JPH0756790B2 - Mass spectrometer - Google Patents
Mass spectrometerInfo
- Publication number
- JPH0756790B2 JPH0756790B2 JP61076276A JP7627686A JPH0756790B2 JP H0756790 B2 JPH0756790 B2 JP H0756790B2 JP 61076276 A JP61076276 A JP 61076276A JP 7627686 A JP7627686 A JP 7627686A JP H0756790 B2 JPH0756790 B2 JP H0756790B2
- Authority
- JP
- Japan
- Prior art keywords
- vacuum
- degree
- measurement
- sample
- ion
- 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.)
- Expired - Lifetime
Links
Description
【発明の詳細な説明】 〈産業上の利用分野〉 本発明は試料をイオン化し得られた質量スペクトルから
試料分子の組成等を分析する質量分析装置に関し、更に
詳しくは、イオン化すべき試料として、低蒸気圧液体を
含有する試料を用いた質量分析装置に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a mass spectrometer for analyzing the composition of sample molecules from a mass spectrum obtained by ionizing a sample, and more specifically, as a sample to be ionized, The present invention relates to a mass spectrometer using a sample containing a low vapor pressure liquid.
〈従来の技術〉 質量分析計において難揮発性で熱的不安定な有機物質を
イオン化する場合、フラグメンテーションを起させずに
親イオンを発生させる方法のひとつにレーザ光を照射す
る方法がある。この場合、固体試料は、水，エタノー
ル，アセトン等の適当な溶媒に溶かし、金属等の試料ホ
ルダー上に滴下した後、乾燥させ、薄膜状にして用いら
れる。しかし、この状態では、親イオンの生成量が微小
で、また、長時間のイオン生成は期待できない。<Prior Art> When ionizing a poorly volatile and thermally unstable organic substance in a mass spectrometer, one of the methods for generating parent ions without causing fragmentation is irradiation with laser light. In this case, the solid sample is dissolved in an appropriate solvent such as water, ethanol, or acetone, dropped on a sample holder such as a metal, and then dried to be used as a thin film. However, in this state, the amount of parent ions produced is very small, and long-term ion production cannot be expected.
本出願人は、イオンの生成量を増大させ、しかもその継
続時間を長くするため、試料溶液に金属微粒子と例えば
グリセリン等の低蒸気圧液体を添加する方法を既に提案
した。しかし、この様な試料作成法によっても、高質量
数物質においてはその親イオンの生成時間は限られてい
る。The present applicant has already proposed a method of adding metal fine particles and a low vapor pressure liquid such as glycerin to a sample solution in order to increase the production amount of ions and prolong the duration thereof. However, even with such a sample preparation method, the generation time of the parent ion is limited in the high mass number substance.
〈発明が解決しようとする問題点〉 通常、飛行時間型質量分析計においては、原理的には１
回の測定で全質量スペクトルが得られるはずであるが、
高質量数インオ等の微少イオンに対しては、何回かの測
定を積算してスペクトルを得ることが行なわれる。この
場合、上述のように親イオンの生成時間が限定されてい
ると、みやみに積算回数を増大しても、親イオン以外の
フラグメントイオンや他のイオンばかり検出され、親イ
オンの検出が困難になる。また、親イオンの検出ができ
ても、非常にSN比の悪いスペクトルしか得られない。<Problems to be Solved by the Invention> Generally, in a time-of-flight mass spectrometer, in principle, 1
The total mass spectrum should be obtained in a single measurement,
For small ions such as high mass number ions, several measurements are integrated to obtain a spectrum. In this case, if the generation time of the parent ion is limited as described above, even if the number of times of integration is unnecessarily increased, only fragment ions other than the parent ion and other ions are detected, and it is difficult to detect the parent ion. become. Moreover, even if the parent ion can be detected, only a spectrum with a very poor SN ratio can be obtained.
〈問題点を解決するための手段〉 本発明の質量分析装置は、イオン源部内の低蒸気圧液体
を含有する試料から発生した親イオンを測定し、その測
定結果に基づいてそのイオンを質量／電荷の比に従って
より分ける質量分析装置であって、上記イオン源部を含
む真空チャンバの真空度を検出する真空度検出手段と、
第１の真空度とそれよりも低い第２の真空度を設定する
ための設定手段と、その設定手段により設定された第１
および第２の真空度と上記真空度検出手段による検出値
とを比較し、当該検出値が、上記第１の真空度に達した
時点でイオン測定を開始し、かつ、上記第２の真空度に
達した時点でイオン測定を終了するように測定動作制御
信号を出力する比較手段を備えていることによって特徴
づけられる。<Means for Solving Problems> A mass spectrometer of the present invention measures parent ions generated from a sample containing a low vapor pressure liquid in an ion source section, and based on the measurement result, mass / ionizes the ions. A mass spectrometer which divides according to a charge ratio, and a vacuum degree detecting means for detecting a vacuum degree of a vacuum chamber including the ion source section,
Setting means for setting the first degree of vacuum and a second degree of vacuum lower than that, and a first means set by the setting means.
And a second vacuum degree and a detection value by the vacuum degree detecting means are compared, and when the detected value reaches the first vacuum degree, the ion measurement is started, and the second vacuum degree is reached. It is characterized in that it comprises a comparison means for outputting a measurement operation control signal so as to terminate the ion measurement at the time when the temperature reaches.
〈作用〉 試料に金属微粒子並びにグリセリン等の低蒸気圧液体を
添加するこという手法により、高質量親イオンの生成が
可能であることは前記したが、本発明は、この手法に基
づいて試料の分析を行うに当たり、親イオンが生成され
る時間帯を有効に利用し、親イオンを確実に測定すると
ともに、不要な測定結果を積算することによりSN比の悪
化を防止しようとするものである。<Operation> It has been described above that high mass parent ions can be generated by the method of adding metal fine particles and a low vapor pressure liquid such as glycerin to the sample, but the present invention is based on this method. In conducting the analysis, the time period in which the parent ion is generated is effectively used, the parent ion is reliably measured, and the unnecessary measurement results are integrated to prevent the deterioration of the SN ratio.
すなわち、この種の試料を用いた場合、第５図に示すよ
うに、親イオン強度は試料の導入から一定の時間帯にお
いて急激に増大し、その後は低下する。このように親イ
オンの生成時間が決定される原因は理論的には定かでは
ないが、実験事実として、グリセリン等の低蒸気圧液体
が完全に蒸発してしまう直前、つまり半渇きの状態で親
イオンの生成量が増大することが確認されている。That is, in the case of using this type of sample, as shown in FIG. 5, the parent ion intensity sharply increases in a certain time period from the introduction of the sample and then decreases. The reason why the generation time of the parent ion is determined is not theoretically clear, but as an experimental fact, the parent ion is generated immediately before the low vapor pressure liquid such as glycerin is completely evaporated, that is, when the parent ion is half thirsty. It has been confirmed that the amount of generated ions increases.
一方、低蒸気圧液体を含有する試料を用いた場合、その
試料の表面の乾燥状態は、イオン源を含む真空チャンバ
の真空度と極めて近い相関を持ち、同一の試料ならば、
ほぼ同一の真空度にまで達した時点で親イオンの生成量
が増大を開始するとともに、その真空度よりも更に低い
真空度にまで達した時点でその生成量は減少する。On the other hand, when a sample containing a low vapor pressure liquid is used, the dry state of the surface of the sample has an extremely close correlation with the vacuum degree of the vacuum chamber containing the ion source, and if the same sample,
The generation amount of the parent ions starts increasing at the time when the vacuum degree reaches almost the same level, and decreases at the time point when the vacuum degree lower than the vacuum degree is reached.
そこで、設定手段により、親イオンの生成量が増大する
第１に真空度と、それよりも低い真空度で、親イオンの
生産量が減少してしまう第２の真空度とを、設定してお
き、これらの真空度と真空度検出手段により検出された
真空チャンバ内の実際の真空度とを比較手段によって比
較し、その比較結果に応じてイオンの測定開始／終了の
制御動作信号を発生することにより、イオンの生成量が
多い最適な時間帯において親イオンの測定を実行するこ
とが可能となる。Therefore, the setting means sets the first degree of vacuum in which the amount of parent ions produced increases and the second degree of vacuum in which the amount of parent ions produced decreases at a lower degree of vacuum. Then, the degree of vacuum and the actual degree of vacuum in the vacuum chamber detected by the degree-of-vacuum detection means are compared by the comparison means, and a control operation signal for starting / ending ion measurement is generated according to the comparison result. As a result, it becomes possible to measure the parent ion in the optimum time zone in which the amount of generated ions is large.
〈実施例〉 第１図は本実施例のレーザイオン化質量分析装置の構成
を示す。<Example> FIG. 1 shows the configuration of a laser ionization mass spectrometer according to this example.
真空チャンバ１は、イオン源部2,分析部３並びに検出部
４を含み、図示しない真空ポンプにより真空に保持され
る。試料５は、試料ホルダ６上に載置されてイオン源部
２に導入される。The vacuum chamber 1 includes an ion source unit 2, an analysis unit 3 and a detection unit 4, and is held in vacuum by a vacuum pump (not shown). The sample 5 is placed on the sample holder 6 and introduced into the ion source unit 2.
測定時には、試料５に図示しないレーザ光源から励起レ
ーザ光が照射され、発生した親イオンが分析部３に導か
れる。At the time of measurement, the sample 5 is irradiated with excitation laser light from a laser light source (not shown), and the generated parent ions are guided to the analysis unit 3.
真空計７は、イオン源部２の試料５の近傍に配置され
る。この真空計７としては、例えば電離真空計球が用い
られる。真空度測定回路８は、真空計７により検出され
た真空度を示す信号を出力する。測定開始／終了真空度
設定回路９は、予め設定された測定を開始するときの真
空度と測定を終了するときの真空度を示す信号を出力す
る。比較回路10は、検出された実際の真空度と設定され
た測定開始真空度および測定終了真空度との大小比較を
行ない、実際の真空度が測定開始真空度より小で且つ測
定終了真空度より大である間、測定動作制御信号を出力
する。質量スペクトル測定回路11は、この測定動作制御
信号の入力に応じて、イオン源部２にて発生した親イオ
ンの質量スペクトルを測定する。The vacuum gauge 7 is arranged near the sample 5 of the ion source unit 2. As the vacuum gauge 7, for example, an ionization vacuum gauge ball is used. The vacuum degree measuring circuit 8 outputs a signal indicating the degree of vacuum detected by the vacuum gauge 7. The measurement start / end vacuum degree setting circuit 9 outputs a signal indicating a preset degree of vacuum when starting the measurement and a degree of vacuum when ending the measurement. The comparison circuit 10 compares the detected actual vacuum degree with the set measurement start vacuum degree and measurement end vacuum degree, and the actual vacuum degree is smaller than the measurement start vacuum degree and less than the measurement end vacuum degree. While it is high, the measurement operation control signal is output. The mass spectrum measurement circuit 11 measures the mass spectrum of the parent ion generated in the ion source unit 2 in response to the input of the measurement operation control signal.
試料ホルダ６に試料を載せずに試料ホルダ６だけをイオ
ン源部２に挿入して真空に引いた場合、真空度の変化は
第２図に示すようになり、短時間で高真空に達する。When only the sample holder 6 is inserted into the ion source 2 and a vacuum is drawn without placing the sample on the sample holder 6, the change in the degree of vacuum becomes as shown in FIG. 2, and the high vacuum is reached in a short time.
一方、金属微粒子とグリセリンを添加した試料５を試料
ホルダ６に載せてイオン源部２に挿入して真空に引いた
場合、第３図に示すように高真空になるまでに長時間を
要する。これは、グリセリンが蒸発するので、高真空に
なるには試料５を乾燥させてしまう必要があり、これに
時間がかかるからである。On the other hand, when the sample 5 to which the metal fine particles and glycerin are added is placed on the sample holder 6 and inserted into the ion source unit 2 and a vacuum is drawn, it takes a long time to reach a high vacuum as shown in FIG. This is because the glycerin evaporates, and it is necessary to dry the sample 5 to obtain a high vacuum, which takes time.
親イオンの生成は、この試料５の乾燥の過程のある時間
帯に起る（第５図）。そして、この時間帯は、試料５が
半渇きの状態になるときであり、試料の種類にもある程
度依存するが、試料，金属微粒子、グリセリンの量を一
定にすると、ほぼ同じ真空度で生成イオン量のピークを
与える。なぜなら、真空度はグリセリンの蒸発量すなわ
ち試料の乾燥度を反映しているからである。The generation of parent ions occurs during a certain period of the drying process of this sample 5 (Fig. 5). This time period is when the sample 5 is in the half-third state and depends to some extent on the type of the sample, but if the amounts of the sample, the metal fine particles and glycerin are constant, the product ions are generated at substantially the same vacuum degree. Gives a peak of quantity. This is because the degree of vacuum reflects the evaporation amount of glycerin, that is, the dryness of the sample.
そこで、生成イオン量がピークになる時間帯から、第４
図に示すように測定を開始する真空度と終了する真空度
とを予め設定する。そして、測定開始／終了真空度設定
回路９にてこの測定開始真空度と測定終了真空度を示す
信号を出力し、真空度測定回路８が出力する実際の真空
度を示す信号と比較回路10にて比較し、実際の真空度が
測定開始真空度と測定終了真空度の範囲内にあるときに
出力される測定動作制御信号により、質量スペクトル測
定回路11は質量スペクトルの測定を行なう。Therefore, from the time when the amount of produced ions reaches its peak,
As shown in the figure, the degree of vacuum at which measurement starts and the degree of vacuum at which measurement ends are preset. Then, the measurement start / end vacuum degree setting circuit 9 outputs signals indicating the measurement start vacuum degree and the measurement end vacuum degree, and the signal indicating the actual vacuum degree output by the vacuum degree measuring circuit 8 and the comparison circuit 10. The mass spectrum measuring circuit 11 measures the mass spectrum according to the measurement operation control signal output when the actual vacuum degree is within the range between the measurement start vacuum degree and the measurement end vacuum degree.
なお、この実施例ではレーザイオン化質量分析装置につ
いて説明したが、本発明はFABやSIMSのような液体マト
リックスを用いる他のイオン源を有する質量分析装置に
も適用できる。Although the laser ionization mass spectrometer has been described in this embodiment, the present invention can also be applied to a mass spectrometer having another ion source using a liquid matrix such as FAB and SIMS.
また、上述の実施例では真空計をイオン源部の試料の近
傍に配置したが、イオン源の状態に真空度があまり左右
されないような位置に他の真空計を配置し、その検出値
を基準にして測定の開始時刻と終了時刻を決定するよう
にしてもよい。Further, although the vacuum gauge is arranged in the vicinity of the sample in the ion source section in the above-mentioned embodiment, another vacuum gauge is arranged at a position where the degree of vacuum is not so much influenced by the state of the ion source, and the detected value is used as a reference. Alternatively, the start time and end time of measurement may be determined.
〈発明の効果〉 以上説明したように本発明においては、測定時間を長く
して親イオンの検出を行うのではなく、親イオンの生成
量が増大する時間帯を真空チャンバの真空度から検出
し、この検出情報に基づいて最良のタイミングで測定を
開始できるようにしたので、親イオンの検出が確実に行
なわれ、測定の信頼度が増す。また、不要なスペクトル
を積算することがないため、SN比の良い測定ができる。
さらに、測定時間を短縮できるとともに、試料の消費量
が少なくて済む。<Effects of the Invention> As described above, in the present invention, the time period during which the amount of parent ions produced increases is detected from the degree of vacuum of the vacuum chamber, instead of extending the measurement time to detect the parent ions. Since the measurement can be started at the best timing on the basis of this detection information, the parent ions are reliably detected and the reliability of the measurement is increased. Moreover, since the unnecessary spectrum is not integrated, the measurement with a good SN ratio can be performed.
Further, the measurement time can be shortened and the sample consumption can be reduced.
第１図は本発明の実施例の構成を示す図、第２図，第３
図並びに第４図は本発明の実施例の真空度の時間変化を
示す図、第５図は質量分析計における親イオン強度の時
間変化を示す図である。 １…真空チャンバ、２…イオン源部 ３…分析部、４…検出部 ５…試料、６…試料ホルダ ７…真空計、８…真空度測定回路 ９…測定開始／終了真空度設定回路 10…比較回路 11…質量スペクトル測定回路FIG. 1 is a diagram showing a configuration of an embodiment of the present invention, FIG. 2, and FIG.
FIG. 4 and FIG. 4 are views showing the time variation of the vacuum degree in the embodiment of the present invention, and FIG. 5 is a view showing the time variation of the parent ion intensity in the mass spectrometer. DESCRIPTION OF SYMBOLS 1 ... Vacuum chamber, 2 ... Ion source part 3 ... Analysis part, 4 ... Detection part 5 ... Sample, 6 ... Sample holder 7 ... Vacuum gauge, 8 ... Vacuum degree measuring circuit 9 ... Measurement start / end Vacuum degree setting circuit 10 ... Comparison circuit 11 ... Mass spectrum measurement circuit
Claims (1)
料から発生した親イオンを測定し、その測定結果に基づ
いてそのイオンを質量／電荷の比に従ってより分ける質
量分析装置であって、上記イオン源部を含む真空チャン
バの真空度を検出する真空度検出手段と、第１の真空度
とそれよりも低い第２の真空度を設定するための設定手
段と、その設定手段により設定された第１および第２の
真空度と上記真空度検出手段による検出値とを比較し、
当該検出値が、上記第１の真空度に達した時点でイオン
測定を開始し、かつ、上記第２の真空度に達した時点で
イオン測定を終了するように測定動作制御信号を出力す
る比較手段を備えていることを特徴とする質量分析装
置。1. A mass spectrometer which measures parent ions generated from a sample containing a low vapor pressure liquid in an ion source and divides the ions according to a mass / charge ratio based on the measurement result. The degree of vacuum detection means for detecting the degree of vacuum of the vacuum chamber including the ion source section, the setting means for setting the first degree of vacuum and the second degree of vacuum lower than that, and the setting means The first and second vacuum degrees are compared with the detected value by the vacuum degree detecting means,
A comparison that outputs a measurement operation control signal so that the ion measurement is started when the detected value reaches the first vacuum degree and the ion measurement is ended when the detected vacuum value reaches the second vacuum degree. A mass spectrometer provided with means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61076276A JPH0756790B2 (en) | 1986-03-31 | 1986-03-31 | Mass spectrometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61076276A JPH0756790B2 (en) | 1986-03-31 | 1986-03-31 | Mass spectrometer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62232848A JPS62232848A (en) | 1987-10-13 |
| JPH0756790B2 true JPH0756790B2 (en) | 1995-06-14 |
Family
ID=13600740
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61076276A Expired - Lifetime JPH0756790B2 (en) | 1986-03-31 | 1986-03-31 | Mass spectrometer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756790B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013057822A1 (en) * | 2011-10-20 | 2013-04-25 | 株式会社島津製作所 | Mass spectrometer |
| CN102842481B (en) * | 2012-08-30 | 2016-04-06 | 昆山禾信质谱技术有限公司 | A kind of buffer gas quick high accuracy continuous control method in mass spectrometer mass analyzer |
| CN106571286B (en) * | 2016-11-07 | 2018-07-31 | 中国科学院广州地球化学研究所 | A kind of device for automatically controlling improving ion microprobe sample cavity vacuum degree |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5746459A (en) * | 1980-09-02 | 1982-03-16 | Toshiba Corp | Mass spectrometer |
-
1986
- 1986-03-31 JP JP61076276A patent/JPH0756790B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62232848A (en) | 1987-10-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4988879A (en) | Apparatus and method for laser desorption of molecules for quantitation | |
| EP0445276B1 (en) | Method for the laser desorption of ions in mass spectrometry | |
| Tsuchiya et al. | Liquid ionization mass spectrometry of nonvolatile organic compounds | |
| Quist et al. | Total yield measurements in matrix‐assisted laser desorption using a quartz crystal microbalance | |
| Eckstein et al. | Diagnostics of an rf sputtering glow discharge-correlation between atomic absorption and mass spectrometry | |
| Efimova et al. | Electrical properties of the µs pulsed glow discharge in a Grimm-type source: comparison of dc and rf modes | |
| Wang et al. | The coupling of solid-phase microextraction/surface enhanced laser desorption/ionization to ion mobility spectrometry for drug analysis | |
| Shaw et al. | Thermal analysis of positive photoresist films by mass spectrometry | |
| Kolaitis et al. | Detection of nonvolatile species by laser desorption atmospheric pressure mass spectrometry | |
| JPH0756790B2 (en) | Mass spectrometer | |
| Seiler et al. | Quantitative mass spectrometry by internal standardisation using a single focusing mass spectrometer and the peak switching facilities of a peak matching device | |
| Li et al. | Resonant two-photon ionization spectroscopic analysis of thin-layer chromatography using pulsed laser desorption/volatilization into supersonic jet expansions | |
| AU763347B2 (en) | Method for detecting elements in solutions and device for realising the same | |
| JPH0756789B2 (en) | Mass spectrometric method by laser ionization mass spectrometer | |
| JP4576775B2 (en) | Time-of-flight mass spectrometer | |
| Laakkonen et al. | Screening of non-steroidal anti-inflammatory drugs, barbiturates and methyl xanthines in equine urine by gas chromatography–mass spectrometry | |
| Little et al. | Two‐laser infrared and ultraviolet matrix‐assisted laser desorption/ionization | |
| Wang et al. | Quantitative analysis of low-molecular-weight polar compounds by continuous flow liquid secondary ion tandem mass spectrometry | |
| Greenwood et al. | Investigation of photoelectron elliptical dichroism for chiral analysis | |
| Cotter | Liquid secondary ion time-of-flight mass spectrometry | |
| JP2005025946A (en) | Time-of-flight mass spectrometry apparatus | |
| Schechter et al. | New sensor for ecological determination of benzene in ambient air | |
| Ketola et al. | Detection of dicarboxylic acids in aqueous samples using membrane inlet mass spectrometry with desorption chemical ionization | |
| Doherty et al. | Preservation of spatial resolution with use of a phase-transition extraction matrix in chromatography/secondary ion mass spectrometry | |
| Davis et al. | A miniature glow discharge for laser excited atomic fluorescence detection of lead |