CN102565172A - Heavy metal ion measurement method and heavy metal ion measurement device - Google Patents
Heavy metal ion measurement method and heavy metal ion measurement device Download PDFInfo
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- CN102565172A CN102565172A CN2011103767469A CN201110376746A CN102565172A CN 102565172 A CN102565172 A CN 102565172A CN 2011103767469 A CN2011103767469 A CN 2011103767469A CN 201110376746 A CN201110376746 A CN 201110376746A CN 102565172 A CN102565172 A CN 102565172A
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Abstract
The invention provides a heavy metal ion measurement method and a heavy metal ion measurement device, wherein measurement error caused by impurities in a liquid sample can be reduced, while the exsolution and disbanding of electrodeposited heavy metal due to the liquid replacement can be avoided. Therefore, the concentration of heavy metal ions can be measured at a high precision. After the heavy metal deposits on a conductive diamond electrode (5), when the reduction potential of the conductive diamond electrode (5) is lower than the reduction potential of the heavy metal as the measurement object, the liquid sample is at least partially displaced into acetic acid buffer solution. Then, the potential of the conductive diamond electrode (5) is scanned toward a higher reduction potential. Therefore, the heavy metal electrodeposited on the conductive diamond electrode (5) is dissolved into the acetic acid buffer solution.
Description
Technical field
The present invention relates to measure the heavy metal ion measuring method and the heavy metal ion measurement mechanism of the concentration of heavy metal ion that contains in the liquor sample.
Background technology
Shown in patent documentation 1, can consider to use stripping voltammetry as the method for measuring the concentration of heavy metal ion that contains in the liquor sample in the past.
Said stripping voltammetry comprises: the electro-deposition operation, and the low current potential of reduction potential of the heavy metal that provides than contains in the liquor sample through the working electrode in being immersed in liquor sample makes heavy metal electro-deposition in the liquor sample on working electrode; The stripping operation, through with the current potential of said working electrode to the electric potential scanning higher than said reduction potential, make the heavy metal of electro-deposition on working electrode from the working electrode stripping.This stripping voltammetry through detect because of said stripping operation at working electrode with the current value that flows through between to electrode, calculate concentration of heavy metal ion according to this current value.
In addition, in said stripping voltammetry, normally make the heavy metal of electro-deposition on working electrode again stripping in the liquor sample that carried out said electro-deposition, measure said concentration of heavy metal ion.
But, in liquor sample, containing under the situation of impurity such as interference component, detected current value can produce error in the stripping operation, and its existence as a result can cause producing the problem of the measuring error of concentration of heavy metal ion.
In addition, also can consider behind the impurity such as interference component in the removal liquor sample, to make the heavy metal electro-deposition on working electrode through before the electro-deposition operation, making liquor sample pass through filtrator etc. in advance.Thus, can reduce the error effect that impurity causes detected current value in the stripping operation to a certain degree.
But; Sensitivity at working electrode further improves in recent years; Even under the situation of having carried out with said filtrator removal impurity, working electrode also has sensitivity to the small amount of impurities that contains in the said liquor sample, aspect the measuring accuracy that improves concentration of heavy metal ion, there is restriction.
Patent documentation 1: Jap.P. open communique spy open 2008-216061 number
Summary of the invention
Therefore; Fundamental purpose of the present invention is to provide a kind of heavy metal ion measuring method and heavy metal ion measurement mechanism; In using the electro-chemical measuring apparatus and method of stripping voltammetry, use solution through liquor sample being replaced into measurement, can reduce the impurity that contains in the liquor sample to influence of measurement error; And through the electro-deposition that prevents to produce because of liquid displacement the stripping of heavy metal ion, measure heavy metal ion concentration accurately.
Promptly; The present invention provides a kind of heavy metal ion measuring method; It is characterized in that use and to electrode with by the working electrode that the conductive diamond electrode constitutes the concentration of heavy metal ion in the liquor sample is carried out electrochemical measurement, said heavy metal ion measuring method comprises: the electro-deposition operation; Make the current potential of said conductive diamond electrode become the current potential lower, thereby make said heavy metal electro-deposition on said conductive diamond electrode than the reduction potential of said heavy metal; The liquid displacement operation; Make said heavy metal electro-deposition after on the said conductive diamond electrode; Said conductive diamond electrode is become under the state of the current potential lower than said reduction potential, at least a portion of said liquor sample is being replaced as to measure uses solution; The stripping operation; With said liquor sample be replaced as said measurement with solution after; With the current potential of said conductive diamond electrode to the electric potential scanning higher than said reduction potential, make the said heavy metal stripping of electro-deposition on said conductive diamond electrode to said measurement with solution in; And the current detecting operation, make said heavy metal stripping to said measurement with solution in the time, detect at said conductive diamond electrode and the said electric current that produces between to electrode.
According to described heavy metal ion measuring method; Through using the conductive diamond electrode as working electrode; Can improve the detection sensitivity of the heavy metal ion of working electrode; And use solution through between electro-deposition operation and stripping operation, being replaced as measurement to liquor sample, can reduce the measuring error that causes because of the impurity in the liquor sample.In addition; In the liquid displacement operation; Owing to make working electrode become the current potential lower than reduction potential, thus heavy metal stripping in the liquid displacement operation that kilowatt-hour has deposited can be prevented, thus can carry out the measurement of the heavy metal ion in the stripping operation accurately.Therefore, can measure the heavy metal ion that contains in the liquor sample accurately.
In addition, the conductive diamond electrode has following premium properties: potential window wide (oxidizing potential and reduction potential are wide); To compare background current low with other electrode materials; Highly sensitive to the redox kind; And be difficult to produce physisorption, so be difficult to presence of oxygen, hydrogen generates peak value in addition because of comparing electrode surface with gold and platinum etc.In addition, the conductive diamond electrode is also good at aspects such as chemical durability, mechanical endurance, conductivity and corrosion stabilitys.In addition, the conductive diamond electrode also has following advantage: so because of its hardness is carried out chemistry easily, physics cleans, thereby the easy state that electrode surface is remained cleaning.
In case behind the discharged liquid sample, provide in the mode of measuring with solution, can not apply voltage at the conductive diamond electrode with between to electrode.Therefore, preferably, in said liquid displacement operation, be replaced as said measurement to said liquor sample several times and use liquid.
In addition, the present invention provides a kind of heavy metal ion measurement mechanism, measures the concentration of heavy metal ion in the liquor sample, it is characterized in that said heavy metal ion measurement mechanism comprises: measuring cell, accommodate said liquor sample; To electrode, contact setting with said liquor sample; Working electrode is made up of the conductive diamond electrode, contacts setting with said liquor sample; Potential change portion makes the current potential of said conductive diamond electrode between the current potential of the said heavy metal stripping on the said conductive diamond electrode, change at current potential on the said conductive diamond electrode and electro-deposition in said heavy metal electro-deposition; Liquid displacement mechanism is replaced as measurement with at least a portion that is housed in the said liquor sample in the said measuring cell and uses solution; Current detecting part detects said conductive diamond electrode and said to the electric current between the electrode; And concentration calculating part; According to calculating concentration of heavy metal ion by the detected current value of said current detecting part; Wherein, Said liquid displacement mechanism makes said heavy metal electro-deposition in back on the said conductive diamond electrode and make said heavy metal before the stripping of said conductive diamond electrode; Said liquor sample is replaced as said measurement uses solution, said potential change portion between locomorphic stage, makes the current potential of said conductive diamond electrode become the current potential of said heavy metal electro-deposition on said conductive diamond electrode with solution to said measurement at the said liquor sample that will be housed in the said measuring cell by said liquid displacement mechanism.
According to described heavy metal ion measurement mechanism,, can improve the detection sensitivity of the heavy metal ion of working electrode through using the conductive diamond electrode as working electrode.In addition, liquid displacement mechanism makes the heavy metal electro-deposition in back on the conductive diamond electrode and before making the heavy metal stripping, is replaced as liquor sample to measure and uses solution, therefore can reduce the measuring error that causes because of the impurity in the liquor sample.In addition; Potential change portion with liquor sample to measuring with solution between locomorphic stage; Make the current potential of conductive diamond electrode become the current potential of heavy metal electro-deposition on said conductive diamond electrode; So can prevent heavy metal stripping when liquid displacement that kilowatt-hour has deposited, can carry out the measurement of heavy metal ion accurately.Therefore, can measure the heavy metal ion that contains in the liquor sample accurately.
The concrete embodiment that carries out liquid displacement as the current potential limit that is used for the electrical diamond electrode of limit guide and provides said electro-deposition; Preferably, liquid displacement is carried out to the liquor sample that is housed in the said measuring cell in the said solution amount limit that electrode and said conductive diamond electrode are contacted with liquor sample of maintenance, said liquid displacement mechanism limit.Specifically, can consider that said liquid displacement mechanism is replaced as said measurement several times and uses liquid being housed in liquor sample in the said measuring cell.
For the limit makes liquor sample and conductive diamond electrode contact edge discharged liquid sample as far as possible, preferably, the mode that said conductive diamond electrode exposes to inside with electrode surface is arranged on the bottom wall portion of said measuring cell; Said liquid displacement mechanism comprises: discharge line; This discharge line comprises: vent pipe, be connected with said measuring cell, and extraction pump; Be arranged on the said vent pipe, be used for discharging the liquid that is housed in said measuring cell to the outside; And supply line, this supply line comprises: ingress pipe is connected with said measuring cell; And charge pump, be arranged on the said ingress pipe, be used for being provided in the said measuring cell with solution being housed in the measurement of measuring with NaOH solution tank NaOH, said vent pipe is connected with the bottom wall portion of said measuring cell.
Under the situation of having used the conductive diamond electrode; Because the temperature of this conductive diamond electrode and the fluid temperature in the measuring cell can cause the heavy metal ion amount of electro-deposition on the conductive diamond electrode or the heavy metal ion quantitative changeization of dissolving from the conductive diamond electrode.In order to address this problem; Preferably; Said conductive diamond electrode is the electrode that is arranged on the cardinal principle writing board shape on the bottom wall portion of said measuring cell with the mode that electrode surface exposes to inside; The back side at said conductive diamond electrode is provided with thermoregulation mechanism, and this thermoregulation mechanism is used for the liquid in said conductive diamond electrode and the said measuring cell is heated.
Preferably, said measuring cell comprises: the resettlement section main body is used to accommodate said liquor sample; And injection part, be arranged on the top of said resettlement section main body, be used to inject said liquor sample, said side wall portion to electrode main body from said resettlement section inserts towards said conductive diamond electrode incline ground and is fixed.Thus, can easily inject liquor sample, can make electrode and conductive diamond electrode as close as possible in addition through injection part.
In order to prevent that liquor sample from flowing out from measuring cell to injection part adverse current and described liquid with solution with measuring; And prevent that described liquid from entering between injection part and the resettlement section main body; Preferably; The side wall portion top of main body is provided with overflow part in said resettlement section, and this overflow part makes above the liquid of ormal weight and discharges.
The present invention according to said formation; In the electro-chemical measuring apparatus and method that use stripping voltammetry; Use solution through liquor sample being replaced as measure; Can reduce the impurity that contains in the liquor sample to influence of measurement error, and through the electro-deposition that prevents to produce because of liquid displacement the stripping of heavy metal ion, measure heavy metal ion concentration accurately.
Description of drawings
Fig. 1 is the figure of structure that schematically illustrates the heavy metal ion measurement mechanism of this embodiment.
Fig. 2 schematically illustrates the stereographic map for the heavy metal ion measurement mechanism of identical embodiment with Fig. 1.
Fig. 3 schematically illustrates the cut-open view for the structure of the measuring cell of identical embodiment with Fig. 1.
Fig. 4 is that expression is the local amplification view around the conductive diamond electrode of identical embodiment with Fig. 1.
Fig. 5 is expression and the process flow diagram of Fig. 1 for the heavy metal ion measuring method of identical embodiment.
Description of reference numerals
100 ... The heavy metal ion measurement mechanism
W ... Liquor sample
2 ... Measuring cell
21 ... The resettlement section main body
211 ... Side wall portion
22 ... Injection part
23 ... Overflow part
3 ... To electrode
5 ... Conductive diamond electrode (working electrode)
5a ... Electrode surface
6 ... Potential change portion
7 ... Liquid displacement mechanism
71 ... Discharge line
711 ... Vent pipe
712 ... Extraction pump
T1 ... Buffering flow container (measure and use NaOH solution tank NaOH)
T2 ... Waste liquid tank
72 ... Supply line
721 ... Supply pipe
722 ... Charge pump
8 ... Current detecting part
9 ... Calculation control device (concentration calculating part)
10 ... Well heater
Embodiment
An embodiment to heavy metal ion measurement mechanism of the present invention describes with reference to the accompanying drawings.
The heavy metal ion measurement mechanism 100 of this embodiment is three electrode modes of electrode, contrast electrode and working electrode are used stripping voltammetry measure the device of the concentration of heavy metal ion that contains in the liquor sample.Any composition or multiple composition in the heavy metal ion such as the Cu that for example, contains in the heavy metal ion measurement mechanism 100 measurement liquor samples of this embodiment, As, Cd, Zn.
< apparatus structure >
Specifically, as shown in Figure 1, heavy metal ion measurement mechanism 100 comprises: measuring cell 2, accommodate liquor sample; To electrode 3, contact setting with liquor sample; Contrast electrode 4; Working electrode 5; Potential change portion 6 makes the potential change of working electrode 5; Liquid displacement mechanism 7 is replaced as at least a portion that is housed in the liquor sample in the measuring cell 2 as the acidic buffer of measuring with solution; Current detecting part 8, testing electrode 5 and to the electric current between the electrode 3; And concentration calculating part 9, according to calculating concentration of heavy metal ion by current detecting part 8 detected current values.
In addition, as shown in Figure 2, said each component parts is housed in the casing C, in the front lower of this casing C, be provided with the buffering flow container T1 that accommodates said acidic buffer with accommodate liquor sample and use after the waste liquid tank T2 of waste liquids such as damping fluid.In addition, in the front upper of casing C, be provided with power on/off button, measure the display part 901 of operations such as start button, calibration knob, cleaning button with button groups B and demonstration measurement result (concentration etc.).In addition, on the top of casing C, be provided with the inlet 22H that is used for injecting liquor sample the injection part 22 of said measuring cell 2.
Particularly measuring cell 2～concentration calculating part 9 each several parts are described below.
As shown in Figure 3, measuring cell 2 is the electrochemical cells with agitating function, and measuring cell 2 comprises: resettlement section main body 21 is used to accommodate liquor sample; And injection part 22, be arranged on the top of said resettlement section main body 21, be used to inject liquor sample.
Resettlement section main body 21 is roughly the rotary body shape, and resettlement section main body 21 comprises: side wall portion 211, the inside that is located at top have prismatic in perimembranous; And bottom wall portion 212, have perimembranous in the taper shape in the inside of setting continuously with said side wall portion 211.
In addition, to electrode 3 and contrast electrode 4 so that the mode of (bottom wall portion 212 1 sides) is inserted and secured on the said side wall portion 211 obliquely towards the below.In addition, the mode exposed with perimembranous in said taper shape of working electrode 5 is fixed on the said bottom wall portion 212.
The injection part 22 chimeric tops that are arranged on the side wall portion 211 of resettlement section main body 21.Between the side wall portion 211 of this injection part 22 and resettlement section main body 21, for example through containment member S1 such as O type ring as fluid-tight.In addition, injection part 22 has the interior lateral circle surface that is roughly the rotary body shape, and upper opening of lateral circle surface constitutes inlet 22H in this, and interior lateral circle surface is along with going diameter to diminish toward the below.In addition, the inlet 22H as upper opening is provided with switch cover 221.This switch cover 221 is that the center can and be opened between the open position of this inlet 22H and rotate (with reference to Fig. 2) at the blocking position that stops up said inlet 22H with the rotation axis that is arranged on injection part 22 tops.
In addition; As shown in Figure 3, in the measuring cell 2 of structure as stated, the top of main body 21 is provided with overflow part 23 in said resettlement section; This overflow part 23 is used for having surpassed under the situation of ormal weight at the liquid that is housed in resettlement section main body 21, discharges the liquid that surpasses this ormal weight.This overflow part 23 is to be arranged on the escape hole on side wall portion 211 tops of resettlement section main body 21 to connect said side wall portion 211 inside and outside modes.This escape hole 23 is connected with the waste liquid tank T2 that is located at casing C front through vent pipe P1.Can prevent liquor sample and measure with solution to injection part 22 adverse currents and prevent that described liquid from flowing out from measuring cell 2 through this overflow part 23, and can prevent that described liquid from getting between injection part 22 and the resettlement section main body 21.
The electrode group of mentioning this embodiment is to electrode 3～working electrode 5; To electrode 3 for example is platinum electrode; Contrast electrode 4 for example is a silver-silver chloride electrode, and working electrode 5 is boron-doped diamond electrodes (below be called conductive diamond electrode 5) that boron is arranged with high-concentration dopant.
As previously mentioned, electrode 3 and contrast electrode 4 are inserted and secured on the side wall portion 211 of resettlement section main body 21 with the mode towards the conductive diamond electrode 5 on the bottom wall portion that is located at resettlement section main body 21 212 obliquely.Thus; Since to electrode 3 and contrast electrode 4 to insert obliquely towards the mode of conductive diamond electrode 5 on the side wall portion 211 that is arranged on resettlement section main body 21; So described electrode 3,4 can be configured to not disturb with structure on every side, simultaneously can as close as possible conductive diamond electrode 5.
In addition, conductive diamond electrode 5 is roughly writing board shape, is arranged in the bottom wall portion 212 of resettlement section main body 21 with the electrode surface 5a mode that perimembranous is exposed in conical.Specifically, conductive diamond electrode 5 is through in the adamas as insulator, sneaking into the electrode that boron has electric conductivity, and is the electrode that on plate shaped base-material, forms boron-doped diamond film.The addition of the boron of sneaking in order to make adamas have electric conductivity is as long as can make adamas have that suitably decision is just passable in the scope of electric conductivity, and for example preferably, the addition of boron is for giving 1 * 10
- 2～10
-6The amount of the electric conductivity about Ω cm.In addition, as what said base-material can be given an example Si (for example monocrystalline silicon), Mo, W, Nb, Ti, Fe, Au, Ni, Co, Al arranged
2O
3, SiC, Si
3N
4, ZrO
2, MgO, graphite, single-crystal diamond, cBN and quartz glass etc., wherein preferably use monocrystalline silicon, Mo, W, Nb, Ti, SiC, single-crystal diamond.In addition, the thickness of boron-doped diamond film does not have special qualification, preferably about 1～100 μ m, more preferably about 5～50 μ m.
Specifically, resettlement section main body 21 has lower openings 21H in bottom wall portion 212, and the lower openings of conical interior perimembranous forms this lower openings 21H, and the mode of stopping up this lower openings 21H with said conductive diamond electrode 5 is provided with.
In more detail; Shown in the local amplification view of Fig. 4; Be formed with in the surrounding edge portion of lower openings 21H and accommodate stage portion 21H1, this is accommodated stage portion 21H1 and is used to accommodate conductive diamond electrode 5, and conductive diamond electrode 5 is embedded in this and accommodates among the stage portion 21H1.Accommodate between the surrounding edge portion of electrode surface 5a of bottom surface and conductive diamond electrode 5 of stage portion 21H1 at this, for example be provided with containment member S2 such as O type ring, make the liquid that can not that is housed in the resettlement section main body 21 drain to the outside from their gap.
The back side at said conductive diamond electrode 5 is provided with laminar electric-conductor 51 with the mode that electrically contacts, and this electric-conductor 51 is used on said conductive diamond electrode 5, applying voltage.
In addition; In this embodiment; The side at the back side of conductive diamond electrode 5; Specifically at the back side of laminar electric-conductor 51, be provided with the laminar well heater 10 as thermoregulation mechanism, this well heater 10 is used for being heated to the temperature of the liquid (liquor sample or acidic buffer) in the temperature of said conductive diamond electrode 5 and the measuring cell 2 necessarily.This well heater 10 is heated to for example 5 ℃～35 ℃ to conductive diamond electrode 5.Thus, the temperature change through conductive diamond electrode 5 reduces measuring error.
In addition, in said measuring cell 2, be provided with magnetic rabbling mechanism 24 (with reference to Fig. 1).This magnetic rabbling mechanism 24 comprises: magnetic stirring bar 241 is housed in the resettlement section main body 21 of measuring cell 2; And magnetic driven device 242, utilize magnetic force that said magnetic stirring bar 241 is rotated.Magnetic driven device 242 is arranged on the bottom of measuring cell 2, specifically is arranged on the downside of conductive diamond electrode 5 (well heater 10 bottoms).
Mention the function of the potential change portion 6 of said potentiostat PS, said potentiostat PS makes the current potential of conductive diamond electrode 5 between the current potential of the heavy metal stripping on the conductive diamond electrode 5, change at conductive diamond electrode 5 lip-deep current potentials and electro-deposition in the heavy metal electro-deposition.Specifically; Potentiostat PS is under conductive diamond electrode 5 and liquor sample state of contact; The current potential of conductive diamond electrode 5 is changed to the negative potential direction; Provide the heavy metal electro-deposition that makes measuring object at conductive diamond electrode 5 lip-deep current potentials, then, electro-deposition has under the conductive diamond electrode 5 and the acetate buffer solution state of contact as acidic buffer of said heavy metal from the teeth outwards; The current potential of conductive diamond electrode 5 to the positive potential scanning direction, is provided to make the current potential of electro-deposition in the 5 lip-deep heavy metal strippings of conductive diamond electrode.
In addition, mention the current sense function of potentiostat PS, through said potential change function the current potential of conductive diamond electrode 5 during to the positive potential scanning direction, potentiostat PS detects at the conductive diamond electrode and the electric current that produces between to electrode 3.
In addition, potentiostat PS makes the certain function of current potential maintenance except having, and also has the current potential of making and scans with certain speed, perhaps makes current potential step to the function of the current potential of appointment at regular intervals.There is no need to make one potentiostat PS to have described function, for example also can keep current potential function and electric potential scanning function to be separately positioned on the different potentiostat PS.
As shown in Figure 1, liquid displacement mechanism 7 comprises: discharge line 71, be used for being discharged to waste liquid tank T2 to the liquid in the measuring cell 2; And supply line 72, be used for to measuring cell 2 acetate buffer solution being provided from buffering flow container T1.
Discharging line 71 has: vent pipe 711 is connected with measuring cell 2; And extraction pump 712, be arranged on the said vent pipe 711, be used for being discharged to the outside to the liquid that is housed in measuring cell 2.Shown in the cut-open view of Fig. 3, vent pipe 711 is arranged on the bottom wall portion 212 of resettlement section main body 21 with the bottom wall portion 212 in the mode holing-through survey pond 2 of conductive diamond electrode 5 near surface openings.In addition, downstream one side of vent pipe 711 is connected with waste liquid tank T2.Extraction pump 712 by after 9 control action times of calculation control device of stating etc.
Said liquid displacement mechanism 7 is controlled by calculation control device 9, and liquid displacement is carried out to the liquor sample that is housed in the measuring cell 2 in the solution amount limit that makes the limit keep at least electrode 3 and conductive diamond electrode 5 being contacted with liquor sample.Specifically, through the extraction pump 712 and charge pump 722 of calculation control device 9 controlling liquid displacement mechanism 7, be replaced as the liquor sample that is housed in the measuring cell 2 several times as the acetate buffer solution of measuring with solution.For example, liquid displacement mechanism 7 for example with each half the mode with liquor sample several times (for example about 4 times) be replaced as acetate buffer solution.As method of replacing,, the acetate buffer solution of the amount that is equivalent to discharge rate is provided through supply line 72 being housed in liquor sample in the measuring cell 2 through after discharging line 71 and discharging half.With described permutations as carrying out repeatedly repeatedly.Also can carry out the discharge of liquor sample and the supply of acetate buffer solution simultaneously in addition.
With reference to Fig. 5 the method for heavy metal ion measurement mechanism 100 measure heavy metal ion of utilizing this embodiment is described below.
1. matting before measuring
Through be located at the power on/off button of casing C front by user's operation, control calculation element 9 makes the primary power conducting of heavy metal ion measurement mechanism 100.After this, press the cleaning button through the user, calculation control device 9 carries out the clean control in the measurement mechanism, specifically carries out the clean control of measuring cell 2.Through using the supply line 72 of liquid displacement mechanism 7, in measuring cell 2, acetate buffer solution is provided, and the acetate buffer solutions that are provided in the measuring cell 2 through 24 pairs of magnetic rabbling mechanisms stir, thereby carry out cleaning before the said measurement.Then, discharge said acetate buffer solution, accomplish preceding cleaning of measurement of measuring cell 2 through discharge line 71 from liquid displacement mechanism 7.In addition, cleaning can at random be carried out by the user before this measurement.
2. sample injection process
After matting finished before the said measurement, the user moved on to open position to the switch cover 221 of the inlet 22H of the injection part 22 that is located at casing C top, injected liquor sample from inlet 22H.After this, if the user presses the measurement start button, then calculation control device 9 accepts to measure commencing signal, and the beginning heavy metal ion is measured.In addition, obtain detection signal through detecting the liquid sensor (not expression among the figure) whether electrode 3, conductive diamond electrode 5 and contrast electrode 4 are contacted with liquor sample this moment, and calculation control device 9 judges whether the electrode group contacts with liquor sample.If be judged as contact, just transfer to following measurement action, under the situation that does not have contact, the demonstration untill further notice of makeing mistakes.
3. electro-deposition operation
4. liquid displacement operation
After the said electro-deposition operation, potentiostat PS makes the current potential of conductive diamond electrode 5 under the state of the current potential lower than said reduction potential, keep fixing.Under this state, calculation control device 9 is replaced as acetate buffer solution to the liquor sample in the measuring cell 2 several times through controlling liquid displacement mechanism 7.In this embodiment, discharging after half is housed in the liquor sample in the measuring cell 2 through discharging line 71, the acetate buffer solution of the amount suitable with discharge rate is provided through supply line 72.Through carrying out repeatedly (for example about 4 times) said action, be replaced as acetate buffer solution to liquor sample.Like this, under than the low potential state of said reduction potential, keep fixing, can prevent that electro-deposition is in the stripping in the liquid displacement operation of the heavy metal on the electrode 5 through the current potential that in the liquid displacement operation, makes conductive diamond electrode 5.In addition, also can be according to efflux time and the discharge rate of service time separate provision liquor sample and the quantity delivered of acetate buffer solution.
5. stripping operation (current detecting operation)
After being replaced as acetate buffer solution in the measuring cell 2, calculation control device 9 is to potentiostat PS output stripping commencing signal through said liquid displacement operation.So potentiostat PS makes the current potential of conductive diamond electrode 5 to the positive potential scanning direction, specifically scan the current potential higher and (for example+0.1V), make the heavy metal ion stripping in acetate buffer solution than the reduction potential of heavy metal.
If the heavy metal ion stripping then produces electric current at conductive diamond electrode 5 with between to electrode 3 thereupon.The electric current that causes because of the heavy metal ion stripping produces near+0.1V, and this electric current (electric signal) is delivered to potentiostat PS, carries out control, the detection of the signal of each electrode.At this; Be sent to calculation control device 9 by the detected signal of potentiostat PS; Calculation control device 9 compares calibration curve and the current value or the quantity of electric charge that obtain; Calculate the concentration of heavy metal ion in the liquor sample, said calibration curve is the concentration of the desirable heavy metal ion that is made in advance and the calibration curve of the current value or the quantity of electric charge.At this moment; Through using the spill current value or the difference quantity of electric charge to calculate concentration of heavy metal ion; Can calculate concentration of heavy metal ion more accurately, the said spill current value or the difference quantity of electric charge are the spill current value or the difference quantities of electric charge that only uses reference current value that carrier solution measures or reference charge amount to obtain in advance from deducting as the current value of measured value or the quantity of electric charge.The concentration of heavy metal ion that calculates like this is presented on the display part that is located at casing C front.
5. electrowinning process after
After electric potential scanning finishes; Through in a period of time, the current potential of conductive diamond electrode 5 being remained on+1.0V; Can make electro-deposition the complete stripping of heavy metal ion, thereby the state before conductive diamond electrode 5 being turned back to measure makes 5 regeneration of conductive diamond electrode.Through making 5 regeneration of conductive diamond electrode like this, can use same electrode repeatedly.In addition, the regeneration of conductive diamond electrode 5 not only can be carried out through keeping certain current potential, also can carry out through under wide current potential, scanning repeatedly.
6. waste liquid operation
After the electrowinning process of said back, calculation control device 9 is discharged to solution after the measurement in the measuring cell 2 among the waste liquid tank T2 through the extraction pump 712 of the discharge line 71 of controlling liquid displacement mechanism 7.After this waste liquid operation finishes, carry out the cleaning of measuring cell, power supply is broken off.
< effect of this embodiment >
According to the heavy metal ion measurement mechanism 100 of this embodiment of said formation,, can improve the detection sensitivity of the heavy metal ion of working electrode 5 through using the conductive diamond electrode as working electrode 5.In addition, liquid displacement mechanism 7 makes the heavy metal electro-deposition in back on the conductive diamond electrode 5 and before making the heavy metal stripping, is replaced as liquor sample to measure and uses solution, therefore can reduce the measuring error that causes because of the impurity in the liquor sample.In addition; Potential change portion 6 liquor sample to measuring with solution between locomorphic stage; Make the current potential of conductive diamond electrode 5 become the current potential of heavy metal electro-deposition on said conductive diamond electrode 5; Therefore heavy metal stripping when carrying out liquid displacement that kilowatt-hour has deposited can be prevented, the measurement of heavy metal ion can be carried out accurately.Therefore, can measure the heavy metal ion that contains in the liquor sample accurately.
< embodiments of other distortion >
In addition, the invention is not restricted to said embodiment.
For example, in said embodiment, through having conductive diamond electrode 5, the three-electrode method of electrode 3 and contrast electrode 4 measured, but also can be through only having conductive diamond electrode 5 and two electrode methods of electrode 3 being measured.Because three-electrode method can be controlled and be applied to conductive diamond electrode 5 and to the absolute value of the voltage between the electrode 3; So can carry out precision and all high measurement of sensitivity; And according to two electrode methods; Because the electrode that uses is a conductive diamond electrode 5 and to 3 two electrodes of electrode, so can make the simple in structure of measuring cell 2 and can make the structure miniaturization of measuring cell 2.
In addition, mention liquid displacement, carry out the mode of liquid displacement, also can use overflow part to carry out liquid displacement except using discharge line and supply line.For example, can consider that the limit makes superfluous part flow out the limit from overflow part and from supply line acetate buffer solution is provided.
In addition, the invention is not restricted to said embodiment, in the scope that does not break away from aim of the present invention, certainly carry out various distortion.
Claims (6)
1. a heavy metal ion measuring method is characterized in that, uses and to electrode with by the working electrode that the conductive diamond electrode constitutes the concentration of heavy metal ion in the liquor sample is carried out electrochemical measurement, and said heavy metal ion measuring method comprises:
The electro-deposition operation makes the current potential of said conductive diamond electrode become the current potential lower than the reduction potential of said heavy metal, thereby makes said heavy metal electro-deposition on said conductive diamond electrode:
The liquid displacement operation; Make said heavy metal electro-deposition after on the said conductive diamond electrode; Said conductive diamond electrode is become under the state of the current potential lower than said reduction potential, at least a portion of said liquor sample is being replaced as to measure uses solution;
The stripping operation; With said liquor sample be replaced as said measurement with solution after; With the current potential of said conductive diamond electrode to the electric potential scanning higher than said reduction potential, make the said heavy metal stripping of electro-deposition on said conductive diamond electrode to said measurement with solution in; And
The current detecting operation, make said heavy metal stripping to said measurement with solution in the time, detect at said conductive diamond electrode and the said electric current that produces between to electrode.
2. a heavy metal ion measurement mechanism is measured the concentration of heavy metal ion in the liquor sample, it is characterized in that said heavy metal ion measurement mechanism comprises:
Measuring cell is accommodated said liquor sample;
To electrode, contact setting with said liquor sample;
Working electrode is made up of the conductive diamond electrode, contacts setting with said liquor sample;
Potential change portion makes the current potential of said conductive diamond electrode between the current potential of the said heavy metal stripping on the said conductive diamond electrode, change at current potential on the said conductive diamond electrode and electro-deposition in said heavy metal electro-deposition;
Liquid displacement mechanism is replaced as measurement with at least a portion that is housed in the said liquor sample in the said measuring cell and uses solution;
Current detecting part detects said conductive diamond electrode and said to the electric current between the electrode; And
The concentration calculating part, according to calculating concentration of heavy metal ion by the detected current value of said current detecting part, wherein,
Said liquid displacement mechanism is replaced as said measurement with said liquor sample and uses solution making said heavy metal electro-deposition in back on the said conductive diamond electrode and make said heavy metal before the stripping of said conductive diamond electrode,
Said potential change portion between locomorphic stage, makes the current potential of said conductive diamond electrode become the current potential of said heavy metal electro-deposition on said conductive diamond electrode with solution to said measurement at the said liquor sample that will be housed in the said measuring cell by said liquid displacement mechanism.
3. heavy metal ion measurement mechanism according to claim 2; It is characterized in that liquid displacement is carried out to the liquor sample that is housed in the said measuring cell in the said solution amount limit that electrode and said conductive diamond electrode are contacted with liquor sample of maintenance, said liquid displacement mechanism limit.
4. according to claim 2 or 3 described heavy metal ion measurement mechanisms, it is characterized in that,
The mode that said conductive diamond electrode exposes to inside with electrode surface is arranged on the bottom wall portion of said measuring cell,
Said liquid displacement mechanism comprises:
Discharge line, this discharge line comprises: vent pipe, be connected with said measuring cell, and extraction pump, be arranged on the said vent pipe, be used for discharging the liquid that is housed in said measuring cell to the outside; And
Supply line, this supply line comprises: ingress pipe is connected with said measuring cell; And charge pump, be arranged on the said ingress pipe, be used for being provided in the said measuring cell with solution being housed in the measurement of measuring with NaOH solution tank NaOH,
Said vent pipe is connected with the bottom wall portion of said measuring cell.
5. according to each described heavy metal ion measurement mechanism in the claim 2 to 4, it is characterized in that,
Said conductive diamond electrode is the electrode that is arranged on the cardinal principle writing board shape on the bottom wall portion of said measuring cell with the mode that electrode surface exposes to inside,
The back side at said conductive diamond electrode is provided with thermoregulation mechanism, and this thermoregulation mechanism is used for the liquid in said conductive diamond electrode and the said measuring cell is heated.
6. according to each described heavy metal ion measurement mechanism in the claim 2 to 5, it is characterized in that,
Said measuring cell comprises: the resettlement section main body is used to accommodate said liquor sample; And injection part, be arranged on the top of said resettlement section main body, be used to inject said liquor sample,
Said side wall portion to electrode main body from said resettlement section inserts towards said conductive diamond electrode incline ground and is fixed.
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| JP2010260145 | 2010-11-22 | ||
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104884946A (en) * | 2012-08-14 | 2015-09-02 | 六号元素技术有限公司 | Electrochemical deposition and x-ray fluorescence spectroscopy |
| CN109270132A (en) * | 2012-12-28 | 2019-01-25 | 株式会社堀场制作所 | Electrochemical determining device and stirrer |
| CN109298062A (en) * | 2018-11-02 | 2019-02-01 | 山东建筑大学 | A kind of material sound state of paddling impregnates the detection device and method of water test |
| CN112827361A (en) * | 2020-12-31 | 2021-05-25 | 平湖爱之馨环保科技有限公司 | Two-chamber three-electrode electrolysis electrodialysis device |
| CN109298062B (en) * | 2018-11-02 | 2024-06-07 | 山东建筑大学 | Detection device and method for dynamic and static soaking water test of wading material |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB201108339D0 (en) | 2011-05-18 | 2011-06-29 | Element Six Ltd | Electrochemical sensors |
| GB201108342D0 (en) * | 2011-05-18 | 2011-06-29 | Element Six Ltd | Electrochemical sensors |
| JP2014130032A (en) * | 2012-12-28 | 2014-07-10 | Horiba Ltd | Electrochemical measuring device and stirrer |
| CN104297324B (en) * | 2014-10-31 | 2017-12-29 | 中国科学院上海微系统与信息技术研究所 | A kind of Portable heavy metal ion detection instrument instrument and method based on Android |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1522410A (en) * | 1975-09-25 | 1978-08-23 | Siemens Ag | Determination of heavy metal ion concentrations |
| CN1540333A (en) * | 2003-04-22 | 2004-10-27 | 英科新创(厦门)科技有限公司 | Sensng device for detecting metallic ion |
| JP2005221299A (en) * | 2004-02-04 | 2005-08-18 | Mitsubishi Electric Corp | Metal ion measuring method and metal ion measuring device |
| WO2008078641A1 (en) * | 2006-12-27 | 2008-07-03 | Keio University | Method for electrochemically measuring zinc ion |
| US20100108526A1 (en) * | 2007-03-05 | 2010-05-06 | Keio University | Electrochemical analysis method using boron-doped electroconductive diamond electrode |
-
2011
- 2011-11-21 JP JP2011253933A patent/JP2012127943A/en not_active Withdrawn
- 2011-11-22 CN CN2011103767469A patent/CN102565172A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1522410A (en) * | 1975-09-25 | 1978-08-23 | Siemens Ag | Determination of heavy metal ion concentrations |
| CN1540333A (en) * | 2003-04-22 | 2004-10-27 | 英科新创(厦门)科技有限公司 | Sensng device for detecting metallic ion |
| JP2005221299A (en) * | 2004-02-04 | 2005-08-18 | Mitsubishi Electric Corp | Metal ion measuring method and metal ion measuring device |
| WO2008078641A1 (en) * | 2006-12-27 | 2008-07-03 | Keio University | Method for electrochemically measuring zinc ion |
| US20100108526A1 (en) * | 2007-03-05 | 2010-05-06 | Keio University | Electrochemical analysis method using boron-doped electroconductive diamond electrode |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104884946A (en) * | 2012-08-14 | 2015-09-02 | 六号元素技术有限公司 | Electrochemical deposition and x-ray fluorescence spectroscopy |
| CN109270132A (en) * | 2012-12-28 | 2019-01-25 | 株式会社堀场制作所 | Electrochemical determining device and stirrer |
| CN109298062A (en) * | 2018-11-02 | 2019-02-01 | 山东建筑大学 | A kind of material sound state of paddling impregnates the detection device and method of water test |
| CN109298062B (en) * | 2018-11-02 | 2024-06-07 | 山东建筑大学 | Detection device and method for dynamic and static soaking water test of wading material |
| CN112827361A (en) * | 2020-12-31 | 2021-05-25 | 平湖爱之馨环保科技有限公司 | Two-chamber three-electrode electrolysis electrodialysis device |
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|---|---|
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