JPH03261062A - Plasma trace element mass spectrometer - Google Patents

Plasma trace element mass spectrometer

Info

Publication number
JPH03261062A
JPH03261062A JP2056359A JP5635990A JPH03261062A JP H03261062 A JPH03261062 A JP H03261062A JP 2056359 A JP2056359 A JP 2056359A JP 5635990 A JP5635990 A JP 5635990A JP H03261062 A JPH03261062 A JP H03261062A
Authority
JP
Japan
Prior art keywords
plasma
ion
torr
area
mass spectrometer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2056359A
Other languages
Japanese (ja)
Inventor
Yukio Okamoto
幸雄 岡本
Soji Shimura
志村 聡司
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP2056359A priority Critical patent/JPH03261062A/en
Priority to DE19914107794 priority patent/DE4107794A1/en
Publication of JPH03261062A publication Critical patent/JPH03261062A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J49/00Particle spectrometers or separator tubes
    • H01J49/02Details
    • H01J49/10Ion sources; Ion guns
    • H01J49/105Ion sources; Ion guns using high-frequency excitation, e.g. microwave excitation, Inductively Coupled Plasma [ICP]

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
  • Electron Tubes For Measurement (AREA)

Abstract

PURPOSE:To reduce the power consumption of a mass spectrometer and miniaturize the spectrometer and reduce the cost of the spectrometer by setting the degree of vacuum of a first actuation area to less than 1Torr. CONSTITUTION:Samples are introduced into atmospheric pressure plasma 10 generated in the area (I) of atmospheric pressure on a plasma generating system so that the samples are ionized. The sample ions are expanded and diffused in the area (II) of 1 to 10<-3>Torr via a plasma sampling system 70 and an ion beam composed of the sample ions, etc., is formed by an ion takeout system provided in the area (III) of 10<-4> to 10<-5>Torr and consisting of an ion takeout electrode 80 and an ion accelerating electrode 90, etc. The ion beam is transported via an ion transporting system 100 to a mass spectrometry system 110 provided in the area (IV) of 10<-6> to 10<-7>Torr and the samples are identified by an ion detecting system 120.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、プラズマを用いた極微量元素質量分析装置に
係り、特に検出限界を低減するための第1差動領域の真
空度に関する。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultratrace element mass spectrometer using plasma, and particularly to the degree of vacuum in the first differential region for reducing the detection limit.

(1) 〔従来の技術〕 従来の代表的なプラズマを用いた極微量元素質量分析装
置については、スペクトロケミ力 アクタ(Spect
rochimica Acta) 40 B (198
5年)第1525頁から第1537頁において論じられ
ている。
(1) [Prior art] As for the typical conventional plasma-based ultratrace element mass spectrometer, the Spectrochemistry Acta
rochimica Acta) 40 B (198
5), pages 1525 to 1537.

第3図は上記従来装置の主要部の概略図を示す。FIG. 3 shows a schematic diagram of the main parts of the conventional device.

ここで、10は大気圧プラズマ、11はプラズマトーチ
、12は高周波コイル、20はプラズマサンプリングコ
ーン、21はサンプリングオリフィス(1、5−上、 
Ommφ)、30はスキーマ、31はスキーマオリフィ
ス(1,5〜0.7mmφ)、40はイオン取り出し電
極を示す。
Here, 10 is atmospheric pressure plasma, 11 is plasma torch, 12 is high frequency coil, 20 is plasma sampling cone, 21 is sampling orifice (1, 5-upper,
30 is a schema, 31 is a schema orifice (1.5 to 0.7 mmφ), and 40 is an ion extraction electrode.

この装置では、前記プラズマトーチ11と前記プラズマ
サンプリングコーン2oの間の大気圧(760Torr
)の領域(1)に、先ず前記高周波コイル12に供給し
た高周波電力によって前記大気圧プラズマ10を生成す
る。次に、前記大気圧プラズマ10を前言己サンプリン
グオリフィス21より前記プラズマサンプリングコーン
2oと前記(2) スキーマ30間の領域(]IIの第1差動領域(1〜3
Torr)に膨張させる。さらに、前記スキーマオリフ
ィス31を通して、領域(■)(〜1O−4Torr)
に前記膨張プラズマを拡散させるとともに前記スキーマ
30と前記イオン取り出し電極40との間に印加した電
圧で、前記プラズマからイオンを取り出す。そして、イ
オンレンズなどから成るイオン輸送系を経て、マスフィ
ルターなどの質量分析系に前記イオンを導き、質量を同
定するよう構成していた。
In this device, the atmospheric pressure (760 Torr) between the plasma torch 11 and the plasma sampling cone 2o is
), the atmospheric pressure plasma 10 is first generated by the high frequency power supplied to the high frequency coil 12. Next, the atmospheric pressure plasma 10 is transferred from the sampling orifice 21 to the plasma sampling cone 2o and the first differential area (1 to 3) of the area (2) between the schema 30
Torr). Further, through the schema orifice 31, the area (■) (~1O-4 Torr)
The expanded plasma is diffused and ions are extracted from the plasma by applying a voltage between the schema 30 and the ion extraction electrode 40. The ions are then introduced to a mass spectrometry system such as a mass filter through an ion transport system consisting of an ion lens, etc., and their masses are identified.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

上記従来技術は、前記領域(I[)の第1差動領域にお
ける分析すべき試料イオンの損失(減衰)については十
分配慮されておらず、検出限界や測定感度に大きな問題
があった。
The above-mentioned conventional technology does not give sufficient consideration to the loss (attenuation) of sample ions to be analyzed in the first differential region of the region (I[), and has a major problem with the detection limit and measurement sensitivity.

本発明は、上記課題を解決することを目的とするととも
に、さらに装置の低電力化、小型化、さらに低価格化を
計ることを目的とする。
The present invention aims to solve the above-mentioned problems, and further aims to reduce the power consumption, size, and cost of the device.

〔課題を解決するための手段〕[Means to solve the problem]

上記目的を遠戚するために、前記領域(II)の(3) 第1差動領域の真空度を、第1図に示すように、従来技
術の3〜I TorrをI Torr未満、より好まし
くは0 、8 Torr以下にしたものである。
In order to achieve the above object distantly, the degree of vacuum in the first differential region (3) of region (II) should be changed from 3 to I Torr in the prior art to less than I Torr, more preferably, as shown in FIG. is 0.8 Torr or less.

〔作用〕[Effect]

前記第1差動領域の高真空化は、前記サンプリングコー
ンから膨張してくるプラズマ中の分析すべき試料イオン
の損失(減衰)を第1図に示すように、大幅に低減する
ように作用する。すなわち、試料イオンの初期の強度を
■。、前記第1差動領域の圧力をP、残留ガス分子など
との全衝突断面積をσ、相互作用の生ずる(反応)距離
をαとすると、反応後の前記試料イオンの強度■は、I
 cc I。exp(−a P Q)なる関係があり、
σ、Q一定とすると、Pの減少により工は指数関数的に
増大する。また、第1図に示すように、バックグランド
ノイズBNも大幅に低減できる作用がある。かかる理由
から第1差動領域の圧力は、I Torr未満、とくに
0 、8 Torr未満に保つのが好ましい。なお、衝
突が無視できる1O−3Torr以下になると、これら
の作用は小さ(4) よって、前記領域(m)の排気装置の容量を小型化でき
るように作用する。
The high vacuum of the first differential region acts to significantly reduce the loss (attenuation) of sample ions to be analyzed in the plasma expanding from the sampling cone, as shown in FIG. . In other words, the initial intensity of the sample ions is ■. , the pressure in the first differential region is P, the total collision cross section with residual gas molecules is σ, and the interaction (reaction) distance is α, then the intensity of the sample ion after reaction is I
cc I. There is a relationship exp(-a P Q),
Assuming that σ and Q are constant, the work increases exponentially as P decreases. Furthermore, as shown in FIG. 1, the background noise BN can also be significantly reduced. For this reason, the pressure in the first differential region is preferably kept below I Torr, particularly below 0.8 Torr. Note that when the collision becomes negligible at 10-3 Torr or less, these effects are small (4).Therefore, the capacity of the exhaust device in the region (m) can be reduced.

〔実施例〕〔Example〕

以下、本発明の一実施例を第1図および第2図を参照し
て説明する。第1図は本発明の効果を示す第1差動領域
の真空度Pに対するイオン強度■(分析すべき試料、例
えば、Mg”、Go”In+など)の変化を示す。第2
図は第1図のデータを求めた本発明の装置を示す。ここ
で、■0は大気圧プラズマ、50はネプライザなどから
成る試料導入系、60はマイクロ波キャビティやプラズ
マトーチなどから成るプラズマ生成系、70はプラズマ
サンプラなどから戊るプラズマサンプリング系、80は
イオン引出し電極、90はイオどから成るイオン輸送系
、110はマスフィルタなどから成る質量分析系、12
0は2次電子増倍(5) 管などから成るイオン検出系を示す。また、■1〜■8
 は真空バルブ、RP、−RP3はロータリポンプやメ
カニカルブースタなどから成る荒引き排気系(到達真空
度−10−3Torr) 、D PlとDP2は油拡散
ポンプやターボモレキュラポンプなどから成る高真空排
気系(到達真空度10−6〜1O−llTorr)を示
す。
An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 shows a change in ion intensity (of a sample to be analyzed, for example, Mg", Go"In+, etc.) with respect to the degree of vacuum P in the first differential region, which shows the effects of the present invention. Second
The figure shows the apparatus of the invention from which the data of FIG. 1 was obtained. Here, ■0 is atmospheric pressure plasma, 50 is a sample introduction system consisting of a nebulizer, etc., 60 is a plasma generation system consisting of a microwave cavity, plasma torch, etc., 70 is a plasma sampling system such as a plasma sampler, and 80 is an ion An extraction electrode, 90 an ion transport system consisting of ions, 110 a mass spectrometry system consisting of a mass filter, etc., 12
0 indicates an ion detection system consisting of a secondary electron multiplier (5) tube, etc. Also, ■1 to ■8
is a vacuum valve, RP, -RP3 is a rough evacuation system (achieved vacuum -10-3 Torr) consisting of a rotary pump, mechanical booster, etc., and D Pl and DP2 are high vacuum evacuation systems consisting of an oil diffusion pump, turbo molecular pump, etc. The system (achieved vacuum level 10-6 to 1 O-ll Torr) is shown.

次に、本装置の動作について説明する。先ず前記プラズ
マ生成系(マイクロ波、高周波、直流電力などによる)
で大気圧の領域(1)に生成した大気圧プラズマ10 
(He、N2.Arなどの)中に分析すべき試料(気体
、液体、固体など)を導入してイオン化(試料イオン)
する。次に、前記大気圧プラズマ10とともに前記試料
イオンを前記プラズマサンプラから成るプラズマサンプ
リング系70を介して1−10−3Torr (I T
orr未満、10 ””Torr以上)の領域(■)(
第1差動領域)に膨張拡散させ、10−4〜10−’T
orr領域(DI)(6) 料イオンなどから成るイオンビームを形成する。
Next, the operation of this device will be explained. First, the plasma generation system (using microwave, high frequency, DC power, etc.)
Atmospheric pressure plasma 10 generated in the atmospheric pressure region (1)
Introducing the sample (gas, liquid, solid, etc.) to be analyzed into (He, N2, Ar, etc.) and ionizing it (sample ion)
do. Next, the sample ions together with the atmospheric pressure plasma 10 are passed through a plasma sampling system 70 consisting of the plasma sampler at 1-10-3 Torr (I T
less than orr, more than 10''Torr) area (■) (
10-4 to 10-'T
ORR region (DI) (6) Forms an ion beam consisting of source ions.

そして、前記イオンビームを前記イオン輸送系100を
介して効率よ< 10−6〜10−7Torr領域(I
V)に設けた前記質量分析系110に輸送するとともに
前記イオン検出系120を用いて分析すべき試料を同定
する。このとき、領域(TI)はRP、  (排気速度
:〜100OQ/min )を、領域(11)はRP2
 (排気速度: −300Q 7m1n)とDP、(排
気速度ニー800Q/5CIC)を、領域(TV)はR
P3 (−200Q/m、in)とDP。
Then, the ion beam is transmitted through the ion transport system 100 with an efficiency of <10-6 to 10-7 Torr (I
The sample to be transported to the mass spectrometry system 110 provided in V) and analyzed using the ion detection system 120 is identified. At this time, the region (TI) is RP, (pumping speed: ~100OQ/min), and the region (11) is RP2.
(Exhaust speed: -300Q 7m1n) and DP, (Exhaust speed knee 800Q/5CIC), area (TV) is R
P3 (-200Q/m, in) and DP.

(排気速度:〜300Q/5ee)を用いて排気すると
、各々前記真空度が得られ、効率よく前記試料イオンを
検出することができる。さらに、バックグラウンドノイ
ズも減少するので信号対雑音比が大きくなり、検出限界
を低減することができる1゜なお、上記において、前記
真空度(I Torr未満〜1O−3Torr以上)以
外は限定するものでなく、種々のプラズマ生成系や試料
導入系、さらにイオン取り出し系などを用いてもよい。
(Evacuation speed: ~300Q/5ee), the above-mentioned degree of vacuum can be obtained, and the sample ions can be detected efficiently. Furthermore, since the background noise is reduced, the signal-to-noise ratio is increased, and the detection limit can be reduced by 1°.In addition, in the above, there are limitations other than the degree of vacuum (less than I Torr to more than 1 O-3 Torr). Instead, various plasma generation systems, sample introduction systems, ion extraction systems, etc. may be used.

本発明によれば、第1図に示したように、領域(7) ([)即ち、第1差動領域の真空度を、従来の↓Tor
r以上からI Torr未満−0、8Torr程度に高
めると、前記断熱膨張したプラズマが前記領域(II)
の残留ガスとの相互作用によって減衰するのが大幅に低
減できるので、分析すべきイオンの電流■を10倍以上
大きくすること(高感度化)ができる。さらに、バック
グラウンドノイズBNも2倍以上低減できるので、信号
対雑音比を20倍以上向上、すなわち、分析の検出限界
を1/20以下と大幅に低減することができる大きな効
果がある。
According to the present invention, as shown in FIG.
When the temperature is increased from more than r to less than I Torr -0.8 Torr, the adiabatically expanded plasma expands into the region (II).
Attenuation due to interaction with residual gas can be significantly reduced, making it possible to increase the current (2) of the ions to be analyzed by more than 10 times (higher sensitivity). Furthermore, since the background noise BN can be reduced by more than twice, there is a great effect that the signal-to-noise ratio can be improved by more than 20 times, that is, the detection limit of analysis can be significantly reduced to 1/20 or less.

さらに、前記領域(I[)の真空度を0 、8 Tor
r以下とすることにより、DPlやDP2の排気速度も
低減できる。特に、DP、の排気速度も従来の、例えば
2000 Q/secから600−1000 fi/s
ecに低減できる効果がある。このため、消費電力や発
熱の低減をはじめ装置の小型化や価格の低減などその効
果は大なるものがある。
Furthermore, the degree of vacuum in the region (I[) is set to 0 and 8 Tor.
By setting it below r, the pumping speed of DPl and DP2 can also be reduced. In particular, the pumping speed of the DP has also increased from the conventional 2000 Q/sec to 600-1000 fi/s.
It has the effect of reducing ec. Therefore, there are significant effects such as reduction in power consumption and heat generation, miniaturization of the device, and cost reduction.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、検出限界や測定感度を改善したプラズ
マ極微量元素質量分析装置が得られる。
According to the present invention, a plasma trace element mass spectrometer with improved detection limits and measurement sensitivity can be obtained.

(8)(8)

【図面の簡単な説明】[Brief explanation of drawings]

第1図は従来技術と本発明との効果の比較図。 第2図は本発明装置の一実施例の構成図、第3図は従来
技術の主要部の構成図である。 10・・・大気圧プラズマ、20・・・プラズマサンプ
リングコーン、30・・・スキーマ、40・・・イオン
取り出し電極、50・・・試料導入系、60・・・プラ
ズマ生成系、70・・・プラズマイオンサンプリング系
、80・・・イオン引出し電極、90・・・イオン加速
電極、100・・・イオン輸送系、110・・・質量分
析系。 (9)
FIG. 1 is a comparison diagram of the effects of the prior art and the present invention. FIG. 2 is a block diagram of one embodiment of the apparatus of the present invention, and FIG. 3 is a block diagram of the main parts of the prior art. DESCRIPTION OF SYMBOLS 10... Atmospheric pressure plasma, 20... Plasma sampling cone, 30... Schema, 40... Ion extraction electrode, 50... Sample introduction system, 60... Plasma generation system, 70... Plasma ion sampling system, 80... Ion extraction electrode, 90... Ion acceleration electrode, 100... Ion transport system, 110... Mass spectrometry system. (9)

Claims (1)

【特許請求の範囲】 1、大気圧プラズマ生成系、試料導入系、プラズマサン
プリング系、イオン取り出し系、イオン輸送系、質量分
析系、イオン検出系、排気系から成るプラズマ極微量元
素質量分析装置において、前記プラズマサンプリング系
と前記イオン取り出し系の間の第1差動領域の真空度を
前記排気系を用いて1Torr未満に保つたことを特徴
とするプラズマ極微量元素質量分析装置。 2、上記第1差動領域の真空度を0.8Torr以下と
したことを特徴とする第1項記載のプラズマ極微量元素
質量分析装置。
[Claims] 1. In a plasma trace element mass spectrometer comprising an atmospheric pressure plasma generation system, a sample introduction system, a plasma sampling system, an ion extraction system, an ion transport system, a mass spectrometry system, an ion detection system, and an exhaust system. . A plasma trace element mass spectrometer, characterized in that the degree of vacuum in the first differential region between the plasma sampling system and the ion extraction system is maintained at less than 1 Torr using the exhaust system. 2. The plasma trace element mass spectrometer according to item 1, wherein the degree of vacuum in the first differential region is 0.8 Torr or less.
JP2056359A 1990-03-09 1990-03-09 Plasma trace element mass spectrometer Pending JPH03261062A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2056359A JPH03261062A (en) 1990-03-09 1990-03-09 Plasma trace element mass spectrometer
DE19914107794 DE4107794A1 (en) 1990-03-09 1991-03-11 Plasma mass spectrometer for trace element analysis - has atmospheric region followed by differential pump region for generation of diffusion plasma

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2056359A JPH03261062A (en) 1990-03-09 1990-03-09 Plasma trace element mass spectrometer

Publications (1)

Publication Number Publication Date
JPH03261062A true JPH03261062A (en) 1991-11-20

Family

ID=13025051

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2056359A Pending JPH03261062A (en) 1990-03-09 1990-03-09 Plasma trace element mass spectrometer

Country Status (2)

Country Link
JP (1) JPH03261062A (en)
DE (1) DE4107794A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE45386E1 (en) 1998-09-16 2015-02-24 Thermo Fisher Scientific (Bremen) Gmbh Means for removing unwanted ions from an ion transport system and mass spectrometer
USRE45553E1 (en) 2002-05-13 2015-06-09 Thermo Fisher Scientific Inc. Mass spectrometer and mass filters therefor
JP2016530680A (en) * 2013-07-19 2016-09-29 スミスズ ディテクション インコーポレイティド Mass spectrometer inlet that allows a reduction in average flow

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5565679A (en) * 1993-05-11 1996-10-15 Mds Health Group Limited Method and apparatus for plasma mass analysis with reduced space charge effects
US5381008A (en) * 1993-05-11 1995-01-10 Mds Health Group Ltd. Method of plasma mass analysis with reduced space charge effects
GB9417700D0 (en) * 1994-09-02 1994-10-19 Fisons Plc Apparatus and method for isotopic ratio plasma mass spectrometry
KR100257903B1 (en) * 1997-12-30 2000-08-01 윤종용 Plasma etching apparatus capable of in-situ monitoring, its in-situ monitoring method and in-situ cleaning method for removing residues in plasma etching chamber
GB2483314B (en) 2010-12-07 2013-03-06 Microsaic Systems Plc Miniature mass spectrometer system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE45386E1 (en) 1998-09-16 2015-02-24 Thermo Fisher Scientific (Bremen) Gmbh Means for removing unwanted ions from an ion transport system and mass spectrometer
USRE45553E1 (en) 2002-05-13 2015-06-09 Thermo Fisher Scientific Inc. Mass spectrometer and mass filters therefor
JP2016530680A (en) * 2013-07-19 2016-09-29 スミスズ ディテクション インコーポレイティド Mass spectrometer inlet that allows a reduction in average flow

Also Published As

Publication number Publication date
DE4107794A1 (en) 1991-09-19

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