Integrated water testing system and method for ultra-low total chlorine detection

Patent metadata

Field	Value
Publication number	US-2016011160-A1
Application number	US-201514865540-A
Country	US
Kind code	A1
Filing date	Sep 25, 2015
Priority date	Oct 22, 2012
Publication date	Jan 14, 2016
Grant date	—

Abstract

A system and method for determining a concentration of total chlorine in dialysis water are provided. The system comprises a main unit housing an iodide/water sample chamber and a reducing agent chamber. An electrode pair bridges the two chambers and generates tri-iodide proportional to the amount of total chlorine in the dialysis water. The electrode pair detects the amount of tri-iodide generated in proportion to the amount of active chloride in the dialysis water. The system is suitable for use in connection with, or for incorporation into, a water purification system for generating dialysis fluid, and may include a display that alerts the user to stop or prevent a hemodialysis treatment if the total chlorine level exceeds a predetermined level.

First claim

What is claimed is:

1 . A method of determining an amount of total chlorine in water, the method comprising:
(a) providing a total chlorine detection system in fluid communication with a water purification machine, the total chlorine detection system including
a first chamber in fluid communication with an iodide reservoir and a water sample source,
a second chamber in fluid communication with a reducing agent reservoir, and
an electrode pair associated with a voltage source, wherein one electrode of the electrode pair is in contact with an iodide fluid in the first chamber and the other electrode of the electrode pair is in contact with a reducing agent solution in the second chamber, and wherein the first and second chambers are separated by a membrane that allows charge but not fluid to pass between the chambers;
(b) measuring a background voltage V B in the electrode pair, the background voltage V B associated with any tri-iodide in the system before introduction of a water sample; (c) providing a water sample from the water purification machine, the water sample including an amount of total chlorine; (d) metering an amount of the water sample into the system; (e) monitoring a baseline voltage V 0 via the electrode pair, the baseline voltage V 0 associated with tri-iodide present in the water sample before application of a tri-iodide generating voltage to the electrode pair; (f) generating a first amount of tri-iodide from the water sample by applying a voltage V 1 to the electrode pair for a time t 1 ; (g) thereafter monitoring a first voltage V 2 in the electrode pair for a time t 2 , the first monitored voltage V 2 associated with a sum of the amount of total chlorine and the first amount of tri-iodide; and (h) calculating the unknown total chlorine concentration in the water sample from the baseline voltage V 0 , the background voltage V B , and the first monitored voltage V 2 .

2 . The method of claim 1 comprising, intermediate the steps of (g) and (h), generating a second amount of tri-iodide from the water sample by applying a voltage V 3 to the electrode pair for a time t 3 , and thereafter monitoring a second voltage V 4 in the electrode pair for a time t 4 , the second monitored voltage V 4 associated with a sum of the amount of total chlorine and the first and second amounts of tri-iodide, wherein the unknown total chlorine concentration in the water sample is calculated from the baseline voltage V 0 , the background voltage V B , and at least one of the first monitored voltage V 2 and the second monitored voltage V 4 .

3 . The method of claim 2 comprising, after the step of generating the second amount of tri-iodide, generating a third amount of tri-iodide from the water sample by applying a voltage V 5 to the electrode pair for a time t 5 , the third amount of tri-iodide corresponding to the third amount of tri-iodide, and monitoring a third voltage V 6 in the electrode pair for a time t 6 , the third monitored voltage V 6 associated with a sum of the amount of total chlorine and the first, second, and third amounts of tri-iodide, wherein the unknown total chlorine concentration in the water sample is calculated from the baseline voltage V 0 , the background voltage V B , and at least one of the first, second, third monitored voltages V 2 , V 4 , and V 6 .

4 . The method of claim 1 comprising alerting the user to perform a corrective action if a level of total chlorine exceeds a predetermined value.

5 . The method of claim 4 , wherein the predetermined value is a value within a range between and including 0.1 ppm and 0.5 ppm.

6 . The method of claim 1 comprising providing a dialysis machine in fluid communication with the water purification machine.

7 . The method of claim 6 comprising allowing the user to perform dialysis if a level of total chlorine is below a predetermined value.

8 . The method of claim 7 , wherein the predetermined value is a value within a range between and including 0.1 ppm and 0.5 ppm.

9 . The method of claim 7 comprising preventing the user from performing the dialysis if the level of total chlorine exceeds the predetermined level until a subsequent level of total chlorine in a subsequent water sample is below the predetermined level.

10 . The method of claim 6 , wherein the water sample is from water for preparing dialysate that has been passed through a filter including carbon.

11 . A method of determining an amount of total chlorine in water for dialysis, the method comprising:
(a) providing a water purification machine in fluid communication with a dialysis machine; (b) providing a total chlorine detection system in fluid communication with the water purification machine; (c) measuring a background voltage V B via the system, the background voltage V B associated with any tri-iodide in the system before introduction of a water sample; (d) providing a water sample including an amount of total chlorine; (e) metering an amount of the water sample into the system; (f) monitoring a baseline voltage V 0 associated with tri-iodide present in the water sample before application of a tri-iodide generating voltage to the electrode pair; (g) generating a first amount of tri-iodide from the water sample by applying a voltage V 1 for a time t 1 ; (h) thereafter monitoring a first voltage V 2 for a time t 2 , the first monitored voltage V 2 associated with a sum of the amount of total chlorine and the first amount of tri-iodide; and (i) calculating the unknown total chlorine concentration in the water sample from the baseline voltage V 0 , the background voltage V B , and the first monitored voltage V 2 .

12 . The method of claim 11 comprising, intermediate the steps of (h) and (i), generating a second amount of tri-iodide from the water sample by applying a voltage V 3 for a time t 3 , and thereafter monitoring a second voltage V 4 for a time t 4 , the second monitored voltage V 4 associated with a sum of the amount of total chlorine and the first and second amounts of tri-iodide, wherein the unknown total chlorine concentration in the water sample is calculated from the baseline voltage V 0 , the background voltage V B , and at least one of the first monitored voltage V 2 and the second monitored voltage V 4 .

13 . The method of claim 12 comprising, after the step of generating the second amount of tri-iodide, generating a third amount of tri-iodide from the water sample by applying a voltage V 5 for a time t 5 , the third amount of tri-iodide corresponding to the third amount of tri-iodide, and monitoring a third voltage V 6 for a time t 6 , the third monitored voltage V 6 associated with a sum of the amount of total chlorine and the first, second, and third amounts of tri-iodide, wherein the unknown total chlorine concentration in the water sample is calculated from the baseline voltage V 0 , the background voltage V B , and at least one of the first, second, and third monitored voltages V 2 , V 4 , and V 6 .

14 . The method of claim 11 comprising alerting the user to perform a corrective action if a level of total chlorine exceeds a predetermined value.

15 . The method of claim 14 , wherein the predetermined value is a value within a range between and including 0.1 ppm and 0.5 ppm.

16 . The method of claim 11 comprising indicating a safe status to a user of a level of total chlorine falls below a predetermined value.

17 . The method of claim 16 , wherein the predetermined value is a value within a range between and including 0.1 ppm and 0.5 ppm.

Assignees

• Baxter Int
• Baxter Healthcare Sa

Inventors

• White Jeff
• Chen Ye
• Ding Yuanpang Samuel
• Titus Joel
• Rohde Justin
• Maliekkal Shincy
• Cooper Kevin

Classifications

• G01N33/0036 Primary

  specially adapted to detect a particular component (physical analysis of gaseous biological material G01N33/497) · CPC title

• G01N27/4168 Primary

  Oxidation-reduction potential, e.g. for chlorination of water (water analysis G01N33/18) · CPC title

• C02F2103/026

  Treating water for medical or cosmetic purposes · CPC title

• Y02W10/33

  using wind energy · CPC title

• G01N27/30

  Electrodes, e.g. test electrodes; Half-cells (G01N27/414 takes precedence) · CPC title