JPS59111052A - Apparatus for concentrating and introducing liquid specimen - Google Patents

Abstract

PURPOSE:To raise measuring sensitivity, by a method wherein a liquid specimen after freezing is transferred under high vacuum to perform freeze drying and the conc. material is introduced into an ion source. CONSTITUTION:A liquid specimen which is cooled by passing a cooling medium such as liquid nitrogen through a cooling pipe 6 and flowed out from an LC column is introduced into a specimen introducing pipe 5 from a specimen effluent pipe 4, the solvent thereof is frozen to be formed into minute ice like crystals and the frozen specimen is extruded onto the introducing belt 8 in a high vacuum region 3 from an opening part to be subjected to freeze drying. The specimen on the introducing belt 8 is melted by an infraed lamp 13 prior to perfectly drying to be converted to a predetermined conc. solution which is in turn introduced into an ion source 2 while receives a matrix such as glycerine added from an introducing pipe 15 and the specimen as the target is irradiated with neutron beam 20 in an ionization part 19 by supplying repeller voltage to obtain ion beam 22. The non-ionized specimen and glycerine are scraped off by a scraper 16 and recovered in a waste specimen sump 18 as drain. By this system, sensitivity can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for concentrating a liquid sample flowing out of a liquid chromatograph and introducing it into an ion source.

LC-MS is a connection part that introduces the liquid sample flowing out of the liquid chromatograph into the ion source of the mass spectrometer.
Belt type, spray type, etc. have been proposed as interfaces, but the flow rate of a typical high performance liquid chromatograph (HPLC) is 0.05-0.5 mlV/
Since there are many cases where the flow rate is around 100 min, a splitter is used to split the flow and only a portion is introduced into the mass spectrometer.

For this reason, the gas chromatograph sample introduction device (
) Compared to the L-MS interface, there was a problem in that the loss in the introduction part was very large, lowering the measurement sensitivity. In addition, LC-M using a microcolumn
Since the amount of sample injected into the S interface is also small, it cannot be expected to lower its detection limit.

This invention is intended to improve the problems of the conventional methods described above. By freeze-drying a liquid sample and introducing it into the ion source in a concentrated state, a large amount of sample can be used and sensitivity can be dramatically increased. The purpose of the present invention is to provide a liquid sample concentration/introduction device that can raise the concentration of a liquid sample.

This invention provides an apparatus for concentrating a liquid sample flowing out of a liquid chromatograph and introducing it into an ion source. and a means for introducing a monthly charge into the ion source.

The present invention will be explained below with reference to illustrated embodiments.

FIG. 1 is a vertical cross-sectional view showing a liquid sample concentration and introduction device according to an embodiment of the present invention, and shows an example in which the device is applied to an L C-F A, B interface.

In the drawing, 1 is an LC column, 2 is an ion source, and a high vacuum region 6 is interposed between the two.

LC column 1 is for HPLC, and its sample outlet tube 4
A sample introduction tube 5 is connected to. The sample introduction tube 5 is made of a material that has low frictional resistance and also functions as a high-voltage insulator, such as Teflon, and its expanding tip is inserted into the high vacuum region 6, and the outer periphery of the inserted portion is cooled. A tube 6 is wrapped around it.

The high vacuum region 6 is connected to a high vacuum system through a vacuum exhaust pipe 7 and maintained at a high vacuum of about 10-5 to 10-6 Torr. An endless introduction belt 8 is provided to transfer the sample. 9 is a driving gear, and 1o and ii are gears.

An infrared lamp 16 is arranged near the end of the outgoing path of the introduction belt 8 and connected to a power supply device 14 via a temperature shielding plate 12, and a matrix introduction pipe 15 is provided further forward. Further, a rubber mecraper 16 is in contact with the return path of the introduction belt 8, and a waste sample reservoir 18 is opened at its lower end via a cock 17.

The ion source 2 is F A B (Fast Atom Bo
mbardment ion source, internal is 10-6 ~
The introduction belt 8 is maintained at a high vacuum of 10-7 Torr.
A FAB gun 21 is provided to irradiate the ionization section 19 with a neutral particle beam 20, and a first electrode 26, a second electrode 26 and a second
It includes an electrode 24, a ground electrode 25, a deflector 26, and a total ion monitor 27.

The mark A indicates the error voltage supply section.

In the above configuration, a refrigerant such as liquid nitrogen is passed through the cooling pipe 6 for cooling, and the HP T,
In the case of 'C, when a liquid sample flowing out at a pressure of 100 ky/crl is introduced from the sample outflow tube 4 to the sample introduction tube 5, the solvent in the liquid sample freezes and becomes fine ice crystals.

The frozen sample that is continuously pushed out from the expanding opening of the sample introduction tube 5 onto the introduction belt 8 in the high vacuum area 6 is freeze-dried under high vacuum while being moved by the introduction belt 8 in the direction of red stamp B. Ru.

Before the sample on the introduction belt 8 is completely dried, it is thawed by a heat source such as an infrared lamp 16 whose light intensity is variable by the power supply 14 to form a predetermined concentrated solution. 11x is added and introduced into the ion source 2 and reaches the ionization section 19. In the ionization section 19, Rissler voltage is supplied to section A, and the sample on the introduction belt 8 is targeted to FA,
A neutral particle beam 20 is irradiated from the B gun 21,
Ionization is performed and an ion beam 22 is obtained. The non-ionized sample and glycerin are transferred to the introduction belt 8.
On the return trip, it is scraped off by a scraper ξ16 and collected as a drain into a waste sample reservoir 18 via a cock 17. The waste sample reservoir 18 can be replaced via a cock 17.

FIG. 2 is a partial vertical cross-sectional view showing another embodiment;
An example of application to a C-B I/CI interface is shown, and the same reference numerals as in FIG. 1 indicate four dimensions or equivalent parts. This embodiment basically has the same configuration as that in FIG. 1, but the ion source 2 uses EI (electron impact ionization) and CI
(Chemical ionization) The frozen sample on the introduction belt 8 is completely freeze-dried in the high vacuum area 6. Reference numeral 28 denotes a laser light source, which is arranged so as to irradiate the sample on the ionization section 19 with laser light 29.

A reactive gas can be supplied from a reactive gas supply source 30 to react with the vaporized sample.

Further, a filament 61 and an electron trap 32 are disposed facing each other in the vicinity of the ionization section 19 of the introduction belt 8, so that an electron beam 66 can be irradiated thereon. A clean-up heater 34 is provided on the return path of the introduction belt 8 and is connected to a power supply device 35.

In the above configuration, the basic operation is performed in the same manner as shown in FIG.
and reaches the ionization section 19. In the ionization section 19, a laser light source 2 is applied to the powder sample on the introduction belt 8.
A laser beam 29 is irradiated from 8, and the sample is locally instantaneously heated and vaporized.

In the case of the EI mode, the reactant gas is not supplied from the reactant gas supply source 3o, and the vaporized sample is irradiated with the electron beam 66 from the filament 61 and ionized, and the ion beam 22 is (I). Then, a reactive gas is supplied from the reactive gas supply source 60 to the ionization unit 19, and is ionized by the electron beam 66, and the vaporized sample is ionized by reaction with the reactive gas ions to obtain the ion beam 22. The remaining sample is evaporated and removed by the cleanup heater 64 on the return path of the introduction belt 8.

FIG. 6 is a vertical sectional view of a part of still another embodiment, and shows an example using an LC/C/spray type C fin interface. This embodiment basically has the same construction as in FIGS. 1 and 2, but a temperature and vacuum shield plate 66 is provided at the location of the temperature shield plate 12 in FIG. 1. The long introduction belt 8 is connected to the opening 67 of the ion source 2.
A spray gas nozzle 68 having an opening of about 100 μm opens at its tip, and sprays the concentrated sample into the ionization chamber 69 of the ion source 2.

In the above configuration, basic operations are as shown in Figures 1 and 2.
The process is carried out in the same manner as shown in the figure, but before the frozen sample is completely freeze-dried, it is thawed using an infrared lamp 16 to become a concentrated sample, and a spray gas such as He gas is ejected from a spray gas nozzle 68 into an ionization chamber 69. is sprayed and vaporized,
Electron beam 6 irradiated from filament 31
3, and an ion beam 22 can be obtained.

In addition, in the above explanation, the means for freezing the liquid sample is not limited to the cooling pipe B, but other cooling means may also be used.
Further, the transfer means may also be other than the introduction belt 8. In this case, under a vacuum of 1o-5 to 1o-6 Torr,
Since it takes about 1° to 20 min to vaporize nl of water, something that can shorten this time lag is preferable.

In addition, the liquid sample is not limited to HI), it may be the effluent of a general LC column, and the ion source may be an atmospheric pressure ion source (
API) Other ion sources may be used.

According to the present invention, the liquid sample is freeze-dried using the high vacuum of the interface and introduced into the ion source in a concentrated state, so that the entire sample can be subjected to measurement. In addition to dramatically increasing sensitivity, the thermally unstable substances in the sample are not decomposed by heat and are concentrated in a very high vacuum, making it easier to connect to material analysis equipment. can get.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a liquid sample concentration and introduction device according to one embodiment of the present invention, and FIGS. 2 and 3 are partial vertical sectional views showing other embodiments. In each figure, the same reference numerals indicate the same or monk parts, and 1 is L.
C column, 2 is an ion source, 6 is a high vacuum region, 4 is a sample outflow tube, 5 is a sample introduction tube, 6 is a cooling tube, 7 is a vacuum exhaust tube,
8 is an introduction belt, 13 is an infrared lamp, 16 is a screener ξ, 18 is a waste sample reservoir, 21 is a gun for FA and B, 2
8 is a laser light source, 60 is a reactive gas supply source, 61 is a filament, 62 is an electron trap, 34 is a clean-up heater 1', and 38 is a spray gas nozzle.

Claims (5)

[Claims] (1) An apparatus for concentrating a liquid sample flowing out of a liquid chromatograph and introducing it into an ion source, which includes a means for freezing the liquid sample, and a means for transferring the frozen sample in a high vacuum to perform freeze-drying and concentrate the sample. A device for concentrating and introducing a liquid sample, comprising means for introducing the sample into the ion source. (2) The liquid sample concentration/introduction device according to claim 1, wherein the means for freeze-drying is an introduction belt provided in a high vacuum region. (3) The liquid sample concentration/introduction device according to claim 1 or 2, wherein the freeze-drying means includes ice-thawing means near the end. (4) The liquid sample concentration/introduction device according to any one of claims 1 to 6, wherein the liquid chromatograph is a high-performance liquid chromatograph. (5) The liquid sample concentration and introduction device according to any one of claims 1 to 4, wherein the ion source is FAB, EI, CI, spray type, or atmospheric pressure ion source.