阅读说明：本技术 一种用于滤膜样品同位素比值分析的反应管 (Reaction tube for isotope ratio analysis of filter membrane sample ) 是由 戴守辉 徐辉龙 沈琪 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种用于滤膜样品同位素比值分析的反应管,所述反应管为石英反应管,其内径小于等于12mm。本发明的优点在于：本反应管通过减少内径与增厚管壁,进而减少反应气体在反应管中的通行体积,使得样品图谱的峰宽变窄,峰高增加,最后达到提高仪器分析同位素比值的灵敏度。由于灵敏度的增加,减少了样品称样量,提高了样品的燃烧效率,进而提高仪器操作人员的工作效率,减轻了质谱组操作人员的工作负担。本反应管适用于任何EA和IRMS的仪器,应用需求量很大,涉及面很广。(The invention discloses a reaction tube for isotope ratio analysis of a filter membrane sample, which is a quartz reaction tube, and the inner diameter of the reaction tube is less than or equal to 12 mm. The invention has the advantages that: the reaction tube reduces the inner diameter and thickens the tube wall, so as to reduce the passing volume of reaction gas in the reaction tube, narrow the peak width of a sample map, increase the peak height, and finally improve the sensitivity of the isotope ratio analyzed by an instrument. Due to the increase of sensitivity, the sample weighing amount is reduced, the combustion efficiency of the sample is improved, the working efficiency of instrument operators is further improved, and the workload of mass spectrometer operators is reduced. The reaction tube is suitable for any EA and IRMS instrument, and has large application demand and wide relating range.)

1. A reaction tube for isotope ratio analysis of a filter membrane sample is characterized in that: the reaction tube is a quartz reaction tube, and the inner diameter of the reaction tube is less than or equal to 12 mm.

2. A reaction tube for filter membrane sample isotope ratio analysis in accordance with claim 1, wherein: the thickness of the tube wall of the reaction tube is 3-6 mm, and the outer diameter of the reaction tube is 18 mm.

3. A reaction tube for filter membrane sample isotope ratio analysis in accordance with claim 1, wherein: the reaction tube both ends form the round tilt ring to its lateral surface slope from the reaction tube medial surface respectively, the inclined plane orientation the reaction tube outside, the tilt ring is inboard certainly the reaction tube tip is outwards protruding.

4. A reaction tube for filter membrane sample isotope ratio analysis in accordance with claim 1, wherein: thickening layers are respectively arranged at two ends of the reaction tube, and the joint of the inner end of each thickening layer and the corresponding reaction tube is an inclined plane.

5. The reaction tube for filter membrane sample isotope ratio analysis of claim 4, wherein: the internal diameter of the reaction tube is 6mm, the external diameter of the middle section of the reaction tube is 10mm, and the external diameters of the two ends of the reaction tube are 18 mm.

6. The reaction tube for filter membrane sample isotope ratio analysis of claim 4, wherein: the length of the upper side surface of the thickening layer is 50 mm.

Technical Field

The invention relates to the technical field of laboratory equipment, in particular to a reaction tube for isotope ratio analysis of a filter membrane sample.

Background

Element-stable isotope ratio mass spectrometers (EA-IRMS) are instruments developed in recent years for determining the composition of elemental stable isotopes, among othersHas wide application prospect in various fields. At present, EA-IRMS has a problem which is generally difficult to solve when measuring isotopes of element carbon and nitrogen of a filter membrane sample, the filter membrane sample is easy to react with a filler and a reaction tube to be hardened after high-temperature combustion, ash is difficult to remove, and the filter membrane sample is cracked after being cooled. At present, the oxidation reduction furnace of the element stable isotope mass spectrometer can be provided with a next standard reaction tube with the outer diameter of 18mm, the inner diameter of 14mm, the wall thickness of 2mm and the filling material (longitudinal) of 50mmCr₂O₃，110mmCu，30mmAg₂CoO₄. It is estimated that one reaction tube is about 200 yuan, and the packing is 1200 yuan.

The new packing of the reaction tube can test about 1000 samples in the process of testing animal and plant samples or sediment samples, and the ash can be removed once every 50-200 samples by adding the memory tube, so that the use efficiency of the packing of the reaction tube is greatly improved. However, when a filter membrane sample is tested, because of high-temperature combustion hardening, a brand-new reaction tube can only be used for 150-plus-200 samples, and the ash cannot be removed, and the reaction tube and the filler cannot be reused after temperature reduction, so that the use efficiency of the filler of the reaction tube is greatly reduced, and the use efficiency of the filler is lower than 20%. Due to the design of the reactor, the longitudinal height of the reactor tube packing cannot be changed.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a reaction tube for isotope ratio analysis of a filter membrane sample.

The invention is realized by the following technical scheme: a reaction tube for isotope ratio analysis of a filter membrane sample is a quartz reaction tube, and the inner diameter of the reaction tube is less than or equal to 12 mm.

The setting of the inner diameter of the quartz reaction tube can reduce the volume of the reaction tube, further reduce the using amount of the filler under the condition of unchanging the longitudinal height of the filler, and finally improve the using efficiency of the filler.

The thickness of the tube wall of the reaction tube is 3-6 mm, and the outer diameter of the reaction tube is 18 mm.

The reaction tube both ends form the round tilt ring to its lateral surface slope from the reaction tube medial surface respectively, the inclined plane orientation the reaction tube outside, the tilt ring is inboard certainly the reaction tube tip is outwards protruding.

Thickening layers are respectively arranged at two ends of the reaction tube, and the joint of the inner end of each thickening layer and the corresponding reaction tube is an inclined plane.

The internal diameter of the reaction tube is 6mm, the external diameter of the middle section of the reaction tube is 10mm, and the external diameters of the two ends of the reaction tube are 18 mm.

The length of the upper side surface of the thickening layer is 50 mm.

Compared with the prior art, the invention has the advantages that: this reaction tube is through reducing internal diameter and bodiness pipe wall, and then reduces the inside volume of reaction tube for under the unchangeable condition of the vertical height of packing, reduced the quantity of packing, improve the availability factor of packing at last. And further, a large amount of filler waste easily caused by the filler when a filter membrane sample is tested is reduced, and the mass spectrometry cost is reduced. The reaction tube is suitable for any EA and IRMS instrument, and has large application demand and wide relating range.

Drawings

FIG. 1 is a schematic structural view of example 1 of the present invention;

fig. 2 is a schematic structural diagram of embodiment 2 of the present invention.

The reference numerals in the drawings mean: 1. and (3) a reaction tube.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and detailed description.

Example 1

Referring to fig. 1, a reaction tube 1 for isotope ratio analysis of a filter membrane sample is shown, wherein the reaction tube 1 is a quartz reaction tube 1, and the inner diameter of the reaction tube 1 is less than or equal to 12 mm.

The setting of the inner diameter of the quartz reaction tube 1 can reduce the volume inside the reaction tube 1, further reduce the amount of the filler under the condition that the longitudinal height of the filler is not changed, and finally improve the service efficiency of the filler.

The thickness of the tube wall of the reaction tube 1 is 3-6 mm, and the outer diameter is 18 mm. In this embodiment, the reaction tube 1 is a tube with a wall thickness of 3mm and an inner diameter of 12 mm.

Two ends of the reaction tube 1 are respectively inclined from the inner side surface of the reaction tube 1 to the outer side surface thereof to form a circle of inclined ring, the inclined surface faces the outer side of the reaction tube 1, and the inner side of the inclined ring protrudes outwards from the end part of the reaction tube 1.

Example 2

Referring to fig. 2, another reaction tube 1 for filter membrane sample isotope ratio analysis, example 2 is different from example 1 in that: two ends of the reaction tube 1 are respectively provided with a thickening layer, and the joint of the inner end of the thickening layer and the reaction tube 1 is an inclined plane.

The inner diameter of the reaction tube 1 is 6mm, the outer diameter of the middle section of the reaction tube 1 is 10mm, and the outer diameters of the two ends of the reaction tube 1 are 18 mm.

The length of the upper side of the thickening layer is 50 mm.

In this example, the reaction tube 1 having an inner diameter of 6mm was selected. In this example, the present reaction tube 1 and the existing standard reaction tube 1 having a 2mm thick wall were subjected to a systematic analysis test. After loading a 6mm reaction tube, debugging the instrument to a standby state, selecting a group of standard samples (protein powder standard samples) and a group of filter membrane samples for testing, wherein the standard samples are selected to have 5 concentrations which are 2 parallel, and the actual filter membrane samples are selected to have 5 concentrations which are 5 parallel.

Tests show that after the 6mm thick-wall reaction tube is loaded, a low nitrogen content standard sample and a filter membrane sample with the peak height of 500mV can be accurately analyzed and tested. The difference between the standard sample and the true value is not more than 0.15 per thousand; the method shows that the filter membrane sample can meet the test requirement when the isotope ratio of the nitrogen content sample is analyzed and tested after the thick-wall reaction tube is used. The daily deviation and the diurnal deviation of the standard sample and the membrane sample are both within 0.15 per thousand, which shows that the reaction tube has better stability in daily and diurnal tests after being modified. The data are all slightly better than the standard reaction tubes and meet the analysis and test standards (the data are attached in the test report after the specific implementation mode).

After the reaction tube 1 is assembled, any other parts or software of the instrument do not need to be modified and upgraded, and seamless butt joint use is achieved. In this embodiment, two ends of the reaction tube 1 are thickened, and the normal thickness of the reaction tube 1 is maintained inside the reaction tube, so that the inner diameter is reduced, most of the tube wall of the middle section is not increased, and the stone is made to be stoneThe cooling efficiency of the quartz reaction tube 1 was not greatly changed. The design can also save quartz materials to a great extent, and the effect of reducing the cost is achieved. In this example, the reaction tube 1 was filled with quartz wool 30mm thick and a dehalogenating agent (Ag) 30mm thick from bottom to top in this order₂Co₃O₄) 10mm thick quartz wool, 110mm thick reducing agent (reducing Cu), 10mm thick quartz wool, 50mm thick oxidizing agent (Cr)₂O₃) And 10mm thick quartz wool.

In this embodiment, the internal diameter 6mm of reaction tube 1, the middle part is high temperature region, and wall thickness 2mm has solved the slow condition of reaction tube 1 rising and falling temperature, and its both ends external diameter and thickening layer form wall thickness 6mm, but adaptation reactor uses. The cost of the material for manufacturing the reaction tube 1 is reduced by 11 percent, the cost of the filler is reduced by 82 percent, the analysis and test of 180 filter membrane samples can be completed only by about 400 yuan of material cost, the total cost is reduced by 71 percent, and the utilization rate of the filler is 100 percent.

Type of device	Technical index name (Filler cost)	Efficiency of use of the filler
			Existing standard reaction tube	1400 Yuan	Less than 20 percent
The invention	400 yuan	100％

Test report of 6mm wall thickness reaction tube and standard reaction tube

After the 6mm thick-walled pipe in this project was developed, the following aspects of system test were carried out:

(1) deviation in day test

(2) Daytime offset test

Deviation test in one day and one day

Test site: sample building 101 of south China academy of sciences

The test purpose is as follows: the accuracy and deviation of isotope ratio of 6mm thick-wall pipe in the determination of standard sample and filter membrane sample are tested.

The instrument is debugged to a standby state, two groups of standard samples and two groups of filter membrane samples (the nitrogen content is not higher than 25 mu g) are selected for testing, 5 gradients are respectively set for the sample weighing of each group of samples, each sample is set in a double-parallel mode, and the test results are shown in the attached table 1.

Second, daytime offset test

Test site: sample building 101 of south China academy of sciences

The test purpose is as follows: the accuracy of isotope ratio and the change stability of deviation in the day time of the isotope ratio of the 6mm thick-wall pipe and the standard pipe in the process of measuring the standard sample and the filter membrane sample are tested.

Three day deviation tests were performed, the method is the same as above, and the test results for three days are shown in the attached tables 1-3.

Third, test conclusion

After the 6mm thick-wall reaction tube is loaded, a low nitrogen content standard sample and a filter membrane sample with the peak height of 500mV can be accurately analyzed and tested. The difference between the standard sample and the true value is not more than 0.15 per thousand; the method shows that the filter membrane sample can meet the test requirement when the isotope ratio of the nitrogen content sample is analyzed and tested after the thick-wall reaction tube is used. The daily deviation and the diurnal deviation of the standard sample and the membrane sample are both within 0.15 per thousand, which shows that the reaction tube has better stability in daily and diurnal tests after being modified.

TABLE 16 mm reaction tube in-day (diurnal) bias test

TABLE 26 mm REACTION TUBE DAYTIME TEST

TABLE 36 mm REACTION TUBE DAYTIME TEST

The above detailed description is specific to possible embodiments of the present invention, and the embodiments are not intended to limit the scope of the present invention, and all equivalent implementations or modifications that do not depart from the scope of the present invention are intended to be included within the scope of the present invention.