Compounds, reagents and procedures for determining cations

Claim 1

A method for determining cations in an aqueous sample having an ion to be detected in the presence of an interfering ion which interfaces with detection of said ion to be detected, said method comprising: (a) preparing a reagent mixture consisting essentially of (i) a surfactant; (ii) a chromogenic cryptand of formula I ##STR14## wherein k and j, either same or different, are equal to 1 to about 5; m and n, either same or different, are equal to 0 to about 4; a and e, either same or different, are equal to 0 to about 2; b and d, either same or different, are equal to 0 to about 5; R, either same or different, is hydrogen, lower alkyl, lower alkylidene, lower alkenyl, allyl, or aryl; and --Q-- is ##STR15## wherein X is CH, N, or COH; and Y includes ##STR16## except that when Q is ##STR17## wherein Y is selected from the group consisting of p-nitrophenylazo, 3-phenylisothiazalyl-5-azo, isothiazolyl-5-azo, thiazolyl-5-azo, 2,4,6-trinitrophenylazo, p-nitrostyryl, p-benzoquinonemonoimino and bis-p-dimethylaminophenyl)hydroxymethyl, then the following condition cannot be present: that simultaneously be is equal to 0 or 1, d is equal to 0 or 1, j is equal to 1, n is equal to 1 or 2, a is equal to 1, e is equal to 1, k is equal to 1 and m is equal to 2; (iii) a buffer; (iv) a solvent medium and (v) a non-chromogenic interfering cation complexing compound mask; (b) adding the reagent mixture to a device consisting of a dimensionally stable, uniformly porous, diffusely reflective single or multi-layer formed of a polymeric matrix; (c) evaporating the solvent medium of the reagent mixture; (d) adding said sample to the device; (e) measuring the reflectance of the device; and (f) comparing the reflectance so measured with the reflectance of a standard composition containing a known concentration of cations.

Claim 2

A method for determining cations in an aqueous sample having an ion to be detected in the presence of an interfering ion which interfaces with detection of said ion to be detected, said method comprising: (a) preparing a reagent mixture consisting essentially of (i) a surfactant; (ii) a chromogenic cryptand of formula I ##STR14## wherein k and j, either same or different, are equal to 1 to about 5; m and n, either same or different, are equal to 0 to about 4; a and e, either same or different, are equal to 0 to about 2; b and d, either same or different, are equal to 0 to about 5; R, either same or different, is hydrogen, lower alkyl, lower alkylidene, lower alkenyl, allyl, or aryl; and --Q-- is ##STR15## wherein X is CH, N, or COH; and Y includes ##STR16## except that when Q is ##STR17## wherein Y is selected from the group consisting of p-nitrophenylazo, 3-phenylisothiazalyl-5-azo, isothiazolyl-5-azo, thiazolyl-5-azo, 2,4,6-trinitrophenylazo, p-nitrostyryl, p-benzoquinonemonoimino and bis-p-dimethylaminophenyl)hydroxymethyl, then the following condition cannot be present: that simultaneously be is equal to 0 or 1, d is equal to 0 or 1, j is equal to 1, n is equal to 1 or 2, a is equal to 1, e is equal to 1, k is equal to 1 and m is equal to 2; (iii) a buffer; (iv) a solvent medium and (v) a non-chromogenic interfering cation complexing compound mask; (b) adding the reagent mixture to a device consisting of a dimensionally stable, uniformly porous, diffusely reflective single or multi-layer formed of a polymeric matrix; (c) evaporating the solvent medium of the reagent mixture; (d) adding said sample to the device; (e) measuring the reflectance of the device; and (f) comparing the reflectance so measured with the reflectance of a standard composition containing a known concentration of cations.