Method for detecting content of barium element in normal saline

Abstract

The invention provides a method for detecting the content of a barium element in normal saline, which comprises the following steps: preparing barium element standard solutions with different concentrations, acquiring the absorbance of the barium element standard solutions with different concentrations, and establishing a barium element standard curve according to the absorbance and the concentrations of the barium element standard solutions; the method comprises the following steps: obtaining a sample solution, adding a digesting agent into the sample solution, digesting the sample solution under a heating condition, and evaporating the sample solution to obtain a digesting product; rinsing the digestion product to obtain a rinsing solution, adding a matrix modifier into the rinsing solution, and uniformly mixing to obtain a to-be-detected sample solution; and obtaining the absorbance of the to-be-detected sample solution, and determining the content of the barium element in the to-be-detected sample solution according to the barium element standard curve and the absorbance of the to-be-detected sample solution. The detection method is high in sensitivity, low in detection cost and small in material taking amount, interference of normal saline matrixes can be reduced or eliminated, and the accuracy of detection results can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of detection methods, and in particular to a method for detecting the content of barium in physiological saline. Background Art

[0002] With the rapid development of modern medical technology, medical devices are increasingly used in clinical treatment. As an important medium for medical device test fluid, the determination of its composition plays an important role in identifying medical device-related hazards and risks. Barium is an impurity or additive that may exist in saline, and the accurate determination of its content is of great significance for evaluating the reliability and safety of the metal ion content of medical devices.

[0003] In the prior art, the barium content in saline is mainly detected by the following two methods: visual colorimetry to detect the total content and instrumentation (such as atomic fluorescence, atomic absorption, ICP). However, visual colorimetry cannot accurately quantify the barium content; atomic fluorescence and inductively coupled plasma-mass spectrometry instruments are expensive and time-consuming to operate, and are not suitable for rapid testing of barium in saline systems; the flame method mode in the atomic absorption method requires the introduction of nitrous oxide (N2O3) when testing high-temperature elemental barium. 2 O), the safety risk is high, the sampling volume is large, and the pre-test processing is cumbersome. The ordinary graphite furnace method is affected by sodium chloride when testing samples in the physiological saline system, and double peaks will appear in the results, resulting in the inability to quantitatively detect. In addition, barium is a high-temperature element and will form difficult-to-dissociate carbides after atomization. If it remains on the surface of the graphite tube, it will produce a memory effect, which will interfere with the accuracy of the next sample test result. Summary of the invention

[0004] The present invention aims to solve the above-mentioned defects of the prior art and provide a method for detecting the barium content in physiological saline. The detection method has high sensitivity, low detection cost, small material amount, and can reduce or eliminate the interference of the physiological saline matrix, which is conducive to improving the accuracy of the detection result.

[0005] In order to solve the above problems, the present invention provides a method for detecting the content of barium in physiological saline, comprising the following steps:

[0006] Prepare barium standard solutions of different concentrations, obtain the absorbance of the barium standard solutions of various concentrations, and establish a barium standard curve according to the absorbance and the concentration of the barium standard solutions;

[0007] Obtaining a sample solution, adding a digestion agent to the sample solution, performing a digestion treatment on the sample solution under heating conditions, evaporating the sample solution, and obtaining a digestion product;

[0008] Rinsing the digestion product to obtain a rinse solution, adding a matrix improver to the rinse solution, and mixing them evenly to obtain a sample solution to be tested;

[0009] The absorbance of the sample solution to be tested is obtained, and the content of the barium element in the sample solution to be tested is determined according to the barium element standard curve and the absorbance of the sample solution to be tested.

[0010] Further, the adding of a digestion agent into the sample solution, digestion treatment of the sample solution under heating conditions, evaporation of the sample solution, and obtaining a digestion product comprises:

[0011] Add a digestion agent to the sample solution, perform a digestion treatment on the sample solution in a constant temperature water bath, evaporate the sample solution to near dryness, and obtain a digestion product, wherein the temperature of the constant temperature water bath is 98° C. to 99° C.;

[0012] During the digestion process, the space where the sample solution is located is kept ventilated.

[0013] Furthermore, the digestion agent is a monoacid digestion oxidant, and the volume ratio of the sample solution to the digestion agent is 100:1 to 100:8.

[0014] Furthermore, rinsing the digestion product to obtain a rinsing solution comprises:

[0015] A rinse agent is added to the digestion product, and the digestion product is rinsed 1 to 3 times to obtain a rinse solution, wherein the rinse agent is deionized water or an acidic solution, and the acidic solution is a nitric acid solution, a sulfuric acid solution or a hydrochloric acid solution, and the volume ratio of the acidic solution is less than 20%.

[0016] Further, the matrix modifier is a combination of one or more of a palladium salt solution, an ammonium salt solution, a nitrate solution and a phosphate solution;

[0017] The palladium salt solution is a combination of one or more of palladium chloride, palladium nitrate and palladium acetate;

[0018] The ammonium salt solution is ammonium chloride;

[0019] The nitrate solution is a combination of one or more of barium nitrate, nickel nitrate, magnesium nitrate and lanthanum nitrate;

[0020] The phosphate solution is cobalt phosphate and / or copper phosphate.

[0021] Further, the graphite furnace atomic absorption spectrometry is used to detect the barium element standard solutions of various concentrations according to a preset temperature increase program to obtain the absorbance of the barium element standard solutions of various concentrations;

[0022] The sample solution to be tested is detected according to the preset temperature increase program using a graphite furnace atomic absorption spectrometry to obtain the absorbance of the sample solution to be tested.

[0023] Furthermore, the preset temperature rising program includes:

[0024] The barium standard solutions of various concentrations or the sample solutions to be tested are dried at a first temperature for a first preset time, then ashed at a second temperature for a second preset time, then desalinated at a third temperature for a third preset time, and then atomized at a fourth temperature for a fourth preset time.

[0025] Further, the first temperature is 60° C. to 250° C., and the first preset time is 15s to 35s;

[0026] The second temperature is 400° C. to 600° C., and the second preset time is 8s to 25s;

[0027] The third temperature is 1200° C. to 1600° C., the third preset time is 3s to 5s, and the third temperature is greater than the melting point of the substrate-improved product;

[0028] The fourth temperature is 2200° C. to 2700° C., and the third preset time is 3s to 5s.

[0029] Furthermore, after the atomization process, a cleaning process is also included, the cleaning process temperature is higher than the fourth temperature and lasts for a fifth preset time, and the fifth preset time is 1s to 2s.

[0030] Furthermore, between the desalination treatment and the atomization treatment, a cooling treatment is also included, the cooling treatment temperature is 600° C., and it lasts for a sixth preset time, and the sixth preset time is 5s to 10s.

[0031] The method for detecting the content of barium in physiological saline of the present invention first digests the sample solution to improve the solubility and stability of barium ions, making the barium ions easy to measure, and at the same time improving the detection range and eliminating the influence of chloride ions, then rinsing the digestion product, and adding a matrix improver to the rinse solution, which can convert the sodium chloride in the matrix of the sample solution to be tested into a volatile compound, which is beneficial to increase the volatility of sodium chloride in the matrix of the sample solution to be tested, reduce or eliminate the interference of sodium chloride in the matrix, and at the same time improve the stability of the barium element in the sample solution to be tested, thereby helping to improve the accuracy of barium element detection in the sample solution to be tested. In addition, the content of barium in the sample solution to be tested is determined according to the barium standard curve and the absorbance of the sample solution to be tested, which can realize the rapid detection of barium in the sample solution to be tested, improve the detection efficiency, and the detection method is easy to operate, has low labor intensity, low detection cost, strong operability, high detection automation, and high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart for detecting the barium content in physiological saline provided by an embodiment of the present invention;

[0033] Figure 2 A graph showing the absorbance of the sample solution to be tested provided in Example 1 of the present invention, wherein the abscissa is time in seconds and the ordinate is absorbance, the same below;

[0034] Figure 3 A graph showing the absorbance of the sample solution to be tested provided in Example 2 of the present invention;

[0035] Figure 4 A graph showing the absorbance of the sample solution to be tested provided in Example 3 of the present invention;

[0036] Figure 5 A graph showing the absorbance of the sample solution to be tested provided in Example 4 of the present invention;

[0037] Figure 6 This is a graph showing the absorbance test results of the sample solution provided in the comparative example of the present invention. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0040] In addition, the terms "comprising", "including", "containing", and "having" are not restrictive, that is, other steps and other components that do not affect the results can be added. Unless otherwise specified, materials, equipment, and reagents are commercially available.

[0041] In addition, although the present invention describes each step in the preparation process in the form of step S110, step S120, step S130, etc., this description method is only for ease of understanding. For example, step S110, step S120, step S130, etc. do not limit the sequence of the steps.

[0042] Combination Figure 1 As shown, the embodiment of the present invention provides a method for detecting the content of barium in physiological saline, comprising the following steps:

[0043] Step S110: prepare barium standard solutions of different concentrations, obtain the absorbance of the barium standard solutions of various concentrations, and establish a barium standard curve according to the absorbance and the concentration of the barium standard solutions.

[0044] Specifically, the following method can be used to prepare standard barium solutions of different concentrations: first, a standard intermediate solution of barium is prepared with a nitric acid solution, and then the standard intermediate solution of barium is diluted with a nitric acid solution by different multiples to obtain a series of standard barium solutions of different concentrations, wherein the concentration of the nitric acid solution can be 0.1% to 5%, and preferably, the concentration of the nitric acid solution is 1%.

[0045] More specifically, accurately measure 1 mL of a 100 mg / L barium standard solution, and quantitatively dilute it with a 1% nitric acid solution to prepare a 10 μg / mL barium standard intermediate solution. Accurately pipette 0.05 mL, 0.1 mL, 0.2 mL, 0.3 mL, 0.4 mL, and 0.5 mL of the 10 μg / mL barium standard intermediate solution into six 10 mL volumetric flasks, dilute and fix to scale with a 1% nitric acid solution, shake well, and prepare a series of barium standard solutions with concentrations of 0.05 μg / mL, 0.1 μg / mL, 0.2 μg / mL, 0.3 μg / mL, 0.4 μg / mL, and 0.5 μg / mL, respectively.

[0046] A series of prepared barium element standard solutions are introduced into the corresponding atomizers in order of mass concentration from low to high, and the barium element standard solutions of various concentrations are detected by graphite furnace atomic absorption method according to a preset heating program to obtain the absorbance of the barium element standard solutions of various concentrations; the barium element standard curve is fitted with the mass concentration of the barium element in the series of barium element standard solutions as the horizontal coordinate and the corresponding absorbance as the vertical coordinate.

[0047] Step S120: obtaining a sample solution, adding a digestion agent to the sample solution, performing a digestion treatment on the sample solution under heating conditions, evaporating the sample solution, and obtaining a digestion product.

[0048] Specifically, a sample solution to be measured is obtained, a digestion agent is added to the sample solution, and the sample solution is digested in a constant temperature water bath, so that the sample solution is evaporated to near dryness to obtain a digestion product, the constant temperature water bath temperature is 98°C to 99°C, and the space where the sample solution is located is kept in a ventilated state during the digestion treatment. Thus, by adding a digestion agent to the sample solution and digesting the sample solution, the chemical structure of the sample can be destroyed and particulate matter can be dissolved, so that the barium ions therein are released, and the digestion agent and the barium ions convert the barium into a soluble barium ion form through complexation, thereby improving the solubility and stability of the barium ions and making the barium ions easy to measure; and the sample usually contains other compounds, which may interfere with the determination of the barium ions. Through the digestion treatment, the interfering substances can be decomposed or removed, which is conducive to improving the accuracy and selectivity of the determination of the barium ions, thereby improving the detection range and eliminating the influence of chloride ions. In this embodiment, the sample solution is digested in a constant temperature water bath, which can ensure that the sample solution will not boil and splash while being evaporated, thereby avoiding the loss of barium and improving the accuracy of the test results. In addition, by placing the sample solution in a constant temperature water bath, it is beneficial to ensure that the sample solution is evenly heated and the efficiency of the digestion treatment is accelerated. By performing the digestion treatment in a ventilated state, the gas circulation in the space where the sample solution is located can be accelerated, which is beneficial to improving the emission efficiency of the volatile products of the digestion treatment.

[0049] On the basis of the above embodiment, as an optional implementation, the digester is a monoprotic acid digestion oxidant. Specifically, the digester can be concentrated nitric acid, concentrated sulfuric acid or concentrated hydrochloric acid with a mass concentration greater than 10g / L. Thus, the above digester has strong acidity, and the chemical structure of the sample can be better destroyed by the strong acidity of the digester.

[0050] Based on the above embodiment, as an optional implementation manner, the concentrated nitric acid can be selected from commercially available concentrated nitric acid with a mass fraction of 63% to 68%, the concentrated hydrochloric acid can be selected from commercially available concentrated hydrochloric acid with a mass fraction of 36% to 38%, and the concentrated sulfuric acid can be selected from commercially available concentrated sulfuric acid with a mass fraction of 96% to 98%.

[0051] Based on the above embodiment, as an optional implementation, the volume ratio of the sample solution to the digestion agent is 100: 1 to 100: 8. Therefore, the sample solution can be better digested when the usage ratio of the sample solution to the digestion agent is within the above range.

[0052] Step S130, rinsing the digestion product to obtain a rinsing solution, adding a matrix improver to the rinsing solution, and mixing them evenly to obtain a sample solution to be tested.

[0053] Specifically, a rinse agent is added to the digestion product, and the digestion product is rinsed 1 to 3 times to obtain a rinse solution, and a matrix modifier is added to the rinse solution, and the volume is fixed to a preset volume, and after uniform mixing, a sample solution to be tested is obtained. Thus, by rinsing the digestion product, on the one hand, impurities in the digestion product can be removed, and on the other hand, the concentration of acid in the digestion product can be reduced, so as to avoid the acid concentration being too high to affect the accuracy of the test results and corrode the graphite tube. By adding a matrix modifier to the rinse solution, it is beneficial to increase the volatility of sodium chloride in the matrix of the sample solution to be tested, reduce the interference of sodium chloride in the matrix, and at the same time improve the stability of the barium element in the sample solution to be tested, so as to increase the ashing temperature in the graphite furnace atomic absorption spectrometry detection.

[0054] On the basis of the above embodiment, as an optional implementation, the rinse agent is deionized water or an acidic solution, the acidic solution is a nitric acid solution, a sulfuric acid solution or a hydrochloric acid solution, and the volume ratio of the acidic solution is less than 20%. For example, if the volume ratio of the acidic solution is 20%, 20 mL of a higher concentration of acidic solution is taken and diluted to 100 mL with deionized water, wherein the mass fraction of the higher concentration of the acidic solution can be consistent with the mass fraction of the digester, that is, the higher concentration of nitric acid solution can choose a commercially available mass fraction of 63% to 68% of concentrated nitric acid, the higher concentration of hydrochloric acid solution can choose a commercially available mass fraction of 36% to 38% of concentrated hydrochloric acid, and the higher concentration of sulfuric acid solution can choose a commercially available mass fraction of 96% to 98% of concentrated sulfuric acid. Preferably, the acidic solution is the same as the matrix in the barium element standard solution. For example, the matrix in the barium element standard solution is a nitric acid solution, and the acidic solution is a nitric acid solution. Therefore, selecting an acidic solution with the same matrix as that in the barium standard solution is beneficial to reducing the interference of impurities in the sample solution to be tested. The volume ratio of the acidic solution is lower than 20%, which can reduce the risk of the acidic solution corroding the graphite tube.

[0055] Based on the above embodiments, as a preferred implementation, the rinse agent is deionized water, whereby the deionized water can further reduce the acid concentration in the sample solution to be tested and can further reduce the risk of corroding the graphite tube.

[0056] On the basis of the above embodiment, as an optional implementation, the matrix modifier is a combination of one or more of palladium salt solution, ammonium salt solution, nitrate solution and phosphate solution; wherein the palladium salt solution is a combination of one or more of palladium chloride, palladium nitrate and palladium acetate; the ammonium salt solution is ammonium chloride; the nitrate solution is a combination of one or more of barium nitrate, nickel nitrate, magnesium nitrate and lanthanum nitrate; the phosphate solution is cobalt phosphate and / or copper phosphate. Thus, the matrix modifier adopts palladium salt solution or nitrate solution, which can stabilize the sample solution to be tested, prevent signal interference caused by matrix effect, and is conducive to improving the accuracy of the test results; the matrix modifier adopts ammonium salt solution, and ammonium chloride is generated by combining ammonium ions with chloride ions. Ammonium chloride decomposes at high temperature, which can reduce the matrix interference of chloride and is conducive to improving the sensitivity of detection; the matrix modifier adopts phosphate, and phosphate is generated by phosphate and the element to be tested (i.e., barium element) at the initial stage of heating, which is conducive to reducing the volatility of the element to be tested, increasing the ashing temperature, and is conducive to the volatilization of sodium chloride in the matrix, thereby helping to improve the accuracy of the test results.

[0057] In this embodiment, the specific concentration ranges of the palladium salt solution, ammonium salt solution, nitrate solution and phosphate solution are not further limited. Those skilled in the art can set them according to actual conditions. For example, the concentration of the palladium salt solution can be 100 mg / L, the concentration of the ammonium salt solution can be 100 mg / L, the concentration of the nitrate solution can be 20 mg / L, and the concentration of the phosphate solution can be 4 g / L.

[0058] In this embodiment, the amount of the matrix modifier is not further limited, as long as the matrix modifier can be added to the rinse solution and the volume is fixed to the preset capacity. In this embodiment, the preset capacity is not further limited, and those skilled in the art can set it according to actual conditions. For example, the preset capacity can be 25 mL.

[0059] Step S140: Obtain the absorbance of the sample solution to be tested, and determine the content of the barium element in the sample solution to be tested according to the barium element standard curve and the absorbance of the sample solution to be tested.

[0060] Specifically, after obtaining the sample solution to be tested, the sample solution to be tested is detected by graphite furnace atomic absorption spectrometry according to a preset temperature rise program to obtain the absorbance of the sample solution to be tested, and the absorbance of the sample solution to be tested is substituted into the barium element standard curve obtained in step S110 to calculate the content of the barium element in the sample solution to be tested. Thus, the content of the barium element in the sample solution to be tested is determined according to the barium element standard curve and the absorbance of the sample solution to be tested, which can achieve rapid detection of the barium element in the sample solution to be tested and improve detection efficiency.

[0061] Based on the above embodiment, as an optional implementation, the preset temperature increase program in step S110 and step S140 includes:

[0062] The barium standard solution or the sample solution of each concentration is dried at a first temperature for a first preset time, then ashed at a second temperature for a second preset time, then desalted at a third temperature for a third preset time, and then atomized at a fourth temperature for a fourth preset time.

[0063] The heating procedure of the existing graphite furnace atomic absorption method usually includes drying treatment, ashing treatment, atomization treatment and purification treatment. When testing physiological saline samples, it is easily affected by sodium chloride, resulting in double peaks in the test results, which makes it impossible to measure quantitatively. In addition, barium is a high-temperature element. After atomization treatment, it will form carbides that are difficult to dissociate. If the carbides remain on the surface of the graphite tube, they will produce a memory effect and interfere with the test results of the next sample. In this embodiment, by inserting a desalting treatment between the ashing treatment and the atomization treatment, the volatility of sodium chloride in the matrix of the sample solution to be tested can be increased to remove or reduce the sodium chloride in the sample solution to be tested, thereby improving the matrix interference of sodium chloride and the memory effect of the presence of high-temperature elements, so as to achieve quantitative measurement of barium in the sample solution to be tested, and to improve the accuracy of the test results. In addition, this embodiment is improved on the basis of the graphite furnace atomic absorption method, so that the detection method has the advantages of small sampling volume, high sensitivity, good selectivity and low analysis cost of the graphite furnace atomic absorption method itself.

[0064] Based on the above embodiments, as an optional implementation manner, the first temperature is 60°C to 250°C, and the first preset time is 15s to 35s; the second temperature is 400°C to 600°C, and the second preset time is 8s to 25s; the third temperature is 1200°C to 1600°C, and the third preset time is 3s to 5s, and the third temperature is greater than the melting point temperature of the matrix improved product; the fourth temperature is 2200°C to 2700°C, and the third preset time is 3s to 5s. Therefore, setting the first temperature to 60°C to 250°C can evaporate the water in the sample solution to be tested and avoid the loss of barium element; setting the second temperature to 400°C to 600°C can avoid the loss of barium element during ashing treatment; setting the third temperature to 1200°C to 1600°C, and the third temperature is greater than the melting point of the matrix improvement product, which is beneficial to further improve the matrix interference of sodium chloride and the memory effect of the presence of high-temperature elements during desalination treatment, and decompose the matrix improvement product to avoid interference of the matrix improver on the test results; setting the fourth temperature to 2200°C to 2700°C, which is the lowest temperature corresponding to the maximum value of the absorbance signal of the barium element, can balance the absorbance signal and stability of the barium element during atomization treatment.

[0065] On the basis of the above embodiment, as an optional implementation, after the atomization treatment, a cleaning treatment is also included, the cleaning treatment temperature is higher than the fourth temperature, and the cleaning treatment lasts for a fifth preset time, and the fifth preset time is 1s to 2s. Specifically, the cleaning treatment can be adjusted according to the fourth temperature and the fourth preset time of the atomization treatment. If the fourth temperature of the atomization treatment is low, it may cause incomplete atomization of some substances, affecting the accuracy of the next sample test. At this time, it is necessary to increase the cleaning treatment. If the fourth temperature of the atomization treatment is high enough, each substance is fully atomized, and the atomization is complete, then no additional cleaning treatment is required at this time. Therefore, the cleaning treatment is conducive to prolonging the atomization treatment, reducing the residue of carbides on the surface of the graphite tube, and avoiding affecting the accuracy of the next sample test.

[0066] Based on the above embodiment, as an optional implementation manner, the temperature of the cleaning process is 200° C. to 300° C. higher than the fourth temperature.

[0067] On the basis of the above embodiment, as an optional implementation, a cooling treatment is also included between the desalination treatment and the atomization treatment, and the cooling treatment temperature is 600°C, which lasts for the sixth preset time, and the sixth preset time is 5s to 10s. Therefore, by adding the cooling treatment between the desalination treatment and the atomization treatment, on the one hand, the ashing treatment can be extended to avoid insufficient ashing treatment, so that the organic matter and other coexisting substances are not fully decomposed and evaporated, affecting the accuracy of the test results; on the other hand, the cooling treatment can prevent the sample to be tested from being at a high temperature all the time. The high temperature causes the elements in the sample to be tested to undergo oxidation-reduction reactions, change the valence state and content of the elements, and affect the accuracy of the test results; in addition, the continuous high temperature will cause the graphite tube to burn out, affecting the stability and repeatability of the test results.

[0068] The detection method of the barium content in the physiological saline provided in this embodiment first digests the sample solution to improve the solubility and stability of the barium ions, making the barium ions easy to measure, and at the same time improving the detection range and eliminating the influence of chloride ions, and then rinsing the digestion product, and adding a matrix improver to the rinse solution, which can convert the sodium chloride in the matrix of the sample solution to be tested into a volatile compound, which is beneficial to increase the volatility of the sodium chloride in the matrix of the sample solution to be tested, reduce or eliminate the interference of the sodium chloride in the matrix, and at the same time improve the stability of the barium element in the sample solution to be tested, thereby helping to improve the accuracy of the detection of the barium element in the sample solution to be tested. In addition, the content of the barium element in the sample solution to be tested is determined according to the barium element standard curve and the absorbance of the sample solution to be tested, which can realize the rapid detection of the barium element in the sample solution to be tested, improve the detection efficiency, and the detection method is easy to operate, low in labor intensity, low in detection cost, strong in operability, high in detection automation, and high in practical value.

[0069] In order to further explain the present invention in detail, the present invention will be further explained in conjunction with specific examples. The experimental methods used in the examples of the present invention are conventional methods unless otherwise specified; the materials, reagents, etc. used in the examples of the present invention are purchased from the market unless otherwise specified.

[0070] Example 1

[0071] This embodiment provides a method for detecting the content of barium in physiological saline, comprising the following steps:

[0072] (1) Establish a barium standard curve: Accurately measure 1 mL of a 100 mg / L barium standard solution and quantitatively dilute it with a 1% nitric acid solution to prepare a 10 μg / mL barium standard intermediate solution. Accurately pipette 0.05 mL, 0.1 mL, 0.2 mL, 0.3 mL, 0.4 mL, and 0.5 mL of the 10 μg / mL barium standard intermediate solution into six 10 mL volumetric flasks, dilute to the mark with a 1% nitric acid solution, shake well, and prepare a series of barium standard solutions with concentrations of 0.05 μg / mL, 0.1 μg / mL, 0.2 μg / mL, 0.3 μg / mL, 0.4 μg / mL, and 0.5 μg / mL, respectively.

[0073] A series of prepared barium standard solutions were introduced into the corresponding atomizers in order of mass concentration from low to high, and the barium standard solutions of various concentrations were detected by graphite furnace atomic absorption method according to the following preset temperature program: drying treatment at 60°C to 250°C for 33s, ashing treatment at 600°C for 10s, desalting treatment at 1600°C for 3s, cooling to 600°C for 10s, and atomization treatment at 2700°C and maintained for 3s. The absorbance of the barium standard solutions of various concentrations was measured; the barium standard curve was obtained by fitting, with the mass concentration of barium in a series of barium standard solutions as the horizontal coordinate and the corresponding absorbance as the vertical coordinate.

[0074] (2) Take 25 mL of the physiological saline sample solution to be measured in a porcelain crucible, add 1 mL of digester for every 100 mL of sample solution, the digester is a nitric acid solution with a concentration greater than 10 g / L, heat the sample solution in a water bath, and set the water bath temperature between 98°C and 99°C to allow the sample solution to evaporate slowly and not boil or splash while evaporating to dryness. During the digestion process, place the sample solution in a fume hood and keep it ventilated. After the sample solution is completely evaporated to dryness, stop heating to obtain a digestion product, take out the digestion product and cool it to room temperature.

[0075] (3) Use an appropriate amount of 1% nitric acid solution to dissolve and rinse the digestion product to obtain a rinse solution, transfer the rinse solution to a 25 mL volumetric flask, add 100 mg / L palladium salt solution and dilute to 25 mL to obtain a sample solution to be tested.

[0076] (4) The sample solution to be tested in step (3) is introduced into the atomizer for on-machine testing. The sample solution to be tested in step (3) is tested by graphite furnace atomic absorption method according to the following preset temperature program: drying treatment at 60°C to 250°C for 33 seconds, ashing treatment at 600°C for 10 seconds, desalting treatment at 1600°C for 3 seconds, cooling to 600°C for 10 seconds, atomization treatment at 2700°C and maintaining for 3 seconds, and the absorbance of the sample solution to be tested is measured. The absorbance of the sample solution to be tested is brought into the barium element standard curve for calculation to obtain the barium element content in the sample solution to be tested.

[0077] Figure 2 is the absorbance detection result of the sample solution to be tested in this embodiment, Figure 2 It can be seen that Figure 2 Only a single peak appeared in the sample solution to be tested, indicating that after the sample solution to be tested was treated, the interference of sodium chloride in the sample solution to be tested could be avoided, which is beneficial to improving the accuracy of the test results.

[0078] Example 2

[0079] This embodiment provides a method for detecting the content of barium in physiological saline, comprising the following steps:

[0080] (1) The method for establishing the barium element standard curve is the same as that in Example 1, except that when measuring the absorbance of the barium element standard solution of each concentration, the barium element standard solution of each concentration is detected according to the following preset temperature program: drying treatment at 60°C to 250°C for 33 seconds, ashing treatment at 600°C for 10 seconds, desalting treatment at 1200°C for 5 seconds, cooling treatment to 600°C for 10 seconds, and atomization treatment at 2700°C and maintaining for 3 seconds.

[0081] (2) Take 25 mL of the physiological saline sample solution to be measured in a porcelain crucible, add 2 mL of digester for every 25 mL of sample solution, the digester is a nitric acid solution with a concentration greater than 10 g / L, heat the sample solution in a water bath, and set the water bath temperature between 98°C and 99°C to allow the sample solution to evaporate slowly and not boil and splash while evaporating to dryness. During the digestion process, place the sample solution in a fume hood and keep it ventilated. After the sample solution is completely evaporated to dryness, stop heating to obtain a digestion product, take out the digestion product and cool it to room temperature.

[0082] (3) Use an appropriate amount of 1% nitric acid solution to dissolve and rinse the digestion product to obtain a rinse solution, transfer the rinse solution to a 25 mL volumetric flask, add 100 mg / L ammonium chloride solution and dilute to 25 mL to obtain the sample solution to be tested.

[0083] (4) The sample solution to be tested in step (3) is introduced into the atomizer for on-machine testing. The sample solution to be tested in step (3) is tested by graphite furnace atomic absorption method according to the following preset temperature program: drying treatment at 60°C to 250°C for 33 seconds, ashing treatment at 600°C for 10 seconds, desalting treatment at 1200°C for 5 seconds, cooling to 600°C for 10 seconds, atomization treatment at 2700°C and maintaining for 3 seconds, and the absorbance of the sample solution to be tested is measured. The absorbance of the sample solution to be tested is brought into the barium element standard curve for calculation to obtain the barium element content in the sample solution to be tested.

[0084] Figure 3 is the absorbance detection result of the sample solution to be tested in this embodiment, Figure 3 It can be seen that Figure 3 Only a single peak appeared in the sample solution to be tested, indicating that after the sample solution to be tested was treated, the interference of sodium chloride in the sample solution to be tested could be avoided, which is beneficial to improving the accuracy of the test results.

[0085] Example 3

[0086] This embodiment provides a method for detecting the content of barium in physiological saline, comprising the following steps:

[0087] (1) The method for establishing the barium element standard curve is the same as that in Example 1, except that, when determining the absorbance of the barium element standard solution of each concentration, the barium element standard solution of each concentration is detected according to the following preset temperature program: drying treatment at 60°C to 250°C for 30 seconds, ashing treatment at 600°C for 10 seconds, desalting treatment at 1600°C for 5 seconds, cooling treatment to 600°C for 5 seconds, atomization treatment at 2200°C and holding for 3 seconds, and cleaning treatment at 2500°C and holding for 2 seconds.

[0088] (2) Take 25 mL of the physiological saline sample solution to be measured in a porcelain crucible, add 2 mL of digester for every 25 mL of sample solution, the digester is a 20% by volume hydrochloric acid solution (a 38% by mass concentrated hydrochloric acid solution is diluted with deionized water to a volume ratio of 20%), heat the sample solution in a water bath, and set the water bath temperature between 98°C and 99°C to allow the sample solution to evaporate slowly and not boil and splash while evaporating. During the digestion process, place the sample solution in a fume hood and keep it ventilated. After the sample solution is completely evaporated, stop heating to obtain a digestion product, take out the digestion product and cool it to room temperature.

[0089] (3) Dissolve and rinse the digestion product 2 to 3 times with an appropriate amount of deionized water to obtain a rinse solution, transfer the rinse solution to a 25 mL volumetric flask, add 20 mg / L lanthanum nitrate solution and dilute to 25 mL to obtain the sample solution to be tested.

[0090] (4) The sample solution to be tested in step (3) is introduced into the atomizer for on-machine testing, and the sample solution to be tested in step (3) is detected by graphite furnace atomic absorption method according to the following preset temperature program: drying treatment at 60°C to 250°C for 30s, ashing treatment at 600°C for 10s, desalting treatment at 1600°C for 5s, cooling to 600°C for 5s, atomization treatment at 2200°C and maintaining for 3s, and cleaning treatment at 2500°C and maintaining for 2s, and the absorbance of the sample solution to be tested is measured. The absorbance of the sample solution to be tested is brought into the barium element standard curve for calculation to obtain the content of barium element in the sample solution to be tested.

[0091] Figure 4 is the absorbance detection result of the sample solution to be tested in this embodiment, Figure 4 It can be seen that Figure 4 Only a single peak appeared in the sample solution to be tested, indicating that after the sample solution to be tested was treated, the interference of sodium chloride in the sample solution to be tested could be avoided, which is beneficial to improving the accuracy of the test results.

[0092] Example 4

[0093] This embodiment provides a method for detecting the content of barium in physiological saline, comprising the following steps:

[0094] (1) The method for establishing the barium element standard curve is the same as that in Example 1, except that when determining the absorbance of the barium element standard solution of each concentration, the barium element standard solution of each concentration is detected according to the following preset temperature program: drying treatment at 60°C to 250°C for 33 seconds, ashing treatment at 600°C for 10 seconds, desalting treatment at 1600°C for 3 seconds, cooling treatment to 600°C for 10 seconds, atomization treatment at 2200°C and holding for 3 seconds, and cleaning treatment at 2500°C and holding for 2 seconds.

[0095] (2) Take 25 mL of the physiological saline sample solution to be measured in a porcelain crucible, add 2 mL of a digester per 25 mL of the sample solution, the digester is a 5% by volume sulfuric acid solution (a 98% by mass concentrated sulfuric acid solution is diluted with deionized water to a volume ratio of 5%), heat the sample solution in a water bath, and set the water bath temperature between 98°C and 99°C to allow the sample solution to evaporate slowly, and not to boil and splash while evaporating to dryness, and place the sample solution in a fume hood during the digestion process, and keep it ventilated. After the sample solution is completely evaporated to dryness, stop heating to obtain a digestion product, take out the digestion product and cool it to room temperature. During the digestion process, the 5% sulfuric acid solution complexes with the barium ions in the sample solution to form a stable barium sulfate complex and replace the chloride ions, then add 2 mL of concentrated nitric acid to the digestion product, and heat at a low temperature until the nitric acid is completely volatilized, and the nitric acid can fully digest the chloride ions in the sample solution.

[0096] (3) Dissolve and rinse the digestion product with an appropriate amount of 5% sulfuric acid solution for 2 to 3 times to obtain a rinse solution, transfer the rinse solution to a 25 mL volumetric flask, add a 4 g / L diammonium phosphate solution and dilute to 25 mL to obtain a sample solution to be tested, wherein the volume ratio of the 5% sulfuric acid solution in the sample solution to be tested is less than 20%.

[0097] (4) The sample solution to be tested in step (3) is introduced into the atomizer for on-machine testing, and the sample solution to be tested in step (3) is detected by graphite furnace atomic absorption method according to the following preset temperature program: drying treatment at 60°C to 250°C for 33 seconds, ashing treatment at 600°C for 10 seconds, desalting treatment at 1600°C for 3 seconds, cooling to 600°C for 10 seconds, atomization treatment at 2200°C and maintaining for 3 seconds, and cleaning treatment at 2500°C and maintaining for 2 seconds, and the absorbance of the sample solution to be tested is measured. The absorbance of the sample solution to be tested is brought into the barium element standard curve for calculation to obtain the barium element content in the sample solution to be tested.

[0098] Figure 5 is the absorbance detection result of the sample solution to be tested in this embodiment, Figure 5 It can be seen that Figure 5 Only a single peak appeared in the sample solution to be tested, indicating that after the sample solution to be tested was treated, the interference of sodium chloride in the sample solution to be tested could be avoided, which is beneficial to improving the accuracy of the test results.

[0099] Comparative Example

[0100] This comparative example provides a method for detecting the content of barium in physiological saline, comprising the following steps:

[0101] (1) The method for establishing the barium element standard curve is the same as that in Example 1, except that when measuring the absorbance of the barium element standard solution of each concentration, the barium element standard solution of each concentration is detected according to the following preset temperature program: drying treatment at 60°C to 250°C for 33 seconds, ashing treatment at 600°C for 23 seconds, atomization treatment at 2200°C and holding for 3 seconds, and cleaning treatment at 2500°C and holding for 2 seconds.

[0102] (2) Take 25 mL of the physiological saline sample solution to be measured in a porcelain crucible, add 2 mL of digester for every 25 mL of sample solution, the digester is a nitric acid solution with a concentration of 10 g / L, heat the sample solution in a water bath, and set the water bath temperature between 98°C and 99°C to allow the sample solution to evaporate slowly and not boil and splash while evaporating to dryness. During the digestion process, place the sample solution in a fume hood and keep it ventilated. After the sample solution is completely evaporated to dryness, stop heating to obtain the digestion product, take out the digestion product and cool it to room temperature.

[0103] (3) Use an appropriate amount of 5% nitric acid solution to dissolve and rinse the digestion product 2 to 3 times to obtain a rinse solution, transfer the rinse solution to a 25 mL volumetric flask to obtain the sample solution to be tested.

[0104] (4) The sample solution to be tested in step (3) is introduced into the atomizer for on-machine testing. The sample solution to be tested in step (3) is tested by graphite furnace atomic absorption method according to the following preset temperature program: drying treatment at 60°C to 250°C for 33 seconds, ashing treatment at 600°C for 23 seconds, atomization treatment at 2200°C and maintained for 3 seconds, and cleaning treatment at 2500°C and maintained for 2 seconds, and the absorbance of the sample solution to be tested is measured. The absorbance of the sample solution to be tested is brought into the barium element standard curve for calculation to obtain the barium element content in the sample solution to be tested.

[0105] Figure 6 is the absorbance test result of the sample solution to be tested in this comparative example, Figure 6 It can be seen that Figure 6 A double peak appeared in the sample solution to be tested, and atomic absorption is quantified by peak height. The appearance of double peaks indicates that the interference peak of sodium chloride in the sample solution to be tested will affect the quantitative detection of low-concentration samples, which is not conducive to improving the accuracy of the test results.

[0106] The sample solution to be tested in Example 1 was used as a blank test solution, and 0.05 μg / mL barium element standard solution was added to the blank test solution as a low-concentration barium element standard solution, 0.2 μg / mL barium element standard solution was added to the blank test solution as a medium-concentration barium element standard solution, and 0.4 μg / mL barium element standard solution was added to the blank test solution as a high-concentration barium element standard solution. The low, medium and high concentration barium element standard solutions were pretreated by the method in Example 1 and used as sample solutions to detect absorbance and barium element concentration. Each concentration was measured 3 times in parallel, and the recovery rate and CV value (coefficient of variation) of the detection method in Example 1 were calculated to obtain the results shown in Table 1.

[0107] Table 1

[0108]

[0109] As can be seen from Table 1, the blank test solution low, medium and high spiked samples were measured three times, and the recoveries were 98.2% to 107.1%, 95.8% to 103.3% and 96.2% to 103.2%, respectively, and the laboratory coefficient of variation CV values ​​were 4.4%, 4.2% and 3.7%, respectively, which met the requirements of GB / T 27417-2017 "Guidelines for Confirmation and Validation of Chemical Analysis Methods for Conformity Assessment". It shows that the detection results of the detection method provided in this embodiment are accurate and reliable.

[0110] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for detecting the content of barium in physiological saline, characterized in that: The steps include: Prepare barium standard solutions of different concentrations, obtain the absorbance of the barium standard solutions of various concentrations, and establish a barium standard curve according to the absorbance and the concentration of the barium standard solutions; Obtaining a sample solution, adding a digestion agent to the sample solution, performing a digestion treatment on the sample solution under heating conditions, evaporating the sample solution, and obtaining a digestion product; Rinsing the digestion product to obtain a rinse solution, adding a matrix improver to the rinse solution, and mixing them evenly to obtain a sample solution to be tested; The absorbance of the sample solution to be tested is obtained, and the content of the barium element in the sample solution to be tested is determined according to the barium element standard curve and the absorbance of the sample solution to be tested.

2. The detection method according to claim 1, characterized in that: The step of adding a digestion agent to the sample solution, performing a digestion treatment on the sample solution under heating conditions, evaporating the sample solution, and obtaining a digestion product comprises: Add a digestion agent to the sample solution, perform a digestion treatment on the sample solution in a constant temperature water bath, evaporate the sample solution to near dryness, and obtain a digestion product, wherein the temperature of the constant temperature water bath is 98° C. to 99° C.; During the digestion process, the space where the sample solution is located is kept ventilated.

3. The detection method according to claim 1 or 2, characterized in that: The digestion agent is a monoacid digestion oxidant, and the volume ratio of the sample solution to the digestion agent is 100:1 to 100:

8.

4. The detection method according to claim 1, characterized in that: The step of rinsing the digestion product to obtain a rinsing solution comprises: A rinse agent is added to the digestion product, and the digestion product is rinsed 1 to 3 times to obtain a rinse solution, wherein the rinse agent is deionized water or an acidic solution, and the acidic solution is a nitric acid solution, a sulfuric acid solution or a hydrochloric acid solution, and the volume ratio of the acidic solution is less than 20%.

5. The detection method according to claim 1, characterized in that: The matrix improver is a combination of one or more of a palladium salt solution, an ammonium salt solution, a nitrate solution and a phosphate solution; The palladium salt solution is a combination of one or more of palladium chloride, palladium nitrate and palladium acetate; The ammonium salt solution is ammonium chloride; The nitrate solution is a combination of one or more of barium nitrate, nickel nitrate, magnesium nitrate and lanthanum nitrate; The phosphate solution is cobalt phosphate and / or copper phosphate.

6. The detection method according to claim 1, characterized in that: Using graphite furnace atomic absorption spectrometry, the barium standard solutions of various concentrations are detected according to a preset temperature increase program to obtain the absorbance of the barium standard solutions of various concentrations; The sample solution to be tested is detected according to the preset temperature increase program using a graphite furnace atomic absorption spectrometry to obtain the absorbance of the sample solution to be tested.

7. The detection method according to claim 6, characterized in that: The preset temperature rise program includes: The barium standard solutions of various concentrations or the sample solutions to be tested are dried at a first temperature for a first preset time, then ashed at a second temperature for a second preset time, then desalinated at a third temperature for a third preset time, and then atomized at a fourth temperature for a fourth preset time.

8. The detection method according to claim 7, characterized in that: The first temperature is 60° C. to 250° C., and the first preset time is 15s to 35s; The second temperature is 400° C. to 600° C., and the second preset time is 8s to 25s; The third temperature is 1200° C. to 1600° C., the third preset time is 3s to 5s, and the third temperature is greater than the melting point of the substrate-improved product; The fourth temperature is 2200° C. to 2700° C., and the third preset time is 3s to 5s.

9. The detection method according to claim 7, characterized in that: After the atomization process, a cleaning process is further included. The cleaning process temperature is higher than the fourth temperature and lasts for a fifth preset time period, and the fifth preset time period is 1 second to 2 seconds.

10. The detection method according to claim 7, characterized in that: A cooling treatment is also included between the desalination treatment and the atomization treatment. The cooling treatment temperature is 600° C. and lasts for a sixth preset time period. The sixth preset time period is 5s to 10s.

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