JP2004340766A - Apparatus for detecting chemical substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically identify kinds of detecting elements in an apparatus for detecting chemical substances, which carries out measurements by using a plurality of piezo-electric elements. <P>SOLUTION: Different kinds of metallic thin films with respect to the plurality of piezo-electric elements are formed on surfaces of the piezo-electric elements, and initial frequencies of the piezo-electric elements are set at different frequencies by kinds of detecting sensors, and a reference frequency is measured by making the set frequencies correspond to the kinds of the thin films as the reference frequency, thereby identifying the kind of the thin film. The kind of the detecting sensor can be automatically identified by measuring the frequency of the piezo-electric element. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３５】
図３には腐食環境監視装置の外観図を、図４には内部機能構成の模式図を示す。腐食環境監視装置は、複数の圧電素子センサから構成されるセンサホルダー部７（但し、図３ではカバーを省略。）を挿入した計測装置８と計測装置の制御とデータの収集と解析を実行するためのノート型パーソナルコンピュータ９から構成される。ここで、計測装置とパーソナルコンピュータの間は、ＲＳ−２３２Ｃの規格に基づいた転送方式に基づき、データ転送を行った。また、計測装置の制御とデータの収集・解析を実行するためのＣＰＵや記憶素子，液晶モニタの様な表示デバイス，計測装置との接続が可能なインターフェースを具備していれば、ノート型パーソナルコンピュータに限ることなく使用することができる。
【００３６】
計測装置は、圧電素子を安定に発振させるために圧電素子センサ各々に接続するための発振回路，発振周波数を計測するための周波数カウンタ，複数のセンサの発振周波数を任意に選択するためのシグナルスキャナ，発振周波数をデジタル信号に変換してパーソナルコンピュータ（ＰＣ）に転送するための信号装置を備えている。
【００３７】
次に本実施例におけるデータの解析方法を示す。図５は、図３に示した腐食環境監視装置におけるデータ解析方法を示すフロー図である。
ステップ１：基準周波数ｆａ〜ｆｘに対応するセンサ金属材料Ｍａ〜Ｍｘのデータベースを入力し、以降の演算処理に用いる。
ステップ２：水晶振動子を用いた腐食量センサの発振周波数を計測し、これを測定開始時の初期値として以降の演算処理に用いる。
ステップ３：ステップ２で計測した周波数がステップ１で入力した基準周波数の何れに相当するかを照合する。
ステップ４：照合結果に基づき、ステップ２で計測したセンサに付着している金属薄膜がステップ１で入力した金属の何れに当たるかを特定する。
ステップ５：照合結果をＰＣに計測データの一部として記憶する。
ステップ６：照合結果をＰＣ画面上に表示する。
ステップ７：監視対象となる場所における腐食環境を計測する。
ステップ８：一定時間（ｔ）が経過した後に、時間ｔ経過後の腐食量センサの発振周波数を計測する。
ステップ９：時間ｔにおける測定値と初期値を比較して、センサの発振周波数の変化量を求め、この変化量の関数として腐食量センサ上の金属の腐食量や、予め求めておいた各種金属の腐食速度から設置環境中の腐食性ガス種類とその平均濃度を換算する演算処理を実行する。
ステップ１０：演算結果を表示し、監視を継続する。
【００３８】
上記測定結果に基づき、腐食量や大気中に存在する腐食性物質量等が、所定の値以上になった時に警報を発生させるためには、予め、腐食量や腐食性物質等の限界値を入力し、演算処理の結果と比較する演算処理をステップ１０からステップ７へのループの間に挿入し、所定の値を超えた場合に、併設した警報発生手段により、腐食量や腐食性物質等が限界値を超えたことを告知するようにすれば、当該監視としての機能が向上する。
【００３９】
上記実施例に示すように、腐食量センサの材料を自動的に特定する機能を有した腐食環境監視装置を得ることができる。
【００４０】
図６は腐食環境監視装置に内蔵されるデータ収集ソフトの画面の一実施例である。メニューバー１０のファイルメニューにより、新規の測定か、あるいは測定中ファイルの選択を行う。新規の場合はファイル名とサンプル名称を入力することで、サンプル名称表示欄１１にサンプル名称が表示できる。
【００４１】
センサ情報の表示領域１２には、必要に応じて計測するチャンネルを選択することが可能なチェックボックスも有している。本実施例では６チャンネルまでの構成例を示しているが、チャンネル数は６チャンネルに限るものではない。
【００４２】
測定間隔の入力領域１３では測定する時間間隔、または、測定回数を測定者が任意に入力することができる。
【００４３】
アラームリミットの入力領域１４では警報を発するための上限及び下限値をチャンネルごとに個別に設定し、警報を発することができる。
【００４４】
上記の設定を行った後、測定開始ボタン１５を押すと、初期の周波数値を取得して初期周波数表示領域１６に周波数値を、センサ情報の表示領域１２に図５のステップ４で特定した金属薄膜の材料名を自動的に表示し、そのデータを登録したファイル名で保存する。また、温湿度表示領域１７には、測定時の温度および湿度を表示することもできる。
【００４５】
動作状況の表示領域１８には、測定中、待機中等の動作状況を表示することにより、測定者は容易に計測状況を把握することができる。腐食量センサの周波数データを取得するとグラフ表示領域１９にグラフとして表示する。このグラフは上には、計測した周波数変化Δｆに変えて、演算処理により腐食量変化に換算した質量変化Δｗを切り替えて表示することもできる。また、測定データの表示領域２０には周波数変化Δｆと質量変化Δｗを数値で表示する。さらに、図中には示していないが、演算処理の結果得られた腐食性ガス種類および／またはその平均濃度を換算した値を画面に表示することもできる。
【００４６】
上記実施例に示すように、金属材料の種類を自動的に表示し、その金属材料の腐食量や大気中の腐食性ガス等の大気腐食に関する情報を簡便に監視できる監視装置を得ることができる。
【００４７】
次に、本発明に係る化学物質検出装置の実施形態を説明する。検出センサとして直径０．５インチの１０ＨＭｚ用の水晶振動子基板を用い、基板上の直径０．４インチの領域に予め金を蒸着し、その上に抗体を形成したものを検出センサとして用いた。抗体の種類を特定するために厚さが異なる水晶振動子基板を準備し、この水晶振動子上に付着量が同一になるように金を蒸着、この金薄膜上にダイオキシン類の中で毒性の強い、２，３，７，８−ＴＣＤＤ、１，２，３，７，８−ＰｅＣＤＤ、１，２，３，４，７，８−ＨｘＣＤＤと、ダイオキシン類と同様に毒性があるＣｏ−ＰＣＢ類のうち、３，３′−４，４′，５−ＰｅＣＢ、３，
３′，４，４′，５，５′−ＨｘＣＢのそれぞれにのみ反応するモノクローナル抗体を付着質量が同じとなるように形成した。この化学物質検出センサが検出するダイオキシン類の種類とその基準周波数，水晶振動子基板の厚さとの関係を纏めた結果を表２に示す。この対応データを予め入力しておき、計測初期に各センサの周波数を計測することにより、各センサが検出するダイオキシン類を自動的に特定できる化学物質検出装置が提供できる。さらに、ここで用いる抗体をビスフェノールＡ抗体やＤＤＴ抗体を用いた場合は、これら有害化学物質の検出装置として使用することができる。
【００４８】
【表２】

【００４９】
次に、本発明に係る弾性表面波デバイスを用いた化学物質検出装置の実施形態を説明する。図７はニオブ酸リチウムを弾性表面波デバイスとして用いた検出部の構成図である。圧電基板２１の両側にはくし歯上の入力用電極２２と出力用電極２３が形成されている。入力用電極２２と出力用電極２３との間の領域には測定対象となる化学物質に特定的に結合する固相化抗原２４が付着されている。さらに入力用電極２２は増幅器２５の出力側に接続され、出力用電極２３は増幅器２５の入力側に接続されている。表面弾性波デバイスの入力用電極２２と出力用電極２３に発振器から電気信号を印加すると、圧電効果により入力用電極２２と出力用電極２３間に互いに逆位相のひずみが生じ表面波が励起され、その周波数は図８に示すくし歯電極の電極幅（λ／４）により制御できる。
【００５０】
図９に示すように、本実施形態における有害化学物質監視装置は、測定対象となる化学物質の濃度を間接的に測定する装置として、サンプリングポンプ２６，サンプラ２７，抗体リザーバ２８，洗浄液サーバ２９，導入ポンプ３０，３１，３２、バルブ３３，３４，３５，３６，３７、反応セル３８を備えており、反応セルには流体導入口３９と流体排出口４０とが接続されているとともに、圧電素子として弾性表面波デバイス４１が収納されている。
【００５１】
サンプリングポンプ２６には、測定対象となる化学物質とガスを含む検体が導入され、この検体がサンプリングポンプ２６の駆動によってサンプラ２７に導入され、サンプラ２７によってサンプリングされた検体が導入ポンプ３０，バルブ３３，３６を介して流体導入口３９から反応セル３８内に導入されるようになっている。また検体と反応させるための抗体は抗体リザーバ２８に収納されており、抗体リザーバ２８に収納された抗体は導入ポンプ３１，バルブ３４，３６を介して流体導入口３９から反応セル３８内に導入されることになっている。ここで、抗体リザーバ中には複数種類の抗体を混合した抗体混合溶液が収納されているが、複数の抗体リザーバの各々に単独の抗体溶液を収納しておき、各々を導入ポンプで個別に反応セル中に導入してもよい。さらに、洗浄液サーバ２９内には反応セル３８内を洗浄するための洗浄液が収納されており、洗浄液サーバ２９内の洗浄液は導入ポンプ３２，バルブ３５，３６を介して流体導入口３９から反応セル３８内に導入されるようになっている。そして検体と抗体が反応セル３８内に導入されるときにはバルブ３７が閉じた状態にあり、洗浄液が反応セル３８内に導入されるときにはバルブ３７が開かれ、反応セル内を洗浄した洗浄液がバルブ３７から反応セル３８外に排出されるようになっている。すなわち、サンプリングポンプ２６，サンプラ２７，抗体リザーバ２８，導入ポンプ３０，３１、バルブ３３，３４，３６は検体およびこの検体中の化学物質に特定的に結合する抗体を導入する導入手段として構成されており、洗浄液サーバ２９，導入ポンプ３２，バルブ３５，３６，３７は反応セル２８中に残留した検体および抗体を反応セル３８の流体排出口４０から排出する排出手段として構成されている。
【００５２】
一方、弾性表面波デバイス４１の圧電基板には固相化抗原（測定対象となる化学物質または化学物質の誘電体であるハプテン）４２が形成されており、この固相化抗原４２は反応セル３８による流体流路中に複数種類収納されている。そして弾性表面波デバイス４１の出力は発振器に接続されている。
【００５３】
上記構成による有害化学物質監視装置を用いて測定対象となる化学物質を監視するに際しては、まず、バルブ３３〜３７はすべて閉じた状態で、サンプリングポンプ２６を駆動して検体をサンプラ２７に一定時間導入する。このとき反応前の発振周波数として弾性表面波デバイス４１の発振周波数Ｆｂを測定する。この後、バルブ３３，３４，３６を開き、導入ポンプ３０，３１の駆動によって反応セル３８内に検体および抗体を導入して固相化抗原４２上で反応させる。反応セル３８内に導入された検体および抗体が固相化抗原４２と反応した後、一定時間経過したときには、バルブ３３，３４を閉じ、代わりにバルブ３７を開き、反応セル３８内の溶液を流体排出口４０，バルブ３７から排出する。この後、バルブ３５を開くとともに導入ポンプ３２を駆動し、洗浄液サーバ２９からの洗浄液を反応セル３８内に導入して反応セル３８内を洗浄し、反応セル３８内から洗浄液を排出し、反応後の弾性表面波デバイス４１の発振周波数Ｆａを測定し、周波数の時間的な変化として、Ｆａ−Ｆｂを測定する。この測定結果から反応セル３８中でハプテンと反応した抗体の質量の変化を求め、この質量の変化を基に反応セル９６中における検体中の化学物質の濃度を、予め求めておいた検量線と比較して算出する。この一連のシーケンスを一定時間間隔で繰り返すことにより検体中の化学物質の濃度を連続して測定することができる。
【００５４】
ここで、複数個の弾性表面波デバイス４１を用い、各弾性表面波デバイス４１に相異なる固相化抗原４２を形成することで、複数種の化学物質を検出することが可能になる。このとき、検出センサとしてニオブ酸リチウム基板を用い、基板上に表面波励起用にＡｕのくし歯上電極と固相化抗原を形成したものを検出センサとして用いた。固相化抗原の種類を特定するために、くし歯上電極の電極幅を４〜１０μｍに変化させた弾性表面波基板を準備し、この基板上に付着量が同一になるように金を蒸着、この金薄膜上にダイオキシン類の中で毒性の強い、２，３，７，８−ＴＣＤＤ、１，２，３，７，８−ＰｅＣＤＤ、ビスフェノールＡ，ＤＤＴの固相化抗原（ハプテン）を付着質量が同じとなるように形成した。この化学物質検出センサが検出する化学物質の種類とその基準周波数、くし歯上電極の電極幅との関係を纏めた結果を表３に示す。この対応データを予め入力しておき、計測初期に各センサの周波数を計測することにより、各センサが検出する化学物質を自動的に特定できる化学物質検出装置が提供できる。
【００５５】
【表３】

【００５６】
本実施例により、複数の弾性表面波デバイス４１を用いて、各センサが検出する化学物質の種類を自動的に特定し、かつ、反応セル３８中に存在する複数種の有害化学物質の種類と濃度を同時に監視することができる。なお、複数の弾性表面波デバイス４１を用いる場合、各弾性表面波デバイス４１を複数の反応セル３８にそれぞれ収納するか構成を採用することもできる。また弾性表面波デバイス４１の代わりに水晶振動子を用いることも可能である。
【００５７】
【発明の効果】
本発明によれば、複数の圧電素子を用いて測定環境中の化学物質の種類とその濃度を同時に検出する化学物質検出装置において、検出素子の種類を自動的に特定する機能を有する化学物質検出装置を得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施例である腐食環境監視装置センサホルダー部の模式構成図である。
【図２】図１で使用した検出センサの模式構成図である。
【図３】本発明の一実施例である腐食環境監視装置の外観図である。
【図４】図３の内部機能構成を示す模式図である。
【図５】腐食環境監視装置におけるデータ解析方法を示すフロー図である。
【図６】腐食環境監視装置に内蔵されるデータ収集ソフトの画面の一実施例である。
【図７】圧電素子として弾性表面波デバイスを用いたときのセンサの構成図である。
【図８】図７の弾性表面波デバイスに形成した入出力用くし歯上電極のパターンを示した図である。
【図９】間接測定法を採用した化学物質検出装置のブロック構成図である。
【符号の説明】
１…検出センサ、２…コネクタ台、３…カバー、４…水晶基板、５…金属薄膜、６…リード線、７…センサホルダー部、８…計測装置、９…ノート型パーソナルコンピュータ、１０…メニューバー、１１…サンプル名称表示欄、１２…センサ情報の表示領域、１３…測定間隔の入力領域、１４…アラームリミットの入力領域、１５…測定開始ボタン、１６…初期周波数表示領域、１７…温湿度表示領域、１８…動作状況の表示領域、１９…グラフ表示領域、２０…測定データの表示領域、２１…圧電基板、２２…入力用電極、２３…出力用電極、２４，４２…固相化抗原、２５…増幅器、２６…サンプリングポンプ、２７…サンプラ、２８…抗体リザーバ、２９…洗浄液サーバ、３０，３１，３２…導入ポンプ、３３，３４，３５，３６，３７…バルブ、３８…反応セル、３９…流体導入口、４０…流体排出口、４１…弾性表面波デバイス。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for detecting a chemical substance, and more particularly to an apparatus for simultaneously detecting the type and concentration of a chemical substance in a measurement environment.
[0002]
[Prior art]
Conventionally, analytical methods such as gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, inductively coupled plasma mass spectrometry, semiconductor detection devices, and electrochemical analysis have been used as methods for detecting chemical substances. On the other hand, a detection method using a piezoelectric element as a detection element is also known (see Patent Documents 1 and 2).
[0003]
[Patent Document 1]
JP 2002-048797 A (Abstract, Claims)
[Patent Document 2]
JP 2001-99777 A (abstract, claims)
[0004]
[Problems to be solved by the invention]
When a measurement is performed using a plurality of piezoelectric elements in a detection device using a piezoelectric element as a detection element, the type of the detection element must be specified. However, there is a problem that a serious error occurs in a measurement result when the measurement result is incorrectly used because it cannot be determined from the appearance or the like.
[0005]
An object of the present invention is to provide a chemical substance detecting device using a plurality of piezoelectric elements, which has a function of specifying the type of the detecting element.
[0006]
[Means for Solving the Problems]
The gist of the present invention that achieves the above object is as follows.
[0007]
(1) Different types of thin films are formed on the surfaces of a plurality of piezoelectric elements, and each of the piezoelectric elements on which the thin films are formed is oscillated by an oscillation circuit, and the frequency output from each of the piezoelectric elements. In a detection device configured to measure the change in the amount of chemical reaction on the thin film, the reference frequency of the piezoelectric element is set to a different reference frequency for each type of the thin film, and the reference frequency of the piezoelectric element is measured. A chemical substance detection device capable of specifying the type of a thin film.
[0008]
(2) A metal thin film is formed on the piezoelectric element, and each of the piezoelectric elements on which the metal thin film is formed is exposed to a measurement environment to measure a change in frequency, and a corrosive substance or corrosive gas in the measurement environment is measured. The corrosion environment monitoring device according to (1), wherein the type and concentration and / or the amount of corrosion of the metal thin film can be measured.
[0009]
(3) A conductive thin film is formed on the surface of the substrate of the piezoelectric element, and different types of metal thin films are deposited on the surface of the conductive thin film for each piezoelectric element. Atmospheric corrosive environment monitoring according to (1), configured to measure a change in frequency upon exposure and to measure the type and concentration of corrosive substances or corrosive gases in the atmosphere and / or the amount of corrosion of metal thin films. apparatus.
[0010]
(4) An antibody that specifically binds to the chemical substance to be measured is attached to the substrate surface of the piezoelectric element, and the piezoelectric element to which the antibody has been attached is exposed to a measurement environment to react with the chemical substance. The chemical substance detection device according to (1), wherein the reaction amount is measured as a frequency change.
[0011]
(5) A chemical substance to be measured or a hapten which is a derivative of the chemical substance is adhered to the substrate surface of the piezoelectric element, and the reaction amount of an antibody reacted with the chemical substance or the hapten is measured as a frequency change. The chemical substance detection device according to (1).
[0012]
(6) The chemical substance detection device according to any one of (1) to (5), wherein the piezoelectric element is formed of a quartz oscillator or a surface acoustic wave device.
[0013]
(7) The chemistry according to any one of (1) to (5), wherein the thickness of the piezoelectric element substrate is changed for each type of the thin film so that the reference frequency of the piezoelectric element is set to a different reference frequency for each thin film. Substance detector.
[0014]
(8) The chemical substance detection according to any one of (1) to (5), wherein the reference frequency of the piezoelectric element is set to a different reference frequency for each of the thin films by changing the amount of deposits on the thin film for each type of the thin film. apparatus.
[0015]
(9) In the chemical substance detection device according to any one of (1) to (5), wherein the surface acoustic wave device is used as the piezoelectric element, the piezoelectric element is changed by changing the electrode period of the interdigital electrode for exciting the surface acoustic wave. The chemical substance detection device according to any one of (1) to (5), wherein the reference frequency is different for each of the thin films.
[0016]
(10) A chemical reaction amount on the thin film is detected based on a measurement result measured based on a change in the frequency of the piezoelectric element, and the chemical species and the concentration and / or the reaction amount of the chemical substance are converted into data input in advance. In a chemical substance detection device provided with an arithmetic processing device for estimating based on the above, and a display device for displaying each calculation result by the arithmetic processing device, the type of the thin film adhered to the piezoelectric element substrate based on the initial frequency measured at the start of the measurement. (1) performing the operation of automatically inputting as the data of the arithmetic processing and / or the operation of displaying the type of the thin film on the display device. Substance detector.
[0017]
The present invention is attained by using a plurality of piezoelectric elements as described above and setting a different reference frequency for each type of thin film to be deposited on the piezoelectric element, and measuring the reference frequency of the piezoelectric element. In the description above and below,
"And / or" means including either or both.
[0018]
The principle of the present invention will be described using a quartz oscillator as a piezoelectric element. When the crystal oscillator substrate on which the thin film is deposited is oscillated by an oscillation circuit, the crystal oscillator oscillates at a constant frequency in proportion to the mass of the deposited thin film.
[0019]
A chemical reaction proceeds on the thin film, and a reaction product is deposited on the thin film. Alternatively, when a part of the thin film is detached from the thin film, a mass change occurs. This change in mass is related to the change in the frequency of the crystal resonator according to equation [1].
[0020]
^{_{Δf = -kf 0 2 (Δw /}} A) ... [1]
Here, f ₀ is the initial frequency of the crystal oscillator, Δf is the amount of change in frequency, Δw is the amount of change in mass, A is the area where the thin film is deposited, and k is a constant.
[0021]
For example, when a quartz oscillator having an initial frequency of 10 MHz is used, when a mass change occurs on a thin film due to a chemical reaction, a 2 ng / cm ² mass change can be measured with a sensitivity of 1 Hz.
[0022]
Furthermore, by using a plurality of quartz oscillators in which different types of thin films are deposited on a quartz substrate, it is possible to measure the amount of chemical reaction for each type of the thin film.
[0023]
As shown in the equation (1), in the measurement using the quartz oscillator, first, the initial frequency of the quartz oscillator is measured, and the measured value is converted into a change in mass. In the present invention, the type of the thin film is specified by measuring the reference frequency by setting the initial frequency to a different frequency for each type of the thin film and associating this frequency with the type of the thin film as a reference frequency.
[0024]
As a method of setting the frequency according to the type of the thin film in the present invention, the reference frequency can be set by controlling the mass of the thin film to be deposited in advance based on the formula [1]. Alternatively, since the formula [2] is established between the frequency of the crystal resonator and the thickness of the crystal resonator substrate, the reference frequency can be set by controlling the thickness of the crystal substrate.
[0025]
f ₀ = k / d _{0 ...} [2]
Here, f ₀ is the set frequency of the crystal resonator, d ₀ is the thickness of the crystal resonator substrate, and k is a constant.
[0026]
When a surface acoustic wave device is used as the piezoelectric element substrate, the frequency control method is as follows: Equation [3] is set between the electrode period and the frequency of the interdigital electrode provided to excite the surface acoustic wave on the surface of the piezoelectric element substrate. Holds, the reference frequency can be set by controlling the period of the interdigital electrode.
[0027]
f ₀ = V / L ... [3]
Here, f ₀ is the set frequency of the surface acoustic wave device, V is the propagation speed of the surface acoustic wave, and L is the period of the interdigital electrode.
[0028]
Further, according to the present invention, the initial frequency measured at the start of the measurement is specified as the input data of the arithmetic processing unit provided in the detection device by specifying the type of the thin film attached to the piezoelectric element substrate in correspondence with the reference frequency. It is possible to automatically execute the operation and the operation of displaying the type of the thin film on the display device.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic configuration diagram of a sensor holder of a chemical substance detection device according to one embodiment of the present invention. The detection device sensor holder section includes six types of detection sensors 1 using piezoelectric elements, a connector base 2 for fixing the piezoelectric elements and connecting the measuring device and the corrosion amount sensor 2, and preventing damage to the detection sensors. A cover 3 is provided.
[0030]
FIG. 2 is a schematic configuration diagram of the detection sensor used in FIG. A crystal oscillator in which a metal thin film 5 having a diameter of 4.5 mm is vapor-deposited on both surfaces of a quartz substrate 4 having a diameter of 8 mm and a reference frequency of 10 MHz, and a lead wire 6 is attached to the thin film with a conductive adhesive in which nickel is dispersed is used as a sensor. Using. The thin film has the same planar shape on both sides, and oscillating and detecting lead wires 6 connected to the metal thin film on both sides from opposite sides are provided at the side end portions.
[0031]
Here, as a thin film to be formed on the quartz oscillator, the amount of corrosion of the deposited metal is measured by using a sensor in which aluminum, silver, cobalt, copper, iron, and nickel are directly evaporated on the quartz oscillator by a sputtering method. It can be used as a corrosive environment monitoring device that can detect corrosive substances in the environment to be measured. Instead of depositing a metal directly on the quartz oscillator, the same measurement can be performed by depositing a metal to be measured after depositing a conductive complex oxide of indium and tin on the quartz oscillator in advance.
[0032]
Furthermore, when high-sensitivity measurement is required, use a surface acoustic wave device such as lithium tantalate as a piezoelectric element, use a sensor in which other metals are vapor-deposited according to the metal whose corrosion is to be monitored, and adhere dust and the like. When measuring the amount, the type and number of piezoelectric elements and the type of metal deposited on the piezoelectric element can be determined according to the material and environment to be measured, such as using a sensor with gold deposited that does not corrode in the environment. , High-precision measurement becomes possible.
[0033]
Here, the time for vapor deposition of the metal thin film is controlled so that the amount of the thin film formed on the crystal unit used for detection becomes a predetermined value, the thin film is formed, and the reference frequency of each metal after the thin film is formed is set. As a result of the measurement, as shown in Table 1, different reference frequencies could be set for each metal. By using the sensor thus created, the type of metal attached to the sensor can be specified by measuring the reference frequency of the sensor.
[0034]
[Table 1]

[0035]
FIG. 3 is an external view of the corrosion environment monitoring device, and FIG. 4 is a schematic diagram of the internal functional configuration. The corrosive environment monitoring device executes the control of the measuring device 8 with the sensor holder 7 (a cover is omitted in FIG. 3) composed of a plurality of piezoelectric element sensors, the control of the measuring device, and the collection and analysis of data. And a notebook personal computer 9. Here, data transfer was performed between the measuring device and the personal computer based on a transfer method based on the RS-232C standard. In addition, a notebook type personal computer is provided if it has a CPU and a storage element for controlling the measuring device and executing data collection / analysis, a display device such as a liquid crystal monitor, and an interface which can be connected to the measuring device. Can be used without limitation.
[0036]
The measuring device includes an oscillation circuit for connecting each piezoelectric element sensor to stably oscillate the piezoelectric element, a frequency counter for measuring the oscillation frequency, and a signal scanner for arbitrarily selecting the oscillation frequency of a plurality of sensors. And a signal device for converting the oscillation frequency into a digital signal and transferring the signal to a personal computer (PC).
[0037]
Next, a data analysis method according to the present embodiment will be described. FIG. 5 is a flowchart showing a data analysis method in the corrosive environment monitoring device shown in FIG.
Step 1: The database of the sensor metal materials Ma to Mx corresponding to the reference frequencies fa to fx is input and used for the subsequent arithmetic processing.
Step 2: The oscillation frequency of the corrosion amount sensor using the quartz oscillator is measured, and this is used as an initial value at the start of the measurement for the subsequent arithmetic processing.
Step 3: Check whether the frequency measured in step 2 corresponds to the reference frequency input in step 1.
Step 4: Based on the collation result, it is specified which of the metals input in step 1 the metal thin film adhering to the sensor measured in step 2 hits.
Step 5: The collation result is stored in the PC as a part of the measurement data.
Step 6: Display the collation result on the PC screen.
Step 7: Measure the corrosive environment in the place to be monitored.
Step 8: After a lapse of a predetermined time (t), the oscillation frequency of the corrosion amount sensor after the lapse of the time t is measured.
Step 9: The measured value at time t is compared with the initial value to determine the amount of change in the oscillation frequency of the sensor, and as a function of the amount of change, the amount of corrosion of the metal on the corrosion amount sensor and various metals determined in advance. An arithmetic process for converting the corrosive gas type in the installation environment and the average concentration thereof from the corrosion rate of the installation environment is executed.
Step 10: Display the calculation result and continue monitoring.
[0038]
Based on the above measurement results, in order to generate an alarm when the amount of corrosion or the amount of corrosive substance present in the atmosphere, etc., exceeds a predetermined value, the limit value of the amount of corrosion or corrosive substance, etc. must be set in advance. An operation to be input and compared with the result of the operation is inserted between the loops from step 10 to step 7, and when the value exceeds a predetermined value, the amount of corrosion, corrosive substance, etc. Is notified that the value exceeds the limit value, the function of the monitoring is improved.
[0039]
As shown in the above embodiment, it is possible to obtain a corrosion environment monitoring device having a function of automatically specifying the material of the corrosion amount sensor.
[0040]
FIG. 6 shows an example of a screen of data collection software built in the corrosive environment monitoring device. A new measurement or a file under measurement is selected by the file menu on the menu bar 10. If it is new, the sample name can be displayed in the sample name display column 11 by inputting the file name and the sample name.
[0041]
The display area 12 for sensor information also has a check box for selecting a channel to be measured as needed. In the present embodiment, a configuration example of up to six channels is shown, but the number of channels is not limited to six channels.
[0042]
In the measurement interval input area 13, the measurer can arbitrarily input the time interval to be measured or the number of measurements.
[0043]
In the alarm limit input area 14, an upper limit and a lower limit for issuing an alarm can be individually set for each channel, and an alarm can be issued.
[0044]
After the above settings, when the measurement start button 15 is pressed, the initial frequency value is acquired, the frequency value is obtained in the initial frequency display area 16, and the metal value specified in step 4 in FIG. Automatically displays the material name of the thin film and saves the data under the registered file name. Further, the temperature and humidity at the time of measurement can be displayed in the temperature and humidity display area 17.
[0045]
By displaying the operation status such as during measurement or waiting in the operation status display area 18, the measurer can easily grasp the measurement status. When the frequency data of the corrosion amount sensor is acquired, it is displayed as a graph in the graph display area 19. In the upper part of this graph, instead of the measured frequency change Δf, a mass change Δw converted into a corrosion amount change by arithmetic processing can be switched and displayed. In the display area 20 of the measurement data, the frequency change Δf and the mass change Δw are numerically displayed. Further, although not shown in the figure, a value obtained by converting the type of corrosive gas and / or its average concentration obtained as a result of the arithmetic processing can be displayed on the screen.
[0046]
As shown in the above embodiment, it is possible to obtain a monitoring device that can automatically display the type of metal material and easily monitor the amount of corrosion of the metal material and information on atmospheric corrosion such as corrosive gas in the atmosphere. .
[0047]
Next, an embodiment of the chemical substance detection device according to the present invention will be described. A 0.5-inch-diameter quartz oscillator substrate for 10 HMz was used as a detection sensor, and gold was previously vapor-deposited on a 0.4-inch-diameter region on the substrate, and an antibody was formed thereon, and used as the detection sensor. . Prepare quartz oscillator substrates with different thicknesses to identify the type of antibody, deposit gold on this quartz oscillator so that the amount of deposition is the same, and dioxin toxic on the gold thin film Strong 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 1,2,3,4,7,8-HxCDD and Co-PCB which is toxic as well as dioxins Of the classes, 3,3'-4,4 ', 5-PeCB, 3,
Monoclonal antibodies reacting only with each of 3 ', 4,4', 5,5'-HxCB were formed to have the same attached mass. Table 2 shows the results obtained by summarizing the relationship between the types of dioxins detected by the chemical substance detection sensor, their reference frequencies, and the thickness of the quartz oscillator substrate. By inputting this correspondence data in advance and measuring the frequency of each sensor at the beginning of measurement, a chemical substance detection device capable of automatically specifying dioxins detected by each sensor can be provided. Further, when a bisphenol A antibody or a DDT antibody is used as the antibody used here, it can be used as a detection device for these harmful chemical substances.
[0048]
[Table 2]

[0049]
Next, an embodiment of a chemical substance detection device using a surface acoustic wave device according to the present invention will be described. FIG. 7 is a configuration diagram of a detection unit using lithium niobate as a surface acoustic wave device. On both sides of the piezoelectric substrate 21, an input electrode 22 and an output electrode 23 on a comb are formed. An immobilized antigen 24 that specifically binds to a chemical substance to be measured is attached to a region between the input electrode 22 and the output electrode 23. Further, the input electrode 22 is connected to the output side of the amplifier 25, and the output electrode 23 is connected to the input side of the amplifier 25. When an electric signal is applied from an oscillator to the input electrode 22 and the output electrode 23 of the surface acoustic wave device, distortions of opposite phases occur between the input electrode 22 and the output electrode 23 due to a piezoelectric effect, and surface waves are excited. The frequency can be controlled by the electrode width (λ / 4) of the comb electrode shown in FIG.
[0050]
As shown in FIG. 9, the harmful chemical substance monitoring device according to the present embodiment includes a sampling pump 26, a sampler 27, an antibody reservoir 28, a cleaning liquid server 29, as a device for indirectly measuring the concentration of a chemical substance to be measured. The apparatus includes inlet pumps 30, 31, 32, valves 33, 34, 35, 36, 37, and a reaction cell 38. The reaction cell is connected to a fluid inlet 39 and a fluid outlet 40, and a piezoelectric element. The surface acoustic wave device 41 is housed.
[0051]
A sample containing a chemical substance and a gas to be measured is introduced into the sampling pump 26, and the sample is introduced into the sampler 27 by driving the sampling pump 26, and the sample sampled by the sampler 27 is introduced into the introduction pump 30 and the valve 33. , 36 through a fluid inlet 39 into the reaction cell 38. An antibody to be reacted with the sample is contained in an antibody reservoir 28, and the antibody contained in the antibody reservoir 28 is introduced into a reaction cell 38 from a fluid introduction port 39 via an introduction pump 31, valves 34 and 36. Is supposed to be. Here, an antibody mixed solution in which a plurality of types of antibodies are mixed is stored in the antibody reservoir.A single antibody solution is stored in each of the plurality of antibody reservoirs, and each is individually reacted by an introduction pump. It may be introduced into the cell. Further, a cleaning liquid for cleaning the inside of the reaction cell 38 is stored in the cleaning liquid server 29, and the cleaning liquid in the cleaning liquid server 29 is supplied from the fluid introduction port 39 through the introduction pump 32 and the valves 35 and 36 to the reaction cell 38. It is being introduced into. When the sample and the antibody are introduced into the reaction cell 38, the valve 37 is in a closed state. When the cleaning liquid is introduced into the reaction cell 38, the valve 37 is opened, and the cleaning liquid that has washed the inside of the reaction cell is supplied with the valve 37. From the reaction cell 38. That is, the sampling pump 26, the sampler 27, the antibody reservoir 28, the introduction pumps 30, 31, and the valves 33, 34, 36 are configured as introduction means for introducing a specimen and an antibody that specifically binds to a chemical substance in the specimen. The washing liquid server 29, the introduction pump 32, and the valves 35, 36, and 37 are configured as discharge means for discharging the sample and the antibody remaining in the reaction cell 28 from the fluid discharge port 40 of the reaction cell 38.
[0052]
On the other hand, on the piezoelectric substrate of the surface acoustic wave device 41, an immobilized antigen (a chemical substance to be measured or a hapten which is a dielectric substance of the chemical substance) 42 is formed. Are accommodated in the fluid flow path of the above. The output of the surface acoustic wave device 41 is connected to an oscillator.
[0053]
When monitoring a chemical substance to be measured using the harmful chemical substance monitoring apparatus having the above configuration, first, the sampling pump 26 is driven and the sample is sent to the sampler 27 for a certain period of time while all the valves 33 to 37 are closed. Introduce. At this time, the oscillation frequency Fb of the surface acoustic wave device 41 is measured as the oscillation frequency before the reaction. Thereafter, the valves 33, 34, 36 are opened, and the analytes and the antibodies are introduced into the reaction cell 38 by driving the introduction pumps 30, 31 to react on the solid-phased antigen 42. When a certain period of time has elapsed after the specimen and the antibody introduced into the reaction cell 38 have reacted with the immobilized antigen 42, the valves 33 and 34 are closed, and the valve 37 is opened instead. The gas is discharged from the discharge port 40 and the valve 37. Thereafter, the valve 35 is opened and the introduction pump 32 is driven to introduce the washing liquid from the washing liquid server 29 into the reaction cell 38 to wash the inside of the reaction cell 38 and discharge the washing liquid from the inside of the reaction cell 38. , The oscillation frequency Fa of the surface acoustic wave device 41 is measured, and Fa-Fb is measured as a temporal change of the frequency. From the measurement result, the change in the mass of the antibody that reacted with the hapten in the reaction cell 38 was determined, and based on the change in the mass, the concentration of the chemical substance in the sample in the reaction cell 96 was determined with a calibration curve determined in advance. Calculate by comparison. By repeating this sequence at regular time intervals, the concentration of the chemical substance in the sample can be measured continuously.
[0054]
Here, by using a plurality of surface acoustic wave devices 41 and forming different solid-phased antigens 42 on each surface acoustic wave device 41, it becomes possible to detect a plurality of types of chemical substances. At this time, a lithium niobate substrate was used as a detection sensor, and a substrate on which a Au electrode on a comb and an immobilized antigen were formed for surface wave excitation was used as a detection sensor. In order to identify the type of immobilized antigen, a surface acoustic wave substrate was prepared in which the electrode width of the interdigital electrode was changed to 4 to 10 μm, and gold was vapor-deposited on this substrate so that the amount of adhesion was the same. An immobilized antigen (hapten) of 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, bisphenol A, DDT, which is the most toxic among dioxins, is placed on this gold thin film. It was formed so that the attached mass was the same. Table 3 shows the results obtained by summarizing the relationship between the type of chemical substance detected by this chemical substance detection sensor, its reference frequency, and the electrode width of the comb-tooth electrode. By inputting this correspondence data in advance and measuring the frequency of each sensor at the beginning of measurement, a chemical substance detection device that can automatically identify the chemical substance detected by each sensor can be provided.
[0055]
[Table 3]

[0056]
According to the present embodiment, by using a plurality of surface acoustic wave devices 41, the type of chemical substance detected by each sensor is automatically specified, and the types of harmful chemical substances present in the reaction cell 38 are determined. The concentration can be monitored simultaneously. When a plurality of surface acoustic wave devices 41 are used, a configuration in which each surface acoustic wave device 41 is stored in each of the plurality of reaction cells 38 may be employed. Further, a quartz oscillator can be used instead of the surface acoustic wave device 41.
[0057]
【The invention's effect】
According to the present invention, in a chemical substance detection device for simultaneously detecting the type and concentration of a chemical substance in a measurement environment using a plurality of piezoelectric elements, a chemical substance detection function having a function of automatically specifying the type of the detection element A device can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a sensor holder section of a corrosion environment monitoring device according to one embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a detection sensor used in FIG.
FIG. 3 is an external view of a corrosion environment monitoring device according to an embodiment of the present invention.
FIG. 4 is a schematic diagram showing an internal functional configuration of FIG. 3;
FIG. 5 is a flowchart showing a data analysis method in the corrosion environment monitoring device.
FIG. 6 is an example of a screen of data collection software built in the corrosion environment monitoring device.
FIG. 7 is a configuration diagram of a sensor when a surface acoustic wave device is used as a piezoelectric element.
FIG. 8 is a diagram showing a pattern of input / output interdigital electrodes formed on the surface acoustic wave device of FIG. 7;
FIG. 9 is a block diagram of a chemical substance detection apparatus employing an indirect measurement method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Detection sensor, 2 ... Connector base, 3 ... Cover, 4 ... Quartz board, 5 ... Metal thin film, 6 ... Lead wire, 7 ... Sensor holder part, 8 ... Measuring device, 9 ... Notebook personal computer, 10 ... Menu Bar, 11: Sample name display field, 12: Sensor information display area, 13: Measurement interval input area, 14: Alarm limit input area, 15: Measurement start button, 16: Initial frequency display area, 17: Temperature and humidity Display area, 18: Operation area display area, 19: Graph display area, 20: Measurement data display area, 21: Piezoelectric substrate, 22: Input electrode, 23: Output electrode, 24, 42: Immobilized antigen , 25 amplifier, 26 sampling pump, 27 sampler, 28 antibody reservoir, 29 washing solution server, 30, 31, 32 introduction pump, 33, 34, 35, 36, 3 ... valve, 38 ... reaction cell, 39 ... fluid inlet, 40 ... fluid outlet, 41 ... surface acoustic wave device.

Claims (10)

On the surfaces of the plurality of piezoelectric elements, different types of thin films are formed for each of the piezoelectric elements, and each of the piezoelectric elements on which the thin films are formed is oscillated by an oscillation circuit, and a change in the frequency output from each of the piezoelectric elements is obtained. Measure, in a detection device that is capable of detecting the amount of chemical reaction on the thin film, by setting the reference frequency of the piezoelectric element to a different reference frequency for each type of the thin film, by measuring the reference frequency of the piezoelectric element, A chemical substance detection device characterized in that a type of a thin film can be specified. A metal thin film is formed on the piezoelectric element, and each piezoelectric element on which the metal thin film is formed is exposed to a measurement environment to measure a change in frequency, and the type and concentration of a corrosive substance or corrosive gas in the measurement environment The detection device according to claim 1, wherein the amount of corrosion of the metal thin film can be measured. A conductive thin film is formed on the substrate surface of the piezoelectric element, a different type of metal thin film is deposited for each piezoelectric element on the conductive thin film surface, and each of the piezoelectric elements on which the metal thin film is formed is exposed to the atmosphere. 2. The detection device according to claim 1, wherein a change in frequency is measured, and the type and concentration of the corrosive substance or corrosive gas in the atmosphere and / or the amount of corrosion of the metal thin film can be measured. An antibody that specifically binds to the chemical substance to be measured is attached to the substrate surface of the piezoelectric element, and the reaction amount of the chemical substance that has reacted with the antibody by exposing the piezoelectric element to which the antibody has been attached to the measurement environment is exposed. The chemical substance detection device according to claim 1, wherein the measurement is performed as a frequency change. The chemical substance to be measured or a hapten which is a derivative of the chemical substance is attached to the substrate surface of the piezoelectric element, and a reaction amount of an antibody reacted with the chemical substance or the hapten is measured as a frequency change. Chemical substance detection device. The chemical substance detecting device according to claim 1, wherein the piezoelectric element is formed of a quartz oscillator or a surface acoustic wave device. The chemical substance detection device according to claim 1, wherein a reference frequency of the piezoelectric element is set to a different reference frequency for each of the thin films by changing a thickness of the piezoelectric element substrate for each type of the thin film. The chemical substance detection device according to claim 1, wherein a reference frequency of the piezoelectric element is set to a different reference frequency for each of the thin films by changing a deposit amount of the thin film for each type of the thin film. 6. The chemical substance detection device according to claim 1, wherein a surface acoustic wave device is used as the piezoelectric element, and the reference period of the piezoelectric element is changed by changing an electrode period of the interdigital electrode for exciting the surface acoustic wave. The chemical substance detection device according to claim 1, wherein a frequency is set to a reference frequency different for each of the thin films. A chemical reaction amount on the thin film is detected based on a measurement result measured based on a change in frequency of the piezoelectric element, and a chemical species and a concentration and / or a reaction amount of the chemical substance are estimated based on data input in advance. In a chemical substance detection device including an arithmetic processing device and a display device for displaying each operation result by the arithmetic processing device, the type of the thin film attached to the piezoelectric element substrate is specified based on the initial frequency measured at the start of the measurement. 6. The chemical substance detecting device according to claim 1, wherein the operation of automatically inputting the data as arithmetic processing data and / or the operation of displaying the type of the thin film on a display device are executed.

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