CN110146583B

CN110146583B - Method for decomposing sample by Carius tube and method for analyzing isotope of Re-Os

Info

Publication number: CN110146583B
Application number: CN201910345201.8A
Authority: CN
Inventors: 高炳宇; 李文君; 张连昌
Original assignee: Institute of Geology and Geophysics of CAS
Current assignee: Institute of Geology and Geophysics of CAS
Priority date: 2019-04-26
Filing date: 2019-04-26
Publication date: 2020-08-11
Anticipated expiration: 2039-04-26
Also published as: CN110146583A

Abstract

The present invention relates to the field of isotope analysisA method for decomposing a sample by Carius tube and a method for isotopic analysis of Re-Os are disclosed. The method for decomposing the sample by the Carius tube comprises the following steps: at-80 to-50 deg.C, the sample to be analyzed, diluent, HCl and HNO₃Adding the mixture into a Carius tube, and after all components are completely frozen, carrying out melt sealing on the Carius tube; the Carius pipe of sealing with the aforesaid melting heats, wherein, the diluent bears through shifting the container the diluent together shifts to in the Carius pipe, shift the container and include mouth of pipe, body and socle, the mouth of pipe that shifts the container is open structure, the body is cylindric structure, the socle is for sealing the column structure, and the material is borosilicate glass. The method provided by the invention can optimize the operation process, save the cost, reduce the environmental pollution and ensure the accuracy of the Re-Os isotope analysis.

Description

Method for decomposing sample by Carius tube and method for analyzing isotope of Re-Os

Technical Field

The invention relates to the technical field of isotope analysis, in particular to a method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis and a method for Re-Os isotope analysis.

Background

Dissolution of geological samples in Re-Os isotopic analysis presents difficulties with Re (0.2 × 10 in Earth's crust) in geological samples^-9～1×10^-9g/g, 0-0.4 × 10 in olivine of the mantle^-9g/g), Os (10 × 10 in crustacean shell 10)^-12～100×10^-12g/g in peridotite 1 × 10^-9～5×10^-9g/g) content is low, and the background value needs to be strictly controlled in the sample dissolving process; highest oxidation state OsO of Os₄Volatile at relatively low temperatures (boiling point of about 130 ℃ at 105 Pa), and cannot be easily treated with oxidizing solutions (e.g., HF-HNO)₃-HClO₄Mixed liquor) was dissolved in an open environment, and polytetrafluoroethylene (Teflon) container pair OsO₄Has strong adsorption effect and can not be used for dissolving a sample at high temperature; the gold blocking effect of Os in the sulfide phase is obvious, and 1g or more of samples are dissolved sometimes to ensure the representativeness of the samples; the isotopic balance between the sample and the diluent is not easily fully homogenized.

Various sample dissolving methods are adopted for solving the problems: alkali fusion method, microwave digestion method, nickel sulfide pyrometallurgical method, Carius tube method. Wherein, the Carius tube method adopts a strong oxidant to dissolve a sample under a closed condition, so that isotope balance between the sample and a diluent is achieved; the low temperature is kept during sample loading and sampling, so that the loss of Os can be prevented; the adopted acid reagent is easy to purify, and the background can be well controlled; and the Carius tube is disposable, so that cross contamination is avoided, and the Carius tube is made of a high borosilicate glass tube and has no adsorption effect on Os. Therefore, in the field of isotopic analysis, the Carius tube method has been widely used since 1995 for the dissolution of samples of mantle rock, sulfide, volcanic rock, sediment, and the like.

The method adopted in the years for isotopic determination of Re-Os is the isotope dilution method, and the Carius tube method is the method mainly used for decomposing samples in the research of the isotopes of Re-Os (Carius et al, 1860; Gordon et al, 1943; Shirey et al, 1995; Cohen and Waters, 1996; Duan et al, 2001). A karuss Tube (calius Tube) is a thick-walled borosilicate glass Tube or quartz Tube that is resistant to high temperatures and pressures. Shirey et al (1995) Carius tube for Re-Os system had a length of about 20cm, an outer diameter of about 1.9cm and an inner diameter of about 1.6 cm; the neck has a length of about 5cm, an outer diameter of about 0.9cm and an inner diameter of about 0.6 cm. Aqua regia or retro-aqua regia is used as a solvent to dissolve rock or mineral samples (such as silicate rock, sulfide, metal minerals and the like) at the high temperature and the high pressure of 230-240 ℃ under the sealing condition. The main operation flow of the Carius tube method comprises the following steps:

1. accurately weighing a certain amount of sample (2mg-1g, accurate to 0.00001g), and adding the weighed sample to the bottom of a Carius tube through a slender neck glass funnel;

2. Re-Os diluent (accurate to 0.00001g) was accurately weighed and the measured Re-Os diluent solution was added to a Teflon (Teflon) vial;

3. slowly adding liquid nitrogen into a thermos cup filled with half cup of ethanol, stirring while adding to make the mixed product into a viscous state, adjusting the temperature of the mixed product to be-80 to-50 ℃ to obtain a refrigerant, and putting a Carius tube filled with a sample into the thermos cup filled with the refrigerant;

4. accurately weighing Re-Os diluent in advance, adding the diluent to the bottom of the Carius tube through a narrow-neck funnel, and sequentially adding HCl and HNO₃Wherein, HCl and HNO₃The dosage ratio of the acid solution to the acid solution is 1: 2-1: 4, the amount of the acid depends on the size of a sample amount, the temperature of the system needs to be controlled between-80 ℃ and-50 ℃ in the adding process of the acid solution, otherwise, the temperature may be controlled by the Re-Os diluent¹⁹⁰A small volatilization loss of Os results in a low age-related value;

5. after the solution in the Carius tube is completely frozen, a gas oxygen flame gun is used for heating and sealing the narrow neck part of the Carius tube, so that the Carius tube filled with the sample to be detected, the Re-Os diluent and the acid agent forms a sealing system, and then the Carius tube is heated in an oven at the temperature of more than 200 ℃ for more than 48 hours to dissolve the sample.

The above is the main step of the Carius tube process. Re-Os diluent is the most critical factor in isotope dilution method, and the final data quality is directly influenced by the loss amount in the process of transferring Re-Os diluent. However, this method has the following drawbacks during the operation of Re-Os diluent transfer:

1) the diluent Re-Os has the hidden trouble of incomplete transfer. First, the diluent solvent, 6M HCl medium, the Teflon material may not have adsorption capacity for lower-valent Os under reducing conditions, but when the diluent is added to the Teflon vial, there may be trace amounts of Os in solution that may be adsorbed by O in air₂Oxidation to OsO₄And a Teflon material pair OsO₄Strong adsorption capacity, and further deviation of final data exists; secondly, the Re-Os diluent, during pouring from Teflon vials into the Carius tubes, could easily cause the diluent to splash if handled carelessly, resulting in loss of Re-Os diluent; thirdly, if the Teflon bottle is not cleaned, the phenomenon of solution wall hanging can occur, and the incomplete transfer of the Re-Os diluent can also be caused;

2) the operation process is complex, and the misoperation rate is high. First, in order to ensure that the diluent is transferred to the Carius tube as much as possible, after the diluent is poured into the Carius tube, the acid agent for decomposing the sample is sequentially washed with Tefl several timesThe on vial was then poured into the Carius tube, the purpose of this operation being to transfer as much diluent as possible remaining in the Teflon vial into the Carius tube, and to act as a rinse for the diluent on the funnel, the sequence of addition of acid being HCl followed by HNO₃. Secondly, the whole operation process is very complicated, especially when the number of samples is large, the diluent cannot be added into the wrong Carius tube in the acid adding process, and due to the different concentrations and the different amounts of the diluent corresponding to different samples, if the Re-Os diluent corresponding to a specific sample is transferred into the Carius tube filled with other samples, the sample is directly wasted. It is also noted that the addition of acid to the wrong Carius tube is not possible, and is costly if the addition of a mistake directly affects the test results for both samples. Errors in the above operations all affect the final result.

3) Long time consumption and large demand of liquid nitrogen. Firstly, because the whole operation process is extremely complicated, when the sample amount is large, the time required by the diluent transfer process accounts for one third of the time required by the whole sample decomposition process; secondly, the Carius tube was placed in a beaker filled with a cryogen during the sample dissolution, and the temperature was maintained between-80 and-50 ℃ by adding liquid nitrogen to the beaker filled with ethanol, the purpose of this operation being to avoid diluent as much as possible¹⁹⁰And the age measurement value is higher due to the small oxidation volatilization loss of Os. However, in the actual operation process, due to the fact that energy is highly concentrated in the diluent transferring process, the temperature control of ethanol is easily ignored, liquid nitrogen cannot be added in time, the temperature of ethanol is increased, and further the problem is caused¹⁹⁰Partial oxidation volatilization loss of Os; thirdly, if the continuous low-temperature state in the diluent transfer process is to be kept, liquid nitrogen needs to be continuously added into the ethanol, and when the sample consumption is large, the diluent transfer operation takes a long time, so that the demand of the liquid nitrogen is large, and the experiment cost is invisibly increased.

4) The Teflon vial cleaning procedure is complex and the wash liquid consumption is large. Teflon vials are used as diluent containers, and their cleanliness is particularly important. Teflon vials are expensive to manufacture and therefore need to be reused in order to prevent different batches of diluent from being used with each otherThe effect is that the Teflon vials of the same batch need to be cleaned when used. Because the Teflon material is fluoropolymer and has strong adsorption effect on Os elements, the traditional flushing method cannot completely wash out Os. To address this problem, most of the current experiments have used Teflon vials placed in HNO₃Or boiling the obtained water, and oxidizing Os to volatile OsO by using nitric acid or strong oxidizing property of the water₄To completely remove the Os background remaining in the Teflon diluent vial. To ensure that the Os in the vial was removed as much as possible, the Teflon vial was typically mixed with the acid solution for more than 2 hours under open conditions. However, during this operation, a large amount of acid is consumed, and in general, about 500-.

Therefore, designing a method for decomposing a sample by using a Carius tube method, which can avoid the transfer loss of a diluent and/or a sample to be analyzed, thereby improving the accuracy of the annual analysis of the Re-Os isotope, simplifying the operation process of the Carius tube method, saving the cost, being environment-friendly and suitable for the pretreatment of the solid sample, is an urgent problem to be solved in the field of annual analysis of the Re-Os isotope.

Disclosure of Invention

The invention aims to overcome the defects that the existing method for decomposing samples by Carius tubes pretreated by rhenium and osmium isotope analysis samples in the process of determining the year by using Re-Os isotopes has incomplete diluent transfer, complex operation process, long consumed time, large liquid nitrogen demand, complex Teflon vial cleaning process, large washing liquid consumption and easily-remained osmium element background, and particularly when the using amount of the samples to be analyzed is low, the accuracy of analysis results is greatly reduced if the samples are not completely transferred, and the like, and provides a method for dissolving samples by Carius tubes for pretreating samples in Re-Os isotope analysis and a method for analyzing Re-Os isotopes, wherein in the method for decomposing samples by using Carius tubes pretreated in Re-Os isotope analysis, the transfer containers can be completely placed in the Carius tubes, the materials of the used transfer containers are the same as those of the Carius tubes, and the method for decomposing samples by using Carius tubes provided by the invention, the method can realize the complete transfer of the diluent, thereby improving the accuracy of analysis data, saving the using amount of an acid agent and improving the operation efficiency, and the transfer container does not need to be cleaned independently, can be synchronously cleaned with a Carius tube, and effectively reduces the background residue of osmium element. Particularly, when the amount of the sample to be analyzed is low, the sample to be analyzed can be loaded by the transfer container and then added into the Carius tube together, so that the phenomenon of insufficient sample transfer can be effectively avoided. When the sample pretreated by the method for decomposing the sample by the Carius tube provided by the invention is used for carrying out the Re-Os isotope analysis, the accuracy of the Re-Os isotope analysis can be effectively improved, the efficiency of the Re-Os isotope analysis is improved, and the use cost of instruments and raw materials is saved.

In order to achieve the above object, the present invention provides in a first aspect a method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis, the method comprising:

(i) respectively adding a sample to be analyzed, a diluent, HCl and HNO at the temperature of-80 to-50 DEG C₃Adding the mixture into a Carius tube, and after the components are completely frozen, performing melt sealing on the tube opening of the Carius tube to obtain a package of a sample to be analyzed, a diluent, HCl and HNO₃The Carius tube of (1);

(ii) (ii) encapsulating the sample to be analysed obtained in step (i), diluent, HCl and HNO₃The Carius tube of (A) is heated at 200 to 240 ℃ for 48 to 72 hours,

wherein the diluent is carried by a transfer container and transferred together into a Carius tube;

the transfer container comprises a pipe orifice, a pipe body and a pipe bottom, the pipe orifice of the transfer container is of an opening structure, the pipe body is of a cylindrical structure, the pipe bottom is of a sealing structure, and the transfer container is made of high borosilicate glass.

In a second aspect, the invention provides a method for isotopic analysis of Re-Os, the method comprising in sequence: decomposing a sample, and separating and purifying and sample injection analysis of an Os element, and separating and purifying and sample injection analysis of an Re element, wherein the method for decomposing the sample is the method for decomposing the sample by the Carius tube for sample pretreatment in the Re-Os isotope analysis.

Through a large number of experiments, the inventor of the invention discovers that the method for decomposing the sample by the Carius tube for pretreating the sample in the Re-Os isotope analysis, which is provided by the invention, can realize that the transfer container can be transferred to the Carius tube together with the diluent, and effectively avoid the transfer loss of the diluent, thereby improving the accuracy of the Re-Os isotope dating analysis, saving the step of flushing the traditional Teflon transfer container by an acid agent, greatly simplifying the operation process of the Carius tube sample decomposition method, and improving the efficiency of sample dissolution. Particularly, when the usage amount of the sample to be analyzed is low, the sample to be analyzed can be loaded by the transfer container and is added into the Carius tube together, so that the phenomenon of insufficient sample transfer can be avoided, the accuracy of an analysis result can be ensured as much as possible, the operation step of washing the sample to be analyzed possibly remaining and adhering to the inner wall of a transfer device for transferring the sample to be analyzed, such as a long-neck funnel, by using an acid agent can be omitted, the usage amount of the acid agent is further saved, the experiment cost is reduced, and the flexibility of transferring materials in the method for decomposing the sample by the Carius tube is improved.

However, if the transfer container is transferred into the Carius tube together with the diluent or the sample to be analyzed, when the transfer container is transferred into the Carius tube with the nozzle facing downward, or when the Carius tube is subjected to a subsequent melting and sealing treatment and then needs to be further heated or stored and sampled for analysis, and the like, because the position of the transfer container is not fixed during the movement of the Carius tube, the nozzle of the transfer container may be in seamless and tight close contact with the inner wall of the Carius tube, thereby forming a local closed space, and particularly when the sample to be analyzed is subjected to a heating process in a heating device such as an oven, if the nozzle of the transfer container is in tight contact with the inner wall of the Carius tube, the release of the material in the transfer container is not facilitated, the accuracy of the analysis is affected, and when the nozzle of the transfer container is further configured to have a notched opening structure, the above-mentioned drawbacks can be effectively overcome, the accuracy of sample analysis is guaranteed.

In addition, in the method for decomposing the sample by using the Carius tube for sample pretreatment in Re-Os isotope analysis, which is provided by the invention, the transfer container can oxidize all Os elements contained in the diluent to generate OsO in the heating process of the decomposed sample₄And because the transfer container is borosilicate glass material, does not have the absorption to Os element, makes the cleaning process of transfer container desorption Os background element can go on with the cleaning process of Carius pipe in step, and it is right subsequently need not to look for the container alone transfer the container and wash, raise the efficiency, energy saving, reduce cost, environmental protection. Furthermore, the glass equipment used in the method for decomposing the sample by the Carius tube for sample pretreatment in Re-Os isotope analysis provided by the invention has low manufacturing cost, and compared with the expensive imported Teflon transfer container used in the diluent transfer process in the traditional Carius tube decomposition sample method, the cost of the equipment can be further reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic view of the structure of a transfer container used in example 1.

Fig. 2 is a schematic view of the measuring boundary of the tube body and the tube bottom of the transfer container provided by the present invention.

FIG. 3 is a schematic structural diagram of a Carius tube according to the present invention.

FIG. 4 is a schematic diagram of the operation of the present invention for transferring the diluent carried in the transfer container to the Carius tube together in the method for decomposing the sample by the Carius tube.

FIG. 5 is a schematic structural diagram of an apparatus used in the process of extracting Os element from the mixed product obtained by pretreating the sample to be analyzed by the method for decomposing a sample by a Carius tube according to the present invention by distillation in the test example of the present invention.

Description of the reference numerals

1. Pipe orifice 2, pipe body 3, pipe bottom L and pipe body length

l, length R of tube bottom, inner diameter R of tube body, outer diameter A of tube body and air pump

B. Gas washing bottle C, electric heating sleeve D, absorption device E and ice water bath

F. Absorption liquid

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, the use of the terms of orientation such as "upper", "lower", "top" and "bottom" generally refers to an orientation relative to the schematic structural view of the transfer container of the present invention, unless otherwise specified. "inner and outer" are defined with respect to the actual configuration of the transfer vessel and/or the Carius tube.

In a first aspect the present invention provides a method of decomposing a sample with a Carius tube for sample pre-treatment in Re-Os isotope analysis, the method comprising:

wherein in step (i), the diluent is carried by a transfer container and transferred together into a Carius tube;

the transfer container comprises a pipe orifice 1, a pipe body 2 and a pipe bottom 3, wherein the pipe orifice 1 of the transfer container is of an opening structure, the pipe body 2 is of a cylindrical structure, the pipe bottom 3 is of a sealing structure, and the transfer container is made of high borosilicate glass.

In the method for decomposing samples by Carius tubes for sample pretreatment in Re-Os isotope analysis, provided by the invention, in the step (i), the material of the transfer container is high borosilicate glass, namely B₂O₃SiO in an amount of 10 mol% or more₂Glasses having a content of more than 78 mol%, e.g. B in the high borosilicate glass₂O₃The content of SiO is 12.5-13.5 mol%₂The content of the high borosilicate glass can be 78-80 mol%, and the high borosilicate glass has an Os isotope and an oxidation product volatile OsO₄No adsorption, thus effectively avoiding the adsorption of the wall of the transfer container to the Os isotope and reaching the background blank of the Os element to the maximum extent.

In the method for decomposing a sample by using a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in the step (i), since the transfer container is transferred together with a diluent into the Carius tube, it is preferable to use a Carius tube which has been subjected to HNO in advance₃And the carrier device cleaned by boiling with deionized water is used for bearing the transfer container, and the carrier device for bearing the transfer container is poured into the Carius tube in a mode of opening downwards in a mode of opening to opening as shown in figure 4, so that the transfer container can be prevented from being exposed in the environment as much as possible, the cleanness of the outer wall of the transfer container is ensured to the maximum extent, and the accuracy of final sample analysis is improved. The loading device is not particularly limited as long as the loading device is an open container closed at one end and has an inner cavity of a size corresponding to that of the transfer container, and for example, the loading device may be a Teflon bottle. However, when the transfer container is transferred into the Carius tube with its nozzle facing downward, or when the Carius tube is subjected to a fusion sealing process and then further heating or storage and sampling for analysis, the position of the transfer container may not be fixed during the movement of the Carius tube, and the nozzle of the transfer container may be seamless with the inner wall of the Carius tubeThe gap is tightly closed and contacted to form a local closed space, and particularly when a sample to be analyzed is heated in an oven or a muffle furnace and the like, if the nozzle of the transfer container is tightly attached to the inner wall of the Carius tube, the release of the material in the transfer container is not facilitated, and the analysis accuracy is influenced. Therefore, in order to prevent the tube orifice 1 of the transfer container from having a seamless and tight closed contact with the inner wall of the Carius tube after the transfer container is loaded into the Carius tube, so as to form a local closed space, hinder the release of the material in the transfer container, influence the isotope system balance of the sample to be dissolved and the diluent, and reduce the accuracy of the Re-Os isotope analysis in the sample, the tube orifice 1 of the transfer container is preferably of an open structure with a notch.

In the method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), the height of the notch of the nozzle 1 in the transfer container, that is, the maximum length of the notch in the axial direction of the tube body 2, is preferably 10% to 15% of the length of the tube body 2.

In the method for decomposing a sample by using a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), the notch of the nozzle 1 in the transfer container used may be a regular or irregular shaped notch, for example, the shape of the notch may be regular polygon, irregular figure, arc, etc. The number of the notches can be 1 or more, when the number of the notches is more than one, the notches can be a regular pattern which is continuously arranged or arranged at equal intervals, an irregular pattern which is continuously arranged or arranged at equal intervals or a combination of the shapes, for example, the notches of the pipe orifice 1 can be zigzag notches or corrugated notches.

In the method for decomposing a sample by using a Carius tube for sample pretreatment in Re-Os isotope analysis, in step (i), in order to enable the transfer container to freely enter and exit from the tube orifice of the Carius tube in the sample decomposing process of the Carius tube and ensure that the total volume of the diluent carried by 1 or more transfer containers meets the requirement of carrying out isotope exchange equilibrium reaction on Re, Os and the diluent in the sample, the length of the tube body 2 in the transfer container can be 2-3cm, the outer diameter can be 0.3-0.7cm, the inner diameter can be 0.1-0.5cm, and the volume of the transfer container can be 0.1-0.3 mL; preferably, the length of the pipe body 2 in the transfer container is 2.5-3cm, the outer diameter is 0.4-0.6cm, the inner diameter is 0.2-0.4cm, and the volume of the transfer container is 0.2-0.24 mL.

According to the present invention, in step (i), the sample to be analyzed may be added into the Carius tube by selecting different sample adding methods according to the actual amount, for example, the sample may be added into the Carius tube through a long-neck funnel, or the sample to be analyzed may be loaded into the Carius tube together through a transfer container. Because the size of the transfer container needs to meet the requirement that the sample can freely enter and exit from the tube orifice of the Carius tube, and the volume is smaller, under the optimal condition, when the using amount of the sample to be analyzed is smaller, for example, the using amount of the sample to be analyzed does not exceed 0.1g, the sample to be analyzed can be loaded by the transfer container and added into the Carius tube together, so that the sufficient transfer of the sample to be analyzed can be effectively ensured, the accuracy of the final analysis result of the sample is improved, the operation step of washing the sample to be analyzed, which is possibly remained and adhered to the inner wall of a transfer device for transferring the sample to be analyzed, such as a long-neck funnel and the like, by using an acid agent can be omitted, the using amount of the acid agent is further saved, the experiment cost is reduced; when the sample to be analyzed is used in a large amount, for example, the amount of the sample to be analyzed is 0.1g or more, the sample to be analyzed, which is accurately weighed in advance, may be transferred into the Carius tube via the long-neck funnel in a conventional manner, and since the sample to be analyzed may be stuck to the wall during the transfer process when the sample to be analyzed is transferred using the long-neck funnel, it is preferable to continue to add HCl and/or HNO into the Carius tube using the same long-neck funnel after the sample to be analyzed is added into the Carius tube₃Solution to avoid transfer losses of the sample to be analyzed to the maximum.

In the method for decomposing a sample by using a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), the tube bottom 3 of the transfer container used may have various seal-like structures, and may be a flat bottom, a round bottom or a conical bottom, for example. Preferably, the bottom 3 of the transfer vessel is preferably conical in order to facilitate the carrying of small amounts of diluent.

According to a specific embodiment of the present invention, in step (i), the structure of the transfer container is schematically shown in fig. 1, the nozzle 1 of the transfer container has a corrugated notch, the tube body 2 of the transfer container has a cylindrical structure, and the tube bottom 3 of the transfer container has a conical bottom.

In the method for decomposing a sample by Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, the measurement boundary of each part size of the transfer container is shown in FIG. 2, wherein L represents the length of the tube body 2, L represents the length of the tube bottom 3, R represents the outer diameter of the tube body 2, and R represents the inner diameter of the tube body 2. When the tube bottom 3 of the transfer container is of a flat bottom structure, the value of l is 0.

In the method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), in order to prevent the nozzle 1 of the transfer container from being too sharp to hurt people, the nozzle 1 is preferably a fused light nozzle. The nozzle of the molten light tube can be gradually narrowed and dulled by the surface tension effect after the nozzle 1 of the transfer container is melted by continuously rotating and heating the nozzle on an alcohol lamp, for example.

In the method for decomposing a sample by using a Carius tube for sample pretreatment in Re-Os isotope analysis, provided by the invention, in step (i), as shown in FIG. 3, the Carius tube is a reducing borosilicate glass tube with a plain round bottom, the Carius tube comprises a reducing tube body and an expanding tube body, the inner diameter of the reducing tube body is smaller than that of the expanding tube body, and a round table-shaped curved surface is formed at the joint of the reducing tube body and the expanding tube body;

the inner diameter of the reducing pipe body is 0.55-0.65cm, the outer diameter is 0.85-0.95cm, and the length is 4-6 cm;

the inner diameter of the expanding pipe body is 1.5-1.7cm, the outer diameter is 1.8-2cm, and the length is 18-22 cm;

the length of a generatrix of a circular truncated cone-shaped curved surface formed at the joint of the reducing pipe body and the expanding pipe body is 0.5-0.7 cm.

In the method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), when the size of the reduced diameter tube body of the Carius tube satisfies the above range, the size of the inner cavity of the reduced diameter tube body of the Carius tube is not only enough to form a sample introduction passage, so that a sample to be analyzed and an acid agent for decomposing the sample are added into the expanded diameter tube body of the Carius tube by a material transfer device such as a long-neck funnel, but also the transfer container can be transferred into the expanded diameter tube body of the Carius tube via the reduced diameter tube body of the Carius tube in the manner shown in FIG. 4.

In the method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), when the size of the expanded diameter tube body of the Carius tube satisfies the above range, the inner cavity space of the expanded diameter tube body of the Carius tube is sufficient to accommodate a sample to be dissolved, a diluent, an acid agent, and at least one transfer container for transferring the diluent.

In the method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis, in the step (i), the Carius tube can be formed into a reducing borosilicate glass tube with a plain round bottom and an inner diameter smaller than that of the diameter-expanding tube by fusing and connecting two parts of the diameter-reducing tube and the diameter-expanding tube into a whole, and the joint of the diameter-reducing tube and the diameter-expanding tube forms a round table-shaped curved surface by fusing.

In the method for decomposing the sample by the Carius tube for sample pretreatment in Re-Os isotope analysis, which is provided by the invention, in the step (i), the Carius tube is made of high borosilicate glass, namely B₂O₃SiO in an amount of 10 mol% or more₂Glasses having a content of more than 78 mol%, e.g. B in the high borosilicate glass₂O₃The content of SiO is 12.5-13.5 mol%₂The content of the high borosilicate glass can be 78-80 mol%, and the high borosilicate glass has an Os isotope and an oxidation product volatile OsO₄No adsorption, thus effectively avoiding the adsorption of the inner wall of the Carius tube to the Os isotope to maximally reach the original Os elementAnd (5) bottom blank.

In the method for decomposing a sample by using a Carius tube for sample pretreatment in Re-Os isotope analysis, provided by the invention, in the step (i), the sample to be analyzed, the diluent, HCl and HNO can be fully frozen at the temperature of-80 to-50 ℃ because each liquid material can be fully frozen₃The order of addition into the Carius tube is not particularly limited, in order to avoid HNO as much as possible₃In the adding process, the Os element is oxidized to generate OsO₄Volatilization loss is preferably controlled by adding the next liquid material after each liquid material is sufficiently frozen and by controlling HNO with strong oxidizing property₃Finally, the addition of the materials in step (i) may be, for example, in the order of: adding a sample to be analyzed, a diluent, HCl and HNO in sequence₃(ii) a Or sequentially adding a diluent, a sample to be analyzed, HCl and HNO₃(ii) a Or sequentially adding a sample to be analyzed, HCl, a diluent and HNO₃(ii) a Or HCl and HNO firstly₃Mixing to form a mixed acid agent, and then sequentially adding a sample to be analyzed, a diluent and the mixed acid agent; or sequentially adding HCl, diluent, sample to be analyzed and HNO₃。

In the method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), when the sample to be analyzed is a solid sample, the solid sample may be a solid sample of silicate rock, sulfide, and metal minerals containing Re and Os elements, such as pyrite, molybdenite, alkali basalt, olivine, spinel, garnet, cormatite, and the like. The solid sample can be used in an amount of 0.004-1g, and the solid sample is weighed to an amount of 0.00001g to improve the accuracy of the final analysis result. The solid sample is introduced into the Carius tube via a long-neck glass funnel or the transfer container according to the invention, as described above, depending on the actual amount.

According to the present invention, in step (i), when the solid sample is transferred into the Carius tube through the long-neck funnel, a phenomenon in which a small amount of the solid sample adheres to the inner wall of the long-neck glass funnel may occur during the transfer, and thus, it is preferableThen, after the sample to be analyzed was added to the bottom of the Carius tube, HCl and/or HNO was added to the Carius tube using the same long-neck funnel₃Therefore, the solid sample adhered to the inner wall of the long-neck glass funnel can be completely flushed into the Carius tube, and the analysis error is reduced as much as possible.

In the method for decomposing a sample by Carius tube for sample pretreatment in isotope analysis of Re-Os provided by the present invention, in step (i), the diluent is used for equilibrium exchange reaction with isotopes of Re and Os in the sample to be analyzed, and the type of the diluent may be selected according to the specific isotope type of Re and Os contained in the sample to be actually tested, for example, the diluent may be a solution containing Re and Os¹⁸⁵Re and¹⁹⁰and the solvent in the mixed solution of Os, the diluent can be hydrochloric acid with the concentration of 6 mol/L. The concentration and amount of the Re and Os isotopes in the diluent can be selected according to the specific sample to be dissolved, for example, when the Re element content in the sample to be analyzed is in the range of 240000-300000ng/g and the Os element content is in the range of 600-700ng/g, the diluent contains Re and Os elements¹⁸⁵The concentration of Re may be 7000-8000ng/g,¹⁹⁰the concentration of Os can be 17-21ng/g, and the dosage of the diluent can be 0.1-0.2 g; when the content of Re element in the sample to be analyzed is in the range of 15000-20000ng/g and the content of Os element is in the range of 20-30ng/g, the diluent is used¹⁸⁵The concentration of Re may be 6800-7200ng/g,¹⁹⁰the concentration of Os can be 10-15ng/g, and the dosage of the diluent can be 0.1-0.2 g.

In the method for decomposing the sample by the Carius tube for sample pretreatment in Re-Os isotope analysis, which is provided by the invention, the method for calculating the molar ratio of Re or Os in the sample to be analyzed and Re or Os in a diluent by adopting an isotope dilution method mainly calculates the molar ratio of corresponding elements in the sample to be analyzed and the diluent according to the change of the isotope ratio after the sample to be analyzed and the diluent are mixed and reach isotope exchange balance. In the present invention, the contents of Re and Os in a sample to be analyzed are calculated by the formula (1):

C＝[M_s·K·(A_s-B_s·R)]/[W·(B_x·R-A_x)]formula (1)

The meanings and values of the variables in formula (1) are shown in Table 1, and if the diluent addition Ms and the content C are both expressed in moles, the value K can be eliminated. Except R in the formula (1), the R ratio is a known quantity, the R ratio can be obtained by ICP-MS measurement, and the obtained ratio is substituted into the formula (1) to obtain the contents of Re and Os elements in a sample to be analyzed.

TABLE 1

In the method for decomposing the sample by the Carius tube for sample pretreatment in Re-Os isotope analysis, provided by the invention, in the step (i), the process of adding all materials into the Carius tube is carried out at the temperature of-80 to-50 ℃, so that the pressure in the Carius tube can be effectively reduced, the subsequent operation of melting and sealing the tube opening of the Carius tube is convenient, and meanwhile, the sample to be analyzed and the Os element contained in the diluent can be effectively prevented from being oxidized to generate volatile OsO₄Causing losses. The low-temperature environment of-80 to-50 ℃ can be formed by slowly adding liquid nitrogen into a thermos cup filled with ethanol under stirring conditions to form a viscous liquid nitrogen-ethanol mixed refrigerant, the adding process of each material into a Carius tube can be controlled within the range of-80 to-50 ℃, the dosage of the liquid nitrogen and the ethanol in the mixed refrigerant can be changed within a certain range along with the adding process of the materials into the Carius tube, for example, the volume ratio of the dosage of the liquid nitrogen to the dosage of the ethanol in the mixed refrigerant can be 3-7: 1.

in the method for decomposing a sample by a Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, the process of transferring the transfer container filled with the diluent into the Carius tube in the step (i) may include: first, a Carius tube was placed in a beaker filled with a mixed refrigerant of liquid nitrogen and ethanol, and then the Carius tube was placed in an inclined state using a previously HN-free tubeO₃And carrying the transfer container by using a carrying device which is cleaned by boiling deionized water, pouring the carrying device carrying the transfer container into the reducing pipe body of the Carius pipe through the pipe orifice of the Carius pipe in a mode of opening to opening, wherein the pipe orifice of the Carius pipe faces downwards, and slowly erecting the Carius pipe to enable the transfer container to slowly move into the expanding pipe body of the Carius pipe, as shown in figure 4. The carrier device is as described above and will not be described in detail here.

In the method for decomposing a sample by using Carius tube for sample pretreatment in Re-Os isotope analysis, provided by the invention, in the step (i), when HCl and HNO are used₃The volume ratio of the dosage of (A) is 1: (2-6), HCl and HNO₃The mixed acid agent forms reverse aqua regia, and can completely dissolve the insoluble phase of a solid sample to be analyzed containing Os and Re elements, wherein the HCl and the HNO₃Should be used in an amount sufficient to completely dissolve the insoluble phase of the solid sample to be analyzed, for example, when the sample to be analyzed is used in an amount of 8-80mg, the HCl concentration is 35-38 wt%, and the HNO is present₃Is 65 to 70 wt%, HCl and HNO₃The amount of the mixed solution formed may be 6-9 mL. And the HCl and HNO₃Does not exceed 1/3 of the total volume of the Carius tube, so that the explosion of the Carius tube during the subsequent heating process can be prevented as much as possible.

In the method for decomposing a sample by Carius tube for sample pretreatment in Re-Os isotope analysis provided by the present invention, in step (i), in order to prevent diluent, HCl and HNO₃During the addition, the temperature rises and the Os contained in the sample to be analyzed and/or in the diluent is oxidized to form OsO₄Volatility dissipation affects the accuracy of the final analytical results, the diluent, HCl and HNO₃The addition process is carried out under the condition that the temperature is required to be kept between 80 ℃ below zero and 50 ℃ below zero.

In the method for decomposing the sample by the Carius tube for sample pretreatment in Re-Os isotope analysis, provided by the invention, in the step (i), after the material in the Carius tube is completely frozen, the process of sealing the mouth of the Carius tube by melting can be completed by heating the reducing tube body of the Carius tube by using an oxygen-gas fire gun, so that the reducing tube body is sealed by melting. Preferably, the distance between the part of the reduced diameter body of the Carius tube heated by the oxygen-gas fire gun and the orifice of the Carius tube is 10-20% of the length of the reduced diameter body of the Carius tube, so that the distance between the part of the reduced diameter body of the Carius tube and the orifice of the Carius tube can be as far as possible from the material at the bottom of the Carius tube, and further the oxidation volatilization loss of Os in the sample to be dissolved can be prevented.

In the method for decomposing a sample by Carius tube for sample pretreatment in Re-Os isotope analysis provided by the invention, in the step (ii), the sample to be analyzed, the diluent, HCl and HNO are encapsulated in the obtained product in the step (i)₃The Carius tube is heated at 200-240 ℃ for 48-72 hours under conditions that ensure adequate decomposition of the sample to be analyzed. The heating process may be performed in a heating device such as an oven.

Generally, each of the devices involved in the Carius tube decomposition sample method requires boiling cleaning with nitric acid and deionized water before use to minimize background blank. According to the invention, the transfer container can be completely placed in the Carius tube, and the transfer container and the Carius tube are made of the same material and are made of the high borosilicate glass, so that the cleaning process of the transfer container can be synchronously finished with the cleaning of the Carius tube, a cleaning link of boiling nitric acid is not required to be independently carried out, and only deionized water is required to be used for cleaning.

According to the method for decomposing the sample by the Carius tube for sample pretreatment in Re-Os isotope analysis, provided by the invention, after the heating process of the Carius tube decomposition sample is finished, the Carius tube is taken out and cooled to room temperature, the Carius tube is placed in a refrigerant environment at-80 to-50 ℃, after the solution in the Carius tube is completely frozen, the hole is opened at the narrow neck part of the Carius tube for pressure relief, the narrow neck part of the Carius tube is scratched after the pressure relief, and the Carius tube is frozen and stored. When the analysis is needed, the Carius tube which is frozen and stored can be placed in an ice water bath, after all substances in the Carius tube are changed into liquid, the neck part of the reducing tube body of the Carius tube is knocked to break the neck part at the scratch part, the liquid in the Carius tube is respectively separated and purified by the Os isotope and the Re isotope, and then the products respectively containing the Os isotope and the Re isotope after separation and purification are sent to an ICP-MS inductively coupled plasma mass spectrometer and other analysis instruments for analysis.

As previously mentioned, a second aspect of the invention provides a method of isotopic analysis of Re-Os, which method comprises, in order: decomposing a sample, and separating and purifying and sample injection analysis of an Os element, and separating and purifying and sample injection analysis of an Re element, wherein the method for decomposing the sample is the method for decomposing the sample by the Carius tube for sample pretreatment in the Re-Os isotope analysis.

According to the method for analyzing the Re-Os isotope, provided by the invention, the Os element can be separated and purified by a distillation method and subjected to sample injection analysis, and the Re element can be separated and purified by an anion column exchange method or an acetone extraction method and subjected to sample injection analysis.

For example, the operation process of separation and purification of Os element and analysis of sample injection by distillation method may specifically include: according to the research of rhenium-osmium isotope geological age determination method of Duan Dao, He Red Liao, Yin Ningwan, et al]The distillation method disclosed in the geological news, 1994(4):339-, the other end of the tube is connected with a glass colorimetric tube with the volume of 25mL as an absorption device D, 5mL of deionized water as absorption liquid F and 20 muL of Ir solution with the concentration of 50ng/mL as internal standard are filled in the absorption device D, and the absorption device D is placed in an ice-water bath E. The round flask is used as a distiller and is placed in an electric kettleStarting the electric heating sleeve C in the heating sleeve C, raising the temperature to 120 ℃, controlling the solution in the round-bottom flask to keep a slightly boiling state, and heating and distilling the materials in the round-bottom flask to obtain OsO₄Starting an air supply device, heating for 1h under the condition that the air flow is adjusted to be 40mL/min by an air pump A, and enabling the OsO in the round-bottom flask₄Is carried to the absorption device D through the air outlet pipe and is completely absorbed by the absorption liquid F in the absorption device D. Will absorb OsO₄The absorption liquid is sent into a sample inlet chamber of an ICP-MS inductively coupled plasma mass spectrometer, ionized gas is obtained through atomization and dissociation, molecular beams are formed, mass separation and counting analysis are carried out, and the content of the Os element and the ratio of the Os isotope in the liquid material in the round-bottom flask are obtained.

Or, the operation process of separation and purification of Os element and sample analysis by distillation method may specifically include: according to the improvement of the method for directly distilling and rapidly separating osmium by using Zhouyimin, Gaoyang, Wangshengu et al]The method disclosed in the mineral testing, 2012,31(3):413-418 ", wherein the frozen Carius tube is placed in an ice-water bath, after all the substances in the Carius tube are changed into liquid, the neck part of the reducing tube body of the Carius tube is knocked to break at the scratch, 6-12mL of ultrapure water is added into the Carius tube, natural rubber is used as a sealing head of the Carius tube and sleeved at the orifice of the reducing tube body of the Carius tube, two polytetrafluoroethylene tubes are inserted at the top of the natural rubber as an air inlet tube and an air outlet tube (with the inner diameter of 0.5mm and the outer diameter of 0.9mm), one end of the air inlet tube is connected with an air supply device, the other end of the air outlet tube is inserted into the bottom of the Carius tube, one end of the air outlet tube is positioned above the liquid level of the materials in the Carius tube, the other end of the air outlet tube is connected with a 5mL glass centrifugal tube as an absorption device, and the absorption device is filled with 5mL of deionized water as an absorption liquid and, and placed in an ice-water bath. Taking Carius tube as distiller, inserting into electric food steamer, starting electric food steamer, and heating and distilling material in Carius tube with water vapor to obtain OsO₄Starting an air supply device, adjusting the gas flow to be 40mL/min, distilling for 1h, and introducing OsO in a Carius tube₄Is carried to the absorption device through the air outlet pipe and is completely absorbed by the deionized water in the absorption device. Will absorb OsO₄Absorption ofAnd (3) delivering the liquid into a sample inlet chamber of an ICP-MS inductively coupled plasma mass spectrometer, and sequentially carrying out atomization and dissociation to obtain ionized gas, forming molecular beams, mass separation and counting analysis to obtain the content of the Os element and the ratio of the Os isotope in the liquid material in the Carius tube.

The operation process of performing separation and purification of the Re element and sample analysis by using an anion column exchange method may specifically include: and transferring the residual liquid obtained after the separation and purification of the Os element into a 50mL beaker, and then placing the beaker on an electric hot plate at 140 ℃ for heating. After the solution in the beaker is evaporated to dryness, adding 5mL of HCl with the concentration of 6mol/L, preserving the heat for 1 hour, adding 5mL of HCl with the concentration of 1mol/L, preserving the heat for 1 hour after the solution is evaporated to dryness, and then transferring the solution into a centrifuge tube for centrifugation. Centrifuge for 10 minutes and wait for column separation. The anion resin is AG1X-8, 2mL of the resin is added into the resin, 10mL of ultrapure water and 10mL of HNO with the concentration of 6mol/L are respectively used₃4mL of ultrapure water was subjected to column washing, 4mL of HCl (1 mol/L) was added to the column to equilibrate the medium, and the sample in the centrifuge tube was introduced into a resin column, followed by 10mL of HCl (1 mol/L) and 10mL of HNO (0.8 mol/L) respectively₃Eluting impurity ions, and finally using 14mL of HNO with the concentration of 6mol/L₃Eluting the Re element, recovering 50mL of Re solution, heating the solution on a 120 ℃ electric hot plate until the solution is nearly dry, metering the volume to 5mL, and sending the solution into ICP-MS for measurement and analysis.

The operation process of separating and purifying the Re element and analyzing the sample by adopting an acetone extraction method specifically comprises the following steps: cooling and transferring residual liquid obtained after separation and purification of Os element into a 50mL glass beaker, steaming the residual liquid to be nearly dry, 10-15mL of 5mol/L NaOH solution until the pH value of the residual liquid is more than 10, transferring the solution into a centrifuge tube, adding 10-15mL of organic extractant acetone into the centrifuge tube, screwing a cover of the centrifuge tube, fully oscillating to ensure that the residual liquid is fully contacted with the organic extractant acetone, then putting the centrifuge tube into a centrifuge for centrifugation so as to completely separate water phase from organic phase, leaving Re element in the upper organic phase, collecting the upper organic phase, transferring the upper organic phase into the 50mL beaker, heating at 110 ℃ to remove the acetone, and then adding H₂O₂Destroying the residual organic phase, and adding 2% sodium nitrateAnd (3) metering the volume of the acid to 5mL, finally sending the acid into a sample chamber of an ICP-MS inductively coupled plasma mass spectrometer, and sequentially carrying out atomization and dissociation to obtain ionized gas, form molecular beams, mass separation and counting analysis to obtain the content of the Re element and the ratio of the Re isotope.

According to the method for decomposing the sample by the Carius tube, the transfer container is integrally transferred to the Carius tube together with the diluent, so that the transfer loss of the diluent can be effectively avoided, the accuracy of the Re-Os isotope dating analysis is improved, the flushing link of an acid agent to the traditional Teflon transfer container can be omitted, the operation process of the method for decomposing the sample by the Carius tube is greatly simplified, and the sample decomposition efficiency is improved. In addition, the transfer container is made of high borosilicate glass and does not adsorb Os elements, so that the cleaning process of removing the Os background elements from the transfer container can be completed in the process of decomposing a sample, and the transfer container does not need to be cleaned independently subsequently, thereby improving the efficiency, saving the energy, reducing the cost and being environment-friendly. Particularly, when the usage amount of the sample to be analyzed is low, the sample to be analyzed can be loaded by the transfer container and is added into the Carius tube together, so that the phenomenon of insufficient sample transfer can be avoided, the accuracy of an analysis result can be ensured as much as possible, the operation step of washing the sample to be analyzed possibly remaining and adhering to the inner wall of a transfer device for transferring the sample to be analyzed, such as a long-neck funnel, by using an acid agent can be omitted, the usage amount of the acid agent is further saved, the experiment cost is reduced, and the flexibility of transferring materials in the method for decomposing the sample by the Carius tube is improved. Furthermore, the transfer container used in the Carius sample dissolving method is low in manufacturing cost, and equipment cost can be further reduced compared with an expensive imported Teflon transfer container. In addition, the cleaning method of the transfer container used in the method for decomposing the sample by the Carius tube is simple, efficient and low in cost, so that the Carius tube can be repeatedly used and can be used as a disposable product, the Carius tube can be properly selected according to different experimental requirements, and the selection space is large.

The present invention will be described in detail below by way of examples.

In each of the following examples and comparative examples,

the diluent is obtained from national laboratory of Oak Ridge (ORNL)¹⁸⁵Re metal powder and¹⁹⁰os powder, hydrochloric acid with concentration of 6mol/L and its preparation method¹⁸⁵Re and¹⁹⁰os mixed solution, spectroscopically pure (NH) using a standard reagent purchased from Johnson Matthey, UK₄)₂OsCl₆And a high purity (99.999 wt%) metallic Re tape, available from Cross, USA, having a density of 1.18-1.19g/cm³。

The specifications for the Carius tube are: the inner diameter of the reducing pipe body is 0.6cm, the outer diameter of the reducing pipe body is 0.9cm, and the length of the reducing pipe body is 6 cm; the inner diameter of the expanding pipe body is 1.6cm, the outer diameter of the expanding pipe body is 1.9cm, and the length of the expanding pipe body is 20 cm; the generating line length of the round table-shaped curved surface formed at the joint of the reducing pipe body and the expanding pipe body is 0.64cm, and the volume of the expanding pipe body of the Carius pipe is about 30 mL.

The HLP of the solid sample to be analyzed is a standard sample which is purchased from a national geological experiment test center and has the brand number of GBW 04436;

the JDC to be analyzed is a standard sample with the brand number of GBW04435 of the national geological experiment testing center;

in the following test examples, an ICP-MS inductively coupled plasma mass spectrometer model ICP-MS ELEMENT XR was obtained from Thermo corporation, USA, and the operating parameters of ICP-MS are shown in the following table. In the test process, the data of each sample to be analyzed, which is automatically tested by the mass spectrometer for 100 times, is recorded as a group, the average value is calculated, 5 groups of data are obtained in total, the average value of each group of data is calculated, and the average value of the 5 groups of data is calculated to be used as the final measurement value of the sample to be analyzed.

Operating parameters of ICP-MS

In the following test examples, the contents of Re and Os in the samples to be analyzed were calculated by the following formula:

C＝[M_s·K·(A_s-B_s·R)]/[W·(B_x·R-A_x)]

wherein C represents the Re or Os content of the sample to be analyzed, expressed in (pg/g or ng/g or μ g/g), M_sRepresents the content of diluent added Re or Os, K represents the atomic weight of Re (Os) in the sample/the atomic weight of Re (Os) in the diluent, A_sRepresents the atomic abundance of the A isotope, B_sThe atomic abundance of the B isotope in the diluent is shown, R represents the isotope ratio after the balance of mass spectrometry, which is the number of A isotope atoms/the number of B isotope atoms, the value range of R is between the respective A/B isotope ratios of the diluent and the sample, W represents the dosage of the sample to be analyzed, and the unit is g, A_xRepresents the atomic abundance of the A isotope, B_xRepresents the atomic abundance of the B isotope. Except R in the formula, the R is a known amount, the R ratio can be obtained by ICP-MS measurement, and the obtained ratio is brought into the formula to obtain the contents of Re and Os elements in a sample to be analyzed.

In the following test examples, the legal annual calculation formula of Re-Os is as follows:

¹⁸⁷Os＝¹⁸⁷Os_i+¹⁸⁷Re(e^λt-1)

in the formula (I), the compound is shown in the specification,¹⁸⁷os represents the present isotopic content of the sample to be analyzed;¹⁸⁷Os_irepresents the content of Os isotope at the time when the Re-Os system starts to be closed for the sample to be analyzed, which is 0 for the molybdenite sample;¹⁸⁷re is in the mineral of the sample to be analyzed¹⁸⁷The content of Re; λ is¹⁸⁷Decay constant of Re; t is the duration of self-sealing.

The dimensions and specifications and numbers of the transfer containers used in examples 1-4 are shown in Table 2.

TABLE 2

Transfer container numbering

Length of pipe body

Outer diameter of pipe body

Inner diameter of pipe body

Shape of notch

Shape of tube bottom

Length of tube bottom

Volume of

T1

2.8cm

0.5cm

0.3cm

Corrugated gap

Conical bottom

0.2cm

0.20mL

T2

2.85cm

0.5cm

0.3cm

Saw-toothed notch

Round bottom

0.15cm

0.21mL

T3

3cm

0.5cm

0.3cm

Corrugated gap

Flat bottom

0

0.21mL

T4

2.8cm

0.5cm

0.3cm

Without gaps

Conical bottom

0.2cm

0.20mL

Example 1

This example is provided to illustrate the use of the method of the present invention for sample pretreatment in Re-Os isotope analysis for Carius tube decomposition of samples

(i) 0.00822g of a standard sample HLP (GBW04436) are weighed out using an analytical balance, added to the transfer container T1 and used previously subjected to HNO₃The Teflon bottle with deionized water boiled cleaned carries the transfer vessel T1, then the Carius tube is tilted using the HNO previously passed₃Clamping a transfer container T1 containing a standard sample HLP (GBW04436) by tweezers boiled and cleaned by deionized water, placing the transfer container into a pipe orifice of a Carius pipe, and slowly erecting the Carius pipe to ensure that the transfer container T1 containing a solid sample to be analyzed slowly slides to the bottom of the Carius pipe along the inner walls of a reducing pipe body and an expanding pipe body of the Carius pipe;

(ii) 0.19003g of diluent (in diluent) are measured out¹⁸⁵The concentration of Re was 7095.32ng/g,¹⁹⁰os concentration of 18.329ng/g), added to 1 transfer vessel T1 and 1 pre-HNO applied₃The transfer container T1 was supported by a Teflon bottle boiled and cleaned with deionized water for use;

(iii) slowly adding liquid nitrogen into a thermos cup filled with ethanol under stirring to form a viscous liquid nitrogen-ethanol mixed refrigerant and provide an environment of-80 to-50 ℃, then placing the Carius tube filled with the solid sample to be analyzed in the step (i) into the mixed refrigerant of-80 to-50 ℃, and transferring the transfer container T1 filled with the diluent into the Carius tube in a mouth-to-mouth mode by using a Teflon bottle carrying the transfer container T1 filled with the diluent in the step (ii) as shown in figure 4;

(iv) maintaining the temperature at-80 to-50 deg.C, after the diluent in the Carius tube was completely frozen, 1.5mL of HCl with a concentration of 37 wt% and 6mL of HNO with a concentration of 68 wt% were sequentially added to the Carius tube via a long-neck glass funnel₃；

(v) After the materials in the Carius tube are completely frozen, a liquefied gas fire gun is used for sealing the tube opening of the Carius tube in a melting way, and a standard sample HLP (GBW04436), a diluent, HCl and HNO are obtained and packaged₃The Carius tube of (1);

(vi) (vi) packaging the standard sample HLP (GBW04436), diluent, HCl and HNO obtained in step (v)₃The Carius tube was placed in an oven and heated at 220 ℃ for 24 h.

Throughout the process of decomposing a sample in a Carius tube, in step (i), the transfer container T1 was used to transfer the standard sample HLP (GBW04436) to the Carius tube, followed by no need to flush the long-neck funnel with an acid agent to transfer the sample to be analyzed entirely into the Carius tube. In step (iii), the diluent is transferred to the Carius tube for 10s, and the transfer container T1 does not closely adhere to the inner wall of the Carius tube to form a local closed space, and the diluent is transferred without flushing the transfer container T1 with an acid agent.

Example 2

(i) 0.08015g of the standard JDC sample (GBW04435) were weighed using an analytical balance and introduced into 1 transfer container T2 using a previously HNO₃The Teflon bottle with deionized water boiled cleaned carries the transfer vessel T2, then the Carius tube is tilted using the HNO previously passed₃The forceps boiled and cleaned by deionized water are used for clamping a transfer container T2 containing a standard sample JDC (GBW04435), the transfer container is placed into the opening of the Carius tube, and then the Carius tube is slowly erected to ensure that the solid sample to be analyzed is containedThe transfer container T2 slowly slides down to the bottom of the Carius tube along the inner walls of the reducing tube body and the expanding tube body of the Carius tube;

(ii) 0.12004g of diluent (in diluent) are measured out¹⁸⁵The concentration of Re was 6952.356ng/g and the concentration of 190Os was 10.4157ng/g), was added to 1 transfer vessel T2 and used previously with HNO₃Carrying and transferring container T2 with Teflon bottle boiled and cleaned by deionized water for standby;

(iii) slowly adding liquid nitrogen into a thermos cup filled with ethanol under stirring to form a viscous liquid nitrogen-ethanol mixed refrigerant and provide an environment at-80 to-50 ℃, then placing the Carius tube filled with the standard sample JDC (GBW04435) in the step (i) into the mixed refrigerant at-80 to-50 ℃, and transferring the transfer container T2 filled with the diluent into the Carius tube in a mouth-to-mouth mode by using the Teflon bottle carrying transfer container T2 in the step (ii) as shown in FIG. 4;

(iv) after the diluent in the Carius tube was frozen, the Carius tube containing the standard sample JDC (GBW04435) and the diluent was kept in a mixed refrigerant at-80 to-50 ℃, and 2mL of HCl with a concentration of 37 wt% and 6mL of HNO with a concentration of 68 wt% premixed with each other were continuously added to the Carius tube through a long-neck glass funnel₃The mixed acid agent of (1);

(v) after the materials in the Carius tube are completely frozen, a liquefied gas fire gun is used for sealing the tube opening of the Carius tube in a melting way, and a standard sample JDC (GBW04435), a diluent, HCl and HNO are packaged₃The Carius tube of (1);

(vi) (vi) encapsulating the standard sample JDC (GBW04435), diluent, HCl and HNO obtained in step (v)₃The Carius tube was placed in an oven and heated at 220 ℃ for 24 h.

Throughout the process of decomposing a sample in a Carius tube, in step (i), a standard sample JDC (GBW04435) was transferred to the Carius tube using transfer vessel T2, followed by no need to flush the long-neck funnel with an acid agent to transfer the sample to be analyzed entirely into the Carius tube. In step (iii), the diluent is transferred to the Carius tube for 10s, and the transfer container T2 does not closely adhere to the inner wall of the Carius tube to form a local closed space, and the diluent is transferred without flushing the transfer container T2 with an acid agent.

Example 3

(i) Slowly adding liquid nitrogen into a thermos cup filled with ethanol under the stirring condition to form a viscous liquid nitrogen-ethanol mixed refrigerant and provide an environment with the temperature of-80 to-50 ℃, and then placing a Carius tube into the mixed refrigerant with the temperature of-80 to-50 ℃;

(ii) 0.12997g of diluent (in diluent) are measured out¹⁸⁵The concentration of Re was 6952.356ng/g,¹⁹⁰os concentration of 10.4157ng/g), added to 1 transfer vessel T3 and used with HNO primed₃And deionized water boiling the cleaned Teflon bottle carrying transfer vessel T3, transfer vessel T3 with diluent into the Carius tube in a "mouth-to-mouth" manner as shown in fig. 4;

(iii) after the diluent in the Carius tube was frozen, 0.08008g of the standard sample JDC (GBW04435) was weighed using an analytical balance, added to 1 transfer vessel T3, and the transfer vessel T3 was carried using a Teflon bottle previously cleaned by boiling with nitric acid and deionized water, and then the Carius tube was kept in a mixed refrigerant of-80 to-50 ℃ while being tilted using a tube previously cleaned with HNO₃Clamping a transfer container T3 containing a standard sample JDC (GBW04435) by tweezers boiled and cleaned by deionized water, placing the transfer container into a tube opening of a Carius tube, and slowly erecting the Carius tube to ensure that the transfer container T3 containing a solid sample to be analyzed slowly slides to the bottom of the Carius tube along the inner walls of a reducing tube body and an expanding tube body of the Carius tube;

(iv) the temperature was maintained at-80 to-50 ℃ and the addition of 2mL of HCl 37 wt% and 6mL of HNO 68 wt% was continued to the Carius tube via a long-neck glass funnel₃；

(vi) (vi) encapsulating the standard sample obtained in step (v)Product JDC (GBW04435), diluent HCl and HNO₃The Carius tube was placed in an oven and heated at 220 ℃ for 24 h.

During the whole process of decomposing the sample by the Carius tube, in the step (ii), the diluent is transferred to the Carius tube for 10s, the phenomenon that the transfer container T3 is tightly attached to the inner wall of the Carius tube to form a local closed space does not occur, and the acid agent is not needed to wash the transfer container T3 after the diluent is transferred. In step (iii), the standard sample JDC (GBW04435) was transferred to the calius tube using transfer vessel T3, followed by no flushing of the long-neck funnel with an acid agent to transfer the sample to be analyzed completely into the calius tube.

Example 4

(i) 0.08011g of the standard sample JDC (GBW04435) was weighed using an analytical balance, and the weighed standard sample JDC (GBW04435) was added to the bottom of the Carius tube via a long-neck glass funnel;

(ii) slowly adding liquid nitrogen into a thermos cup filled with ethanol under stirring to form a viscous liquid nitrogen-ethanol mixed refrigerant and provide an environment at-80 to-50 ℃, and then placing the Carius tube filled with the standard sample JDC (GBW04435) in the step (i) into the mixed refrigerant at-80 to-50 ℃;

(iii) continuing to add HCl to the Carius tube at a concentration of 37 wt% via 3mL of the same long-neck glass funnel, maintaining the conditions at-80 to-50 ℃;

(iv) 0.12990g of diluent (in diluent) are measured out¹⁸⁵The concentration of Re was 6952.356ng/g,¹⁹⁰os concentration of 10.4157ng/g), added to 1 transfer vessel T4 and used with HNO primed₃Carrying and transferring container T4 with Teflon bottle boiled and cleaned by deionized water for standby;

(v) keeping the temperature at-80 to-50 ℃, moving out the long-neck glass funnel, after HCl in the Carius tube is frozen, using a Teflon bottle to bear a transfer container T4, as shown in figure 4, transferring the transfer container T4 filled with diluent into the Carius tube in a mouth-to-mouth mode, wherein after the transfer, the transfer container T4 is tightly attached to the inner wall of the Carius tube to form a local closed space, and the diluent in the transfer container T4 can be released only by repeatedly shaking the Carius tube or transferring the Carius tube again;

(vi) maintaining the temperature at-80 to-50 ℃, after the diluent in the Carius tube was frozen, 6mL of HNO with a concentration of 68 wt.% was continuously added to the Carius tube via the same long-neck glass funnel₃；

(vii) After the materials in the Carius tube are completely frozen, a liquefied gas fire gun is used for sealing the tube opening of the Carius tube in a melting way, and a standard sample JDC (GBW04435), a diluent, HCl and HNO are packaged₃The Carius tube of (1);

(viii) (vii) encapsulating the standard sample JDC (GBW04435), diluent, HCl and HNO obtained in step (vi)₃The Carius tube was placed in an oven and heated at 220 ℃ for 24 h.

In the whole process of decomposing a sample by the Carius tube, in the step (v), after the diluent is transferred to the Carius tube, the diluent in the transfer container T4 can be released only by repeatedly shaking the Carius tube due to the phenomenon that the transfer container T4 is tightly attached to the inner wall of the Carius tube to form a local closed space, so that the diluent is transferred for 1min, and the acid agent is not needed to wash the transfer container T4 after the diluent is transferred.

Comparative example 1

This comparative example serves to illustrate the procedure for sample pretreatment in Re-Os isotope analysis for Carius tube decomposition of samples as a reference

(i) 0.00804g of the standard sample HLP (GBW04436) were weighed using an analytical balance, and the weighed standard sample HLP (GBW04436) was added to the bottom of the Carius tube via a long-neck glass funnel;

(ii) slowly adding liquid nitrogen into a thermos cup filled with ethanol under stirring to form a viscous liquid nitrogen-ethanol mixed refrigerant and provide an environment at-80 to-50 ℃, and then placing the Carius tube filled with the standard sample HLP (GBW04436) in the step (i) into the mixed refrigerant at-80 to-50 ℃;

(iii) 0.19987g of diluent (in diluent) are measured out¹⁸⁵The concentration of Re was 7095.32ng/g,¹⁹⁰os concentration of 18.329ng/g) was added to 1 container having an inner diameter of 1.8cm, an outer diameter of 2.2cm and a height of 3.3cmA cylindrical Teflon transfer device with a volume of 8.4 mL;

(iv) (iv) holding the Carius tube containing the standard sample HLP (GBW04436) in a mixed refrigerant at-80 to-50 ℃, then pouring the diluent contained in the Teflon transfer device of step (iii) into the Carius tube along the same long-neck glass funnel used in step (i), and flushing the Teflon transfer device 6 times with 2mL of hydrochloric acid having a concentration of 37% by weight to completely transfer the diluent in the Teflon transfer device into the Carius tube;

(v) after the diluent in the Carius tube was frozen, the Carius tube containing the standard sample HLP (GBW04436) and the diluent was kept in a mixed refrigerant at-80 to-50 ℃, and 1mL of HCl with a concentration of 37 wt% and 6mL of HNO with a concentration of 68 wt% were sequentially added to the Carius tube via the same long-neck glass funnel as in steps (i) and (iv)₃；

(vi) After the materials in the Carius tube are completely frozen, a liquefied gas fire gun is used for sealing the tube opening of the Carius tube in a melting way, and a standard sample HLP (GBW04436), a diluent, HCl and HNO are obtained and packaged₃The Carius tube of (1);

(vii) (vii) encapsulating the standard sample HLP (GBW04436), diluent, HCl and HNO obtained in step (vi)₃The Carius tube was placed in an oven and heated at 220 ℃ for 24 h.

Throughout the process of decomposing the sample by Carius tube, in step (iv), after the diluent was transferred to the Carius tube using the Teflon transfer device, the Teflon transfer device was rinsed 6 times with 2mL of 37 wt% hydrochloric acid to transfer the diluent in the Teflon transfer device into the Carius tube in its entirety, taking 10min for the diluent transfer.

Comparative example 2

A sample was decomposed in the same manner as in comparative example 1, except that the sample to be analyzed was 0.07998g of the standard sample JDC (GBW04435) and the amount of the diluent was 0.13021g (in the diluent)¹⁸⁵The concentration of Re was 6952.356ng/g,¹⁹⁰os concentration of 10.4157ng/g), step (iv), after the diluent was poured into the Carius tube, the Teflon transfer device was rinsed 5 times with 1.5mL of 37 wt% hydrochloric acid to completely transfer the diluent in the Teflon transfer device into the Carius tube, step (v), followed by(iii) continuously to the Carius tube via the same long-neck glass funnel as in steps (i) and (iv) were added sequentially 1.5mL of 37 wt.% HCl and 6mL of 68 wt.% HNO₃。

Throughout the process of decomposing the sample by Carius tube, in step (iv), after the diluent was transferred to the Carius tube using the Teflon transfer device, the Teflon transfer device was rinsed 5 times with 1.5mL of 37 wt% hydrochloric acid to transfer the diluent in the Teflon transfer device into the Carius tube in its entirety for 5 min.

Test example

(1) Re-Os isotope content and chronologic analysis in samples to be analyzed in each example and comparative example

After the Carius tube in each example and comparative example is heated, the Carius tube is taken out and cooled to room temperature, then the Carius tube is placed in a refrigerant environment at-80 to-50 ℃, after the solution in the Carius tube is completely frozen, the hole is opened on the part of the reducing pipe body of the Carius tube for pressure relief, the fine neck part of the Carius tube is scratched after the pressure relief, and then the Carius tube is placed in a freezer for freezing and storage.

According to the research of rhenium-osmium isotope geological age determination method of Duan Dao, He Red Liao, Yin Ningwan, et al]The distillation method disclosed in the geological news, 1994(4):339-, the other end is connected with a glass colorimetric tube with the volume of 25mL as an absorption device D, and the absorption device D is internally provided with absorption liquidF in 5mL of deionized water and 20. mu.L of an Ir solution with a concentration of 50ng/mL as internal standard and placed in an ice-water bath E. The round-bottom flask is used as a distiller and is placed in an electric heating sleeve C, the electric heating sleeve C is started, the temperature is raised to 120 ℃, the solution in the round-bottom flask is controlled to keep a slightly boiling state, and materials in the round-bottom flask are heated and distilled to obtain OsO₄Starting an air supply device, heating for 1h under the condition that the air flow is adjusted to be 40mL/min by an air pump A, and enabling the OsO in the round-bottom flask₄Is carried to the absorption device D through the air outlet pipe and is completely absorbed by the absorption liquid F in the absorption device D. Will absorb OsO₄The absorption liquid is sent into a sample inlet chamber of an ICP-MS inductively coupled plasma mass spectrometer, ionized gas is obtained through atomization and dissociation, molecular beams are formed, mass separation and counting analysis are carried out, and the content of the Os element and the ratio of the Os isotope in the liquid material in the round-bottom flask are obtained.

After the above-mentioned residue obtained after the Os element was extracted by distillation was cooled and transferred to a 50mL glass beaker, and then the beaker was heated on an electric hot plate at 140 ℃. After the solution in the beaker is evaporated to dryness, adding 5mL of HCl with the concentration of 6mol/L, preserving the heat for 1 hour, adding 5mL of HCl with the concentration of 1mol/L, preserving the heat for 1 hour after the solution is evaporated to dryness, and then transferring the solution into a centrifuge tube for centrifugation. Centrifuge for 10 minutes and wait for column separation. The anion resin is AG1X-8, 2mL of the resin is added into the resin, 10mL of ultrapure water and 10mL of HNO with the concentration of 6mol/L are respectively used₃4mL of ultrapure water was subjected to column washing, 4mL of HCl (1 mol/L) was added to the column to equilibrate the medium, and the sample in the centrifuge tube was introduced into a resin column, followed by 10mL of HCl (1 mol/L) and 10mL of HNO (0.8 mol/L) respectively₃Eluting impurity ions, and finally using 14mL of HNO with the concentration of 6mol/L₃Eluting the Re element, recovering 50mL of Re solution, heating to be nearly dry on a 120 ℃ electric heating plate, metering the volume to be 5mL, and sending to ICP-MS for determination and analysis to obtain the content of the Re element and the ratio of the Re isotope in the Re recovered solution.

Based on the Os element content and Os isotope ratio, and the Re element content and Re isotope ratio in the sample to be analyzed obtained by the above tests, the duration of the sample to be analyzed in each example and comparative example, which was self-sealing up to now, was calculated.

The isotope contents of Re-Os in the samples to be analyzed and the results of the annual analysis in each of examples and comparative examples are shown in Table 3.

(2) After the Re-Os isotope content in the analysis samples of each example and comparative example and the annual analysis were completed, the transfer containers used in each example and comparative example were cleaned, and the cleaning conditions and times were compared as shown in table 4.

(3) Blank background contents of Re element and Os element in examples and comparative examples

A blank sample was pretreated according to the method of Carius tube decomposition sample for sample pretreatment in Re-Os isotope analysis of examples 1-4 and comparative examples 1-2, and the treated Carius tube was subjected to analysis of Re-Os isotope content according to the method of test example to obtain blank background contents of Re element and Os element in each example and comparative example, except that no sample to be analyzed was added and the diluent used was calibrated,¹⁸⁵the concentration of Re was 9.3625ng/g,¹⁹⁰the concentration of Os was 0.94ng/g, and the analysis results are shown in Table 5.

TABLE 3

In table 3, Ma represents a million years.

TABLE 4

TABLE 5

Numbering	Blank background Re content (pg)	Blank background Os content (pg)
			Example 1	2.0±0.2	0.31±0.07
Example 2	1.2±0.2	0.32±0.06
			Example 3	1.1±0.3	0.51±0.05
Example 4	3.0±0.6	0.43±0.04
			Comparative example 1	4.1±0.6	2.35±0.18
Comparative example 2	3.1±0.4	1.16±0.09

As can be seen by comparing the results of examples 1-4 and comparative examples 1-2, the method for decomposing samples by Carius tube for sample pretreatment in Re-Os isotope analysis and the method for Re-Os isotope analysis provided by the invention can select proper specification and using amount of the transfer container according to the using amount of the sample to be analyzed, and the obtained Re-Os isotope analysis accuracy and the Re-Os isotope system annual analysis accuracy are higher and have lower blank background. In addition, the method for decomposing the sample by the Carius tube for sample pretreatment in Re-Os isotope analysis provided by the invention greatly simplifies the operation process and shortens the diluent transfer time and the cleaning time of equipment used in the analysis process. In the sample pretreatment method to be analyzed of comparative examples 1-2, the diluent is transferred by using a traditional Teflon transfer device, and the diluent is transferred to a Carius tube and then needs to be washed for multiple times by using an acid agent, so that the time consumption is long, the temperature control difficulty in the transfer process is high, the oxidation volatilization loss of the Os element is easily caused, and the Re-Os isotope content analysis and the dating result with high accuracy can be obtained by spending a large amount of time and continuously repeating the experiment. Particularly, when the usage amount of the sample to be analyzed is low, the sample to be analyzed is loaded by the transfer container and is added into the Carius tube, so that the phenomenon of insufficient sample transfer can be avoided, the accuracy of an analysis result can be ensured as much as possible, the operation step of washing the sample to be analyzed possibly remaining and adhering to the inner wall of a transfer device for transferring the sample to be analyzed, such as a long-neck funnel, by using an acid agent can be omitted, the usage amount of the acid agent is further saved, the experiment cost is reduced, and the flexibility of transferring materials in the method for decomposing the sample by the Carius tube is improved. Comparing example 2 and example 4, it can be seen that when the size and shape of the transfer container used in the method for decomposing a sample using a Carius tube for sample pretreatment in Re-Os isotope analysis provided in the present invention are within the preferable ranges of the present invention, the Re-Os isotope content in the sample and the sample chronologic analysis are performed with better operability and less time consumption.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A method for decomposing a sample with a Carius tube for sample pretreatment in Re-Os isotope analysis, the method comprising:

(i) under the condition of-80 ℃ to-50 ℃,respectively mixing a sample to be analyzed, a diluent, HCl and HNO₃Adding the mixture into a Carius tube, and after the components are completely frozen, performing melt sealing on the tube opening of the Carius tube to obtain a package of a sample to be analyzed, a diluent, HCl and HNO₃The Carius tube of (1);

(ii) (ii) encapsulating the sample to be analysed obtained in step (i), diluent, HCl and HNO₃The Carius tube is heated at 200 to 240 ℃ for 48 to 72 hours;

wherein in step (i), the diluent is carried by the transfer container and poured into the Carius tube with the tube orifice downward;

the transfer container comprises a pipe orifice (1), a pipe body (2) and a pipe bottom (3), wherein the pipe orifice (1) of the transfer container is of an opening structure, the pipe body (2) is of a cylindrical structure, the pipe bottom (3) is of a sealing structure, and the transfer container is made of high borosilicate glass;

the pipe orifice (1) in the transfer container is of an opening structure with a notch, and the notch is a regular or irregular notch.

2. The method according to claim 1, wherein in step (i), the indentations of the spout (1) in the transfer container are saw-toothed indentations or corrugated indentations.

3. The method according to claim 1, wherein in step (i) the tube bottom (3) in the transfer vessel is a flat bottom, a round bottom or a conical bottom.

4. A method according to any one of claims 1 to 3, wherein in step (i), the process of carrying the diluent together with the transfer container into the calius tube comprises: the transfer container is carried using a previously cleaned carrier device and then the carrier device carrying the transfer container is utilized.

5. The method according to any one of claims 1 to 3, wherein in step (i), the sample to be analyzed is added to the Carius tube via a long-neck funnel.

6. A method according to any one of claims 1 to 3, wherein in step (i), the sample to be analysed is loaded into the calius tube by a transfer container together with the sample to be analysed.

7. A method according to any one of claims 1 to 3, wherein the Carius tube is a plain round-bottomed, reducing borosilicate glass tube, the Carius tube comprising a reducing body and an expanding body, the reducing body having an internal diameter smaller than the internal diameter of the expanding body, the transfer container being provided with a body (2) having an external diameter smaller than the internal diameter of the orifice of the reducing body of the Carius tube.

8. The method of any one of claims 1-3, wherein the diluent is¹⁸⁵Re and¹⁹⁰and mixed solution of Os.

9. A method of isotope analysis for Re-Os, comprising in sequence: decomposing sample, separation and purification and sample injection analysis of Os element, and separation and purification and sample injection analysis of Re element, wherein the method for decomposing sample is the method of any one of claims 1 to 8.