Analyzing device including an ion-permeable channel connecting a sample chamber with a reaction space

• US 5,496,521 A
• Filed: 11/15/1991
• Issued: 03/05/1996
• Est. Priority Date: 02/15/1991
• Status: Expired due to Term

• Current Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Original Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Inventors: Leiner, Marco
• Primary Examiner(s): Warden, Robert J.
• Assistant Examiner(s): Soderquist, Arlen
• Application Number:
  US07/792,671
• Time in Patent Office: 1,572 Days
• Field of Search: 422/58, 422/81, 422/82.04, 422/82.05, 422/82.06, 422/82.09, 422/86, 436/113, 436/122, 436/129, 436/163
• US Class Current: 422/82.05
• CPC Class Codes: G01N 27/4162 investigating the composition of gases, by the influence exerted on ionic conductivity in a liquid conductometry in general G01N27/06; amperometric gas sensors G01N27/404
• CPC Class Codes: Y10T 436/175383 Ammonia
• CPC Class Codes: Y10T 436/186 Sulfur dioxide
• CPC Class Codes: Y10T 436/201666 Carboxylic acid

Abstract

In a device for determining the concentration of a reagent from a group consisting of gases with acid or alkaline reaction in aqueous environments, and volatile acids and bases in liquid or gaseous samples, a sample chamber is situated in a housing and a unit for pH measurement with a reaction space is separated from the sample chamber by an ion-impermeable, gas-permeable membrane. The feeding of the reaction space with buffer solution is facilitated by connecting the reaction space by means of an ion-permeable channel to a reservoir for a buffer solution located outside of the pH measuring unit.

Claims

1. A device for determining the concentration of a reagent from a group consisting of gases having an acid reaction in aqueous environments, gases having an alkaline reaction in aqueous environments, and volatile acids and bases in liquid or gaseous samples, comprising a housing defining a sample chamber, a unit for pH measurement with a reaction space separated from said sample chamber by an ion-impermeable, gas-permeable membrane, said sample chamber containing a buffer solution at least during storage, and means forming an ion-permeable channel configured as a capillary or filled with an ion-permeable material which connects said reaction space with said sample chamber while bypassing said ion-impermeable, gas-permeable membrane.

2. A device according to claim 1, wherein said reaction space contains an indicator layer covered by said ion-impermeable, gas-permeable membrane and wherein said indicator layer is in contact with said ion-permeable channel.

3. A device according to claim 2, comprising a two-part housing with a lower part having a depression, wherein a sensor comprising a supporting layer, said indicator layer and said ion-impermeable, gas-permeable membrane is cemented or pressed or fitted into said depression, and wherein said means forming said ion-permeable channel comprises a recess on one side of said depression such that said ion-permeable channel is in lateral contact with said indicator layer.

4. A device according to claim 2, including means forming separate sample feeding and drainage lines connected to said sample chamber, one of said feeding and drainage lines including a branchoff line for feeding a buffer solution into said sample chamber, and wherein said ion-permeable channel extends from said reaction space to said branchoff line.

5. A device according to claim 3, wherein an indicator substance of said indicator layer is dissolved in said buffer solution.