WO2011052863A1

WO2011052863A1 - Portable gcms for monitoring a volatile organic compound in real-time

Info

Publication number: WO2011052863A1
Application number: PCT/KR2010/001977
Authority: WO
Inventors: Han Oh Park; Yang Won Lee; Young-Mi Koo
Original assignee: Bioneer Corporation
Priority date: 2009-10-28
Filing date: 2010-03-31
Publication date: 2011-05-05
Also published as: KR101345759B1; KR20110046179A

Abstract

Provided is a portable gas chromatograph-mass spectrometer (GCMS) capable of quantitatively/qualitatively analyzing volatile organic compounds in the air up to an infinitesimal amount in real-time, more particularly, to the portable GCMS for monitoring volatile organic compounds in real time which integrally includes a Gas Chromatograph (GC) including a sampling device into which volatile organic compounds are injected, a small-sized gas chromatograph module, and a nitrogen supply source for supplying carrier gases of the gas chromatograph module; a Mass Spectrometer (MS) including a vacuum chamber and a quadrupole mass spectrometer included in the vacuum chamber; and a GCMS interface connecting the GC and the MS, as is constituted in one body. The portable GCMS is easy to use on the spot, minimizes the consumable parts, detects promptly in real-time on the spot.

Description

[DESCRIPTION]

[Invention Title]

Portable GCMS for monitoring a volatile organic compound in real-time [Technical Field]

The present invention relates to a portable gas chromatograph-mass spectrometer (GCMS) capable of quant itatively/qualitatively analyzing volatile organic compounds in the air up to an infinitesimal amount in real^¬ time, and more particularly, to a portable gas chromatograph-mass spectrometer capable of directly sampling and analyzing the volatile organic compounds in the air on the spot and in real-time, which is small and light, and minimizes consumable parts.

[Background Art]

In general, the gas chromatograph-mass spectrometer, which will be called GCMS hereinafter, is an equipment for separat ing/analyzing vapor izable elements according to a time. Like this GCMS, the basic constitution of the portable GCMS includes a gas chromatograph and a mass spectrometer.

U.S. Patent No. 5,426,300 discloses "Portable GCMS System Using Getter Pump", which includes a gas chromatograph and a vacuum chamber interfacing with a membrane, wherein the devices related to a portable analysis module including the mass spectrometer and the getter pump and a service module are disclosed in the vacuum chamber. For keeping high vacuum in the vacuum chamber, a non-evaporative getter pump used in the chamber and an ion getter pump as an auxiliary pump of the getter pump may be used, and the service module as being a module for forming initial high vacuum of the portable analysis module, individually includes a high vacuum pump such as a turbo pump or a diffusion pump, for high vacuum. Since the non-evaporative getter pump used for keeping high vacuum in the vacuum chamber of the portable analysis module cannot discharge inert gases, the ion getter pump needs to be used as the auxiliary pump for removing the remaining inert gases from the portable analysis module. Further, when the non-evaporative getter pump is used for a predetermined period, pumping speed of the non-evaporative getter pump becomes worse due to absorption of the remaining getter material in the vacuum chamber, and the non-evaporative getter pump results in finishing of a life as a high vacuum pump. Accordingly, the non-evaporative getter pump is highly consumable and expensive as consumable parts, and needs an individual service module for making high vacuum whenever replaced. Regardless of the portable analysis device, the service module having a size similar to that of the portable analysis device is an essential option to the engineer, accordingly, it needs for him to go to the spot after making the service module to the high vacuum state whenever he goes to the spot. When the vacuum degree becomes worse, it is inconvenient to deal with the worsen vacuum degree.

U.S. Patent No. 5,525,799 titled "Portable Gas Chromatograph Mass Spectrometer" as a related art discloses a vacuum system using the ion/sorption pump in the vacuum chamber including the mass spectrometer, which has weak points as described above although the GCMS is more conveniently suited in a suit-case than the existing portable GCMS.

U.S. Patent No. 6,351,983 titled "Portable Gas Chromatograph Mass Spectrometer for On-site Chemical Analyses" discloses portable GCMS with the weight of ~25kg, as a basic laboratory-based type GCMS. The gas chromatograph may be divided into a GC column and an injection part and adopts a method for injecting a sample into a mass spectrometer through a column by vaporizing the sample by heating after injection using the micro- syringe. For high vacuum of the vacuum chamber including the mass spectrometer, a turbo pump and a diaphragm pump as an auxiliary pump are used, and an ionized pump is mounted for keeping a vacuum state while a sample is not analyzed. Operating states of a vacuum pump, a heater, a valve, and the like may be displayed by mounting a Light Emitting Diode (LED) display panel on this device, and tuning, works by a heater, a pump and a fan, collecting and searching of data may be executed after connecting the note-book computer.

There is a difficulty in analyzing volatile organic compounds in real- time on the spot due to the structure of the sample injecting part which injects the sample with micro-syringe by individually collecting a sample.

In the related art described above, a mass filter part of the mass spectrometer is used as a quadrupole, but the U.S. Patent No. 5,515,061 titled "Miniaturized Chromatograph Mass Spectrometer System" discloses a GCMS having a mass spectrometer using a magnetic sector analyzer where a sample injecting part and a GC column module are integrally formed in a thermal zone. A turbo pump and a mechanical pump may be used for keeping a vacuum state of the vacuum chamber including the magnetic sector analyzer. By improving the existing GCMS, various sample injecting methods including a concentration device are suggested, but it is formed of a passage using only a 2-way or 3-way valve. More particularly, the injection focusing of the samples is never executed when the sample is injected into the gas chromatograph or the mass spectrometer, since it is injected in a single direction regardless of a molecular weight of the injected volatile organic compound when injecting the sample using the concentration device and is discharged in the injected direction from the concentration device. Also, since the GC column is inside the oven, there is a limit to power consumption and miniaturization.

Therefore, in order to quantitatively and qualitatively analyze the volatile organic compound in the air up to a infinitesimal amount in real^¬ time on the spot, development of the portable GCMS that is small, light, highly, easily maintained, and excellent in performance is required.

[Disclosure]

[Technical Problem]

Therefore, the object of the present invention is to provide a portable gas chromatograph-mass spectrometer (GCMS) for executing quantitative and qualitative analysis up to a infinitesimal amount after sampling the volatile organic compound in the air on the spot in real-time.

[Technical Solution]

The portable gas chromatograph-mass spectrometer (GCMS) for monitoring volatile organic compounds in real-time according to the present invention integrally includes a Gas Chromatograph (GC) including a sampling device that volatile organic compounds are injected, a small-sized gas chromatograph module and a nitrogen supply source for supplying carrier gases of the gas chromatograph module; a Mass Spectrometer (MS) including a vacuum chamber for keeping a vacuum state by a vacuum system, and a quadrupole mass spectrometer included in the vacuum chamber; and a GCMS interface connecting the GC and the MS.

Meanwhile, the sampling device includes a air sample preconcentrator including an absorbent formed of metal nanocomposite with carbon nanotubes. Preferably, the sampling device includes a air sample preconcentrator or a sampling loop that may be inserted after being exchanged, and it is also desirable that the sampling device includes a switching valve for passage shifting as a similar open/shut locking device.

Meanwhile, it is desirable that the vacuum system includes a small- sized turbo pump and a small-sized diaphragm pump.

Further, the nitrogen supply source may be recharged for portability, and the small-sized gas chromatograph module is attachable/detachable.

The portable GCMS for monitoring a volatile organic compound in real-time according to the present invention integrally further includes at least one of a self powered supply system using a secondary battery and a small-sized computer for analyzing data of the GC and the MS and enabling wire/wireless data transmission-reception with inner-outer parts.

[Advantageous Effects]

As described above, the portable GCMS for monitoring the volatile organic compound in real-time according to the present invention can detect, classify, and monitor the volatile organic compound on the spot up to the concentration range of infinitesimal amount.

Consequently, as an environment improving effect, a pollution level may be minimized by recognizing a fountainhead of a pollution source for prompt management by grasping detailed information on discharge or generation of a pollution source through real-time spot detection of noxious materials in the air. The portable GCMS may be effectively used for detecting smuggling of prohibited drugs or terror of the airplane at the airport or harbors, used in a real-time monitoring field of a pollution source inside a semiconductor manufacturing equipment and very small process noxious gases of high-tech field like the semiconductor related industry as well as used for detecting the biology material or military chemical substances and for diagnosis in the medical industry, and used in analyzing the material of bio-industry as a key industry of the future.

[Description of Drawings]

The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

Fig. 1 is a block diagram of a portable gas chromatograph-mass spectrometer (GCMS) for monitoring a volatile organic compound in real-time in accordance with an embodiment of the present invention.

Fig. 2 is a perspective view illustrating the portable GCMS 10 for monitoring a volatile organic compound in real-time in accordance with an embodiment of the present invention.

[Detailed Description of Main Elements]

10 : portable GCMS 11 : GC

12 : GCMS interface 20 ^'· Small-Sized column module

21 ^'· small-sized gas chromatograph module 22 ^'· sampling device 23 : nitrogen supply source

31 : vacuum chamber 32 : vacuum system

32a : small-sized turbo pump 32b : small-si zed diaphragm pump

33 : vacuum gauge 34 : mass spectrometer

40 : self powered supply system

51 : GC control device 52 : MS control device

53 : small-si zed computer

[Best Mode]

Hereinafter, a portable gas chromatograph-mass spectrometer (GCMS) 10 for monitoring volatile organic compounds in real-time of the present invention will be described in detail with reference to the accompanying drawings. In the following detailed description, when it is determined that detailed description on related known functions or configurations may blur the point of the present invention, the detailed description will be omitted. Some features suggested in the drawings are magnified, reduced or simplified. The drawings and its constituent elements may not be illustrated in a proper proportion. However, those skilled in the art would understand such detailed matters. Hereinafter, a portable GCMS 10 for monitoring volatile organic compounds in real-time of the present invention will be described in detail.

Fig. 1 is a block diagram of the portable GCMS for monitoring volatile organic compounds in real-time according to the present invention. Fig. 2 is a perspective view illustrating the portable GCMS 10 for monitoring a volatile organic compound in real-time according to the present invention.

The portable GCMS 10 for monitoring real-time volatile organic compounds according to the present invention includes a Gas Chromatograph (GC) 11 including a sampling device 22 into which a volatile organic compound is injected, a small-sized gas chromatograph module 21 and a nitrogen supply source 23 for supplying carrier gas of the gas chromatograph module; an Mass Spectrometer (MS) 13 including a vacuum chamber 31 keeping vacuum by using a vacuum system 32 and a quadrupole mass spectrometer 34 included in the vacuum chamber 31; a GCMS interface 12 connecting the GC 11 and the MS 13; a self powered supply system 40 using a secondary battery; and a small-sized computer 53 for analyzing data of the GC 11 and the MS 13 and enabling wire/wireless data to be transmitted to and received from inner-outer parts.

The sampling device 22 includes a air sample preconcentrator and/or a sampling loop, whose exchange/ insert ion is possible, as a configuration into which a volatile organic compound is injected, that enables selective sampling according to the density and feature of the volatile organic compound. Also, it is controlled using the switching valve for passage shift as the similar open/shut locking device.

It is desirable to take the effect of high incrassation simultaneously with. direct sampling of the volatile organic compound in the air by applying a metal nanocomposite with carbon nanotubes on the spot since the air sample preconcentrator of the sampling device 22 includes an absorbent formed of the metal nanocomposite with carbon nanotubes.

The metal nanocomposite with carbon nanotubes used as the absorbent is described in the U.S. Patent No. 7,217,311 titled "Method of Producing Metal Nanocomposite Powder reinforced with Carbon Nano-tubes and the Powder prepared thereby", and KR Patent Publication No. 10-2005-0012556 titled "Metal nanocomposite powder reinforced with Carbon nanotubes and preparing method thereof" .

The nitrogen supply source 23 supplies nitrogen as a carrier gas of the volatile organic compound injected through the air sample preconcentrator or the sampling loop of the small-sized gas chromatograph module 21, and it is designed to mount a portable canister charged with nitrogen of 100-150 psi. To prevent consuming of the carrier gas mostly used for operating equipments on the spot, it may be a rechargeable type by using a carrier gas cartridge. When the supply of nitrogen having a high degree of purity is possible, nitrogen in a high degree of purity may be supplied to the GCMS directly.

The volatile organic compound injected through the air sample preconcentrator or the sampling loop of the sampling device 22 passes through the small-sized gas chromatograph module 21. The small-sized gas chromatograph module 21 removes oven of a column holding most of the existing gas chromatograph, and it makes a module by uniformly rewinding the heat line for elevating temperature together with a capillary column. Also, the volume is greatly reduced while unchangeably maintaining the separating capability of capillary column, wherein the temperature of the small-sized gas chromatograph module 21 is correctly measured by inserting a temperature sensor in a center of a column module, with a fan for cooling the small-sized gas chromatograph module 21 being mounted.

Since the simple small-sized gas chromatograph module 21 uses the capillary column differently according to the features of the volatile organic compound in a material to be analyzed or a period that the capillary column is used, only the small-sized gas chromatograph module 21 itself may be separated from the portable GCMS 10 for monitoring the volatile organic compound in real-time in the present invention.

The Gas Chromatograph (GC) 11 includes the sampling device 22, the small-sized gas chromatograph module 21, the nitrogen supply source 23, the small-sized diaphragm pump 32b for sampling and the flow control device (not shown), with the volume of 150 X 150 X 100 mm, weight under 3kg. The GC control device 51 automatically controls GC 11, that is, controls the temperature in the small-sized gas chromatograph module 21, controls the temperature in the fan, heater, and sampling device 22, controls the small- sized diaphragm pump 32b for sampling and the heater operation to prevent condensing inside the passing duct before injecting of the volatile organic compound to the mass spectrometer 34 and controls operation of switching valves for shifting the passing duct, and 2-way and 3^~way valves and etc.

The GCMS interface 12 connecting the MS 13 and the GC 11 described later maintains high vacuum between the small-sized gas chromatograph module

-6

21 of air pressure and the vacuum chamber 31 of 10 torr high vacuum using a semi -permeable membrane of PDMS(polydimethylsi loxane) . It is possible to measure the infinitesimal density in a lower detecting limit of the volatile organic compound in real time on the spot since the semi -permeable membrane takes more than 100 times concentration effect of the volatile organic compound in a course of introducing the sample of the small-sized quadrupole mass spectrometer 34.

The vacuum chamber 31 includes the mass spectrometer 34. The volatile organic compound injected in the sample introducing part of the quadrupole mass spectrometer 34 through the GCMS interface 12 is ionized in the vacuum chamber 31 by an electronic shock, and the generated ions pass through the quadrupole filter to obtain the information on the structure and the molecular weight of the volatile organic compound by measuring the ion according to every mass.

The vacuum system 32 uses a small-sized turbo pump 32a and a small- sized diaphragm pump 32b as an auxiliary pump of the small-sized turbo pump 32a to maintain high vacuum of the vacuum chamber 31 that should maintain the high vacuum continuously. The vacuum system 32 has a monolithic structure with the portable GCMS 10 for monitoring the volatile organic compound in real time according to the invention. Accordingly, the size of the vacuum chamber 31 including the mass spectrometer 34 is 190 X 360 X 120 mm, and the total weight including the vacuum system 32 is about 6.0 kg. In comparison with other high vacuum pumps, the turbo pump used in the vacuum system 32 has strong points in that the beginning and ending courses of the operation are simpler and faster, and it is easily maintained and is well operated when polluted. Although there is a little vibration, vibration may be reduced to a certain degree by installing a vibration isolator. Also, the mechanical pump may be needed when using the turbo pump. In this case, the small-sized diaphragm pump 32b is used. The diaphragm pump may be used in fields of absorbing, transporting, compressing the air, neutral gas, some corrosive gas, especially moving is easy due to small size.

It is considered that the weight of the equipment and the cost of consumable goods regarding the maintenance, managing, repair are reduced by introducing the small-sized turbo pump 32a and diaphragm pump 32b to the vacuum system 32.

The control system of the present invention includes the GC control device 51 and an MS control device 52. As described above, the GC control device 51 automatically controls from the real time sampling of the volatile organic compound to the GCMS interface 12, and the operation of the quadrupole mass spectrometer 34 including the vacuum system 32 is automatically controlled by the MS control device 52.

The above-mentioned small computer 53 is mounted on the main body for easy and convenient real-time control and analysis. The data transmitting system between the GC control device 51 and MS control device 52 is RS 422, and the GC control device 51 communicates with the small computer 53 via the MS part control device. The MS control device receives the required data from the device or controls the device via the USB communication with the small computer 53 mounted. Therefore, the small-sized computer 53 in a type of touch screen based on the Windows XP having the size of 271 X 205 X 27 mm and the weight of 1.25 kg mounted on the main body of the device according to the present invention includes device operation software and analyzing software and enables the user to perform real-time analysis on the spot and prepare files.

The above-mentioned self powered supply system 40 is used in analyzing the spot as the power supply for the operation of the constitution. Any battery will do as long as it is a rechargeable secondary battery, and in the embodiment of the present invention, the lithium-polymer battery having the size of 200 X 52 X 45 mm and the weight of 1.7 kg, such 6 batteries (3.7volt/voltage per cell) are preferable to be constituted in series where the battery is used to the portable GCMS 10 for over two hours in real time on the spot with 22.2 volt, 10600 mAh in the normal state.

Since the portable GCMS 10 for monitoring the volatile organic compound in real-time on the spot is small, light and portable, and reduces consuming wastes, prompt moving to the spot and easy quant i tat ive/quali tat ive analysis are possible.

Claims

[CLAIMS]

[Claim 1]

A portable gas chromatograph-mass spectrometer (GCMS) for monitoring a volatile organic compound in real-time, comprising:

a Gas Chromatograph (GC) including a sampling device into which a volatile organic compound is injected, a small-sized gas chromatograph module, and a nitrogen supply source for supplying carrier gas of the gas chromatograph module;

a Mass Spectrometer (MS) including a vacuum chamber keeping a vacuum state by using a vacuum system taking primary vacuum by using a small-sized diaphragm pump and forming high vacuum through a connected small-sized turbo pump, and a quadrupole mass spectrometer included in the vacuum chamber; and a GCMS interface connecting the GC and the MS.

[Claim 2]

The portable GCMS for monitoring a volatile organic compound in real^¬ time according to claim 1, wherein the sampling device includes an air sample preconcentrator including an absorbent formed of a metal nanocomposite with carbon nanotubes.

[Claim 3]

The portable GCMS for monitoring a volatile organic compound in real^¬ time according to claim 1, wherein the sampling device includes an air sample preconcentrator or a sampling loop that is inserted after being exchanged.

[Claim 4]

The portable GCMS for monitoring a volatile organic compound in real^¬ time according to claim 1, wherein the sampling device includes a switching valve for passage shifting as a similar open/shut locking device.

[Claim 5]

The portable GCMS for monitoring a volatile organic compound in real^¬ time according to claim 1, further comprising at least one of a self powered supply system using a secondary battery and a small-sized computer for analyzing data of the GC and the MS and for enabling wire and wireless data

/ transmission to and data reception from inner and outer parts.

[Claim 6]

The portable GCMS for monitoring a volatile organic compound in real^¬ time according to claim 1, wherein the nitrogen supply source is portable and rechargeable.

[Claim 7]

The portable GCMS for monitoring a volatile organic compound in real^¬ time according to claim 1, wherein the small-sized gas chromatograph module is attachable and detachable.