Compositions for Conjugating a Sulfonephthalein Dye to a Substrate
The present invention provides derivatized indicator compounds, such as pH indicator compounds, which can be covalently immobilized to a variety of solid substrates to produce an indicator pad. Such pads can be used to monitor water quality in variety of settings. In particular, the pads of the invention are useful in devices which monitor the quality of recreational water, such as water in swimming pools, hot tubs, and amusement park attractions. including water slides, and water-based rides. The present invention overcomes the limitations of commercially available pad chemistries.
1 . (canceled)
2 . The method of claim 17 , wherein the pH indicator compound is a phenolic dye modified to have the functional group capable of reacting with an aromatic, hydroxyl, amino or carboxyl group to form a covalent bond.
3 . The method of claim 2 , wherein the pH indicator compound is a modified sulfonephthalein dye.
4 . The method of claim 3 , wherein the modified sulfonephthalein dye is selected from the group consisting of modified phenol red, modified cresol red, modified m-cresol purple, modified xylenol blue, modified thymol blue, modified chlorophenol red, modified bromophenol blue, modified bromocresol purple, modified bromocresol green, modified bromothymol blue, modified xylenol orange, and modified methylthymol blue.
5 . The method of claim 4 , wherein the pH indicator compound is selected from the group consisting of modified phenol red, modified cresol red, modified m-cresol purple, modified xylenol blue, modified thymol blue, modified chlorophenol red, and modified xylenol orange.
6 . The method of claim 1 , wherein the pH indicator compound has having a hydroxymethyl, carboxy-linker- or NH 2 -linker-group.
7 . The method of claim 6 , wherein the pH indicator compound has a carboxy-linker- or NH 2 -linker-group and the linker is a straight chain or branched C 1 -C 6 -alkylene.
8 . The of claim 7 , wherein the linker is a straight chain or branched C 3 -C 6 -alkylene.
9 . The method of claim 8 , wherein the pH indicator compound has a 2-aminoethyl group or a 3-carboxy-n-propyl group.
10 . The method of claim 1 , wherein the pH indicator compound is represented by Formula (I)
wherein R 1 , R 2 and R 3 for each compound are set forth in Table 2,
TABLE 2
Compound
R 1
R 2
R 3
1
HOCH 2 —
H
H
2
Me
HOCH 2 —
H
3
HOCH 2 —
H
Me
4
H
HOCH 2 —
Me
5
Me
HOCH 2 —
Me
6
i-Pr
HOCH 2 —
Me
7
Cl
HOCH 2 —
H
8
CH 2 N(CH 2 COOH) 2
HOCH 2 —
Me.
11 . The method of claim 1 , wherein the pH indicator compound is represented by Formula (II),
where the combinations of R 1 , R 2 and R 3 are as set forth in the table below,
Example
R 1
R 2
R 3
1
H
H
H
2
Me
H
H
3
H
H
Me
4
Me
H
Me
5
i-Pr
H
Me
6
Cl
H
H
7
Br
Br
H
8
Br
Me
H
9
Br
Br
Me
10
i-Pr
Br
Me
11
CH 2 N(CH 2 COOH) 2
H
Me
12
CH 2 N(CH 2 COOH) 2
iPr
Me
and one of R 4 and R 5 is hydrogen and the other is NH 2 -linker or HOOC-linker-;
wherein the linker is a bivalent chemical moiety.
12 . The method of claim 11 , wherein the linker is a straight chain or branched C 1 -C 6 -alkylene.
13 . The method of claim 11 , wherein one of R 4 and R 5 is hydrogen and the other is 2-aminoethyl or 3-carboxy-n-propyl.
14 . The method of claim 11 , wherein the pH indicator compound is represented by one of Formulas (IIa) and (IIb),
15 . (canceled)
16 . (canceled)
17 . A method of producing a composition comprising a pH indicator compound covalently attached to a substrate, comprising reacting a substrate having aromatic groups, hydroxyl groups, amino groups, carboxyl groups or a combination thereof, with a modified pH indicator compound comprising a functional group capable of reacting with an the aromatic, hydroxyl, amino or carboxyl group to form a covalent bond.
18 . The method of claim 17 , wherein the substrate is a polymer.
19 . The method of claim 18 , wherein the polymer is hydroxylated.
20 . The method of claim 19 , wherein the polymer is selected from cellulose, cellulose derivatives, polyvinyl alcohol, derivatives of polyvinyl alcohol, polyallyl alcohol and derivatives of polyallyl alcohol.
21 . The method of claim 18 , wherein the polymer comprises aromatic groups.
22 . The method of claim 21 , wherein the polymer is polyethylene terephthalate or polystyrene.
23 - 27 . (canceled)
28 . A composition comprising a modified pH indicator compound covalently attached to a substrate, said composition being produced by the method of claim 17 .
29 . A device comprising the composition of claim 28 and an automated reader or a reflectance spectrophotometer.
30 . (canceled)
31 . A method of monitoring the pH of a recreational water source, comprising contacting the water with the device of claim 29 and determining the pH of the water.