CN214252158U - Device for determining methyl tert-butyl ether by adopting gas chromatography-mass spectrometry - Google Patents

Abstract

The application relates to a device for determining methyl tert-butyl ether by adopting a gas chromatography-mass spectrometry, which comprises a sampling device for sampling, a trap for collecting the methyl tert-butyl ether in a sample, a gas chromatography-mass spectrometry combined instrument for detection and an enrichment device, wherein the enrichment device comprises an enrichment cylinder, a shell for fixing the enrichment cylinder, a stirring assembly arranged in the enrichment cylinder and a cover body for sealing the enrichment cylinder; the stirring assembly comprises a support piece arranged in the enrichment cylinder, a stirring shaft in running fit with the support piece and stirring blades fixed on the stirring shaft, magnetic pieces are fixedly arranged at two ends of the stirring shaft, a drive is arranged in the shell, a power piece for rotating the magnetic pieces is arranged in the shell, an air inlet pipe is communicated with the side wall of the enrichment cylinder, and a sample discharge pipe is communicated with the cover body. The method and the device have the effect of improving the test accuracy.

Description

Device for determining methyl tert-butyl ether by adopting gas chromatography-mass spectrometry

Technical Field

The application relates to the technical field of methyl tert-butyl ether detection, in particular to a device for determining methyl tert-butyl ether by adopting a gas chromatography-mass spectrometry method.

Background

With the enhancement of environmental awareness of people, people use methyl tert-butyl ether to replace tetraethyl lead as a gasoline additive, so that the content of lead in automobile exhaust is reduced. However, in recent years, it has been found that methyl t-butyl ether causes pollution to natural environments such as water, soil, and air, and therefore, it is necessary to examine the content of methyl t-butyl ether in soil on both sides of roads and in places such as near gas stations and oil depots. A common detection method is a blowing and trapping method, and sampling equipment is required to sample soil at a sampling site before detection.

Chinese patent No. CN207280779U discloses a purging and trapping-gas chromatography-mass spectrometry detection device for analyzing methyl tert-butyl ether in soil, which comprises a sampling device, wherein the sampling device comprises a first support frame, a piston rod, a feeding pipeline, a hydraulic cylinder and a housing, the lower end of the first support frame is provided with the hydraulic cylinder, the housing is internally provided with the piston rod, the upper end of the piston rod is connected with the hydraulic cylinder, the lower end of the piston rod is provided with a sliding base, the feeding pipeline is connected with the sliding base, the lower end of the feeding pipeline is provided with a drill, the upper end of the drill is provided with a sampling component, and the left side and the right side of the upper end of the feeding pipeline are provided with a first feeding hole; the left side and the right side of the feeding pipeline are provided with storage bins, the upper ends of the inner sides of the storage bins are provided with second feeding holes corresponding to the first feeding holes, the outer side surfaces of the storage bins are provided with discharging holes, and multiple parts of soil can be weighed through the storage bins.

With respect to the related art in the above, the inventors consider that the measurement accuracy of the above device is low.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem of low accuracy of the methyl tert-butyl ether determination, the application provides a device for determining the methyl tert-butyl ether by using a gas chromatography-mass spectrometry method.

The device for determining methyl tert-butyl ether by adopting the gas chromatography-mass spectrometry adopts the following technical scheme:

the device for determining the methyl tert-butyl ether by adopting the gas chromatography-mass spectrometry comprises a sampling device for sampling, a trap for collecting the methyl tert-butyl ether in a sample, a gas chromatography-mass spectrometry combination instrument for detecting and an enrichment device, wherein the enrichment device comprises an enrichment cylinder, a shell for fixing the enrichment cylinder, a stirring assembly arranged in the enrichment cylinder and a sealing assembly for sealing the enrichment cylinder; the stirring assembly comprises a support piece arranged in the enrichment cylinder, a stirring shaft in running fit with the support piece and stirring blades fixed on the stirring shaft, magnetic pieces are fixedly arranged at two ends of the stirring shaft, a drive is arranged in the shell, a power piece for rotating the magnetic pieces is arranged in the shell, an air inlet pipe is communicated with the side wall of the enrichment cylinder, and a sample discharge pipe is communicated with the cover body.

By adopting the technical scheme, when the device is used, a soil sample at a sampling place is sampled by using a sampling device, then a proper amount of sample is taken and put into an enrichment cylinder, a certain amount of extraction liquid is added to mix the extraction liquid with the sample, a power part is turned on to drive a magnetic part to rotate, the magnetic part drives a stirring shaft to rotate, stirring blades on the stirring shaft cut and disperse the sample, the extraction liquid is fully mixed with the sample, the extraction liquid extracts methyl tert-butyl ether combined with soil sticky particles, the methyl tert-butyl ether adsorbed in the sample soil is desorbed, and the methyl tert-butyl ether is enriched; then high-purity carrier gas is introduced into the gas inlet pipe, the methyl tert-butyl ether in the enrichment cylinder is discharged through the sample discharge pipe under the pushing action of the carrier gas and then captured by the capture trap, the collection efficiency of the sample is improved, and finally, the methyl tert-butyl ether is analyzed and determined by a gas chromatography-mass spectrometer, so that the methyl tert-butyl ether test accuracy is high and the reliability is good.

Optionally, the support member includes a supporting platform and a plurality of supporting rods, the supporting rods are fixedly connected between the supporting platform and the enrichment cylinder, and the stirring shaft is rotatably connected to the supporting platform.

Through adopting above-mentioned technical scheme, the bracing piece is fixed a supporting bench in the enrichment section of thick bamboo, and the (mixing) shaft rotates on a supporting bench, carries out the dispersion stirring to the sample, and the sample is in encapsulated situation at the stirring in-process, does not contact with external environment, has reduced external impurity and has caused the probability of polluting the sample.

Optionally, the supporting platform comprises a supporting part and a limiting part, the supporting part and the limiting part are detachably sleeved together, a rotating cavity is arranged between the supporting part and the limiting part, a bearing is arranged in the rotating cavity, and the stirring shaft is fixedly connected with the bearing in a coaxial mode.

Through adopting above-mentioned technical scheme, when the (mixing) shaft rotated on the brace table, the sliding friction between (mixing) shaft and the brace table was changed into rolling friction to the bearing, and the frictional force between (mixing) shaft and the brace table that has significantly reduced made the (mixing) shaft rotate the resistance that receives reduce, and is more smooth and easy during the rotation.

Optionally, the stirring blades are uniformly arranged on the outer side wall of the stirring shaft at intervals.

Through adopting above-mentioned technical scheme, stirring vane's cutting can all be received at each orientation to the sample by the even interval setting of stirring vane, makes sample and extraction liquid mix more even, makes methyl tert butyl ether separate with soil clay more easily.

Optionally, one end of the stirring blade, which faces away from the stirring shaft, is hinged with a shearing blade.

Through adopting above-mentioned technical scheme, shear blade cuts the sample under stirring vane's drive, makes the sample also receive the shearing force along enrichment section of thick bamboo axis direction, makes the formation convection current in the sample, and the dispersibility of sample is better.

Optionally, the shearing blades are arranged in a polygon.

By adopting the technical scheme, when a sample passes through the edge of the polygonal shearing blade at a high speed, the shearing blade shears and disperses from multiple directions, turbulent flow is formed in the enrichment cylinder, the dispersibility of the sample is further improved, and the desorption and extraction of the methyl tert-butyl ether are facilitated.

Optionally, the power part includes magnetic steel, and the casing is provided with the drive in enrichment section of thick bamboo below the drive the magnetic steel pivoted driving piece.

By adopting the technical scheme, the driving part drives the magnetic steel to rotate, and the magnetic steel generates periodic magnetic repulsion force to the magnetic part when rotating, so that the magnetic part rotates continuously in an accelerated manner until the magnetic part stably rotates at a certain speed ratio with an output shaft of the driving part.

Optionally, a jacket is arranged on the outer side wall of the enrichment cylinder, and a heating element for heating the enrichment cylinder is arranged in the jacket.

By adopting the technical scheme, the heating element heats the enrichment cylinder in the process of extracting the sample, so that the enrichment cylinder is kept at a certain temperature, the molecular movement rate in the sample is improved, and the separation of methyl tert-butyl ether and soil clay particles is facilitated; when needs are collected methyl tert butyl ether, promote the temperature of enrichment section of thick bamboo through the heating member, make methyl tert butyl ether separate from the extraction liquid, conveniently carry out the entrapment to methyl tert butyl ether, sampling efficiency is higher, convenient and fast.

Optionally, the seal assembly comprises a cover body detachably connected with the enrichment cylinder, a seal groove matched with the end wall of the enrichment cylinder is formed in the cover body, and a seal gasket is arranged in the seal groove.

Through adopting above-mentioned technical scheme, when screwing up the lid, lid tip gets into in the seal groove and seals up the pad and support tightly, reduces the condition that external impurity got into in the enrichment section of thick bamboo, reduces the influence of impurity to the test result, improves the accuracy of test result.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the sample and the extraction liquid are dispersedly stirred by the stirring component under the sealed condition, so that the enrichment degree of the methyl tert-butyl in the extraction liquid is improved, and the condition that external impurities enter an enrichment cylinder to cause sample pollution is reduced, thereby greatly improving the measurement accuracy of the methyl tert-butyl ether;

2. the dispersion degree of the sample is further improved through the stirring blade and the shearing blade, and the separation and desorption of the methyl tert-butyl ether and soil granules are facilitated;

3. the heating assembly is used for providing proper temperature for the enrichment cylinder, so that the extraction and the capture of the methyl tert-butyl ether are facilitated, and the measurement efficiency of the sample is higher.

Drawings

Fig. 1 is a schematic view of the overall structure of the present application.

FIG. 2 is a schematic view of the construction of the stirring assembly of the present application.

Fig. 3 is a partially enlarged schematic view of a portion a in fig. 2.

Description of reference numerals: 1. a housing; 11. a mounting cavity; 2. an enrichment cylinder; 21. an extraction chamber; 22. an air inlet pipe; 23. a shunt tube; 24. a sample discharge pipe; 25. a seal assembly; 251. a cover body; 252. a sealing groove; 253. a gasket; 26. a jacket; 27. a heating cavity; 28. a heating member; 3. a stirring assembly; 31. a stirring shaft; 311. a screw hole; 312. fastening a bolt; 32. a magnetic member; 321. installing blind holes; 322. a countersunk hole; 323. a through hole; 33. a stirring blade; 34. a support member; 341. a support table; 3411. a support portion; 3412. a limiting part; 3413. a bearing; 3414. rotating the disc; 3415. rotating the hole; 342. a support bar; 35. shearing the blade; 4. a power member; 41. a drive member; 42. magnetic steel; 43. and (4) mounting the groove.

Detailed Description

The present application is described in further detail below with reference to figures 1-3.

The embodiment of the application discloses a device for determining methyl tert-butyl ether by adopting a gas chromatography-mass spectrometry method. Referring to fig. 1, the apparatus for measuring methyl t-butyl ether by gas chromatography-mass spectrometry comprises a sampling device for sampling, an enrichment device, a trap, and a gas chromatography-mass spectrometer. Enrichment device is including enrichment section of thick bamboo 2 and the casing 1 that is used for fixed enrichment section of thick bamboo 2, and an enrichment section of thick bamboo 2 is one end open-ended rectangular cylinder, and casing 1 is the cylinder structure, has seted up columniform installation cavity 11 in the casing 1, and the vertical fixed placing of an enrichment section of thick bamboo 2 is in installation cavity 11. The enrichment cylinder 2 is internally provided with an extraction cavity 21 for processing samples, the extraction cavity 21 is internally provided with a stirring component 3, when in use, the samples and the extraction liquid are added into the extraction cavity 21, and the samples and the extraction liquid are stirred and dispersed by the stirring component 3 to extract and enrich the methyl tert-butyl ether. The sealing assembly 25 is installed to enrichment section of thick bamboo 2 opening part, and sealing assembly 25 includes threaded connection at the lid 251 of enrichment section of thick bamboo 2 opening part, and lid 251 seals extraction chamber 21, reduces the probability that the material among the external environment gets into in the extraction chamber 21 and causes the pollution to the sample. The side wall of the enrichment cylinder 2 is communicated with an air inlet pipe 22 and a shunt pipe 23, the top of the cover body 251 is communicated with a sample discharge pipe 24, carrier gas of high-purity nitrogen or helium enters the extraction cavity 21 through the air inlet pipe 22 to purge a sample, methyl tert-butyl ether in the sample is discharged through the sample discharge pipe 24 and enters a trap, and finally the methyl tert-butyl ether is analyzed and determined through a gas chromatography-mass spectrometer.

Referring to fig. 1 and 2, in order to reduce sample contamination, the sample needs to be stirred under a sealed condition, so a magnetic stirring manner is selected. The stirring assembly 3 comprises a stirring shaft 31 positioned at the bottom of the enrichment cylinder 2, magnetic parts 32 fixed at two ends of the stirring shaft 31, stirring blades 33 welded and fixed on the side wall of the stirring shaft 31, and a support part 34 for supporting the stirring shaft 31, wherein the stirring shaft 31 is rotatably installed on the support part 34. The stirring shaft 31 is long-strip-shaped, the cross section of the stirring shaft 31 along the length direction is circular, and the axis of the stirring shaft 31 is superposed with the axis of the enrichment cylinder 2. The magnetic member 32 is a shuttle-shaped block structure, two tip ends of the shuttle shape of the magnetic member 32 are respectively an N pole and an S pole, and the magnetic pole directions of the two magnetic members 32 are the same. In order to mount the magnetic member 32 and the stirring shaft 31 together, two opposite side walls of the magnetic member 32 are symmetrically provided with a blind mounting hole 321 and a counter bore 322, and the cross sections of the blind mounting hole 321 and the counter bore 322 along the axial direction of the stirring shaft 31 are both circular. The diameter of the stirring shaft 31 is matched with that of the mounting blind hole 321, and two ends of the stirring shaft 31 are respectively inserted into the corresponding mounting blind holes 321. A through hole 323 is formed between the counter bore 322 and the installation blind hole 321 in a through manner, both ends of the stirring shaft 31 are opposite to the through hole 323 and are provided with screw holes 311, and the axes of the screw holes 311, the installation blind hole 321 and the through hole 323 are overlapped. A fastening bolt 312 is arranged in the counter bore 322, the fastening bolt 312 passes through the through hole 323 and is in threaded connection with the screw hole 311, and the magnetic member 32 is fixed at two ends of the stirring shaft 31 by tightening the fastening bolt 312.

Referring to fig. 1, in order to provide a magnetic repulsive force to the magnetic member 32 to rotate the magnetic member 32, a power member 4 is disposed in the housing 1, and the power member 4 includes a magnetic steel 42 and a driving member 41 for driving the magnetic steel 42 to rotate. The magnetic steel 42 is a disk-shaped structure and made of a magnetic material. The mounting groove 43 has been seted up on the interior diapire of installation cavity 11, and mounting groove 43 is the cylinder type cell body, and the axis of mounting groove 43 coincides with the axis of installation cavity 11, and driving piece 41 is fixed in mounting groove 43. The driving part 41 is set as a servo motor, the output shaft of the driving part 41 is vertically arranged and is coaxially and fixedly connected with the magnetic steel 42, and a space is arranged between the magnetic steel 42 and the bottom wall of the enrichment cylinder 2. When the device is used, the driving part 41 drives the magnetic steel 42 to rotate, the magnetic steel 42 generates a magnetic repulsive force to the magnetic part 32 at the bottom of the enrichment cylinder 2, so that the magnetic part 32 rotates, and the stirring shaft 31 is driven to rotate to dispersedly stir a sample.

Referring to fig. 2 and 3, in order to make the stirring shaft 31 rotate smoothly, the supporting member 34 includes a supporting base 341 and a plurality of supporting rods 342, the supporting base 341 is in a circular truncated cone shape and is disposed horizontally, the axis of the supporting base 341 coincides with the axis of the enrichment cylinder 2, and the stirring shaft 31 is rotatably connected to the supporting base 341. The number of the support rods 342 is three, one end of each support rod 342 is welded and fixed on the circumferential surface of the support platform 341, and the other end of each support rod 342 is welded and fixed on the inner cylinder wall of the enrichment cylinder 2. The three support rods 342 are evenly distributed along the circumferential surface of the support platform 341 at intervals, and the support platform 341 is stably fixed in the enrichment cylinder 2 through the support rods 342.

With continued reference to fig. 2 and 3, the support platform 341 includes a support portion 3411 and a stopper portion 3412 detachably connected together. Supporting part 3411 and spacing portion 3412 are cylindricly, and spacing portion 3412 is offered towards the one end of supporting part 3411 and is used for holding the spacing chamber of supporting part 3411, all offers the screw thread of looks adaptation on the inner wall in spacing chamber and the face of cylinder of brace table 341, and spacing portion 3412 threaded connection and cover are established on brace table 341. A rotating cavity is formed in one side, facing the limiting portion 3412, of the supporting table 341, the rotating cavity is cylindrical, and the axis of the rotating cavity coincides with the supporting table 341. A rotation hole 3415 is formed through the support 3411 and the stopper 3412, the rotation hole 3415 has a circular cross section along the longitudinal direction, the axis of the rotation hole 3415 coincides with the axis of the support 3411, and the stirring shaft 31 is rotatably fitted in the rotation hole 3415. A bearing 3413 is coaxially fixed in the rotating cavity, a rotating disc 3414 is coaxially welded and fixed on the outer side wall of the stirring shaft 31, and the outer side wall of the rotating disc 3414 is welded and fixed with the inner side wall of the bearing 3413. The friction between the stirring shaft 31 and the supporting base 341 is reduced by the bearing 3413, so that the stirring shaft 31 can rotate more smoothly and more easily.

Referring to fig. 2, in order to improve the stirring effect of the stirring shaft 31 on the sample, the stirring blade 33 is configured to be a rectangular strip-shaped sheet structure, and the stirring blade 33 is made of a wear-resistant and corrosion-resistant material. Four sets of stirring blades 33 are provided, and the four sets of stirring blades 33 are installed on both sides of the supporting table 341 in pairwise symmetry. The number of each group of stirring blades 33 is three, the three stirring blades 33 are uniformly distributed along the outer side surface of the stirring shaft 31 at intervals, and the three stirring blades 33 in the same group are positioned on the same horizontal plane. Because stirring vane 33 stirs the sample at the stirring in-process on the horizontal direction, in order also to carry out the dispersion stirring to the sample in vertical direction, stirring vane 33 deviates from that the one end of (mixing) shaft 31 is articulated to have shear blade 35, and shear blade 35 is the polygon, and shear blade 35 sets up to triangle-shaped in this embodiment, and shear blade 35 and stirring vane 33's pin joint is located shear blade 35's apex angle department.

Referring to fig. 1, the outer side wall of the enrichment cylinder 2 near the bottom is further coated and welded with a jacket 26, a heating cavity 27 is formed between the jacket 26 and the outer side wall of the enrichment cylinder 2, a heating element 28 is arranged in the heating cavity 27, the heating element 28 is an electric heating wire, and the electric heating wire is spiral. The heating wire is electrically connected with a current regulator. When the device is used, the electric heating wires are electrified and heat the enrichment cylinder 2, and the current regulator can regulate the current of the electric heating wires according to requirements to control the heating temperature.

Referring to fig. 1, an annular sealing groove 252 is formed on the inner bottom surface of the cover 251, and the end of the enrichment cylinder 2 can be snap-fitted into the sealing groove 252. The sealing gasket 253 is arranged in the sealing groove 252, the sealing gasket 253 is made of corrosion-resistant rubber, when the cover body 251 is screwed, the end part of the enrichment cylinder 2 is tightly abutted against the sealing gasket 253, so that the enrichment cylinder 2 is well sealed, and the probability of pollution to a sample is reduced.

The implementation principle of the device for determining the methyl tert-butyl ether by adopting the gas chromatography-mass spectrometry is as follows: sampling at a sampling point by using a sampling device, weighing a certain amount of sample, putting the sample into the enrichment cylinder 2, adding a proper amount of extract liquor, screwing the cover body 251 to seal the extraction cavity 21; then, the driving part 41 is opened to drive the magnetic steel 42 to rotate, the magnetic part 32 is driven to rotate, the stirring shaft 31 is enabled to mix and stir the sample and the extraction liquid in the extraction cavity 21, the methyl tert-butyl ether in the sample enters the extraction liquid, then the tetrabutyl tert-butyl ether is volatilized under the heating condition, carrier gas is introduced into the air inlet pipe 22, the methyl tert-butyl ether above the sample is blown into the trapping trap through the sample discharge pipe 24, then the gas chromatography-mass spectrometer is used for analysis and determination, and the test accuracy of the methyl tert-butyl ether in the sample is improved.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (9)

1. An apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry, which comprises a sampling device for sampling, a trap for collecting methyl tert-butyl ether in a sample, and a gas chromatography-mass spectrometer for detection, and is characterized in that: the device further comprises an enrichment device, wherein the enrichment device comprises an enrichment cylinder (2), a shell (1) for fixing the enrichment cylinder (2), a stirring assembly (3) arranged in the enrichment cylinder (2), and a sealing assembly (25) for sealing the enrichment cylinder (2); stirring subassembly (3) are including setting up support piece (34) in the enrichment section of thick bamboo (2), with support piece (34) normal running fit's (mixing) shaft (31) and fixing stirring vane (33) on (mixing) shaft (31), (mixing) shaft (31) both ends are fixed and are provided with magnetic part (32), be equipped with the drive in casing (1) magnetic part (32) pivoted power part (4), seal assembly (25) are including lid (251) of threaded connection at an enrichment section of thick bamboo (2) opening part, the intercommunication has intake pipe (22) on an enrichment section of thick bamboo (2) lateral wall, the intercommunication has layout pipe (24) on lid (251).

2. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 1, wherein: the supporting piece (34) comprises a supporting platform (341) and a plurality of supporting rods (342), the supporting rods (342) are fixedly connected between the supporting platform (341) and the enrichment cylinder (2), and the stirring shaft (31) is rotatably connected to the supporting platform (341).

3. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 2, wherein: the supporting table (341) comprises a supporting part (3411) and a limiting part (3412), the supporting part (3411) and the limiting part (3412) are detachably sleeved together, a rotating cavity is formed between the supporting part (3411) and the limiting part (3412), a bearing (3413) is arranged in the rotating cavity, and the stirring shaft (31) is coaxially and fixedly connected with the bearing (3413).

4. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 1, wherein: the stirring blades (33) are uniformly arranged on the outer side wall of the stirring shaft (31) at intervals.

5. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 4, wherein: and one end of the stirring blade (33) departing from the stirring shaft (31) is hinged with a shearing blade (35).

6. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 5, wherein: the shearing blades (35) are arranged in a polygonal shape.

7. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 1, wherein: the power part (4) comprises magnetic steel (42), and the shell (1) is provided with a driving part (41) for driving the magnetic steel (42) to rotate below the enrichment cylinder (2).

8. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 1, wherein: the outer side wall of the enrichment cylinder (2) is provided with a jacket (26), and a heating element (28) for heating the enrichment cylinder (2) is arranged in the jacket (26).

9. The apparatus for detecting methyl tert-butyl ether by gas chromatography-mass spectrometry as claimed in claim 1, wherein: the sealing assembly (25) comprises a cover body (251) detachably connected with the enrichment cylinder (2), a sealing groove (252) matched with the end wall of the enrichment cylinder (2) is formed in the cover body (251), and a sealing gasket (253) is arranged in the sealing groove (252).

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