CN220120510U - Pretreatment device for solid sample mercury isotope analysis determination - Google Patents

Abstract

The utility model relates to the technical field of mercury sampling analysis, in particular to a pretreatment device for solid sample mercury isotope analysis and determination. The device includes sample support, heating pipe, heating furnace, catalytic tube, reaction tank and zero gas pitcher, the sample support sets up heating pipe one end, just be provided with the air inlet on the heating pipe, the heating pipe other end with catalytic tube connects, the catalytic tube is provided with second heating device outward, the heating furnace sets up the heating pipe middle part, and right the heating pipe heats, catalytic tube lets in confined in the reaction tank, reaction tank top export with zero gas pitcher intercommunication. By introducing the secondary heating and catalysis processes of the sample, the sample pretreatment method of the solid sample mercury isotope analysis is unified, the full and complete conversion and oxidation preservation of mercury in the sample are ensured, and the precision and accuracy of the solid sample mercury isotope analysis measurement are improved.

Description

A pretreatment device for mercury isotope analysis and determination of solid samples

Technical field

The utility model relates to the technical field of mercury sampling and analysis, and in particular to a pretreatment device used for the analysis and determination of mercury isotope of solid samples.

Background technique

With the rapid development of mercury isotope analysis technology in recent years, it has been widely used in geology, environment, archaeology and other fields. According to the fractionation mechanism of mercury isotopes, the migration and transformation process of mercury in samples can be analyzed to study various environmental processes and characteristics. However, before using multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) for mercury isotope analysis and determination, a series of pretreatments are required on the sample. For solid samples, the mercury in the sample first needs to be digested and extracted through wet chemical methods, or all the mercury in the sample needs to be transferred to an oxidizing solution for storage through high-temperature thermal analysis, and then the mercury is reduced to elemental mercury through a reducing reagent, and then enters MC-ICP -MS for mercury isotope determination. However, there is no unified standard for solid sample pretreatment methods, and there is no relatively complete pretreatment device. Therefore, in the process of mercury isotope determination of solid samples, due to inconsistent sampling and heating methods, the mercury in the sample is insufficiently oxidized and reduced, and is easily contaminated by the outside atmosphere. The sample processing efficiency is not high, and errors are prone to occur.

At present, the pretreatment methods for mercury isotope analysis of solid samples mainly include two categories: one is chemical digestion method, including electric hot plate digestion, microwave digestion and water bath digestion, etc. The main principle is to take a certain amount of sample and add a specific strong acid solution (hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, perchloric acid, etc.), and then use heating and microwave to fully dissolve the sample. After the mercury in the sample is fully oxidized, transfer the supernatant or washing liquid to After adding the fixative solution to the volumetric flask, shake evenly after adjusting to volume, and then use the machine to analyze mercury isotopes in the next step. The second is the high-temperature pyrolysis method. The main method is to put the sample into a muffle furnace and heat it at 500-1000°C. Through the high temperature, all the mercury in the sample is converted into elemental mercury and precipitated, and then the strong acid solution is loaded into the sample through the carrier gas. After oxidation and fixation, the sample is finally taken and reduced to elemental mercury by a reducing agent for measurement of mercury isotopes on a machine.

Due to the complex forms of mercury in solid samples, the pretreatment steps for solid samples by digestion method are cumbersome, require the preparation of a large number of chemical reagents, and are easy to introduce human errors and reagent blanks. Different samples require different acid digestion samples, and there are digestion inaccuracies. Completely, there is no risk such as complete oxidation of mercury in the sample. In addition, the digestion process requires professional experimenters and is carried out in a fume hood, which is difficult for ordinary people to complete, and the waste gas and waste liquid produced during the experiment are harmful to the human body. High-temperature pyrolysis is an effective pretreatment method for mercury analysis of solid samples. However, the sample injection method and heating tube structure are currently inconsistent, and the analytical gas (carrier gas) is not reheated and catalyzed before entering the oxidation solution. , resulting in incomplete conversion of mercury in the sample into elemental mercury, and the oxidation solution is not isolated from the outside atmosphere. The atmospheric mercury solution in the environment dissolves into the oxidation solution, thus affecting the analysis and research of mercury isotopes.

Utility model content

(1) Technical problems to be solved

The utility model aims to solve the technical problem that due to inconsistent sampling and heating methods, the mercury in the sample is insufficiently oxidized and reduced, and is easily contaminated by the external atmosphere.

(2) Technical solutions

In order to solve the above technical problems, the present invention provides a pretreatment device for solid sample mercury isotope analysis and determination, including a sample holder, a heating tube, a heating furnace, a catalytic tube, a reaction tank and a zero gas tank. The sample holder is provided with An air inlet is provided at one end of the heating tube. The other end of the heating tube is connected to the catalytic tube. A second heating device is provided outside the catalytic tube. The heating furnace is provided on The middle part of the heating tube is heated, the catalytic tube is passed into the closed reaction tank, and the top outlet of the reaction tank is connected to the zero gas tank.

Further, the second heating device is a heating wire placed outside the catalytic tube, and the heating wire is used to reheat the catalytic tube.

Further, one end of the sample holder is provided with a sealing plug, and one end of the heating tube is provided with a wedge-shaped socket that matches the sealing plug. The sample holder is inserted into the wedge-shaped socket and the heating tube through the sealing plug. Connect one end.

Further, the sealing plug and/or the wedge-shaped socket are coated with petroleum jelly.

Further, the other end of the sample holder is provided with a groove.

Further, the catalyst in the catalytic tube uses silicon carbide.

Further, the oxidizing reagent in the reaction tank is anti-aqua regia.

Further, the mercury-absorbing material in the zero gas tank is activated carbon.

(3) Beneficial effects

The above technical solution of the utility model has the following advantages: by introducing the secondary heating and catalytic process of the sample, the sample pretreatment method for mercury isotope analysis of solid samples is unified, ensuring the sufficient and complete conversion and oxidation preservation of mercury in the sample, and improving The precision and accuracy of mercury isotope analysis and measurement of solid samples are improved. The traditional wet chemical digestion method is abandoned, which greatly reduces the consumption of samples and reagents, the generation of waste liquid and gas, and reduces human errors and reagent errors.

Description of the drawings

Figure 1 is a schematic structural diagram of a pretreatment device for mercury isotope analysis and determination of solid samples according to the present invention;

In the picture: 1. Sample holder; 2. Heating tube; 3. Heating furnace; 4. Catalytic tube; 5. Reaction tank; 6. Zero gas tank; 7. Air inlet; 8. Heating wire; 9. Sealing plug.

Detailed ways

Specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner", "outside", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model. and simplified description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. Detachable connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Please refer to Figure 1. The utility model provides a pretreatment device for solid sample mercury isotope analysis and determination, including a sample holder 1, a heating tube 2, a heating furnace 3, a catalytic tube 4, a reaction tank 5 and a zero gas tank 6 . The sample holder 1 is set at one end of the heating tube 2, and the heating tube 2 is provided with an air inlet 7. The air inlet 7 can be connected to a 1/4-inch Teflon tube and an oxygen tube to ensure oxygen. The outlet of the heating tube 2 is designed to be connected to a 1/4-inch Teflon tube. The other end of the heating tube 2 is connected to the catalytic tube 4 through a Teflon tube. The catalytic tube A second heating device is provided outside 4. The heating furnace 3 is arranged in the middle of the heating tube 2 and heats the heating tube 2. The catalytic tube 4 passes into the closed reaction tank 5, so The top outlet of the reaction tank 5 is connected to the zero gas tank 6 . The sample holder 1, heating tube 2 and reaction tank 5 are all made of quartz material, and other pipe fittings and connectors are made of quartz or Teflon to prevent the material from adsorbing mercury; the heating furnace 3 is designed to be suitable for new heating tubes 2 tube heating furnaces 3, and can be programmed to control temperature.

When in use, the solid sample on the sample holder 1 in the heating tube 2 is heated by the heating furnace 3 to convert various forms of mercury in the solid sample into elemental mercury, and then enters the catalytic tube 4 along with the oxygen introduced from the air inlet 7 , since the catalytic tube 4 is equipped with a secondary heating device, by introducing the secondary heating and catalytic process of the sample, the sample pretreatment method for mercury isotope analysis of solid samples is unified, ensuring the full and complete conversion and oxidation preservation of mercury in the sample. The precision and accuracy of mercury isotope analysis and measurement of solid samples are improved. At the same time, the traditional wet chemical digestion method is abandoned. The mercury in the precipitated gas of the reaction tank 5 can be filtered through the zero gas tank 6 and then discharged into the atmosphere. The mercury in the outside atmosphere entering the reaction tank 5 can also be filtered out, thereby ensuring The pollution and interference of external atmospheric mercury on the oxidation solution greatly reduces the consumption of samples and reagents, the generation of waste liquid and gas, and reduces human errors and reagent errors.

In some embodiments, the second heating device is a heating wire 8 placed outside the catalytic tube 4. The heating wire 8 is used to reheat the catalytic tube 4. The heating wire 8 can be Resistive heating achieves the purpose of heating by passing in direct current to heat the resistor.

In some embodiments, one end of the sample holder 1 is provided with a sealing plug 9 , one end of the heating tube 2 is provided with a wedge-shaped socket that matches the sealing plug 9 , and the sample holder 1 is inserted through the sealing plug 9 . The wedge-shaped socket is connected to one end of the heating tube 2 to ensure that the outside atmosphere cannot enter the heating tube 2 . Further, the sealing plug 9 and/or the wedge-shaped socket are coated with petroleum jelly, which enhances the sealing between the sealing plug 9 and the wedge-shaped socket.

In some embodiments, the other end of the sample holder 1 is provided with a groove, and the groove is used to hold the solid sample that has been ground into powder.

In some embodiments, the catalyst in the catalytic tube 4 uses high-temperature refractory materials such as silicon carbide or adaptable chips.

In some embodiments, the oxidizing reagent in the reaction tank 5 is aqua regia (a mixture of concentrated nitric acid and concentrated hydrochloric acid in a volume ratio of 1:3). Other strong oxidizing reagents can also be sampled according to subsequent analysis requirements.

In some embodiments, the mercury-absorbing material in the zero gas tank 6 uses activated carbon or other mercury-absorbing materials.

The above are only the preferred embodiments of the present invention. It should be pointed out that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present utility model.

Claims (8)

1. A pretreatment device for mercury isotope analysis and determination of solid samples, characterized in that it includes a sample holder, a heating tube, a heating furnace, a catalytic tube, a reaction tank and a zero gas tank, and the sample holder is arranged on the heating One end of the tube, and the heating tube is provided with an air inlet, the other end of the heating tube is connected to the catalytic tube, a second heating device is arranged outside the catalytic tube, and the heating furnace is arranged on the heating tube. The heating tube is heated in the middle, the catalytic tube is passed into the closed reaction tank, and the top outlet of the reaction tank is connected with the zero gas tank. 2. The pretreatment device for mercury isotope analysis and determination of solid samples according to claim 1, characterized in that the second heating device is a heating wire sleeved outside the catalytic tube, and the heating wire is The catalytic tube is heated twice. 3. The pretreatment device for mercury isotope analysis and determination of solid samples according to claim 1, characterized in that one end of the sample holder is provided with a sealing plug, and one end of the heating tube is provided with a sealing plug that matches the sealing plug. The wedge-shaped socket is inserted into the wedge-shaped socket through a sealing plug, and the sample holder is connected to one end of the heating tube. 4. The pretreatment device for mercury isotope analysis and determination of solid samples according to claim 3, characterized in that the sealing plug and/or the wedge-shaped socket are coated with petroleum jelly. 5. The pretreatment device for mercury isotope analysis and determination of solid samples according to claim 3, characterized in that the other end of the sample holder is provided with a groove. 6. The pretreatment device for mercury isotope analysis and determination of solid samples according to claim 1, characterized in that the catalyst in the catalytic tube is silicon carbide. 7. The pretreatment device for mercury isotope analysis and determination of solid samples according to claim 1, characterized in that the oxidizing reagent in the reaction tank is aqua regia. 8. The pretreatment device for mercury isotope analysis and determination of solid samples according to claim 1, characterized in that the mercury-absorbing material in the zero gas tank adopts activated carbon.