JPH09178705A - Liquid choromatography mass spectrograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent erroneous setting when an ionization part is replaced. SOLUTION: An ionization means mounting part 33a where an electro spray ionization part 31 and an atmospheric pressure chemical ionization part can be mounted compatibly is provided at an interface part 30 an identification means 40 identifies whether the ionization part which is mounted at this location is either the electro spray ionization part 31 or the above atmospheric chemical ionization part. Parameters are automatically set by an automatic setting part 41 according to an identification result by the identification means 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid chromatograph mass spectrometer (hereinafter referred to as LC / MS), and more specifically to an electrospray ionization probe,
Atmospheric pressure chemical ionization probe and LC / MS which can be selectively attached and used.

[0002]

2. Description of the Related Art In LC / MS, the components separated in a liquid chromatograph section are ionized and introduced into a mass spectrometric section. Therefore, an interface for ionizing the separated components is needed. Commonly used interfaces for LC / MS are electrospray interface (ESI) and atmospheric pressure chemical ionization interface (A
There are several types, such as PCI).

In the ESI method, a liquid sample is sent to the tip of a thin nozzle and a high voltage is applied to the tip of the nozzle. As a result, a strong unequal electric field is formed at the tip of the nozzle, the liquid sample is sprayed as charged droplets by this strong electric field, and further, the Coulomb repulsive force of the ions in the droplets causes the droplets to split and ionize. Is done.

On the other hand, in the APCI method, a liquid sample is forcibly sprayed by a gas flow in a nebulizer (atomizer), and the liquid sample is desolvated by heating the liquid sample. Then, buffer ions generated by corona discharge are used. The sample is ionized (chemical ionization). Figure 3 shows the conventional LC /
It is a figure showing the general composition of MS. Reference numeral 10 denotes a liquid chromatograph unit, and reference numeral 20 denotes a mass spectrometric unit. An interface unit 30 has an electrospray ionization unit 31 using the ESI method. The electrospray ionization unit 31 is fixed by the fixing member 33. The fixing member 33 has a fixed position with respect to the pipe 32 serving as an inlet of the sample to the mass spectrometric section 20. In this figure, a housing shared with the mass spectrometric section 20 is used as the fixing member 33. That is, the hole 33a provided in the housing functions as a mounting portion for the electrospray ionization unit 31, and the electrospray ionization unit 31 is inserted into the hole 33a and fixed with a mounting screw (not shown), whereby electrospray ionization is performed. The positional relationship between the part 31 and the mass spectrometric part 20 is determined. The electrospray probe 31a of the electrospray ionization section 31 has a thin tube through which the sample liquid sent from the liquid chromatograph section 10 passes, and the tip on the side facing the pipe 32 has a needle shape and passed through the thin tube. Liquid is ejected from the nozzle portion at the tip of the needle. Then, a high voltage of about several KV is applied to the electrospray probe 31a from a high voltage generating circuit (not shown). By setting in this way, the liquid sample sent from the liquid chromatograph unit 10 is drawn out in a spray form by the strong electric field formed near the nozzle at the tip of the needle, and becomes ions or charged microdroplets to form the pipe 3
Enter 2.

In the pipe 32, the charged fine droplets are heated by a wound heater (not shown) to evaporate the solvent, and further collide with other particles to be further miniaturized and ionized. The promoted and generated ions are extracted from the pipe 32 and sent into the mass spectrometric unit 20.

On the other hand, when performing ionization by the APCI method, an atmospheric pressure chemical ionization part 34 as shown in FIG. 4 is attached to the hole 33a of the housing which is the fixing member 33 instead of the electrospray ionization part 31 of FIG. To be That is, the probe 34a has a thin tube through which the sample liquid passes and has a needle-shaped tip, an atomization chamber 34b provided so as to surround the needle portion of the probe 34a, and a discharge electrode 34c attached to the front surface of the opening of the atomization chamber. Atmospheric pressure chemical ionization unit 34 including is attached. The atomization chamber 34b is heated by a heater (not shown), and a voltage of several KV is applied to the discharge electrode 34c. By doing so, the liquid sample sent from the liquid chromatograph unit 10 is separately provided in the probe 34a.
The atomizing gas from the gas line connected to is sprayed from the nozzle at the tip of the needle of the probe 34a into the atomizing chamber 34b, and after being desolvated by the heater, contact with buffer ions generated at the discharge electrode Ionized. Then, the generated ions are sent to the mass spectrometric analysis unit 20 through the heated pipe 32 while being promoted to be ionized similarly to the above-mentioned ESI method.

[0007]

In the conventional LC / MS, either the electrospray ionization unit 31 or the atmospheric pressure chemical ionization unit 34 is selected according to the sample to be measured, and the appropriate one is attached to the interface unit. The measurement was performed after resetting the parameters according to the ionization part.

The operator performs the work of exchanging the electrospray ionization section with the atmospheric pressure chemical ionization section and the subsequent setting of parameters such as set voltage. At that time, which ionization section is attached? Since the decision was made visually by the measurer, there is a risk of erroneous operation, and if the erroneous operation is performed, the ionization part may be destroyed or measurement may be performed under inappropriate setting conditions. The present invention has solved the above problems, and when exchanging the ionization part, the correct setting is automatically performed according to the attached ionization part so as to eliminate erroneous operation.
It is intended to provide S.

[0009]

A liquid chromatograph mass spectrometer (LC / MS) of the present invention made to solve the above problems is a liquid chromatograph between a liquid chromatograph section and a mass spectrometric section. In a liquid chromatograph mass spectrometer equipped with an interface section for ionizing a liquid sample given from the section to the mass spectrometric section, an electrospray ionization section and an atmospheric pressure chemical ionization section that can be attached to and detached from the interface section, and The ionization means attachment part of the interface part to which the electrospray ionization part and the atmospheric pressure chemical ionization part can be attached interchangeably, and whether the attached ionization part is the electrospray ionization part or the atmospheric pressure chemical ionization part According to the identification means and the identification result by the identification means Characterized by comprising an automatic setting unit for the recto b ionization unit or parameter setting of atmospheric pressure chemical ionization unit.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the LC / MS of the present invention, the interface section is provided with identification means for identifying whether the attached probe is an electrospray ionization section or an atmospheric pressure chemical ionization section. It is identified which ionization part is attached. And
Depending on the result of the identification means, the automatic setting unit automatically makes settings suitable for the electrospray ionization unit or the atmospheric pressure chemical ionization unit. As a result, since the setting is made according to the ionization section, there is no problem due to erroneous operation.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a main part of an LC / MS showing an embodiment of the present invention. The same parts as those in the conventional example are designated by the same reference numerals as those in FIGS.

As shown in FIG.
The electrospray ionization part 31 is inserted into a hole 33a as an attachment part of a fixing member 33 using a housing. Then, the electrospray ionization unit 31
In the vicinity of the needle tip of the electrospray probe 31a, a pipe 32 as a sample introduction path to the mass spectrometric section 20 is attached to face the needle tip. This pipe 32
Is provided with a heater (not shown). Further, as shown in FIG. 2, the atmospheric pressure chemical ionization section 34 can be attached to the hole 33a by replacing the electrospray ionization section 31. That is, both the electrospray ionization unit 31 and the atmospheric pressure chemical ionization unit 34 can be attached to and detached from the hole 33a. A micro switch 40 is attached to the inside of the interface unit 30.
The 0 contact is OFF when the electrospray ionization unit 31 is attached, and is ON when the atmospheric pressure chemical ionization unit 34 is attached. That is, as shown in FIG. 2, when the atmospheric pressure ionization section 34 is inserted into the hole 33a, the contact of the microswitch is pushed, while when the electrospray ionization section 31 is attached as shown in FIG. There is no such thing. In this embodiment, the microswitch is switched by utilizing the difference in the axial length of the two ionization parts.
However, the present invention is not limited to this. For example, one ionization unit may be provided with a convex portion for pushing a contact, and the switch may be switched by this. In short, the contacts may be pushed only when one of the ionization parts is attached. The contact signal of the micro switch 40 is connected so as to be sent to the CPU 41 of the computer that controls the liquid chromatograph mass spectrometer (indicated by A in the figure), and any ionization unit is connected by the signal from the micro switch 41. It has become possible to identify whether it is being done. The CPU 41
A high-voltage power supply device for applying a high voltage to the electrospray ionization unit 31, a high-voltage power supply device for applying a high voltage to the atmospheric pressure chemical ionization unit 34 (may be shared with the electrospray ionization unit), and A heater temperature control device is connected by a cable and also controls these.

Next, the operation of this embodiment will be described. First, the electrospray portion 31 is attached to the hole 33a. Then, the CPU 41 determines that the electrospray ionization unit 31 is currently mounted because the contact of the microswitch 40 is not pressed, and in order to set, for example, 4 KV as the set voltage signal from the CPU 41 to the high-voltage power supply device. The setting signal of is sent. The high voltage power supply device receives this signal and sets the parameter to the set value indicated by the setting signal.

Next, when the ionization section is replaced with the atmospheric pressure chemical ionization section 34, the contact point of the microswitch 40 is pushed, which makes it judged that the atmospheric pressure chemical ionization section 34 is currently mounted. . And CP
As a set voltage signal from the U41 to the high-voltage power supply device, a set signal for setting, for example, 5 KV is sent, and a set signal for setting the set temperature, for example, to 400 degrees Celsius is sent to the heater temperature adjusting device. In response to these signals, the high-voltage power supply device and the temperature control device are set to their respective set values.

Since the measurer starts the measurement after the automatic setting is made in this way, there is no problem due to erroneous setting when the ionization part is replaced.

[0016]

As described above, as described above, the LC / M according to the present invention is used.
In S, since the identification means for identifying the ionization section attached to the interface section is provided and the signal from the identification section is received, appropriate parameter setting is automatically performed.
No erroneous settings will occur. Therefore, it is possible to prevent the ionization portion from being damaged due to an incorrect setting, and to prevent measurement under an incorrect setting.

[Brief description of the drawings]

FIG. 1 is a configuration diagram when an electrospray ionization unit is attached to an interface unit of a liquid chromatograph mass spectrometer that is an embodiment of the present invention.

FIG. 2 is a configuration diagram when an atmospheric pressure chemical ionization unit is attached to an interface unit of a liquid chromatograph mass spectrometer which is an embodiment of the present invention.

FIG. 3 is a block diagram of a conventional liquid chromatograph mass spectrometer (ESI method).

FIG. 4 is a block diagram of a conventional liquid chromatograph mass spectrometer (APCI method).

[Explanation of symbols]

 10: Liquid chromatograph part 20: Mass spectrometric part 30: Interface part 31: Electrospray ionization part 33: Fixing member, 33a: Hole (ionization means attachment part) 34: Atmospheric pressure chemical ionization part 40: Micro switch (identification means) 41: CPU (automatic setting unit)

Claims (1)

[Claims] 1. A liquid chromatograph mass spectrometer, comprising: an interface section between a liquid chromatograph section and a mass spectrometric section for ionizing a liquid sample given from the liquid chromatograph section and giving it to the mass spectrometric section. An electrospray ionization part and an atmospheric pressure chemical ionization part which can be attached to and detached from the interface part, and an ionization means attachment part of the interface part to which the electrospray ionization part and the atmospheric pressure chemical ionization part can be attached interchangeably, Identification means for identifying whether the ionization section is an electrospray ionization section or an atmospheric pressure chemical ionization section, and automatic setting for setting parameters of the electrospray ionization section or atmospheric pressure chemical ionization section according to the identification result by the identification section With the department Characteristic liquid chromatograph mass spectrometer.