Earl Edward Burt

US Patent:

49138219, Apr 3, 1990

Filed:

Apr 27, 1989

Appl. No.:

7/343967

Inventors:

Richard G. Melcher - Midland MI
Earl E. Burt - Cincinnati OH

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

B01D 1508

US Classification:

210635

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.