The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Apr. 03, 1990

Filed:

Apr. 27, 1989
Applicant:
Inventors:

Richard G Melcher, Midland, MI (US);

Earl E Burt, III, Cincinnati, OH (US);

Assignee:

The Dow Chemical Company, Midland, MI (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
210635 ; 210656 ; 210659 ; 2101982 ; 210909 ; 436131 ; 436140 ; 436161 ; 436178 ;
Abstract

A chromatographic method for the determination of individual phenols in water by adding a halogenating agent to the water, e.g., using the bromate-bromide reaction to generate tribromide ions which react with the phenols to form bromo-derivatives of the phenols, then to permeate the bromo-derivatives across a membrane, e.g., a silicone rubber membrane, into a liquid extractant, e.g., a dilute aqueous solution of sodium hydroxide and acetonitrile, and then determining the permeated bromo-derivatives in the liquid extractant by chromatography, e.g., by injecting the liquid extractant containing the permeated bromo-derivatives into a reverse phase liquid chromatographic system. The use of a membrane is essential in the present invention because it allows the use of a high enough concentration of halogenating agent to completely halogenate most any sample and provides for the removal of the halo-derivatives from the halogenation reaction site before any substantial degradation of the halo-derivatives occurs from a relatively high concentration of halogenating agent. Total phenols as a group can be determined by modifying the method to use backflow liquid chromatography to eliminate potential interferences and to elute the halo-derivatives in a single chromatographic peak.


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