US 7,491,546 B2
	Reagent delivery and photometric chlorine analysis
Ivars Jaunakais, Rock Hill, S.C. (US)
Assigned to Industrial Test Systems, Inc., Rock Hill, S.C. (US)
Filed on Sep. 27, 2004, as Appl. No. 10/949,315.
Prior Publication US 2006/0073603 A1, Apr. 06, 2006
Int. Cl. G01N 33/00 (2006.01); G01N 31/22 (2006.01)

U.S. Cl. 436—125  [422/56; 422/58; 422/82.09; 436/164; 436/169; 436/810; 435/287.7; 356/436]

17 Claims

1. A touch-free colorimetric method for chlorine analysis comprising obtaining a blank reading for an aqueous sample, and then delivering into said sample an effective amount of a DPD salt from a water permeable, insoluble fibrous matrix disposed on a reagent delivery device and also providing a mixing action by moving a portion of said reagent delivery device in said sample, wherein said aqueous sample is disposed in a photometric instrument during reagent delivery, and within one minute of introducing said DPD salt into said sample, photometrically analyzing the sample color for the free chlorine in said sample, wherein said DPD salt is suitable for chlorine analysis.