CN101923067A

CN101923067A - Polarographic flow-through cell

Info

Publication number: CN101923067A
Application number: CN 201010147301
Authority: CN
Inventors: 许建民
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-04-15
Filing date: 2010-04-15
Publication date: 2010-12-22
Anticipated expiration: 2030-04-15
Also published as: CN101923067B

Abstract

The invention discloses a polarographic flow-through cell. The polarographic flow-through cell comprises a reference electrode installing passage, a liquid inlet, a mercury propeller, a shell, a working electrode installing passage, a liquid outlet, a cavity, mercury drops and an auxiliary electrode installing passage, wherein the shell is a main member; the central position of the shell is provided with the cavity; the lower end of the shell is connected with the cavity and provided with the liquid outlet; the upper end of the shell is connected with the cavity and provided with the liquid inlet; the central position is provided with the working electrode installing passage which is communicated with the cavity; the inner end of the working electrode installing passage is used for forming the mercury drops; and the mercury propeller is horizontally arranged on the shell at the position which is right-angled opposite to the working electrode installing passage. By changing the flow-through cell in the conventional polarographic working form, the to-be-measured solution can pass through the flow-through cell in turn to come into contact with three electrodes for electrochemical detection and analysis, so that the conventional polarographic analysis method can be expanded to other application fields. The polarographic flow-through cell has the advantages of simple structure, convenient operation and use, high stability and high reliability.

Description

A kind of Polarographic flow-through cell

Technical field

The present invention relates to the electrochemical analysis detection and use device, relate in particular to a kind of Polarographic flow-through cell.

Background technology

Nineteen twenty-four Czech chemist sea Lip river Paderewski invention polarograph, so-called polarograph, just be meant with renewable mercury and drip as working electrode, on working electrode, apply the scanning current potential, detect a kind of electrochemical analytical instrument that obtains corresponding electric current, can be used for qualitative and quantitative detection and some theoretical researches of chemical constitution.Behind the invention polarograph, its electrode structure citation form is just definite, and the mercury with quick following during beginning drips as working electrode, does once experiment and will consume a lot of mercury that drip.The polarograph detection sensitivity that the electrode of this form is made is not high, and practical value is limited, also has so far and uses, and is applied to student experimenting mostly, is used to demonstrate classical polarograph ultimate principle and basic experiment.A kind of polarographic method that is referred to as singly to sweep has appearred in the sixties in last century, makes the form of electrode and analytical approach that very big improvement all arranged.This method is to allow mercury pass through the superfine kapillary of endoporus, forms a mercury to the kapillary lower end and drips, total time general 7 second of time spent.Be used for the growth that mercury drips in preceding 5 seconds, the later stage is scanned, and be 2 seconds general sweep time, and this form is the citation form of polarograph in modern age, is referred to as singly to sweep polarography.Derive multiple scan method on this basis again,, be referred to as modern polarographic analysis, wherein singly sweep polarography and use the most general as square wave polarogram, pulse polarography etc.The appearance of modern polarographic method makes polarographic method really move towards practical, and there are many detection methods in China, and the regulation National Standard Method is singly sweeps polarographic method.

To modern polarogram, the citation form of electrode changes little from classical polarogram, just needs tens to up to a hundred mercury from once analyzing, and only needs a mercury as electrode to once analyzing, and does not still break away from the restriction of dropping-mercury electrode.In analytic process, mercury drips continuous increase, will come off automatically by gravity effect after to a certain degree greatly, and mercury drips genus and comes off automatically, and is uncontrolled, and this has just limited the application of polarographic method greatly.To last century the eighties released a kind of controlled dropping-mercury electrode, the domestic ruhende electrode that is referred to as.Kind electrode row mercury is controlled, mercury drips and can hang for a long time, make polarographic analysis before go a step further again, but the citation form of polarographic analysis does not change, remaining kapillary lower end suspension mercury drips, the opening direction of electrolytic cell upwards, kapillary is as the carrier that drips mercury or ruhende electrode, is immersed in the solution in the electrolytic cell that opening direction makes progress with other electrode and detects.Multiple flow analysis method is arranged in modern chemical analysis, for example liquid chromatography, chromatography of ions, flow injection etc., these analytical approachs all have after the separation or reacted detection problem, the main flow that tradition is widely applied is the photometric detection method, other method is for auxiliary, and for example electricity is led, Electrochemical Detection.Electrochemical Detection is highly sensitive in photometric detection, but only limits to solid electrode, and application is very limited, and uses polarographic analysis very widely in the traditional electrical chemical analysis, owing to limit by form, can not be used for the detection of these last type of analysis methodologies.

The citation form of traditional electrical chemistry polarographic analysis is three electrode directed downwards, the electrolytic cell opening direction upwards, three electrodes are immersed in the electrolytic solution cell to be analyzed, and the distribution of the solution in the electrolytic cell is uniform, chemical constitution to be measured also is to be evenly distributed in the solution, analyze and finish back replacing solution or change electrolytic cell and solution simultaneously, after the mercury that more renews drips, carry out next time again and analyze.Because the upwards straight-through atmosphere of electrolytic cell opening direction, element to be measured is evenly to distribute, and solution can't pass through electrode surface successively, and sometimes analyzing and testing needs to after sample separation or the reaction a certain specific region solution to be detected; Also sometimes solution stops to flow after flowing to a certain specific region earlier, forms one section piston-shaped liquid regions, and then detects.These detect and require can't realize with traditional polarographic method.Again owing to three electrodes are immersed in the solution to be measured that is placed in the bulge, need take more chemical reagent solution, and can not carry out timesharing, the subregion is detected, so traditional galvanochemistry polarographic analysis electrode form, make galvanochemistry polarogram working method can not realize automatic continuous analysis, comprise the country that some science and technology are flourishing, as the U.S., the instrument that Switzerland produces with polarogram function, still adopt three traditional electrode direction downward, the electrolytic cell opening direction upwards, change solution after hours by hand or change solution and electrolytic cell simultaneously, the working method of instrument still is traditional manual operations that is.

Liquid chromatography is a detection method after a kind of separation commonly used, be particularly useful for organic analysis, and the polarographic method analyzing organic substance particularly is good at, and sensitivity is higher, but owing to limited by form, traditional galvanochemistry polarographic method of past can not be used for liquid chromatography, chromatography of ions, reach the Flow Injection Analysis detection.Electrochemiluminescence analysis is a kind of high-sensitivity analysis method that immediate development is got up, but owing to limit by electrode form, present bibliographical information all is to use solid electrode, and can't be applied to renewable quiet mercury or static horizontal mercury electrode, and this has also limited applying of electrochemiluminescence analysis.

Summary of the invention

The objective of the invention is to, a kind of flow cell that changes traditional polarogram working forms is proposed, on the basis of using quiet mercury or static horizontal mercury electrode, make solution to be measured can pass through flow cell in order successively, contact with three electrodes, carry out Electrochemical Detection, make traditional polarographic method can be extended to other application, as liquid chromatography, chromatography of ions, Flow Injection Analysis, electrochemiluminescence analysis etc., and can realize the continuous and automatic analysis.

A kind of Polarographic flow-through cell of the present invention includes that contrast electrode installs that passage, working electrode install that passage, inlet, mercury push controller, mercury drip, housing, liquid outlet, cavity and auxiliary electrode install passage and form.Housing is the main component of a kind of Polarographic flow-through cell of the present invention, and the middle position of housing is provided with cavity.In the lower end of housing, be connected with cavity, be provided with liquid outlet; In the upper end of housing, be connected with cavity, be provided with inlet.The middle position in other words in position placed in the middle substantially, is provided with the working electrode that is connected with cavity passage is installed, and in the inner that said working electrode is installed passage, the mercury that the work of being used to form is used drips.With respect to working electrode the rectangular position of passage is installed, on housing, is horizontally disposed form, be provided with mercury push controller.Here said mercury push controller is will be after analyze finishing, and mercury is dripped turn down, and enters into the discharge opeing position in the cavity.Reach and drip to push away and fall to entering in the cavity analyzing mercury with mistake, here can there be two kinds form is set, a kind of be working electrode install passage under form, another kind is that working electrode is installed passage in last form, passage and mercury push controller two are inner to be connected reliable as long as working electrode is installed, can reach with analyze with mercury drip and push away the effect that falls to entering in the cavity.Housing adopts transparent material to make, and forms visual form in the cavity.

A kind of Polarographic flow-through cell of the present invention, this is a kind of flow cell that changes traditional polarogram working forms, can make solution to be measured pass through flow cell in order successively, contact with three electrodes, carry out the Electrochemical Detection analysis, make traditional polarographic method can be extended to other application,, and easily be automated analysis as liquid chromatography, chromatography of ions, Flow Injection Analysis, electrochemiluminescence analysis etc.One-piece construction of the present invention is simple, and is easy for operation, good stability, reliability height.

Description of drawings

Accompanying drawing 1 is the structural representation of a kind of Polarographic flow-through cell of the present invention.Accompanying drawing 2 is structural representations of the Polarographic flow-through cell after the working electrode installation channel change direction.1-contrast electrode is installed passage 2-inlet 3-mercury push controller 4-housing 5-working electrode installation passage 6-liquid outlet 7-cavity 8-mercury and is dripped 9-auxiliary electrode installation passage

Embodiment:

Referring now to accompanying drawing 1 and accompanying drawing 2, be described as follows in conjunction with the embodiments: a kind of Polarographic flow-through cell of the present invention, include contrast electrode install passage 1, inlet 2, mercury push controller 3, housing 4, working electrode install passage 5, liquid outlet 6, cavity 7, mercury drip 8 and auxiliary electrode passage 9 be installed formed.Housing 4 is main components of a kind of Polarographic flow-through cell of the present invention, and the middle position of housing 4 is provided with cavity 7.In the lower end of housing 4, be connected with cavity 7, be provided with liquid outlet 6; In the upper end of housing 4, be connected with cavity 7, be provided with inlet 2.The middle position in other words in housing 4 position placed in the middle substantially, is provided with the working electrode that is connected with cavity 7 passage 5 is installed, and in the inner that said working electrode is installed passage 5, the mercury that the work of being used to form is used drips 8.With respect to working electrode passage 5 rectangular positions are installed, on housing 4, are horizontally disposed form, be provided with mercury push controller 3.Here said mercury push controller 3 is mercury to be dripped 8 turn down after analyzing end, enters into the discharge opeing position in the cavity 7.Reach and drip 8 and push away to fall to entering in the cavity 7 analyzing mercury with mistake, here can there be two kinds form is set, a kind of be working electrode install passage 5 under form, another kind is that working electrode is installed passage 5 in last form, 3 liang of passage 5 and mercury push controllers are inner to be connected reliable as long as working electrode is installed, and can reach to drip 8 with the mercury of crossing and push away and fall to entering into the interior effect of cavity 7 analyzing.Housing 4 adopts transparent material to make, and forms visual form in the cavity 7.A kind of Polarographic flow-through cell of the present invention, this is a kind of flow cell that changes traditional polarogram working forms, can make solution to be measured pass through flow cell in order successively, contact with three electrodes, carry out the Electrochemical Detection analysis, make traditional polarographic method can be extended to other application,, and easily be automated analysis as liquid chromatography, chromatography of ions, Flow Injection Analysis, electrochemiluminescence analysis etc.One-piece construction of the present invention is simple, and is easy for operation, good stability, reliability height.

Housing 4 materials are that plastics, glass or corrosion-resistant metal are made, the solution to be measured that peristaltic pump extracts from sample, send into flow cell by inlet 6, analyze and finish, mercury push controller 3 will drip 8 as the mercury of working electrode to be turned down in the cavity 7, it is relatively stricter that both positions are connected requirement, discharges outside the ponds through liquid outlet 6; Working electrode, contrast electrode, this three electrode of auxiliary electrode all communicate with flow cell cavity 7, and isolate with atmospheric sealing.A kind of Polarographic flow-through cell of the present invention can have three kinds of working methods:

Analytical work mode 1 of the present invention: the working electrode discharge mercury of being installed in the passage 5 by working electrode drips, forming electrode mercury at the kapillary port drips, from sample, extract solution to be measured by peristaltic pump, solution to be measured flows along pipeline and to the utmost point composes the flow cell electrode position, when three electrodes all contacted with solution, peristaltic pump stopped operating.This moment, auxiliary electrode C applied stationary voltages and scanning voltage by solution to the working electrode of being made up of static horizontal mercury electrode, when being scanned up to a certain current potential, on working electrode, obtain corresponding faradic currents or electric potential signal, the concentration positive correlation of element to be measured in this electric current and the solution can obtain the information of test substance content.After treating that analytic process finishes, mercury push controller 3 drips 8 with mercury to be turned down and drains, and the solution that peristaltic pump will start after will analyzing is once more drained, and behind the pipe blow-through, repeats last analytic process, and analyzing and testing is next time carried out in preparation.

Analytical work mode 2 of the present invention: the end that the inlet of Polarographic flow-through cell is connect liquid chromatography or ion chromatographic separation post, the mercury that upgrades electrode drips, start instrument, solution flows out from the end of separating column, enter three electrodes of flowing through behind the inlet of Polarographic flow-through cell, flow out from the outlet of Polarographic flow-through cell the back after testing.After treating that an analytic process finishes, mercury push controller 3 drips 8 with mercury to be pushed away away, upgrades mercury and drips, and carries out the course of work next time again.

Analytical work mode 3 of the present invention: Polarographic flow-through cell integral body is placed in the lighttight camera bellows, press close to the working electrode place in the side of Polarographic flow-through cell and place photomultiplier, solution is that specific switching on causes its luminous solution, replicate analysis working method 1 is when solution arrival assigned address, after three electrodes all immerse solution, apply voltage, will produce the chemiluminescence phenomenon, this light intensity and content of material positive correlation can be known the content of certain material by photometry intensity.

A kind of Polarographic flow-through cell of the present invention, its Polarographic flow-through cell inlet are located at the upper end, and liquid outlet can be located at the lower end, the solution after the work and with after mercury drip all and discharge by peristaltic pump.The Polarographic flow-through cell working electrode, kapillary mouth of pipe direction can make progress, and mercury drips and is statically placed on the kapillary mouth of pipe, and is vertical with horizontal direction; Also but small angle inclination is not more than 30 degree with the vertical direction angle, and this is for adopting the static horizontal mercury electrode mode.The Polarographic flow-through cell working electrode, the capillary exit direction can be downward, and this is for adopting the ruhende electrode mode.The Polarographic flow-through cell mercury push controller, the cross sectional shape that pushes away the mercury bar is cylindric, also can be square, and material is that plastics, glass or corrosion-resistant metal are made.It is vertical that the installation direction of mercury push controller and kapillary go out the mercury mouth, is close to capillary exit, can come and go to slide along the capillary exit horizontal direction to promote mercury and drip mobile.A kind of Polarographic flow-through cell of the present invention, working electrode, contrast electrode, this three electrode channel of auxiliary electrode and mercury push controller all communicate with the flow cell cavity, and isolate by seal approach and atmospheric sealing.

Claims

1. a Polarographic flow-through cell is characterized in that the middle position of housing (4) is provided with cavity (7); Lower end in housing (4) is connected with cavity (7), is provided with liquid outlet (6); Upper end in housing (4) is connected with cavity (7), is provided with inlet (2); In housing (4) position placed in the middle substantially, be provided with the working electrode that is connected with cavity (7) passage (5) is installed, in the inner that said working electrode is installed passage (5), the mercury that the work of being used to form is used drips (8).

2. a kind of Polarographic flow-through cell according to claim 1 is characterized in that with respect to working electrode the rectangular position of passage (5) being installed, and is horizontally disposed form on housing (4), is provided with mercury push controller (3).

3. a kind of Polarographic flow-through cell according to claim 1 is characterized in that housing (4) adopts transparent material to make, and forms visual form in the cavity (7).