 11 elements including Na, Mg, Pb, Bi, Co, As, Se, Zn, Ni, Cu, and Mn in the single STD detection mode.

10. The method for quickly detecting the content of element Ca and other elements in water based on ICP-MS according to claim 2, characterized in that: Add HNO3 to the filtrate to make the acidity of the solution reach 2%-5%. The volume ratio of filtrate to HNO3 added to the filtrate is 20ml:(400μL-1000μL).

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