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US 3,941,563 AGranted
Method and apparatus for detecting hexavalent chromium
AssigneeE. I. Du Pont de Nemours and Company
InventorRobert S. Saltzman
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Abstract
Disclosed herein is a process and apparatus for quantitatively determining the amount of hexavalent chromium (CR.sup..sup.+6) in a process stream by comparing the optical density of the process stream with a reference sample produced by reducing Cr.sup..sup.+6 to Cr.sup..sup.+3 by contacting it with a sulfur dioxide reducing agent.
Claims9
A process for quantitatively determining the amount of Cr.sup.+.sup.6 in at least one process stream comprising the steps of:
- a. monitoring the absorbance of at least a portion of the process stream;
- b. introducing a sulfur dioxide reducing agent into at least a portion of the process stream to form a reference sample;
- and
- c. after a time sufficient to allow the sulfur dioxide agent to reduce Cr.sup.+.sup.6 to Cr.sup.+.sup.3, measuring the difference in the absorbance of the process stream and the reference sample.
1 more element
Dependencies are inferred from the claim text.