JP3388102B2 - Ion source - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion source for ionizing a sample for an analyzer for analyzing an ionized sample under a high vacuum such as a mass spectrometer (hereinafter also referred to as MS). Belongs to the technical field of.

[0002]

2. Description of the Related Art Conventionally, when analyzing a sample using MS, first, a liquid chromatograph (Liquid Chromatog
The sample to be analyzed is mixed with a solvent to form a mixed solution by means of a raph (hereinafter, also referred to as LC), and the mixed solution is flown out into the atmospheric pressure and atomized to be separated under the atmospheric pressure. Then, the atomized effluent from the LC, that is, the mobile phase, is indirectly heated by the heating heater unit that constitutes the vaporizer, and the remaining solvent is further vaporized, so that ions are generated under atmospheric pressure. The generated ions are guided to a mass spectrometric section (MS spectrometric section) under high vacuum for analysis.

By the way, as a method of ionizing the atomized mobile phase from the LC, as described above, atmospheric pressure ionization (Atmospheric Pr
essure Ionization; hereinafter also referred to as API) is widely used. This API mainly has the following three methods.

One is an electro spray ionization method (hereinafter also referred to as ESI), which is a method of generating ions by electrostatic field spraying using a high voltage under atmospheric pressure. .

The other one is the Atmospheric Pressure Chemical Ionization (hereinafter referred to as "atmospheric pressure chemical ionization").
This is also referred to as APCI), and this APCI is a method in which ions are generated by chemical ionization by corona discharge after spraying at atmospheric pressure.

[0006] Still another one is Sonic Spray Ionization (hereinafter also referred to as SS), which is atomized by gas under atmospheric pressure,
This is a method of generating ions by ionizing by the action effect of the ejected gas.

FIG. 8 is a diagram schematically showing an example of a conventional ESI ion source. In the figure, 1 is LC, 2 is LC
A needle tube through which the mixed liquid from 1 flows, 3 is an atomizing probe, 4 is a block-shaped heater unit (vaporizer), 5 is a heater arranged in the heater unit 4, and 6 is a heater unit 4.
Is a hole through which the atomized mobile phase flows, 7 is a first orifice, 8 is a first vacuum pressure chamber held at a first vacuum pressure by a first vacuum pump (not shown), and 9 is First
A ring lens arranged in the vacuum pressure chamber 8, 10 is a second orifice, 11 is a second vacuum pressure chamber which is maintained at a second vacuum pressure higher than the first vacuum pressure by a second vacuum pump (not shown), 12 Is an ion focus lens arranged in the second vacuum pressure chamber 11, 13 is a main slit portion, and 14 is an MS analysis portion.

A predetermined high voltage is applied between the needle thin tube 2 and the heater portion 4, and a predetermined high voltage is applied to the first and second orifices 7 and 10 and the ring lens 9, respectively. ing.

In the conventional ESI ion source thus constructed, a high voltage is applied to the needle capillaries 2 to ionize the sample in the mixed liquid of the sample and the solvent flowing from the LC 1. In this state, the atomization probe 3
When the atomizing nitrogen gas is ejected from the mixture, the mixed liquid of the sample of LC1 and the solvent flows out through the needle thin tube 2 into the atmospheric pressure in the form of a mist to be atomized, so that the ionized sample and the solvent are separated. And the mobile phase of the sample atomized and separated flows through the pores 6 of the heater unit 4. At this time, the flowing liquid in the pores 6 is heated by the heater 5 via the heater unit 4, and the remaining solvent is vaporized, and the ions of the sample itself that can be analyzed by the MS analysis unit 14 are generated. The generated ions are introduced into the first vacuum pressure chamber 8 through the first orifice 7, and further, the ions are passed through the second orifice 10 by the ring lens 9 in the first vacuum pressure chamber 8 to generate the first ions. 2 is introduced into the vacuum pressure chamber 11. Finally, the ions in the second vacuum pressure chamber 11 pass through the main slit portion 13 by the ion focus lens 12 and the MS analysis portion 1 under high vacuum.
4 is focused, and mass analysis is performed by the MS analysis unit 14.

[0010]

However, in this conventional ESI ion source, the mobile phase α of the sample, which is ejected from the needle capillary 2 and atomized and separated, is located in the vicinity of the entrance of the pore 6 and is just cold. Not the heater part 4
Since the heater 5 is separated from the pores 6 and the mobile phase in the pores 6 is heated at a relatively low temperature, the vaporization of the mobile phase in the pores 6 is not sufficiently performed, and the ions of the sample are Hard to generate. Therefore, by applying a high voltage to the needle thin tube 2, L
There is the problem that the sample in the mixture from C1 must be ionized, which requires a high voltage.
Similarly, this high voltage is also needed in APCI ion sources.

Further, when the mobile phase is simply passed through the heated pores 6, stable analysis can be performed only when the flow rate of the mobile phase is at most about 100 μL / min or less. In particular, when a mobile phase containing a large amount of water is used, not only the dryness of the mobile phase deteriorates but also the stability deteriorates. Therefore, the flow rate of the mobile phase that can be introduced from the LC1 to the heater unit 4 is limited. By the way, since the analytical condition of LC1 which is usually used is 1000 μL / min, if the flow rate of the mobile phase is restricted in this way, it is not possible to directly connect the LC1 and the MS analysis section 14 under this analytical condition. Extremely difficult. Therefore, conventionally, the mixed liquid from LC1 was split into a few fractions to a few tens of fractions,
It is arranged to be introduced into the heater unit 4. For this reason,
Since the sample introduced into the MS analysis unit 14 is also split, the analysis sensitivity of the MS analysis unit 14 cannot be said to be sufficient. In addition, it is necessary to set troublesome conditions such as setting conditions for such a split, which makes the analysis complicated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ion source capable of easily ionizing a large amount of samples without requiring a high voltage. That is.

[0013]

In order to solve the above-mentioned problems, the invention of claim 1 jets a mixed liquid of a sample and a solvent from a thin tube, and heats the mist-like droplets of the jetted mixed liquid. In the ion source for generating ions of the sample by vaporizing the solvent, a block-shaped heating provided with a large hole through which a relatively large flow rate of the droplets of the mixed liquid ejected from the thin tube flows A heater portion is provided, the heater is provided so as to intersect with the thick hole of the heating heater portion, and an annular groove that communicates the front and rear of the heater of the thick hole is formed, and the heater ejects from the thin tube. The feature is that the atomized droplets are made to directly collide with the heater.

According to a second aspect of the present invention, the ejection direction of the thin tube is set to any one of the same direction, the orthogonal direction, and the direction of a predetermined angle with respect to the introduction direction of the generated ions. Is characterized by.

According to a third aspect of the present invention, a second heater is provided downstream of the heater in the direction in which the liquid droplets of the mixed liquid flow, and the liquid droplets of the mixed liquid are supplied to the second heater. The feature is that it was made to collide.

[0016]

Further, in the invention of claim 5, the heating heater portion further comprises pores through which droplets of the mixed liquid ejected from the thin tube and having a relatively small flow rate flow, and the ejection direction of the thin tube is set. At least one of the thin tube and the heater unit is movably provided so as to be selectively set to either the thick hole or the fine hole.

[0018]

In the ion source of the present invention having such a structure, the atomized droplets of the mixed liquid of the sample and the solvent ejected from the thin tube directly collide with the heater, and the droplets are heated by the heater at a high temperature. Directly heated. For this reason, the solvent of the droplets is vaporized more effectively. As a result, a large amount of droplets of the mixed liquid are efficiently heated at a high temperature, and a large amount of sample ions are generated. In that case, even if the droplet is heated at a high temperature, the sample is not heated due to the heat of vaporization of the solvent, so that thermal decomposition of the sample does not occur. Then, since a large amount of ions are introduced into an analysis unit such as a mass analysis unit, an analysis with good sensitivity is performed, and
Since there is no need to split the sample, complicated condition setting for splitting is not required, and analysis is facilitated.

In addition, unlike the conventional method of generating ions by applying a high voltage, the structure of the ion source is simplified and the cost is reduced.

In particular, in the invention of claim 3, since the atomized droplets of the mixed liquid are effectively heated by the two heaters, a large amount of higher-grade ions are generated.

In the invention of claim 4, when a large amount of samples are to be observed, the ejection direction of the thin tube is selectively set to the direction toward the thick hole. As a result, a large amount of mist-like droplets of the mixed liquid ejected from the thin tube are directly heated at a high temperature by the heater, and a large amount of ions are generated. Further, in the case of measuring a small amount of sample, the ejection direction of the thin tube is selectively set to the direction toward the pore.
As a result, the atomized droplets of the small amount of the mixed liquid ejected from the thin tube are indirectly heated by the heater via the heater unit at a relatively low temperature, and ions are generated. In that case, since the heating temperature is relatively low, thermal decomposition of the sample does not occur even under the condition of a small flow rate.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an example of an embodiment of an ion source according to the present invention. The same components as those of the ion source shown in FIG. 8 described above are designated by the same reference numerals, and detailed description thereof will be omitted.

In the conventional heater portion 4 shown in FIG.
Is provided at a position deviated from the axis connecting the needle thin tube 2 and the first orifice 7, and the heater 5 is provided apart from these pores 6. Then, as shown in FIG. 1, the fine hole 6 is removed, and the thick hole 15 is provided so as to penetrate in the coaxial line direction on the axis connecting the needle thin tube 2 and the first orifice 7. The cross-sectional area of the thick hole 15 is set to a value considerably larger than that of the large hole 6.

Further, in the heater portion 4 of FIG. 8, the heater 5 is provided separately from the fine pores 6, but in the heater portion 4 of this example, the inner peripheral surface of the thick hole 15 on the needle capillary 2 side. An annular groove 16 is formed in the cartridge heater 5, and the cartridge heater 5 is disposed so as to penetrate the annular groove 16 and intersect the thick hole 15. That is, the needle thin tube 2
The atomized mobile phase flowing out of the cartridge directly contacts the cartridge heater 5.

Further, the high voltage applied between the needle capillary 2 and the heater portion 4 in the ion source of FIG. 8 is eliminated in the ion source of this example. Reference numeral 17 is a temperature sensor that detects the temperature of the heater section 4 and the cartridge heater 5 to control the temperature of the heater section 4.

The other structure is the same as that of the conventional ion source shown in FIG.

In the ion source of the present embodiment thus constructed, the atomizing probe 3 ejects the atomizing nitrogen gas so that the mixed liquid of the sample and the solvent in the LC 1 passes through the needle thin tube 2. It is atomized and ejected toward the heater portion 4. As the atomizing gas, oxygen gas, rare gas, air, hot air, or the like can be used instead of nitrogen.
The atomized droplets of the sprayed mixed liquid are cartridge heaters 5.
Is directly collided with and is heated by the cartridge heater 5 at a high temperature of, for example, 200 ° C. or higher. In that case, the temperatures of the heater unit 4 and the cartridge heater 5 are controlled based on the temperature of the heater unit 4 detected by the temperature sensor 17.

By this high temperature heating, the droplets of the mixed solution are effectively desolvated, and the ions of the sample are generated. The generated ions pass through the first orifice 7, the first vacuum pressure chamber 8, the second orifice 10, the second vacuum pressure chamber 11 and the main slit portion 13 as in the conventional ion source shown in FIG. Focus on the MS analysis unit 14 under high vacuum
Mass analysis is performed by the analysis unit 14.

According to the ion source of this example, since the atomized droplets of the mixed liquid of the sample and the solvent sprayed from the needle capillary 2 are effectively heated by the cartridge heater 5 at a high temperature, The droplets in the thick hole 15 are vaporized sufficiently and reliably, and the ions of the sample are easily generated. Therefore, it is not necessary to apply a high voltage to the needle thin tube 2, the structure of the ion source is simplified, and it is possible to inexpensively form a new ion source that utilizes spraying and contact high temperature heating. .

Further, since the droplets are vaporized sufficiently and reliably by the high temperature heating by the cartridge heater 5 and the ions can be efficiently generated, stable and excellent analysis can be performed even if the flow rate of the mixed liquid is increased. As a result, the restriction on the flow rate of the mixed liquid is greatly reduced as compared with the conventional ion source. As a specific numerical value, for example, in the conventional electrospray method, the flow rate of the mixed solution is from several μL / min to 5 μL / min.
Although it was restricted to a range of about 0 μL / min, the method using the ion source of this example enables stable and excellent analysis with a high sensitivity even when the flow rate of the mixed solution exceeds 1 mL / min.

Further, since it is possible to ionize a large flow rate of the mixed solution, it is not necessary to split the sample, so that complicated condition setting for splitting is not required and the analysis is facilitated.

FIG. 2 is a diagram partially showing a modification of the ion source shown in FIG. In each of the subsequent examples of the embodiment of the present invention, the same components as those of the ion source shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. The configuration of the ion source other than the portion shown in FIG. 2 is the same as that shown in FIG.

In the ion source shown in FIG. 1, the needle thin tube 2
Is arranged so that the spray direction of the mixed liquid of the sample and the solvent from the needle thin tube 2 and the first and second orifices 7 and 10 and the main slit portion 13 are coaxial with each other.
In the ion source of this modified example, as shown in FIG. 2, the needle thin tube 2 has a spray direction of the mixed liquid of the needle thin tube 2 and a first,
The second orifices 7 and 10 and the main slit portion 13 are arranged so as to be orthogonal to each other. Therefore, the atomized droplets of the mixed liquid sprayed from the needle capillaries 2 are heated to a high temperature by the cartridge heater 5 to be desolvated, and the generated ions bend at a right angle and move toward the first orifice 7. . The effect of this modification is almost the same as the effect of the example shown in FIG. 1, but the ion source of the present example is more effectively arranged when there is no installation space for the ion source in the uniaxial direction.

In the needle thin tube 2, as shown in FIG. 1, from the position where the spray direction of the mixed solution and the first and second orifices 7 and 10 and the main slit portion 13 are coaxial,
It is possible to arrange the sprayed direction of the mixed liquid and the first and second orifices 7 and 10 and the main slit portion 13 at an arbitrary inclination angle between the mutually orthogonal positions.

Further, the cartridge heater 5 and the heater unit 4 of each example shown in FIGS. 1 and 2 have any shape as long as all the droplets of the mixed liquid are heated to a sufficiently high temperature. May be formed in. Further, the higher the heating temperature is 200 ° C. or higher, the better.

Further, in each of the above-mentioned examples, the heater part 4 can be omitted. That is, as shown in FIG. 3A, only the cartridge heater 5 is provided between the needle thin tube 2 and the first orifice 7, and the droplets of the mixed liquid sprayed from the needle thin tube 2 are directly supplied to only the cartridge heater 5. Alternatively, the solvent may be collided to vaporize the solvent to generate ions, and the ions may be sucked toward the first vacuum pressure chamber 8 through the first orifice 7. In that case, as shown in FIG. 5B, the needle thin tube 2 may be tilted by a predetermined angle, and the mixed liquid may be sprayed from the tilted needle thin tube 2 to directly collide with the cartridge heater 5.

Further, in the ion source of each of the examples shown in FIGS. 1 and 2, when it is desired to vaporize the droplets of the mixed liquid to a higher degree, the space between the needle capillary tube 2 and the heater unit 4 is conventionally changed. You may make it apply a high voltage like this.

FIG. 4 is a diagram showing another example of the embodiment of the present invention.

In each of the ion sources shown in FIGS. 1 and 2, the heater unit 4 and the cartridge heater 5 are used as a means for heating the mist-like droplets of the mixed liquid sprayed from the needle capillaries 2. However, as shown in FIG. 4, the ion source of this example uses a predetermined number (three in the illustrated example) of thermoplates 18. And the needle thin tube 2
The atomized droplets sprayed from the first collide with the first thermoplate 18 and are reflected. At the time of this collision, the droplets are heated by the first thermoplate 18 at a high temperature and vaporized to some extent to be desolvated by a predetermined amount. Then, the droplets reflected by the first thermoplate 18 and desolvated by a predetermined amount collide with the second thermoplate 18 again to be reflected. At the time of this collision, the liquid droplets are still on the second thermoplate 18
At a high temperature, it is further vaporized and further desolvated by a predetermined amount. Finally, the droplets reflected by the second thermoplate 18 and desolvated by a predetermined amount are again collided with the third thermoplate 18 and reflected. Even during this collision, the droplets are heated to a high temperature by the third thermoplate 18 and further vaporized, so that the droplets are completely desolvated and ions of the sample are generated. The ions are guided to the first orifice 7 by being reflected by the third thermoplate 18.

The other structure of the ion source of this example is the same as that of the ion source shown in FIG. 1, and the ion source of this example also has the same effect as the ion source shown in FIG.

The number of thermo plates 18 is not limited to three, and one or more thermo plates 18 can be provided. Similarly, the spraying direction of the mixed liquid of the needle thin tube 2 and the first and second orifices 7 and 10 and the main slit portion 13 are not limited to be coaxially arranged, and the ion shown in FIG. Similarly to the source, the spray direction of the mixed liquid in the needle thin tube 2 and the first and second orifices 7 and 10 and the main slit portion 13 may be arranged so as to be orthogonal to each other.

FIG. 5 is a diagram showing still another example of the embodiment of the present invention.

The heater heater 4 of the ion source shown in FIG. 1 is provided with a cartridge heater 5 and a thick hole 15,
In the ion source of this example, as shown in FIGS. 5A and 5B, one pore 6 similar to the pore 6 in the conventional ion source shown in FIG. It is provided. That is, the heater section 4 is provided with two lines of passage lines for the sample to pass through. Further, in the ion source of this example, a syringe pump can be used in addition to the LC, and these are collectively indicated by reference numeral 1 '. Further, the needle thin tube 2 is provided separately to the LC or syringe pump 1 ', and is supported by the support member 19 so as to be rotatable about a fulcrum 20 via a grommet 21. Therefore, the atomizing probe 3 can also be rotated together with the needle thin tube 2. The needle thin tube 2 is rotationally controlled by advancing and retracting the tilting screw 22 attached to the support member 19. Further, the needle thin tube 2 is connected to the LC or syringe pump 1'by a flexible tube 23, and even if the flexible thin tube 23 connects the needle thin tube 2 to the LC or syringe pump 1 ', 2 is rotatable by a predetermined amount.

Further, normally, in the needle thin tube 2, the jet direction of the mixed liquid is the direction toward the inlet of the thick hole 15 (FIG. 5).
It is set to the first rotation position shown by the solid line in (a), and when the tilting screw 22 is turned when necessary, the ejection direction of the mixed liquid is the direction shown by the two-dot chain line which is the direction toward the inlet of the pore 6. It is set to 2 positions. In that case, the tilting screw 22 may be turned to adjust the inclination of the needle capillary 2 while observing the monitor of the mass spectrometer, and the rotation angle of the needle capillary 2 may be adjusted to the first and second rotation positions. Since the rotation angle of the tilting screw 22 is set in advance, the tilt of the needle capillary 2 may be adjusted by adjusting the rotation angle of the tilting screw 22.

Further, in the ion source of this example, a high voltage is applied between the needle capillary 2 and the heater section 4 by closing the normally open switch 24.
Other configurations of the ion source of this example are the same as the configurations of the ion source shown in FIG.

In the ion source of this example, LC
When sample ions are generated from a large flow rate of 0.1 to 2 ml / min from 1 ', the needle capillary 2 is set to the first position.
By setting the rotary position, similarly to the ion source shown in FIG. 1, atomized droplets are directly heated and vaporized by the cartridge heater 5 at a high temperature to desolvate and generate sample ions. That is, in this LC mode, by directly applying a large amount of droplets of the mixed liquid to the surface of the cartridge heater 5, the solvent of the droplets can be efficiently vaporized, and the heater surface is cooled by the heat of vaporization of this solvent, No thermal decomposition of the ions occurs. In this case, normally, it is not necessary to apply the high voltage between the needle thin tube 2 and the heater unit 4 without closing the switch 24, but in some cases, the switch 24 is closed to apply the high voltage. You may do it.

In some cases, instead of LC, a syringe pump 1'is used to generate sample ions from a mixed liquid having a small flow rate of 1 to 20 .mu.l / min for long-term measurement. In this case, if a small amount of atomized droplets of the mixed liquid is directly applied to the cartridge heater 5, the heater temperature is too high and a thermal decomposition peak is likely to occur, resulting in poor reproducibility of measurement. Therefore,
In this case, by setting the needle thin tube 2 to the second rotation position, atomized droplets pass through the pores 6 and heat of the cartridge heater 5 is generated by the heater as in the conventional ion source shown in FIG. The ions of the sample are generated by indirectly heating and vaporizing via the section 4 to desolvate. In that case, the switch 24 may be closed as necessary to apply a high voltage between the needle thin tube 2 and the heater unit 4. That is, in the syringe pump mode, since a small amount of liquid droplets of the mixed liquid is indirectly heated by the heat of the cartridge heater 5 via the heating heater unit 4, the surface temperature of the vaporization unit does not become so high and the peak of thermal decomposition occurs. Can be suppressed.

As described above, in the ion source of this example, it is possible to optimally vaporize by selecting whether to measure ions of a large flow rate sample or to measure ions of a small flow rate sample. As a result, A spectrum with less thermal decomposition can be obtained.

The effect of the ion source of this example is the same as the effect of the ion source of the example shown in FIG.

Although only one pore 16 is provided in the example shown in FIG. 5, two or more pores 16 can be provided in an appropriate number as shown in FIG. 6A, for example. Further, in the example shown in FIG. 5, the pores 16 are completely independent of the large holes 15, but the small holes 16 are joined to the large holes 15 on the way as shown in FIG. 6B, for example. You can also

Further, in the example shown in FIG.
Although it is rotatably provided, the needle-like tube 2 may be provided so as to be vertically movable. Further, the needle rod 2 may be fixed and the heater unit 4 may be provided movably, or both the needle rod 2 and the heater unit 4 may be provided movably.

FIG. 7 is a diagram showing still another example of the embodiment of the present invention.

In the ion source of the example shown in FIG. 1, the heater heater 4 is provided with one cartridge heater 5 and the annular groove 16 in the large hole 15. However, in the ion source of this example, as shown in FIG.
In addition to these cartridge heaters (hereinafter referred to as “first cartridge heater” in this example) 5 and annular groove (hereinafter referred to as “first annular groove” in this example) 16 as shown in FIG. A second cartridge heater 25 and a second annular groove 26 are provided in the thick hole 15. In that case, the second cartridge heater 25 is provided in a direction orthogonal to the first cartridge heater 5 and the thick hole 15.

The other configuration of the ion source of this example is the same as the configuration of the ion source of the example shown in FIG.

In the ion source of this example having the above-described structure, as in the ion source of the example shown in FIG. 1, the atomized droplets of the mixed liquid sprayed from the needle capillaries 2 are directly connected to the first cartridge heater. After colliding with 5, it flows through the first annular groove 16. At this time, a large amount of droplets are heated by the high temperature heat of the first cartridge heater 5, and most of the solvent is vaporized. The liquid droplets which have passed through the first annular groove 16 and in which most of the solvent has evaporated further impinge on the second cartridge heater 25 again through the thick holes 15, and then flow through the second annular groove 26 similarly. At this time, similarly, a large amount of droplets are heated by the high temperature heat of the second cartridge heater 25, and the remaining solvent is further vaporized. In this way, a large amount of droplets are heated by the two cartridge heaters 5 and 25, the solvent is more effectively vaporized, and a large amount of ions are easily generated. Moreover, even though the heating temperature of both cartridge heaters 5 and 25 is high due to the heat of vaporization of a large amount of solvent, the generated sample ions do not undergo thermal decomposition.

As described above, a large amount of these ions, which are not affected by thermal decomposition, are introduced into the MS analysis section 14 through the vacuum chamber and mass analyzed. The mass analysis has high sensitivity and high quality. Analysis results can be obtained.

In the example shown in FIG. 7, the first and second
Although the cartridge heaters 5 and 25 are arranged in a direction orthogonal to each other, the first and second cartridge heaters 5 and 25 may be arranged in parallel. Further, three or more cartridge heaters can be provided along the thick hole 3.

Further, the ion source of the present invention can be applied to any atmospheric pressure ionization such as ESI and APCI described above as long as the ionization is performed at atmospheric pressure.

[0060]

As is apparent from the above description, according to the ion source of the present invention, the atomized droplets of the mixed liquid of the sample and the solvent ejected from the thin tube are directly heated by the heater at a high temperature. As a result, the solvent of the droplet can be more effectively vaporized. As a result, since it becomes possible to efficiently heat a large amount of liquid droplets of the mixed liquid, it is possible to generate a large amount of sample ions without causing thermal decomposition. Then, by introducing a large amount of generated ions into an analysis unit such as a mass analysis unit, it becomes possible to perform analysis with good sensitivity.

Further, unlike the conventional ion source, a high voltage for heating the thin tube is not required, so that the structure of the ion source can be made simple and inexpensive.

Furthermore, since it is not necessary to set the conditions for splitting the sample as in the conventional case, the analysis can be performed easily.

In particular, according to the third aspect of the invention, since the droplets of the mixed liquid can be effectively heated by the two heaters, it becomes possible to generate a large amount of higher-grade ions.

According to the invention of claim 4, not only can a relatively large amount of sample be observed with one ion source, but also a relatively small amount of sample can be observed for a long time. Become.

[Brief description of drawings]

FIG. 1 shows an example of an embodiment of an ion source according to the present invention, (a) is a diagram schematically showing the entire apparatus, and (b) is a sectional view taken along line IB-IB in (a). .

FIG. 2 is a diagram showing another example of the embodiment of the present invention.

FIG. 3 shows still another example of the embodiment of the present invention,
(A) is a figure which shows the example which ejects a mixed liquid in the same direction as an ion introduction direction, (b) is a figure which shows an example which ejects a mixed liquid in the direction of a predetermined angle with respect to an ion introduction direction.

FIG. 4 is a diagram showing still another example of the embodiment of the present invention.

FIG. 5 shows still another example of the embodiment of the present invention,
(A) is a figure which shows the whole apparatus typically, (b) is sectional drawing which follows the VB-VB line in (a).

6 shows a modified example of the example shown in FIG. 5, (a) is a diagram showing an example in which two pores are provided, and (b) is a diagram showing an example in which the pores are communicated in the middle of a thick hole. Is.

FIG. 7 shows still another example of the embodiment of the present invention,
(A) is a figure which shows the whole apparatus typically, (b) is sectional drawing which follows the VIIB-VIIB line in (a).

FIG. 8 is a diagram showing an example of a conventional ion source.

[Explanation of symbols]

1 ... Liquid chromatograph (LC), 2 ... Needle thin tube,
3 ... Atomization probe, 4 ... Heating heater part, 5 ... (First) cartridge heater, 6 ... Pore, 14 ... Mass spectrometric part (MS
Analytical section), 15 ... Large hole, 16 ... (First) annular groove, 17 ...
Temperature sensor, 18 ... Thermo plate, 19 ... Support member,
20 ... Support point, 21 ... Grommet, 22 ... Tilt screw, 23
... flexible tube, 25 ... second cartridge heater, 2
6 ... second annular groove

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H01J 49/16 H01J 49/16 (56) Reference JP-A-6-102246 (JP, A) JP-A-6-331313 (JP , A) JP 5-217545 (JP, A) JP 8-145950 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 49/10 H01J 49/16 H01J 27/02 H01J 37/08 G01N 27/62 G01N 30/72

Claims (4)

(57) [Claims] 1. An ion source for producing an ion of the sample by ejecting a mixture of a sample and a solvent from a thin tube, and heating the atomized droplets of the ejected mixture to vaporize the solvent, A relatively large flow rate of the mixed liquid ejected from the thin tube
Block-shaped heater with a large hole through which droplets flow
And the heater intersects the thick hole of this heater part.
And the heater of the large hole.
An annular groove communicating is formed before and after the ion source being characterized in that so as to collide the mist of droplets ejected from said capillary directly the heater. 2. The ejection direction of the thin tube is set to any one of the same direction, the orthogonal direction, and the direction of a predetermined angle with respect to the introduction direction of the generated ions. 1. The ion source according to 1. 3. The droplets of the mixed liquid flow from the heater
A second heater is provided on the downstream side in the direction of
Make the liquid droplets of the mixed liquid collide with this second heater as well.
Ion source according to claim 1, wherein it has to. 4. The heater section further comprises fine holes through which liquid droplets of the mixed liquid having a relatively small flow rate ejected from the thin tube flow, and the ejection direction of the thin tube is the thick hole or the fine hole. as it is selectively set to either one of the hole, claims 1, wherein at least one of said capillary and said heater portion is movable
3. The ion source according to any one of 3 above.