Electrochemical analysis process

• US 5,830,343 A
• Filed: 03/11/1996
• Issued: 11/03/1998
• Est. Priority Date: 07/11/1994
• Status: Expired due to Fees

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Paeschke, Manfred, Uhlig, Albrecht, Hintsche, Rainer
• Primary Examiner(s): TUNG, TA HSUNG
• Application Number:
  US08/613,621
• Time in Patent Office: 967 Days
• Field of Search: 204/413, 204/434, 204/415, 205/775, 205/789, 205/789.5
• US Class Current: 205/775
• CPC Class Codes: G01N 27/27 Association of two or more measuring systems or cells, each measuring a different parameter, where the measurement results may be either used independently, the systems or cells being physically associated, or combined to produce a value for a further parameter
• CPC Class Codes: G01N 27/42 Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte

Abstract

A process is provided for the electrochemical analysis of compounds of solutions, such as can, e.g., be used in chemical analysis or for control measurements in industrial and environmental sectors. Identification or detection of individual substances takes place by the deposition thereof on electrodes and subsequent detection of the deposited substances. In the process, use is made of a plurality of electrodes. The substances to be identified from the solution are so simultaneously deposited on the electrodes that each electrode is coated with a different substance or substance mixture. Then, the deposited substances are simultaneously identified on the individual electrodes. Thus, the measuring time is significantly shortened and the risk of faulty measurements due to interactions between the substances to be identified on the electrodes is significantly reduced.

Claims

1. A process for electrochemical analysis of a solution, the process comprising the steps of:

bringing a silicon chip having arranged thereon a planar multi-electrode array including a reference electrode and several other electrodes into contact with the solution to be analyzed, said other electrodes each comprising an array of individual microstructured microelectrodes, with said reference electrode and each of said other electrodes being capable of independently receiving electrical steady-state and pulse potentials;

simultaneously depositing metal from the solution to be analyzed on said other electrodes such that each of said other electrodes formed of the array of individual microstructured microelectrodes is coated with one of a different metal and different metal mixture; and

subsequently, approximately simultaneously oxidizing the deposited metals to metal ions on individual ones of said other electrodes formed of the array of individual microstructured microelectrodes to identify the metals;

wherein each of the individual microstructured microelectrodes has a surface area of 25 μ

m².

2. The process according to claim 1, wherein for the depositing of different metals, the method further comprises the step of simultaneously applying different potentials to the individual ones of the electrodes.

3. The process according to claim 2, wherein for approximately simultaneously identifying the metals deposited on the electrodes, the process further comprises the steps of approximately simultaneously scanning the individual ones of the electrodes formed of the arrayed individual microstructured microelectrodes in a different potential range through an application of one of a potential ramp and sequence of potential pulses;

and

selecting the potential ramp or sequence of potential pulses such that a different metal is identified on each electrode formed of the arrayed individual microstructured microelectrodes in a selective manner.

4. The process according to claim 1, wherein for approximately simultaneously identifying the metals deposited on the electrodes, the process further comprises the steps of approximately simultaneously scanning the individual ones of the electrodes formed of the arrayed individual microstructured microelectrodes in a different potential range through an application of one of a potential ramp and sequence of potential pulses;

and

selecting the potential ramp or sequence of potential pulses such that a different metal is identified on each electrode formed of the arrayed individual microstructured microelectrodes in a selective manner.

5. The process according to claim 1, wherein the electrodes are formed from one of a metal, metal oxide and carbon.

6. The process according to claim 1, wherein electrodes formed of platinum or gold are used during the process of electrochemical analysis.

7. The process according to claim 1, the process further comprising the step of:

coating at least one of the arrays of individual microstructured microelectrodes with a homogenous mercury film prior to analyzing the solution.

8. The process according to claim 7, wherein for said coating step, the method further comprising the step of bringing the at least one array of individual microstructured microelectrodes into contact with a mercury-containing electrolyte.