Calcium complexing dyes and their use in analytical compositions, elements and methods
AssigneeEastman Kodak Company
InventorsJohn L. Toner, Bruce J. Murray, Bruce E. Babb, Michael W. Sundberg
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Abstract
Novel chromogenic derivatives of 1,2-bis-(o-aminoaryloxy)ethane-N,N,N',N'-tetraacetic acid are useful for the determination of calcium ions in both solution and dry assays. These compounds comprise a dye moiety which is directly conjugated to the acetic acid substituted-nitrogen atom and which enables the compounds to exhibit maximum absorbance at a wavelength generally greater than 400 nm before complexation. When the compounds are complexed with calcium ions, the absorbance shifts to a shorter wavelength.
Claims16
A substituted or unsubstituted compound of the structure ##STR39## wherein Z and Z' independently represent the carbon, oxygen, nitrogen, sulfur, selenium and tellerium atoms necessary to complete a 5- to 10-membered aromatic, unsaturated carbocyclic or unsaturated heterocyclic ring, R is a dye moiety which is directly conjugated through said ring to the nitrogen atom, each R' is independently formyl, substituted or unsubstituted alkyl, substituted or unsubstituted acyl or halo and n is 0, 1 or 2, provided that said compound exhibits a maximum electromagnetic absorption greater than about 400 nm in the absence of calcium ions.
An aqueous composition buffered to a pH of from about 6 to about 9 and containing a substituted or unsubstituted compound of the structure ##STR40## wherein Z and Z' independently represent the carbon, oxygen, nitrogen, sulfur, selenium and tellerium atoms necessary to complete a 5- to 10-membered aromatic, unsaturated carbocyclic or unsaturated heterocyclic ring, R is a dye moiety which is directly conjugated through said ring to the nitrogen atom, each R' is independently formyl, substituted or unsubstituted alkyl, substituted or unsubstituted acyl or halo and n is 0, 1 or 2, provided that said compound exhibits a maximum electromagnetic absorption greater than about 400 nm in the absence of calcium ions.
An analytical element for the determination of calcium ions comprising an absorbent carrier material containing a substituted or unsubstituted compound of the structure ##STR41## wherein Z and Z' independently represent the carbon, oxygen, nitrogen, sulfur, selenium and tellerium atoms necessary to complete a 5- to 10-membered aromatic, unsaturated carbocyclic or unsaturated heterocyclic ring, R is a dye moiety which is directly conjugated through said ring to the nitrogen atom, each R' is independently formyl, substituted or unsubstituted alkyl, substituted or unsubstituted acyl or halo and n is 0, 1 or 2, provided that said compound exhibits a maximum electromagnetic absorption greater than about 400 nm in the absence of calcium ions.
An analytical element for the determination of calcium ions comprising a nonporous support having thereon a reagent zone and a porous spreading zone, said element containing in at least one of said zones a substituted or unsubstituted compound of the structure ##STR42## wherein Z and Z' independently represent the carbon, oxygen, nitrogen, sulfur, selenium and tellurium atoms necessary to complete a 5- to 10-membered aromatic, unsaturated carbocyclic or unsatured heterocyclic ring, R is a dye moiety which is directly conjugated through said ring to the nitrogen atom, each R' is independently formyl, substituted or unsubstituted alkyl, substituted or unsubstituted acyl or halo and n is 0, 1 or 2, provided that said compound exhibits a maximum electromagnetic absorption greater than about 400 nm in the absence of calcium ions.
A method for the determination of calcium ions comprising the steps of:
- A. contacting a sample of a liquid suspected of containing calcium ions with a substituted or unsubstituted compound of the structure ##STR43## wherein Z and Z' independently represent the carbon, oxygen, nitrogen, sulfur, selenium and tellerium atoms necessary to complete a 5- to 10-membered aromatic, unsaturated carbocyclic or unsaturated heterocyclic ring, R is a dye moiety which is directly conjugated through said ring to the nitrogen atom, each R' is independently formyl, substituted or unsubstituted alkyl, substituted or unsubstituted acyl or halo and n is 0, 1 or 2, provided that said compound exhibits a maximum electromagnetic absorption greater than about 400 nm in the absence of calcium ions, and
- B. determining the optical density change resulting from the complexation of calcium ions with said compound.
Dependencies are inferred from the claim text.