Ion analysis device

Abstract

An ion analysis apparatus (10) is provided for generating product ions by irradiating precursor ions derived from a sample component with free radicals and analyzing the product ions. The ion analysis apparatus (10) includes: a reaction chamber (142) for introducing the precursor ions; a free radical generation section (151) for generating free radicals; and a free radical delivery tube (152) connecting the free radical generation section (151) and the reaction chamber (142). At least a portion of the inner wall surface of the free radical delivery tube (152) is made of a material that, compared to alumina or quartz, results in less adhesion or weaker adhesion of the free radicals to the inner wall surface of the free radical delivery tube (152). Preferably, one end (1523) of the free radical delivery tube (152) is disposed within the reaction chamber (142) in a direction toward a predetermined region (1424) of ion bias within the reaction chamber (142).

Description

Technical Field

[0001] This invention relates to an ion analysis apparatus that generates product ions by irradiating precursor ions derived from sample components with free radicals and then performs mass spectrometry analysis, ion mobility analysis, and the like. Background Technology

[0002] To identify or analyze the structure of polymers, mass spectrometry is used to dissociate ions (precursor ions) originating from the polymer compound once or multiple times to generate product ions, which are then separated and detected according to their mass-to-charge ratio. A representative method for ion dissociation is collision-induced dissociation (CID), which involves colliding ions with inert gas molecules such as nitrogen. CID utilizes the collision energy with inert molecules to dissociate ions, thus enabling the dissociation of various ions; however, the selectivity for the dissociation site is low. Therefore, CID is not suitable for situations where dissociation at a specific location within the ion is required for structural analysis.

[0003] Methods for dissociating ions at specific locations have traditionally included electron transfer dissociation (ETD), where negative ions collide with precursor ions, and electron capture dissociation (ECD), where electrons are irradiated onto the precursor ion. In these methods, negative ions and electrons are irradiated onto the precursor ion, generating unpaired electrons at specific locations within the precursor ion, where dissociation occurs. However, in ETD and ECD methods, when the precursor ion is positive, the valence of the ion decreases during dissociation. Therefore, if a monovalent positive ion dissociates, a neutral molecule is generated. Consequently, ETD and ECD methods are not suitable when the precursor ion contains a large number of monovalent positive ions.

[0004] Patent Document 1 describes a method for dissociating precursor ions at specific locations by irradiating them with a free radical. In this method, unpaired electrons are generated at specific locations within the precursor ion through free radical irradiation, thereby causing dissociation at those specific locations. This method shares the same aspect of generating unpaired electrons as the ETD and ECD methods, but the valence of the ion does not change during dissociation, thus it can also be applied when the precursor ion is a monovalent positive ion. The free radicals used for irradiating the precursor ion can be hydrogen radicals, hydroxyl radicals, oxygen radicals, nitrogen radicals, etc.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. WO2020 / 152806

[0008] Non-patent literature

[0009] Non-Patent Literature 1: DR. Warren, “Surface effects in combustion reactions. Part 2. - Activity of surfaces towards some possible chain-carriers and combustion intermediates”, Transactions of the Faraday Society, published by the Royal Society of Chemistry, (UK), 1957, Vol. 53, pp. 206-209. Summary of the Invention

[0010] The problem the invention aims to solve

[0011] In the apparatus described in Patent Document 1, free radicals generated in a free radical generation chamber are introduced into a reaction chamber such as an ion trap or a collision chamber through a free radical delivery tube made of alumina or quartz. Then, the precursor ions are dissociated by irradiating the free radicals into the reaction chamber. At this time, some of the free radicals adhere to the inner wall surface of the free radical delivery tube, reducing the amount of free radicals supplied to the reaction chamber to the amount corresponding to the free radicals adhering to the inner wall surface. As a result, the efficiency of precursor ion dissociation is reduced.

[0012] This explanation has taken the example of mass spectrometry analysis of product ions generated by the dissociation of precursor ions through irradiation with free radicals. However, the same problem arises when other methods are used to analyze product ions.

[0013] The problem to be solved by the present invention is to provide an ion analysis device that can utilize free radicals to more efficiently dissociate precursor ions.

[0014] Solution for solving the problem

[0015] The first technical solution of the ion analysis apparatus of the present invention, which addresses the above-mentioned problems, is an ion analysis apparatus that generates product ions by irradiating precursor ions derived from sample components with free radicals and then analyzes these product ions.

[0016] The ion analysis device includes:

[0017] A reaction chamber for introducing the precursor ions;

[0018] The radical generation section, which generates free radicals; and

[0019] A free radical delivery tube connects the free radical generation section and the reaction chamber.

[0020] At least a portion of the inner wall surface of the free radical delivery tube is composed of a material to which the free radicals adhere less or have weaker adhesion than alumina or quartz.

[0021] The second technical solution of the ion analysis device of the present invention is an ion analysis device that generates product ions by irradiating precursor ions derived from sample components with free radicals and then analyzes the product ions.

[0022] The ion analysis device includes:

[0023] A reaction chamber for introducing the precursor ions;

[0024] The radical generation section, which generates free radicals; and

[0025] A free radical delivery tube connects the free radical generation section and the reaction chamber.

[0026] One end of the free radical delivery tube is disposed in the reaction chamber, facing a predetermined region of ion bias within the reaction chamber.

[0027] A third technical solution of the ion analysis device of the present invention is an ion analysis device that generates product ions by irradiating precursor ions derived from sample components with free radicals and then analyzes the product ions.

[0028] The ion analysis device includes:

[0029] A reaction chamber for introducing the precursor ions;

[0030] The radical generation section, which generates free radicals; and

[0031] A free radical delivery tube connects the free radical generation section and the reaction chamber.

[0032] The ion analysis device also includes:

[0033] A connector having a cylindrical portion and an enlarged portion, one end of the cylindrical portion being connected to the interior of the reaction chamber through an opening in the reaction chamber, the cylindrical portion having an inner diameter smaller than the diameter of the opening for insertion of the free radical delivery tube, the enlarged portion being connected to the other end of the cylindrical portion, the inner diameter increasing as it moves away from the other end; and

[0034] A retainer that holds the connector so that it can move along the outer surface of the reaction chamber.

[0035] The effects of the invention

[0036] <First Technical Solution>

[0037] In the ion analysis apparatus of the first technical solution, a free radical delivery tube is used, the inner wall surface of which is at least partially made of a material that has a lower amount or lower adhesion of free radicals (i.e., free radicals generated in the free radical generation section) compared to alumina, quartz, etc. This suppresses the adhesion of free radicals generated in the free radical generation section to the inner wall surface of the free radical delivery tube, increasing the amount of free radicals supplied to the reaction chamber. Therefore, the ion analysis apparatus of the first technical solution can improve the efficiency of precursor ion dissociation. Here, the "adhesion amount" and "adhesion force" of free radicals to the surface of an object (in this invention, the inner wall surface of the free radical delivery tube) are determined in relation to the probability (adhesion probability) of free radicals in contact with the surface of that object. In other words, the lower the adhesion probability, the lower the amount of free radicals adhering to the surface of the object, and the lower the adhesion force. Borosilicate glass is an example of a material that has a lower amount or lower adhesion force of free radicals to a surface compared to alumina, quartz, etc. Borosilicate glass has the advantage of being less susceptible to adhesion to hydrogen and oxygen free radicals compared to alumina and quartz.

[0038] <Second Technical Solution>

[0039] In reaction chambers such as ion traps and collision chambers, the distribution of the electric field typically becomes non-uniform. Furthermore, in collision chambers, the electric field is intentionally tilted relative to the ion's direction of travel to achieve high-speed ion convergence. If such a non-uniform or tilted electric field distribution is formed, ions (including precursor ions and ions intermediate in the process of multiple dissociations of precursor ions) are biased into a specific region within the reaction chamber. In the ion analysis apparatus of the second technical solution, one end of the free radical delivery tube is oriented towards this ion-biased region, thereby enabling efficient supply of free radicals to that region and further improving the efficiency of ion dissociation.

[0040] To orient one end of the radical delivery tube toward the ion bias region, the tube can be installed either obliquely on the wall of the reaction chamber or vertically, with the tube bent within the chamber so that its tip faces the region. However, when the tube is bent, radicals readily collide with the inner wall at the bend, resulting in radical adhesion and a decrease in the amount of radicals supplied to the reaction chamber. In the second technical solution's ion analysis apparatus, a radical delivery tube is used, which has the advantage of making it difficult for radicals (especially oxygen radicals) to adhere compared to materials like alumina or quartz. Therefore, even with the bend, the decrease in the amount of radicals supplied to the reaction chamber can be suppressed.

[0041] <Technical Solution 3>

[0042] In mass spectrometry apparatuses, reaction chambers such as ion traps and collision chambers are typically housed within a vacuum container. In contrast, the radical generation unit, being a larger component with associated electric and magnetic fields, is located outside the vacuum container. Therefore, the radical delivery tube needs to be installed from outside the vacuum container into the reaction chamber inside. During this installation (especially installation inside the reaction chamber), operators cannot visually confirm the position of the opening in the reaction chamber through which the radical delivery tube should pass. This poses a risk of pushing the radical delivery tube in an misaligned position, resulting in breakage. For example, when using a glass radical delivery tube, which has lower mechanical strength compared to conventional radical delivery tubes made of alumina, quartz, etc., as the radical delivery tube used in this invention, breakage is more likely.

[0043] Therefore, in the ion analysis apparatus of the third technical solution, a connector held by a retainer and movable along the outer surface of the reaction chamber is used to insert a free radical delivery tube into the opening of the reaction chamber. When installing the free radical delivery tube into the reaction chamber, the tube is inserted through the expanded portion of the connector, through the cylindrical portion, and into the reaction chamber opening. Even if the position of the free radical delivery tube is slightly offset from the position of the cylindrical portion, the connector can be moved along the outer surface of the reaction chamber by the tip of the free radical delivery tube pressing against the inner wall of the expanded portion, thus inserting the free radical delivery tube into the cylindrical portion. Furthermore, the diameter of the opening is larger than the inner diameter of the cylindrical portion (the inner diameter of the cylindrical portion is smaller than the diameter of the opening), so even if the connector moves slightly along the outer surface, the free radical delivery tube that has passed through the cylindrical portion also passes through the opening. Therefore, the free radical delivery tube can be easily installed into the reaction chamber without damage. Attached Figure Description

[0044] Figure 1 This is a schematic diagram showing the overall structure of a mass spectrometry analysis apparatus as one embodiment of the ion analysis apparatus of the present invention.

[0045] Figure 2 This is a magnified view of a portion of the mass spectrometry analysis apparatus of this embodiment.

[0046] Figure 3 This is a magnified view of a portion of the mass spectrometry analysis apparatus of this embodiment, including the connector.

[0047] Figure 4 This diagram illustrates the state in which the first part of the free radical delivery tube is inserted into the collision chamber when the central axis of the first part of the free radical delivery tube is offset from the center of the collision chamber opening.

[0048] Figure 5 This diagram shows the state in which the connector has moved to the left when the free radical delivery pipe is installed in the collision chamber.

[0049] Figure 6 The graph shows the results of measuring OAD (oxygen adsorption dissociation) efficiency when using a free radical transport tube made of borosilicate glass (equivalent to this embodiment) and a free radical transport tube made of alumina (comparative example), respectively. Detailed Implementation

[0050] use Figures 1-6 The embodiments of the ion analysis apparatus of the present invention will be described.

[0051] (1) Structure of the ion analysis device (mass spectrometry device) in this embodiment

[0052] exist Figure 1 The structure of the mass spectrometry analysis apparatus 10, which is the ion analysis apparatus of this embodiment, is roughly shown in the figure. Figure 2 The detailed structure of this part is shown in a magnified view of a portion of the mass spectrometry analysis apparatus 10. The mass spectrometry analysis apparatus 10 has a multi-stage differential venting system structure: a first intermediate vacuum chamber 12 and a second intermediate vacuum chamber 13 are provided between an ionization chamber 11 at approximately atmospheric pressure and an analysis chamber 14 with a high vacuum vented by a vacuum pump (not shown), where the vacuum level is progressively increased. An ESI probe 111 is provided, for example, in the ionization chamber 11. An ion guide 121 is provided in the first intermediate vacuum chamber 12 and an ion guide 131 is provided in the second intermediate vacuum chamber 13 to converge ions and transport them to subsequent stages. The analysis chamber 14 is provided with a pre-stage quadrupole mass filter 141 that separates ions according to their mass-to-charge ratio, a collision chamber 142 (corresponding to the reaction chamber) with a multi-stage ion guide 143 inside, a post-stage quadrupole mass filter 144 that separates ions according to their mass-to-charge ratio, and an ion detector 145.

[0053] The mass spectrometry analysis apparatus 10 also includes a free radical generation and irradiation unit 15. The free radical generation and irradiation unit 15 has a free radical generation device 151 and a free radical delivery tube 152.

[0054] The free radical generation apparatus 151 includes a free radical generation chamber 1511, a gas supply source 1512 for supplying a gas that becomes a raw material for free radicals into the free radical generation chamber 1511, and a high-frequency electromagnetic field source 1513. The raw material gas may be oxygen, air, water vapor, etc. The high-frequency electromagnetic field source 1513 includes a coil and a high-frequency power supply (not shown). A high-frequency current flows from the high-frequency power supply to the coil, thereby forming a high-frequency electromagnetic field within the free radical generation chamber 1511. After the free radical raw material gas is introduced from the gas supply source 1512 into the free radical generation chamber 1511, a high-frequency electromagnetic field is formed within the free radical generation chamber 1511 using the high-frequency electromagnetic field source 1513, thereby generating free radicals within the free radical generation chamber 1511. For example, oxygen free radicals are generated when the raw material gas is oxygen, oxygen and nitrogen free radicals are generated when the raw material gas is air, and hydrogen, oxygen, and hydroxyl free radicals are generated when the raw material gas is water vapor.

[0055] The free radical delivery tube 152 connects the free radical generation chamber 1511 and the collision chamber 142, and is used to introduce free radicals generated in the free radical generation chamber 1511 into the collision chamber 142. In this embodiment, the free radical delivery tube 152 is made of borosilicate glass. A representative example of borosilicate glass is Belle (registered trademark) manufactured by Corning Incorporated. Compared to tubes using alumina, quartz, etc., the free radical delivery tube 152 made of borosilicate glass has the advantage of making it difficult for free radicals (especially oxygen free radicals) to adhere, i.e., resulting in a smaller amount of adhesion and weaker adhesion.

[0056] The free radical delivery tube 152 is inserted into the collision chamber 142 through the analysis chamber opening 146 provided in the analysis chamber (corresponding to the above-mentioned vacuum container) 14 and the collision chamber opening (corresponding to the "opening provided in the reaction chamber") 1421 provided in the collision chamber 142.

[0057] In this embodiment, the free radical generation chamber 1511 is constructed from a borosilicate glass tube integral with the free radical delivery tube 152. Therefore, similar to the free radical delivery tube 152, free radicals are difficult to adhere to the free radical generation chamber 1511. However, this is not essential in this invention, and a separate free radical generation chamber 1511 relative to the free radical delivery tube 152 can also be used. While a separate free radical generation chamber 1511 is preferred, it is also not essential in this invention.

[0058] A connector 16 is provided on the outside of the collision chamber 142. Figure 3The image shows an enlarged view of the vicinity of connector 16. Connector 16 includes a cylindrical portion 161, an expanded diameter portion 162, and a sealing plate 163. One end of the cylindrical portion 161 is connected to the interior of the collision chamber 142 through a collision chamber opening 1421, and the cylindrical portion 161 has an inner diameter smaller than the collision chamber opening 1421. The expanded diameter portion 162 is connected to the other end of the cylindrical portion 161 and has a diameter that increases with distance from the other end of the cylindrical portion 161 (or the collision chamber 142) towards... Figure 3 The upper part of the tube 161 has a flared shape with an expanded inner diameter. The free radical delivery tube 152 is inserted into the aforementioned cylindrical part 161 and the expanded diameter part 162. The sealing plate 163 is a plate-shaped member that extends radially outward from one end of the cylindrical part 161 and contacts the outer surface 1420 of the collision chamber 142, which is located around the collision chamber opening 1421. A vacuum seal 164 composed of O-rings is provided between the sealing plate 163 and the outer surface 1420 of the collision chamber 142.

[0059] The connector 16 is mounted on the outer surface 1420 of the impact chamber 142 by bolts (corresponding to the aforementioned retainer) 1632 that pass through two through holes 1631 provided in the sealing plate 163 and are fastened to the outer surface 1420 of the impact chamber 142. The diameter of the through hole 1631 is smaller than the diameter of the head of the bolt 1632 and larger than the diameter of the shank of the bolt 1632. Therefore, a gap 1633 is formed between the edge of the through hole 1631 and the shank of the bolt 1632. In this embodiment, it is designed such that when the center of the through hole 1631 is aligned with the central axis of the bolt 1632 (at which time, the central axis of the cylinder 161 is also aligned with the center of the impact chamber opening 1421), a gap 1633 of about 1 mm is formed around the shank, but the design value of the size of the gap 1633 can also be appropriately changed. The connector 16 can move along the outer surface 1420 of the impact chamber 142 in accordance with this gap 1633.

[0060] A flange 1461 is provided around the opening 146 of the analysis chamber. A cover 1462 with a free radical delivery tube 152 passing through its center is installed on the flange 1461. In addition, a vacuum seal 1463 made of an annular copper plate is provided between the flange 1461 and the cover 1462. Thus, the opening 146 of the analysis chamber is airtightly sealed.

[0061] The free radical delivery pipe 152 is divided within the cylindrical portion 161 into a first portion 1521 on the side of the free radical generation chamber 1511 and a second portion 1522 on the side of the collision chamber 142. Furthermore, vacuum seals 1611, each consisting of an O-ring, are provided between the first portion 1521 and the inner wall of the cylindrical portion 161, and between the second portion 1522 and the inner wall of the cylindrical portion 161. The joint between the first portion 1521 and the second portion 1522 is not bonded, and no vacuum seal is provided at this joint. However, vacuum seals 1611 are provided between the first portion 1521 and the second portion 1522 and the inner wall of the cylindrical portion 161, thereby preventing free radicals from leaking from this joint to the outside of the connector 16.

[0062] The first portion 1521 of the free radical transport tube 152 is entirely straight. In contrast, the second portion 1522, disposed within the collision chamber 142, is straight within the connector 16, but outside the connector 16 (on the collision chamber 142 side), a bend 1524 is provided in the free radical transport tube 152 such that its tip (one end) 1523 faces the area near the ion outlet 1423 of the collision chamber 1422 (the "predetermined area") 1424. The area 1424 near the ion outlet 1423 on the top side facing the tip 1523 of the free radical transport tube 152 becomes an area where ions are easily retained and the ion concentration in the collision chamber 142 as a whole is relatively high.

[0063] (2) Operation during assembly of the mass spectrometry analysis apparatus of this embodiment

[0064] Next, the operation of assembling the mass spectrometry analysis apparatus 10 of this embodiment, particularly the operation of installing the free radical delivery tube 152 into the collision chamber 142, will be described.

[0065] First, the tube consisting of the first part 1521 and the free radical generation chamber 1511 integral with the first part 1521 in the free radical delivery tube 152 is inserted into the coil of the high-frequency electromagnetic field source 1513. Simultaneously, the straight portion of the second part 1522 is inserted into the cylindrical portion 161 of the connector 16. The connector 16 and the second part 1522 inserted into it are mounted to the outer surface 1420 using bolts 1632 before the collision chamber 142 is placed in the analysis chamber 14. At this time, as described above, a gap 1633 of approximately 1 mm is formed around the shank of the bolt 1632.

[0066] After the collision chamber 142 is placed inside the analysis chamber 14, the first part 1521 of the free radical delivery tube 152, which is fixed to the high-frequency electromagnetic field source 1513, is inserted into the analysis chamber 14 from outside through the analysis chamber opening 146, and then inserted into the cylindrical part 161 of the connector 16. At this time, the operator cannot visually confirm the position of the connector 16 inside the analysis chamber 14. Therefore, with the central axis of the free radical delivery tube 152 and the central axis of the cylindrical part 161 misaligned, it is possible that the top end of the free radical delivery tube 152 may be pressed against the connector 16. Figure 4 In this situation, the inner wall surface of the expanded section 162, formed by expanding the diameter from the side of the cylinder 161, is pushed by the top end of the free radical delivery pipe 152, thereby causing the connector 16 to move along the outer surface 1420 of the collision chamber 142 (in Figure 5 (In the example shown, it moves to the left). Thus, the central axis of the free radical delivery tube 152 is aligned with the central axis of the cylinder 161, allowing the first portion 1521 of the free radical delivery tube 152 to be inserted into the cylinder 161. At this time, the collision chamber opening 1421 is larger than the inner diameter of the cylinder 161 (and the outer diameter of the second portion 1522), so the second portion 1522, pre-installed in the cylinder 161, can also move together with the connector 16. Thus, the installation of the free radical delivery tube 152, consisting of the first portion 1521 and the second portion 1522, is completed.

[0067] When using borosilicate glass, which has relatively weak mechanical strength, as the material for the free radical delivery tube 152 in this embodiment, there is a risk of breakage if the collision chamber 142 is forcibly installed when the free radical delivery tube 152 is not positioned correctly. However, according to this embodiment, even if the central axis of the free radical delivery tube 152 and the central axis of the cylinder 161 are misaligned at the initial time point, the free radical delivery tube 152 can still be inserted into the cylinder 161, thus preventing breakage due to forcibly pushing the free radical delivery tube 152 in.

[0068] Furthermore, in this embodiment, the free radical delivery tube 152 is divided into a straight first portion 1521 and a second portion 1522 with a bend 1524 (bent). Therefore, by pre-installing the second portion 1522 on the connector 16 before placing the collision chamber 142 into the analysis chamber 14, only the straight first portion 1521 needs to be inserted into the connector 16 from outside the analysis chamber 14 through the analysis chamber opening 146, thus simplifying the operation.

[0069] Furthermore, in the mass spectrometry analysis apparatus 10 of this embodiment, depending on the insertion position of the first part 1521 during assembly, the position of the final fixed tip 1523 of the free radical delivery tube 152 may vary within a range (approximately ±1 mm) corresponding to the gap 1633 around the shank of the bolt 1632 in the direction of ion movement in the collision chamber 142. However, since the direction of ion movement in the collision chamber 142 is sufficiently large compared to the magnitude of this positional difference, this positional difference is not a practical problem.

[0070] (3) Operation of the mass spectrometry analysis device in this embodiment

[0071] The operation of the mass spectrometry analysis apparatus 10 according to this embodiment is explained. Before the analysis begins, a vacuum pump is used to exhaust the space from the ionization chamber 11 to the analysis chamber 14 to a predetermined vacuum level. At the start of the analysis, a liquid sample, for example, passed through a liquid chromatography column (not shown), is supplied to the ESI probe 111. In the ESI probe 111, the liquid sample is sprayed into the ionization chamber 11 through a capillary, and a high voltage is applied between the capillary and ground. As a result, the solvent of the liquid sample is removed in the ionization chamber 11, generating ions derived from the sample. The generated ions are introduced into the first intermediate vacuum chamber 12 and focused by the ion guide (ion lens) 121, and then introduced into the second intermediate vacuum chamber 13 and further focused by the octet type ion guide 131. The ions focused by the ion guide 131 are introduced into the pre-quadrupole mass filter 141 in the analysis chamber 14. In the pre-quadrupole mass filter 141, only ions with a specific mass-to-charge ratio corresponding to the applied voltage pass through. In this way, the ions that have passed through the pre-stage quadrupole mass filter 141 are introduced into the collision chamber 142 as precursor ions.

[0072] In the collision chamber 142, precursor ions are dissociated by colliding an inert gas (CID gas) with precursor ions passing through the multipolar ion guide 143. Furthermore, free radicals generated in the free radical generation chamber 1511 are supplied into the collision chamber 142 through the free radical delivery pipe 152. Thus, precursor ions or ions resulting from the dissociation of precursor ions come into contact with free radicals, causing these ions to dissociate. This generates various product ions. The generated product ions are separated according to each mass-to-charge ratio using a subsequent quadrupole mass filter 144 and detected according to each mass-to-charge ratio in an ion detector 145.

[0073] In the mass spectrometry analysis apparatus 10 of this embodiment, the free radical delivery tube 152, which supplies free radicals to the collision chamber 142, is made of borosilicate glass. As described in Non-Patent Document 1, borosilicate glass has the advantage of making it difficult for free radicals, especially oxygen free radicals, to adhere, i.e., the amount of free radicals adhering is small and the adhesion is weak. Therefore, it is possible to suppress the adhesion of free radicals to the inner wall surface of the free radical delivery tube 152 and increase the amount of free radicals supplied to the collision chamber 142. As a result, the efficiency of dissociating precursor ions in the collision chamber 142 can be improved.

[0074] Here, the results of experiments conducted to determine the OAD efficiency using borosilicate glass and alumina free radical transport tubes, respectively, to confirm the effect of free radical adhesion to the inner wall of the free radical transport tube, are shown. "OAD" stands for Oxygen Attachment Dissociation, and "OAD efficiency" is expressed as a percentage, calculated by dividing the amount of ions that underwent the OAD reaction by the amount of precursor ions. A higher OAD efficiency indicates that oxygen free radicals are less likely to adhere to the inner wall of the free radical transport tube. Furthermore, alumina free radical transport tubes are difficult to bend (bend 1524 is provided); therefore, in this experiment, to clarify that the difference in free radical adhesion inhibition effect is due to material differences, the borosilicate glass free radical transport tube, like the alumina free radical transport tube, used a free radical transport tube without the bend 1524.

[0075] exist Figure 6 The figures represent the experimental results. It can be seen that compared to free radical transport tubes made of alumina, free radical transport tubes made of borosilicate glass have higher OAD efficiency, and oxygen free radicals are less likely to adhere to the inner wall surface.

[0076] Furthermore, in the mass spectrometry analysis apparatus 10 of this embodiment, a bend 1524 is provided in the radical delivery tube 152 such that the tip 1523 of the radical delivery tube 152 faces the region 1424 near the ion outlet 1423 of the collision chamber 142. As described above, this region 1424 is a region with a high ion concentration in the entire collision chamber 142, so by directing the tip 1523 of the radical delivery tube 152 towards such a region 1424, radicals can be efficiently supplied to this region 1424. As a result, the efficiency of dissociating precursor ions within the collision chamber 142 can be further improved.

[0077] Compared to the straight portion, the curved portion 1524 allows free radicals to more easily contact the inner wall surface, thus easily leading to free radical loss. However, in this embodiment, the material of the free radical delivery pipe 152 is borosilicate glass, which is difficult for free radicals to adhere to, so even with the curved portion 1524, free radical loss can be suppressed.

[0078] (4) Variations

[0079] This invention is not limited to the embodiments described above and can be modified in various ways. For example, the free radical delivery tube 152 can be made entirely of borosilicate glass, or its inner wall can be made of borosilicate glass while its outer wall is made of other materials. As an example of the latter, by using a tube with a double-layer structure in which a quartz and alumina wall surrounds the borosilicate glass wall, it is possible to make it difficult for free radicals to adhere to the inner wall and improve mechanical strength. Furthermore, while it is preferable that the inner wall of the free radical delivery tube is entirely made of borosilicate glass, even if it is only partially made of borosilicate glass, the effects of this invention are achieved. Moreover, any material other than borosilicate glass can be used as long as it has a lower amount of free radical adhesion and a lower adhesion force compared to alumina and quartz.

[0080] In the above embodiment, it has the features that the top end 1523 of the free radical delivery pipe 152 faces the predetermined region 1424 and that the connector 16, which has a cylindrical portion 161 and an expanded diameter portion 162, is held in place by bolts (retainers) 1632 so that it can move along the outer surface 1420 of the collision chamber (reaction chamber) 142. However, it may also have only one of these two features. Furthermore, these two features can also be modified in various ways as follows.

[0081] In the above embodiment, the tip 1523 is oriented toward the region 1424 by providing a bend 1524 in the free radical delivery tube 152. Alternatively, the tip of the free radical delivery tube can be oriented toward the predetermined region by inserting a straight free radical delivery tube at an angle relative to the direction of ion travel within the collision chamber 142.

[0082] In the above embodiment, by making the diameter of the through hole 1631 provided in the sealing plate 163 of the connector 16 larger than the diameter of the shank of the bolt 1632 that holds the connector 16 on the outer surface 1420 of the collision chamber 142, the connector 16 can move along the outer surface 1420 of the collision chamber 142 by an amount corresponding to the gap between the edge of the through hole 1631 and the shank of the bolt 1632. Alternatively, the connector can be held on the guide rail by moving the connector along the guide rail provided on the outer surface 1420 of the collision chamber 142.

[0083] In the above embodiment, free radicals are supplied to the collision chamber 142. An ion trap can also be used instead of the collision chamber 142 as the reaction chamber. The ion trap, for example, consists of a ring-shaped ring electrode and a pair of end cap electrodes (inlet-side end cap electrode and outlet-side end cap electrode) arranged opposite each other across the ring electrode. In this ion trap, precursor ions with a specific mass-to-charge ratio are selectively captured by applying a predetermined voltage to the ring electrode or the like. The captured precursor ions are dissociated into product ions by irradiating them with free radicals. The product ions thus generated are released from the ion trap by applying a voltage between the inlet-side and outlet-side end cap electrodes and introduced into a mass separator (e.g., a time-of-flight mass separator). In such an ion trap, similar to the collision chamber 142 in the above embodiment, a tube made of borosilicate glass can be used to supply free radicals into the ring. Furthermore, a bend can be provided in the free radical delivery tube to direct the tip of the free radical delivery tube toward a predetermined region within the ring. Furthermore, in order to install the free radical delivery tube in the reaction chamber housing the ion trap, the same connector as described in the above embodiment can also be used.

[0084] In the above embodiments, a mass spectrometry analysis device was used as an example for explanation, but the same structure can also be used in other ion analysis devices such as ion mobility analyzers.

[0085] Alternatively, the structures of the above embodiments or modifications can be adopted using free radical delivery tubes made of materials other than borosilicate glass. For example, in a structure where the tip 1523 of the free radical delivery tube 152 faces the predetermined region 1424, the loss due to free radicals adhering to the inner wall increases when the free radical delivery tube has a bend, especially in a free radical delivery tube made of materials other than borosilicate glass. However, even so, a bend can be provided to supply more free radicals to the predetermined region. Furthermore, by inserting a straight free radical delivery tube at an angle relative to the direction of ion travel in the collision chamber and with the tip facing the predetermined direction, the loss of free radicals at the inner wall surface of the free radical delivery tube can be suppressed regardless of the material of the free radical delivery tube. A structure that allows the joint to move along the outer surface of the collision chamber (reaction chamber) also prevents breakage when using a free radical delivery tube made of materials other than borosilicate glass.

[0086] [plan]

[0087] Those skilled in the art will understand that the above-described embodiments are specific examples of the following solutions.

[0088] [Item 1]

[0089] The ion analysis apparatus in item 1 is an ion analysis apparatus that generates product ions by irradiating precursor ions derived from sample components with free radicals and then analyzes these product ions.

[0090] The ion analysis device includes:

[0091] A reaction chamber for introducing the precursor ions;

[0092] The radical generation section, which generates free radicals; and

[0093] A free radical delivery tube connects the free radical generation section and the reaction chamber.

[0094] At least a portion of the inner wall surface of the free radical delivery tube is composed of a material to which the free radicals adhere less or have weaker adhesion than alumina or quartz.

[0095] According to the ion analysis apparatus of claim 1, by using a free radical delivery tube whose inner wall surface is at least partially made of a material that has a lower amount or weaker adhesion of free radicals (i.e., free radicals generated in the free radical generation section) compared to materials such as alumina and quartz, it is possible to suppress the adhesion of free radicals generated in the free radical generation section to the inner wall surface of the free radical delivery tube and increase the amount of free radicals supplied to the reaction chamber. Therefore, the efficiency of dissociating precursor ions can be improved.

[0096] [Item 2]

[0097] Based on the ion analysis apparatus in item 1, in the ion analysis apparatus in item 2,

[0098] The material is borosilicate glass.

[0099] [Item 3]

[0100] Based on the ion analysis apparatus in item 2, in the ion analysis apparatus in item 3,

[0101] The free radical generation section generates oxygen free radicals.

[0102] Borosilicate glass has the advantage of making it difficult for various free radicals, such as hydrogen free radicals and oxygen free radicals, to adhere, especially oxygen free radicals. Therefore, in cases where oxygen free radicals are used to dissociate ions, i.e., when oxygen free radicals are generated in the free radical generation section, using a free radical transport tube whose inner wall surface is at least partially made of borosilicate glass is particularly effective.

[0103] [Item 4]

[0104] The ion analysis apparatus in item 4 is an ion analysis apparatus that generates product ions by irradiating precursor ions derived from sample components with free radicals and then analyzes these product ions.

[0105] The ion analysis device includes:

[0106] A reaction chamber for introducing the precursor ions;

[0107] The radical generation section, which generates free radicals; and

[0108] A free radical delivery tube connects the free radical generation section and the reaction chamber.

[0109] One end of the free radical delivery tube is disposed in the reaction chamber, facing a predetermined region of ion bias within the reaction chamber.

[0110] According to the ion analysis device in item 4, one end of the free radical delivery tube is directed toward the region where precursor ions introduced into the reaction chamber and ions plasma biased during the multiple dissociation of precursor ions are located, thereby enabling efficient supply of free radicals to this region and further improving the efficiency of ion dissociation.

[0111] [Item 5]

[0112] Based on the ion analysis apparatus in item 4, in the ion analysis apparatus in item 5,

[0113] The free radical delivery tube is bent.

[0114] In this way, the free radical delivery tube is bent, making it easier for one end of the free radical delivery tube to face the predetermined region.

[0115] [Item 6]

[0116] The ion analysis apparatus in item 6 is an ion analysis apparatus that generates product ions by irradiating precursor ions derived from sample components with free radicals and then analyzes these product ions.

[0117] The ion analysis device includes:

[0118] A reaction chamber for introducing the precursor ions;

[0119] The radical generation section, which generates free radicals; and

[0120] A free radical delivery tube connects the free radical generation section and the reaction chamber.

[0121] The ion analysis device includes:

[0122] A connector having a cylindrical portion and an enlarged portion, one end of the cylindrical portion being connected to the interior of the reaction chamber through an opening in the reaction chamber, the cylindrical portion having an inner diameter smaller than the diameter of the opening for insertion of the free radical delivery tube, the enlarged portion being connected to the other end of the cylindrical portion, the inner diameter increasing as it moves away from the other end; and

[0123] A retainer that holds the connector so that it can move along the outer surface of the reaction chamber.

[0124] According to the ion analysis apparatus of item 6, when the radical delivery tube is installed in the reaction chamber, even if the position of the radical delivery tube is slightly offset from the position of the cylindrical part of the connector, the connector can be moved along the outer surface of the reaction chamber by the top end of the radical delivery tube pressing against the inner wall surface of the expanded section, thus inserting the radical delivery tube into the cylindrical part. Furthermore, the diameter of the opening is larger than the inner diameter of the cylindrical part (the inner diameter of the cylindrical part is smaller than the diameter of the opening), so even if the connector moves slightly along the outer surface, the radical delivery tube that has passed through the cylindrical part also passes through this opening. Therefore, the radical delivery tube can be easily installed in the reaction chamber without damage.

[0125] [Item 7]

[0126] Based on the ion analysis apparatus in item 6, in the ion analysis apparatus in item 7,

[0127] The joint also includes a sealing plate, which is a plate-shaped member extending radially outward from one end of the cylinder towards the outer side of the cylinder, and has two through holes.

[0128] The retainer is a bolt that passes through each of the two through holes and is fastened to the outer surface. The diameter of the bolt head is larger than the diameter of the through hole, and the diameter of the shank is smaller than the diameter of the through hole.

[0129] In the ion analysis apparatus of item 7, the diameter of the shank of the bolt serving as a retainer is smaller than the diameter of the through hole in the sealing plate, thus creating a gap between the edge of the through hole and the shank of the bolt. The connector can move along the outer surface of the reaction chamber by an amount corresponding to this gap.

[0130] Explanation of reference numerals in the attached figures

[0131] 10. Mass spectrometry apparatus; 11. Ionization chamber; 111. ESI probe; 12. First intermediate vacuum chamber; 121, 131. Ion guide; 13. Second intermediate vacuum chamber; 14. Analytical chamber; 141. Pre-stage quadrupole mass filter; 142. Collision chamber; 1420. Outer surface of the collision chamber; 1421. Collision chamber opening; 1423. Ion outlet; 1424. Region near the ion outlet; 143. Multi-stage ion guide; 144. Post-stage quadrupole mass filter; 145. Ion detector; 146. Analytical chamber opening; 1461. Flange of the analytical chamber opening; 1462. Analytical... Cover of chamber opening; 1463, 1611, 164, vacuum seal; 15, free radical generation and irradiation section; 151, free radical generation device; 1511, free radical generation chamber; 1512, gas supply source; 1513, high-frequency electromagnetic field source; 152, free radical delivery pipe; 1521, first part of free radical delivery pipe; 1522, second part of free radical delivery pipe; 1523, top end of free radical delivery pipe; 1524, bend; 16, connector; 161, cylindrical section; 162, enlarged diameter section; 163, sealing plate; 1631, through hole; 1632, bolt; 1633, gap.

Claims

1. An ion analysis device, which generates product ions by irradiating precursor ions derived from a sample component with free radicals and then analyzes the product ions, wherein... The ion analysis device includes: A reaction chamber for introducing the precursor ions; The radical generation section, which generates free radicals; and A free radical delivery tube connects the free radical generation section and the reaction chamber. At least a portion of the inner wall surface of the free radical delivery tube is composed of a material to which the free radicals adhere less or have weaker adhesion compared to alumina or quartz. The ion analysis device also includes: A connector having a cylindrical portion and an enlarged portion, one end of the cylindrical portion being connected to the interior of the reaction chamber through an opening in the reaction chamber, the cylindrical portion having an inner diameter smaller than the diameter of the opening for insertion of the free radical delivery tube, the enlarged portion being connected to the other end of the cylindrical portion, the inner diameter increasing as it moves away from the other end; and A retainer that holds the connector so that it can move along the outer surface of the reaction chamber.

2. The ion analysis apparatus according to claim 1, wherein, The material is borosilicate glass.

3. The ion analysis apparatus according to claim 2, wherein, The free radical generation section generates oxygen free radicals.

4. The ion analysis apparatus according to claim 1, wherein, One end of the free radical delivery tube is disposed in the reaction chamber, facing a predetermined region of ion bias within the reaction chamber.

5. The ion analysis apparatus according to claim 4, wherein, The free radical delivery tube is bent.

6. The ion analysis apparatus according to claim 1, wherein, The joint also includes a sealing plate, which is a plate-shaped member extending radially outward from one end of the cylinder toward the outer side of the cylinder, and has two through holes. The retainer is a bolt that passes through each of the two through holes and is fastened to the outer surface. The diameter of the bolt head is larger than the diameter of the through hole, and the diameter of the shank is smaller than the diameter of the through hole.

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