JPH0574774B2 - - Google Patents
Info
- Publication number
- JPH0574774B2 JPH0574774B2 JP27134184A JP27134184A JPH0574774B2 JP H0574774 B2 JPH0574774 B2 JP H0574774B2 JP 27134184 A JP27134184 A JP 27134184A JP 27134184 A JP27134184 A JP 27134184A JP H0574774 B2 JPH0574774 B2 JP H0574774B2
- Authority
- JP
- Japan
- Prior art keywords
- mode
- current
- hollow cathode
- emission
- hcl
- 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
- 238000001228 spectrum Methods 0.000 claims description 18
- 238000010521 absorption reaction Methods 0.000 claims description 15
- 238000000295 emission spectrum Methods 0.000 claims description 5
- 238000003705 background correction Methods 0.000 claims description 4
- 238000002835 absorbance Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 230000035945 sensitivity Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 101100343605 Arabidopsis thaliana LOG1 gene Proteins 0.000 description 3
- 101150083341 LOG2 gene Proteins 0.000 description 3
- 238000005375 photometry Methods 0.000 description 3
- 238000000889 atomisation Methods 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- 239000012491 analyte Substances 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/3103—Atomic absorption analysis
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Description
【発明の詳細な説明】
イ 産業上の利用分野
本発明は一ランプ方式の原子吸光分析装置でバ
ツクグランド補正の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an improvement in background correction in a one-lamp type atomic absorption spectrometer.
原子吸光分析は、分析しようとする元素の輝線
スペクトルの波長の光を試料原子化部を透過させ
て、その光の吸収を測定するものであるが、試料
原子化部には波長に対して非特異的な吸収及び散
乱があつて分析対象の元素が存在しない場合で
も、見掛上輝線スペクトル波長の光が吸収が検出
される。このような見掛上の吸収に対する補正
が、こゝに云うバツクグラウンド補正で、その方
法は分析しようとする元素の輝線スペクトルに近
接した波長の光の試料原子化部における吸収を測
定して補正データとする。こゝで分析対象元素の
輝線スペクトルの光源とその輝線スペクトルに近
接した波長の光を得る光源（通常輝線スペクトル
光の波長を含みそれより広い波長分布を持つた光
源）の二光源を用いる方式と一光源を用いる方式
があり、本発明は後者の方式の原子吸光分析装置
に関するものである。 In atomic absorption spectrometry, light with a wavelength in the emission line spectrum of the element to be analyzed is transmitted through a sample atomization section and the absorption of the light is measured. Even if there is specific absorption and scattering and the element to be analyzed is not present, absorption of light at the apparent emission line spectrum wavelength is detected. Correction for this apparent absorption is called background correction, and the method is to measure and correct the absorption in the atomized part of the sample of light with a wavelength close to the emission line spectrum of the element to be analyzed. Data. Here, a method using two light sources: a light source with the emission line spectrum of the element to be analyzed and a light source that obtains light with a wavelength close to the emission line spectrum (usually a light source with a wavelength distribution wider than the wavelength of the emission line spectrum light). There is a method using one light source, and the present invention relates to an atomic absorption spectrometer using the latter method.
ロ 従来の技術
第４図は−ランプ方式の原子吸光分析装置の一
般的な構成を示す。HCLは光源のホローカソー
ドランプ、ATMは試料原子化部の炎、MCは分
光器、PMは光検出器、PMは光検出器、PAはプ
リアンプ、Ｓ１，Ｓ２は切換えスイツチ、LOG
１，LOG２は吸光度変換器、SUBは引算器で、
その出力として試料の原子吸光度が得られる。
LPは光源の点灯制御回路で、切換スイツチＳ１，
Ｓ２の切換えも制御している。この構成で光源の
ホローカソードランプHCLには二種の点灯モー
ドがあつて制御回路LPで点灯モードの切換えが
行われると共に、その切換えと同期してスイツチ
Ｓ１，Ｓ２の切換えも行われる。HCLの二つの
点灯モードの一つは鋭い輝線スペクトルの光を発
するもので、Ｓモードと云うことにする。他の点
灯モードは輝線スペクトル波長を含む幅の広いス
ペクトルの発光をするもので、Ｂモードと云うこ
とにする。HCLがＳモードのときスイツチＳ１
が閉じ、Ｓ２が開き、輝線スペクトル光に対する
光検出出力が吸光度変換器LOG１に入力される。
LOG１の出力は輝線スペクトル光に対する吸光
度信号で、試料中の分析対象元素による吸収とバ
ツクグラウンド吸収の両方の信号の和である。
HCLがＢモードになつているとき、スイツチＳ
１が開、Ｓ２が閉となつて幅広のスペクトル光に
対する光検出出力がLOG２に入力される。LOG
２の出力は輝線スペクトル光に隣接する波長の光
に対する吸光度信号（輝線スペクトル光に対する
吸光度信号も含まれるが比率上微小で無視でき
る）であり、これは原子吸光のバツクグラウンド
の信号であるから、LOG１の出力からLOG２の
出力を引算することでバツクグラウンド補正がな
される。B. Prior Art FIG. 4 shows a general configuration of a -lamp type atomic absorption spectrometer. HCL is the hollow cathode lamp of the light source, ATM is the flame of the sample atomization section, MC is the spectrometer, PM is the photodetector, PM is the photodetector, PA is the preamplifier, S1 and S2 are the changeover switches, and LOG
1.LOG2 is an absorbance converter, SUB is a subtractor,
The atomic absorbance of the sample is obtained as the output.
LP is the lighting control circuit for the light source, and the switch S1,
It also controls switching of S2. With this configuration, the hollow cathode lamp HCL as a light source has two lighting modes, and the lighting mode is switched by the control circuit LP, and the switches S1 and S2 are also switched in synchronization with the switching. One of the two HCL lighting modes emits light with a sharp bright line spectrum, and is referred to as the S mode. The other lighting mode emits light in a wide spectrum including the wavelength of the bright line spectrum, and will be referred to as B mode. Switch S1 when HCL is in S mode
is closed, S2 is opened, and the photodetection output for bright line spectrum light is input to the absorbance converter LOG1.
The output of LOG1 is an absorbance signal for bright line spectrum light, which is the sum of the signals of both the absorption by the analyte element in the sample and the background absorption.
When HCL is in B mode, switch S
1 is open and S2 is closed, and the photodetection output for wide spectrum light is input to LOG2. LOG
The output of 2 is an absorbance signal for light with a wavelength adjacent to the bright line spectrum light (it also includes an absorbance signal for the bright line spectrum light, but it is relatively small and can be ignored), and this is a background signal of atomic absorption, so Background correction is performed by subtracting the output of LOG2 from the output of LOG1.
従来はホローカソードランプHCLの二つの点
灯モードの切換えを、HCLに供給する電流を大
小切換えることによつて行つていた。即ちHCL
に大電流を流すと発光スペクトルは幅の広がつた
ものとなり、小電流のときは鋭い輝線スペクトル
を示す。その様子を第６図に示す。この図でＢが
ＢモードＳがＳモードのスペクトルのプロフアイ
ルを示し、発光強度の比はこの図では表わし切れ
ないがＢモードはＳモードの数百倍にも達する。
他方HCLにＢモード用の大電流を長時間流すこ
とはできないので、HCLへの供給電流は第７図
に示すような波形でＳモードに対応するバイアス
電流値Ibに数十μS幅のパルス状の電流Ipを重畳
した波形にしている。 Conventionally, switching between the two lighting modes of the hollow cathode lamp HCL was performed by changing the magnitude of the current supplied to the HCL. i.e. HCL
When a large current is passed through the material, the emission spectrum becomes broader, and when a small current is applied, a sharp emission line spectrum is exhibited. The situation is shown in FIG. In this figure, B indicates the spectral profile of B mode, S and S mode, and although the ratio of emission intensities cannot be fully expressed in this figure, the B mode is several hundred times as large as the S mode.
On the other hand, since it is not possible to flow a large current for B mode into HCL for a long period of time, the current supplied to HCL has a waveform as shown in Figure 7, and the bias current value Ib corresponding to S mode is pulsed with a width of several tens of microseconds. The waveform is a superimposition of the current Ip.
ハ 発明が解決しようとする問題点
上述した従来例ではHCLの発光強度がＳモー
ドとＢモードとで数百倍も異つているが、吸光変
換器は対数変換増幅器で適当な入力範囲でリニヤ
リテイが得られるものであるから、Ｓモード，Ｂ
モード何れの場合でも、吸光度変換器への入力レ
ベルは上記した範囲に収まつているように、Ｓモ
ード、Ｂモードの切換えに応じて光検出器PMの
感度或はプリアンプPAのゲインを切換える必要
がある。しかしＢモードは前述したように数十
μSの幅しかないので、その時間内に測光系の感
度或はゲインを切換えて感度なりゲインが安定す
るようにするためには測光系の回路構成に高度の
技術が必要であつた。本発明はこのような従来の
一ランプ方式の原子吸光分析装置の技術上の困難
性を解消しようとするものである。C. Problems to be solved by the invention In the conventional example described above, the emission intensity of HCL differs by several hundred times between S mode and B mode, but the absorption converter is a logarithmic conversion amplifier, and linearity can be maintained within an appropriate input range. Since it is obtained, S mode, B
Regardless of the mode, it is necessary to switch the sensitivity of the photodetector PM or the gain of the preamplifier PA according to switching between S mode and B mode so that the input level to the absorbance converter is within the above range. There is. However, as mentioned above, mode B has a width of only a few tens of microseconds, so in order to switch the sensitivity or gain of the photometry system within that time and stabilize the sensitivity or gain, the circuit configuration of the photometry system must be highly sophisticated. technology was required. The present invention aims to solve the technical difficulties of such a conventional one-lamp type atomic absorption spectrometer.
ニ 問題解決のための手段及び作用
本発明はホローカソードランプHCLの点灯方
式の改良により、前述したＳモードとＢモードの
切換えに応じて測光系の感度を切換えることを不
必要とするもので、第１図に示すようにＳモード
点灯においてホローカソードランプに供給する電
流をパルス状の電流に高周波電流を重畳したもの
とし、Ｂモードは従来と同様のパルス状電流とし
た。パルス状の大電流をホローカソードランプに
供給すると幅の広がつたスペクトルの発光を程す
るが、第１図に示すようにパルス状の電流に高周
波電流を重畳した電流を与えると、第２図に示す
ようにＢモードと同じ発光強度を保つてスペクト
ル幅をせまくすることができる。これによつて、
Ｓモード，Ｂモードの切換えに応じて測光系の感
度を切換える必要がなくなる。D. Means and action for solving the problem The present invention improves the lighting method of the hollow cathode lamp HCL, thereby making it unnecessary to switch the sensitivity of the photometry system in response to switching between the S mode and B mode as described above. As shown in FIG. 1, in the S mode lighting, the current supplied to the hollow cathode lamp was a pulsed current with a high frequency current superimposed, and in the B mode, a pulsed current similar to the conventional one was used. When a large pulsed current is supplied to a hollow cathode lamp, it emits light with a broadened spectrum, but when a pulsed current with a high frequency current superimposed on it as shown in Figure 1 is applied, as shown in Figure 2. As shown in Figure 3, the spectral width can be narrowed while maintaining the same emission intensity as B mode. By this,
There is no need to switch the sensitivity of the photometric system in response to switching between S mode and B mode.
ホ 実施例
第３図は本発明の一実施例におけるホローカソ
ードランプ点灯回路を示す。HCLはホローカソ
ードランプで、第４図のHCLに相当する。ib，
Ib，Ipは夫々HCLに電流を供給する電源で、ibは
高周波電源で周波数は160MHz程度である。Ibは
直流バイアス電源でIpはパルス用直流電源であ
る。Sbは高周波電源をHCLに接離するスイツチ、
Spはパルス用直流電源をHCLに接離するスイツ
チで、これらのスイツチが第４図の点灯制御回路
LPによつてオン，オフされる。第５図ＡはHCL
に供給される電流波形、SpはスイツチSpのオン
オフを示し、SbはスイツチSbのオンオフを示し、
スイツチSb，Spともオンしている時間幅は数〜
数100μsの範囲で大体同じ値に設定される。なお
この実施例ではHCLには常時Ibの直流バイアス
電流が供給されているが、原理上これはなくても
よいものである。E. Embodiment FIG. 3 shows a hollow cathode lamp lighting circuit in an embodiment of the present invention. HCL is a hollow cathode lamp and corresponds to the HCL in Figure 4. ib,
Ib and Ip are power supplies that supply current to the HCL, respectively, and ib is a high frequency power supply with a frequency of about 160MHz. Ib is a DC bias power supply and Ip is a pulse DC power supply. Sb is a switch that connects and disconnects the high frequency power supply to HCL,
Sp is a switch that connects and disconnects the pulse DC power supply to HCL, and these switches are the lighting control circuit shown in Figure 4.
Turned on and off by LP. Figure 5 A is HCL
The current waveform supplied to , Sp indicates on/off of switch Sp, Sb indicates on/off of switch Sb,
The duration of time that both switches Sb and Sp are on is several to
It is set to roughly the same value within a range of several 100 μs. In this embodiment, a DC bias current of Ib is always supplied to the HCL, but in principle, this is not necessary.
ヘ 効果
本発明によれば、ホローカソードランプのＳモ
ード，Ｂモード何れの点灯モードでも発光強度が
略同じであるから、測光系の感度は固定したまゝ
でよく、測光回路の要求特性が緩和され、回路構
成上の技術的困難性が解消され、Ｓモードの発光
強度をＢモードの発光強度程度に高めているの
で、測光系のＳ／Ｎ比も向上する。F. Effects According to the present invention, the luminous intensity is approximately the same in both the S mode and B mode of the hollow cathode lamp, so the sensitivity of the photometric system can remain fixed, and the required characteristics of the photometric circuit are relaxed. This eliminates technical difficulties in circuit configuration and increases the S-mode light emission intensity to the same level as the B-mode light emission intensity, which also improves the S/N ratio of the photometric system.
第１図は本発明におけるホローカソードランプ
の電流の波形図、第２図は本発明におけるホロー
カソードランプの二点灯モードにおける発光スペ
クトルを示す図、第３図は本発明の一実施例にお
けるホローカソードランプ点灯回路の図、第４図
は−ランプ方式原子吸光分析装置の一般的な構成
概要を示すブロツク図、第５図は本発明の−実施
例におけるホローカソードランプの点灯モード切
換えのタイムチヤート、第６図は従来例における
ホローカソードランプの二点灯モードにおける発
光スペクトルの図、第７図は同じくホローカソー
ドへの供給電流波形図である。
FIG. 1 is a current waveform diagram of the hollow cathode lamp according to the present invention, FIG. 2 is a diagram showing the emission spectrum in two lighting modes of the hollow cathode lamp according to the present invention, and FIG. 3 is a diagram showing the emission spectrum of the hollow cathode lamp according to an embodiment of the present invention. A diagram of a lamp lighting circuit, FIG. 4 is a block diagram showing a general configuration overview of a lamp-type atomic absorption spectrometer, and FIG. 5 is a time chart of lighting mode switching of a hollow cathode lamp in an embodiment of the present invention. FIG. 6 is a diagram of the emission spectrum of a conventional hollow cathode lamp in the dual lighting mode, and FIG. 7 is a diagram of the current waveform supplied to the hollow cathode.
Claims (1)
流を変えることで発光スペクトルの幅を変えバツ
クグランド補正を行う方式の原子吸光分析装置で
あつて、 鋭いスペクトル発光を行わせるモードにおいて
はホローカソードランプに矩形波状パルス電流に
高周波電流を重畳した電流を供給し、 幅の広がつたスペクトル発光を行わせるモード
においてはホローカソードランプに矩形波状パル
ス電流を供給し、 上記両モードにおいてホローカソードランプの
発光強度を略等しくしたことを特徴とする原子吸
光分析装置。[Scope of Claims] 1. An atomic absorption spectrometer that uses one hollow cathode lamp and performs background correction by changing the width of the emission spectrum by changing the supplied current, in a mode that produces sharp spectrum emission. supplies a current in which a high-frequency current is superimposed on a rectangular waveform pulse current to the hollow cathode lamp, and in a mode that produces a wide spectrum emission, a rectangular waveform pulse current is supplied to the hollow cathode lamp; An atomic absorption spectrometer characterized in that the emission intensities of cathode lamps are made approximately equal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27134184A JPS61148348A (en) | 1984-12-21 | 1984-12-21 | Atomic absorption spectrochemical analyzer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27134184A JPS61148348A (en) | 1984-12-21 | 1984-12-21 | Atomic absorption spectrochemical analyzer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61148348A JPS61148348A (en) | 1986-07-07 |
| JPH0574774B2 true JPH0574774B2 (en) | 1993-10-19 |
Family
ID=17498708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27134184A Granted JPS61148348A (en) | 1984-12-21 | 1984-12-21 | Atomic absorption spectrochemical analyzer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61148348A (en) |
-
1984
- 1984-12-21 JP JP27134184A patent/JPS61148348A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61148348A (en) | 1986-07-07 |
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