Method for cleaning organic matters in ICP (inductively coupled plasma) central tube

Abstract

The invention discloses a method for cleaning organic matters in an ICP (inductively coupled plasma) central tube, which belongs to the technical field of ICPs and comprises the following steps: S1, cleaning the organic matters; s2, aqua regia preparation; and S3, carbonized organic matter removal: horizontally placing the ICP central tube in a beaker, pouring the prepared aqua regia to immerse the ICP central tube, placing the beaker in a fuming cupboard to soak for 2.0-3.0 hours, taking out the ICP central tube after the carbonized organic matter in the ICP central tube is completely removed, cleaning the ICP central tube with distilled water, and drying the ICP central tube. According to the method, firstly, the mixed solution of methylbenzene and acetone is used for cleaning organic matter easy to remove so as to maintain the activity of aqua regia in the next step, then the aqua regia with extremely high chemical properties such as corrosivity, solubility and oxidability is used for oxidizing and removing carbonized organic matter in the ICP central pipe, meanwhile, metal oxide is dissolved in the solution, the material of the ICP central pipe is not damaged, and the method is suitable for industrial production. And the effects of cleaning the central pipe and prolonging the service life are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of ICP, and in particular to a method for cleaning organic matter in an ICP central tube. Background Art

[0002] The ICP center tube is a key component used in ICP-OES (Inductively Coupled Plasma-Atomic Emission Spectrometer), and its main function is to transport sample aerosols to the plasma area. ICP center tubes are widely used in various fields, including nanotechnology, catalysis, energy, chemical industry, biology, geology, environmental protection, medicine, food, metallurgy and agriculture. It is mainly used for elemental analysis and quantitative analysis of samples, and can analyze more than 70 elements in the periodic table. However, during the use of the ICP center tube to determine organic matter such as gasoline and diesel, carbonized organic matter will be deposited at the cone of the center tube, and gasoline, diesel, colloids, etc. will stick to the inner wall, so it needs to be washed after use.

[0003] The conventional method for washing the central tube generally involves heating and boiling a mixture of concentrated nitric acid and hydrochloric acid and then washing with water. However, this method is difficult to wash away the deposited carbonized organic matter, thus rendering the central tube unusable.

[0004] For example, the prior art CN201810764511 discloses a method for washing an ICP central tube, comprising: first washing the ICP central tube by heating and boiling it with a sodium hydroxide solution, and then washing it by heating and boiling it with concentrated hydrochloric acid. The present invention can better remove the sediment on the ICP central tube by first washing it by heating and boiling it with a sodium hydroxide solution and then washing it by heating and boiling it with concentrated hydrochloric acid. The method provided by the present invention is for washing the deposited carbonized organic matter at the nozzle of the ICP central tube, and has a fast washing speed and high cleaning quality, and can extend the service life of the ICP central tube.

[0005] The main cleaning object of the prior art is the inorganic salts in the ICP central tube, which plays a role in cleaning and removing the inorganic salts. However, when the ICP measures organic matter such as gasoline and diesel, the organic matter such as gasoline and diesel in the central tube will accumulate on the inner wall of the central tube to form carbonized organic matter due to high temperature carbonization. When the central tube is cleaned by the existing method, the cleaning effect on the organic matter is small. Therefore, in view of the problem that carbonized organic matter is difficult to clean, the present invention solves the problem of carbonized accumulated organic matter when the ICP central tube measures gasoline and diesel.

[0006] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0007] The purpose of the present invention is to provide a method for cleaning organic matter in an ICP central tube, by which the carbonized and accumulated organic matter in the ICP central tube when measuring gasoline and diesel can be effectively cleaned.

[0008] To achieve the above object, the present invention provides a method for clearing organic matter from an ICP central tube, the method comprising the following steps:

[0009] S1, organic cleaning: soak the ICP center tube in a mixed solution of toluene and acetone to remove organic matter such as gasoline, diesel, colloid, etc. on the center tube wall, take it out and dry it;

[0010] S2, aqua regia preparation: mixing, stirring and cooling concentrated nitric acid and concentrated hydrochloric acid to prepare aqua regia;

[0011] S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to immerse the ICP central tube, soak it in a fume hood, and take it out after the carbonized organic matter in the ICP central tube is completely removed, rinse it with distilled water, and let it dry.

[0012] In an optional embodiment, in S1, the volume ratio of toluene to acetone is 1:1, and the purity of toluene and acetone is above analytical grade.

[0013] In an optional embodiment, in S1, the ICP central tube is immersed in a mixed solution of toluene and acetone for about 30 to 60 minutes.

[0014] In an optional embodiment, in S2, the aqua regia preparation includes the following steps: pouring concentrated nitric acid into a container in a fume hood, then slowly pouring concentrated hydrochloric acid into the concentrated nitric acid, and slowly stirring to obtain aqua regia, and after the mixed liquid is cooled to room temperature, it can be used.

[0015] In an optional embodiment, in S2, the mixture is stirred and cooled uniformly to obtain aqua regia.

[0016] In an optional embodiment, in S2, the volume ratio of concentrated nitric acid to concentrated hydrochloric acid is 3:1.

[0017] In an optional embodiment, in S2, the concentrations of concentrated nitric acid and concentrated hydrochloric acid are 65% to 70% and 36% to 38%, respectively.

[0018] In an optional embodiment, in S3, the sample is placed in a fume hood and soaked for 2 to 3 hours.

[0019] In an optional embodiment, in S2, the concentrations of concentrated nitric acid and concentrated hydrochloric acid are 68% and 37%, respectively.

[0020] In an optional embodiment, the organic matter is one or more of gasoline, diesel, and colloid.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] In the specific method of the present invention, a mixed solution of toluene and acetone is first used to clean the easily removable organic matter to maintain the activity of aqua regia in the next step, and then aqua regia with strong chemical properties such as corrosiveness, solubility, and oxidizing properties is used to oxidize and remove the carbonized organic matter in the ICP central tube, and at the same time, the metal oxide is dissolved in the solution without damaging the material of the ICP central tube, thereby cleaning the central tube and extending its service life;

[0023] Furthermore, using a mixed solution of toluene and acetone to pre-treat the easily removable organic matter on the central tube wall helps to maintain the activity of aqua regia in the next step when removing the carbonized organic matter, so that the carbonized organic matter can be removed more thoroughly;

[0024] Furthermore, the strong oxidizing property of aqua regia is used to oxidize and decompose various organic matters such as carbonized organic matters on the inner wall of the ICP central tube, thus overcoming the disadvantage that the carbonized organic matters cannot be cleaned in the prior art.

[0025] Furthermore, the strong solubility of aqua regia is utilized to dissolve the metal oxides on the inner wall and the nozzle of the ICP central tube in the solution, thereby omitting the steps of washing by heating and boiling with a sodium hydroxide solution and then washing by heating and boiling with concentrated hydrochloric acid in the prior art. Firstly, the steps are optimized and the cleaning efficiency is improved, and secondly, the difficulty that some substances cannot be dissolved by a single concentrated alkali or concentrated acid is overcome.

[0026] Furthermore, the strong corrosiveness of aqua regia is used to corrode and dissolve certain substances in the ICP central tube, which also overcomes the difficulty that certain substances cannot be dissolved by a single concentrated alkali or concentrated acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure is a schematic flow chart of a method for washing organic matter in an ICP central tube according to an embodiment of the present invention.

[0028] Specific implementation logic

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0032] like Figure 1 As shown, the present invention discloses a method for washing organic matter in an ICP central tube, the method comprising the following steps: S1, organic matter cleaning -> S2, aqua regia preparation -> S3, carbonized organic matter removal to clean up, wherein,

[0033] The organic cleaning is as follows: the ICP central tube is immersed in a mixed solution of toluene and acetone to remove organic matter such as gasoline, diesel, colloid, etc. on the central tube wall, and then taken out and dried;

[0034] The aqua regia is prepared by mixing concentrated nitric acid and concentrated hydrochloric acid, stirring, and cooling to obtain the aqua regia;

[0035] The carbonized organic matter removal is as follows: the ICP central tube is horizontally placed in a beaker, the aqua regia prepared just above is poured in to submerge the ICP central tube, and the tube is placed in a fume hood for soaking. After the carbonized organic matter in the ICP central tube is completely removed, the tube is taken out, cleaned with distilled water, and cooled and dried.

[0036] The invention uses a mixed solution of toluene and acetone to clean easily removable organic matter first, so as to maintain the activity of aqua regia in the next step, and then uses aqua regia with strong chemical properties such as corrosiveness, solubility and oxidizing properties to oxidize and remove carbonized organic matter in the ICP central tube, and dissolves metal oxides in the solution without damaging the material of the ICP central tube, thereby cleaning the central tube and extending its service life.

[0037] Example 1

[0038] The present invention provides a method for washing organic matter in an ICP central tube, the method comprising the following steps:

[0039] S1, organic cleaning: Soak the ICP center tube in a mixed solution of 150 mL toluene and 150 mL acetone for 30 minutes to remove organic matter such as gasoline, diesel, and colloid on the center tube wall, and then take it out and dry it;

[0040] S2, aqua regia preparation: Pour 300 mL of concentrated nitric acid into a container in a fume hood, then slowly pour 100 mL of concentrated hydrochloric acid into the concentrated nitric acid, stirring constantly to prevent the reaction from being too violent, and stir evenly to obtain aqua regia, wherein the concentration of concentrated nitric acid in the aqua regia is 65%, and the concentration of concentrated hydrochloric acid is 36%;

[0041] In this embodiment, concentrated nitric acid is poured into a container in a fume hood, and then concentrated hydrochloric acid is slowly poured into the concentrated nitric acid, and slowly stirred to obtain aqua regia. After the mixed liquid is cooled to room temperature, it can be used;

[0042] S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to submerge the ICP central tube, and soak it in a fume hood for 2.0 hours. After the carbonized organic matter in the ICP central tube is completely removed, take it out, rinse it with distilled water, and let it dry.

[0043] Example 2

[0044] The present invention provides a method for washing organic matter in an ICP central tube, the method comprising the following steps:

[0045] S1, organic cleaning: Soak the ICP center tube in a mixed solution of 200 mL toluene and 200 mL acetone for 45 minutes to remove organic matter such as gasoline, diesel, and colloid on the center tube wall, and then take it out and dry it;

[0046] S2, aqua regia preparation: Pour 360 mL of concentrated nitric acid into a container in a fume hood, then slowly pour 120 mL of concentrated hydrochloric acid into the concentrated nitric acid while stirring constantly to prevent the reaction from being too violent, and stir evenly to obtain aqua regia, wherein the concentration of concentrated nitric acid in the aqua regia is 68%, and the concentration of concentrated hydrochloric acid is 37%;

[0047] In this embodiment, concentrated nitric acid is poured into a container in a fume hood, and then concentrated hydrochloric acid is slowly poured into the concentrated nitric acid, and slowly stirred to obtain aqua regia. After the mixed liquid is cooled to room temperature, it can be used;

[0048] S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to immerse the ICP central tube, and soak it in a fume hood for 2.5 hours. After the carbonized organic matter in the ICP central tube is completely removed, take it out, rinse it with distilled water, and let it dry.

[0049] Example 3

[0050] The present invention provides a method for washing organic matter in an ICP central tube, the method comprising the following steps:

[0051] S1, organic cleaning: Soak the ICP center tube in a mixed solution of 300 mL toluene and 300 mL acetone for 50 minutes to remove organic matter such as gasoline, diesel, and colloid on the center tube wall, and then take it out and dry it;

[0052] S2, aqua regia preparation: Pour 420 mL of concentrated nitric acid into a container in a fume hood, then slowly pour 140 mL of concentrated hydrochloric acid into the concentrated nitric acid while stirring constantly to prevent the reaction from being too violent, and stir evenly to obtain aqua regia, wherein the concentration of concentrated nitric acid in the aqua regia is 70%, and the concentration of concentrated hydrochloric acid is 38%;

[0053] In this embodiment, concentrated nitric acid is poured into a container in a fume hood, and then concentrated hydrochloric acid is slowly poured into the concentrated nitric acid, and slowly stirred to obtain aqua regia. After the mixed liquid is cooled to room temperature, it can be used;

[0054] S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to submerge the ICP central tube, and soak it in a fume hood for 2.8 hours. After the carbonized organic matter in the ICP central tube is completely removed, take it out, rinse it with distilled water, and let it dry.

[0055] Example 4

[0056] The present invention provides a method for washing organic matter in an ICP central tube, the method comprising the following steps:

[0057] S1, organic cleaning: Soak the ICP center tube in a mixed solution of 250 mL toluene and 250 mL acetone for 45 minutes to remove organic matter such as gasoline, diesel, and colloid on the center tube wall, and then take it out and dry it;

[0058] S2, aqua regia preparation: Pour 300 mL of concentrated nitric acid into a container in a fume hood, then slowly pour 100 mL of concentrated hydrochloric acid into the concentrated nitric acid, stirring constantly to prevent the reaction from being too violent, and stirring evenly to obtain aqua regia, wherein the concentration of concentrated nitric acid in the aqua regia is 68%, and the concentration of concentrated hydrochloric acid is 38%;

[0059] In this embodiment, concentrated nitric acid is poured into a container in a fume hood, and then concentrated hydrochloric acid is slowly poured into the concentrated nitric acid, and slowly stirred to obtain aqua regia. After the mixed liquid is cooled to room temperature, it can be used;

[0060] S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to submerge the ICP central tube, and soak it in a fume hood for 3 hours. After the carbonized organic matter in the ICP central tube is completely removed, take it out, rinse it with distilled water, and let it dry.

[0061] Example 5

[0062] The present invention provides a method for washing organic matter in an ICP central tube, the method comprising the following steps:

[0063] S1, organic cleaning: Soak the ICP center tube in a mixed solution of 200 mL toluene and 200 mL acetone for 45 minutes to remove organic matter such as gasoline, diesel, and colloid on the center tube wall, and then take it out and dry it;

[0064] S2, aqua regia preparation: Pour 420 mL of concentrated nitric acid into a container in a fume hood, then slowly pour 140 mL of concentrated hydrochloric acid into the concentrated nitric acid while stirring constantly to prevent the reaction from being too violent, and stir evenly to obtain aqua regia, wherein the concentration of concentrated nitric acid in the aqua regia is 70%, and the concentration of concentrated hydrochloric acid is 37%;

[0065] In this embodiment, concentrated nitric acid is poured into a container in a fume hood, and then concentrated hydrochloric acid is slowly poured into the concentrated nitric acid, and slowly stirred to obtain aqua regia. After the mixed liquid is cooled to room temperature, it can be used;

[0066] S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to submerge the ICP central tube, and soak it in a fume hood for 3 hours. After the carbonized organic matter in the ICP central tube is completely removed, take it out, rinse it with distilled water, and let it dry.

[0067] Example 6

[0068] The present invention provides a method for washing organic matter in an ICP central tube, the method comprising the following steps:

[0069] S1, organic cleaning: Soak the ICP center tube in a mixed solution of 380 mL toluene and 380 mL acetone for 60 minutes to remove organic matter such as gasoline, diesel, and colloid on the center tube wall, and then take it out and dry it;

[0070] S2, aqua regia preparation: Pour 510 mL of concentrated nitric acid into a container in a fume hood, then slowly pour 170 mL of concentrated hydrochloric acid into the concentrated nitric acid while stirring constantly to prevent the reaction from being too violent, and stir evenly to obtain aqua regia, wherein the concentration of concentrated nitric acid in the aqua regia is 68%, and the concentration of concentrated hydrochloric acid is 36%;

[0071] In this embodiment, concentrated nitric acid is poured into a container in a fume hood, and then concentrated hydrochloric acid is slowly poured into the concentrated nitric acid, and slowly stirred to obtain aqua regia. After the mixed liquid is cooled to room temperature, it can be used;

[0072] S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to submerge the ICP central tube, and soak it in a fume hood for 3 hours. After the carbonized organic matter in the ICP central tube is completely removed, take it out, rinse it with distilled water, and let it dry.

[0073] Comparative Example 1

[0074] Different from Example 2, only toluene is used in step S1 without using acetone.

[0075] Comparative Example 2

[0076] The difference from Example 2 is that in step S2, concentrated nitric acid is replaced by sodium hydroxide.

[0077] Comparative Example 3

[0078] The difference from Example 2 is that only toluene is used in step S1, and toluene is not used.

[0079] Comparative Example 4

[0080] The difference from Example 2 is that in step S2, concentrated hydrochloric acid is replaced by sodium hydroxide.

[0081] Comparative Example 5

[0082] The difference from Example 2 is that the S1 step is missing.

[0083] The ICP central tube was cleaned using Examples 1-6 and Comparative Examples 1-4, and the cleaning conditions were observed and tested as shown in the following table:

[0084]

[0085]

[0086] From the above comparison, it can be seen that pre-treating the easily removable organic matter on the central tube wall with a mixed solution of toluene and acetone helps to maintain the activity of aqua regia in the next step when removing the carbonized organic matter, making the removal of the carbonized organic matter more thorough.

[0087] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for cleaning organic matter in an ICP central tube, characterized in that: The method comprises the following steps: S1, organic matter cleaning: soak the ICP central tube in a mixed solution of toluene and acetone to remove organic matter on the central tube wall, take it out and dry it; S2, aqua regia preparation: mixing, stirring and cooling concentrated nitric acid and concentrated hydrochloric acid to prepare aqua regia; S3, removal of carbonized organic matter: Place the ICP central tube horizontally in a beaker, pour in the aqua regia prepared above to immerse the ICP central tube, soak it in a fume hood, and take it out after the carbonized organic matter in the ICP central tube is completely removed, rinse it with distilled water, and let it dry.

2. A method for cleaning organic matter in an ICP central tube according to claim 1, characterized in that: In S1, the volume ratio of toluene to acetone is 1:1, and the purity of toluene and acetone is above analytical grade.

3. A method for cleaning organic matter in an ICP central tube according to claim 1, characterized in that: In S1, the ICP center tube is immersed in a mixed solution of toluene and acetone for about 30 to 60 minutes.

4. A method for cleaning organic matter in an ICP central tube according to claim 1, characterized in that: In S2, the aqua regia preparation includes the following steps: pouring concentrated nitric acid into a container in a fume hood, then slowly pouring concentrated hydrochloric acid into the concentrated nitric acid, and slowly stirring to obtain aqua regia, and after the mixed liquid is cooled to room temperature, it can be used.

5. A method for cleaning organic matter in an ICP central tube according to claim 4, characterized in that: In S2, aqua regia is just prepared and then cooled.

6. A method for cleaning organic matter in an ICP central tube according to claim 4, characterized in that: In S2, the volume ratio of concentrated nitric acid to concentrated hydrochloric acid is 3:

1.

7. A method for cleaning organic matter in an ICP central tube according to claim 4, characterized in that: In S2, the concentrations of concentrated nitric acid and concentrated hydrochloric acid are 65% to 70% and 36% to 38%, respectively.

8. A method for cleaning organic matter in an ICP central tube according to claim 4, characterized in that: Soak in S3 in a fume hood for 2 to 3 hours.

9. A method for cleaning organic matter in an ICP central tube according to claim 7, characterized in that: In S2, the concentrations of concentrated nitric acid and concentrated hydrochloric acid are 68% and 37%, respectively.

10. A method for cleaning organic matter in an ICP central tube according to any one of claims 1 to 9, characterized in that: The organic matter is one or more of gasoline, diesel and colloid.

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