Combined titration and pH electrode for the preparation of liquid samples in particular for NMR spectroscopy

• US 20070138011A1
• Filed: 12/13/2006
• Published: 06/21/2007
• Est. Priority Date: 12/20/2005
• Status: Abandoned Application

• Current Assignee: Bruker Biospin GMBH (Bruker Corporation)
• Original Assignee: Bruker Biospin GMBH (Bruker Corporation)
• Inventors: Hofmann, Martin, Hofmann, Gudrun
• Application Number:
  US11/637,877
• Publication Number:
  US 20070138011A1
• Time in Patent Office: Days
• US Class Current: 204/405
• CPC Class Codes: G01N 27/286 Power or signal connectors associated therewith
• CPC Class Codes: Y10T 436/116664 with automated titrator

Abstract

An electrode rod (1;21) for a pH meter, comprising a measuring end (2; 22) for immersion into a liquid test sample (31), wherein the measuring end (2; 22) has a pH measuring element, and wherein electrical feed lines (5) in the electrode rod (1;21) extend towards the pH measuring element, is characterized in that at least one capillary (8, 9, 10; 23) for feeding a liquid into the test sample (31) extends in the electrode rod (1; 21), and the at least one capillary (8, 9, 10; 23) has an outlet opening (11, 12, 13; 24) in the area of the measuring end (2; 22). The inventive electrode rod facilitates and accelerates preparation of liquid test samples, in particular, adjustment of a pH value for small amounts of test samples or narrow sample containers.

Claims

1. An electrode rod for a pH meter, the electrode rod for immersion into a liquid test sample, the rod comprising:

a measuring end for immersion into the liquid sample;

a pH measuring element disposed in said measuring end;

electrical feed lines extending in the electrode rod to said pH measuring element; and

at least one capillary extending within the electrode rod for feeding a fluid into the sample, said capillary having an outlet opening proximate said measuring end.

2. The electrode rod of claim 1, wherein several, 2, 3, or 4 capillaries are provided in the electrode rod, each having an outlet opening in an area of said measuring end.

3. The electrode rod of claim 1, wherein said capillary is made from glass, quartz glass of high purity, “

fused silica”

, metal, stainless steel, plastic material, PTFE (polytetrafuoroethylene), or PEEK (polyetheretherketone).

4. The electrode rod of claim 1, wherein said pH measuring element has a sensor chip or an ISFET (ion sensitive field effect transistor) and a reference electrode.

5. The electrode rod of claim 1, further comprising a temperature sensor disposed in an area of said measuring end.

6. The electrode rod of claim 1, wherein the electrode rod has an outer diameter of between 2 mm and 7 mm in an area of said measuring end.

7. The electrode rod of claim 1, wherein said capillary has an inner diameter of between 50 μ

m and 500 μ

m.

8. The electrode rod of claim 1, wherein said measuring end is pointed or bevelled.

9. The electrode rod of claim 1, wherein an outlet opening of a lower capillary is closer to an end of the electrode rod than said pH measuring element.

10. The electrode rod of claim 9, wherein outlet openings of other capillaries are further away from an end of the electrode rod than said outlet opening of said lower capillary.

11. Use of the electrode of claim 1 for adjusting a pH value of a liquid test sample, wherein a titration liquid is supplied through said at least one capillary.

12. The use of claim 11, wherein an acid is supplied through a first capillary and a base is supplied through a second capillary.

13. The use of claim 12, wherein a gas, an inert gas, nitrogen, a noble gas, or air is supplied through a third capillary or through a lower capillary.

14. The use of claim 12, wherein a buffer solution is supplied through a fourth capillary.

15. A titration unit having the electrode rod of claim 2, the titration unit further comprising:

a pH meter connected to said pH measuring unit;

an acid reservoir;

an acid pump connected to said acid reservoir to pass acid to one of said capillary outlet openings;

a base reservoir;

a base pump connected to said base reservoir to pass base to an other one of said capillary outlet openings; and

means for controlling said acid pump and said base pump to supply defined amounts of acid and base to the sample.

16. The titration unit of claim 15, wherein said controlling means is designed to automatically, iteratively adjust a pH value of the liquid test sample.

17. The titration unit of claim 15, further comprising a gas pump to supply gas through a capillary or through a lower capillary, wherein said controlling means drives said gas pump in such a manner that gas can be supplied during and/or after supplying acid and/or base.

18. The titration unit of claim 15, further comprising a buffer reservoir and a buffer pump for supplying buffer solution from said buffer reservoir through a capillary.