Chemistry: analytical and immunological testing – Sulfur containing
Reexamination Certificate
1999-06-04
2001-07-03
Warden, Jill (Department: 1743)
Chemistry: analytical and immunological testing
Sulfur containing
C436S120000, C436S123000, C436S125000, C436S169000, C436S164000, C436S810000, C436S815000, C436S904000, C422S051000, C435S004000, C435S805000, C427S002130
Reexamination Certificate
active
06255117
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to a device and method for determining the concentration of monopersulfate salts or ions in aqueous solutions.
BACKGROUND OF THE INVENTION
Monopersulfate salts, such as potassium monopersulfate, are useful as oxidants in many applications including swimming pool treatment denture cleaning and paper recycling. Although monopersulfate salts (MPS) are not sanitizers and cannot be used alone in pools and spas, they are used as auxiliary oxidants (shocking agent) in conjunction with copper/silver ionizers or chlorine or bromine sanitizers to reduce organic content in swimming pool or spa water. In this manner MPS improves the sanitizer's efficiency and the aesthetic quality of the pool water.
Shocking can be defined as a pool or spa water treatment that oxidizes chloramines and other organic contaminants making pool and spa water clear. Many organic contaminants, such as perspiration, body oils, deodorants, and suntan lotions are introduced into pool and spa water by the bather. Other contaminants are introduced by external forces, such as wind and rain; these include dust and dirt, pollen and other plant debris, lawn fertilizer, grass clippings, and airborne pollutants.
It is widely known and accepted that proper sanitation is critical for maintaining pool and spa water free of disease and infection causing bacteria, viruses, and other micro-organisms. When organic contaminants build up, they chemically react with swimming pool sanitizing and disinfecting chemicals, consuming a large portion of the available sanitizer. As this occurs, the sanitizer must be added at higher doses to achieve the same level of disinfection. As the level of organic contaminants increases in pool and spa water, the sanitizer concentration and disinfection efficiency decreases.
Contaminants which contain nitrogen, such as ammonia, can combine with chlorine sanitizers to form chloramines, or combined chlorines. There are many problems associated with the presence of combined chlorines. They react with active chlorine, they irritate eyes and mucous membranes, they create chlorine-like odors, and they are poor sanitizers.
In addition to reducing sanitizer efficiency and generating irritating and odorous chloramines, organic contaminants also adversely affect the aesthetic quality of swimming pool and spa water. They make the water appear dull, thick, slow, and cloudy.
Monopersulfate shocking eliminates organic contaminants, increases sanitizer efficiency, and restores sparkle and clarity to pool and spa water.
While monopersulfate are, accordingly, useful either as alternative or in addition to other water treatments such as chlorine shocking, it is important to be able to quickly and effectively determine the concentration of monopersulfate in the aqueous medium if the treatment is to be safe and effective.
SUMMARY OF THE INVENTION
In accordance with the present invention, a composition, method and device are provided for determining the concentration of monopersulfate ions in aqueous solution. The device of the invention includes an absorbent matrix, such as cellulose based paper, onto which the indicator reagent composition is absorbed and then dried to form a test strip. The composition of the invention is capable of reacting with monopersulfate in aqueous solution at concentrations from 0-50 ppm to give a color change indicative of the concentration of monopersulfate present.
The method of the invention comprises contacting a test solution with the composition of the invention, which may be a dried deposit on an absorbent matrix, observing the resultant color change and comparing the resultant color with a standard color index of colors at specific monopersulfate concentrations to quantitatively determine the monopersulfate concentration.
DETAILED DESCRIPTION OF THE INVENTION
The composition, method and device of the present invention for measuring the monopersulfate ion concentration in aqueous solutions includes an indicator reagent composition deposited on a carrier matrix of suitable bibulous material such as a cellulosic matrix and capable of reacting with monopersulfate ions to form iodine and reacting with the iodine to give a color change in proportion to the concentration of monopersulfate ion present over a range of 0-50 ppm. The indicator composition comprises:
Redox indicator that gives a color change on reaction with iodine, such as heterocyclic azine and benzidine type indicators
A buffer for buffering the composition in the pH range 5-7, such as an alkalic metal phosphate
0.1-2% of a cationic surfactant
0.1-2% of a polymer to increase solubility and compatibility
Source, such as potassium or sodium iodide, which on reaction with monopersulfate ions forms Iodine
A suitable carrier matrix of bibulous material either natural or synthetic such as absorbent paper.
Typical redox indicators for the invention are compounds of the formula:
where R and R′ are selected from the group consisting of hydroxy and amino groups and X,X′,Y and Y′ are selected from the group consisting of hydrogen, hydroxy, methyl, methoxy, ethyl and ethoxy groups
REFERENCES:
patent: 4092115 (1978-05-01), Rupe et al.
patent: 4393142 (1983-07-01), Stephens
patent: 4904605 (1990-02-01), O'Brien et al.
patent: 5491094 (1996-02-01), Ramana et al.
patent: 5811254 (1998-09-01), Wu
patent: 5972713 (1999-10-01), Kuzuhara et al.
patent: 5976823 (1999-11-01), Wu
patent: 6028045 (2000-02-01), Bianchetti et al.
patent: 6030842 (2000-02-01), Peachey-Stoner
patent: 6087089 (2000-07-01), Wu
patent: 6180412 (2001-01-01), Kroll
J. Liebermann, Jr. et al., “Development of the FACTS Procedure for Combined Forms of Chlorine and Ozone in Aqueous Solutions,” Environ. Sci. Technol., 14, 11, 1395-1400 (1980).
Cole Monique T.
Gipple & Hale
Lamotte Company
Warden Jill
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