Nitrite detection technique

1. A diagnostic test kit for detecting the presence or absence of nitrites within a urine test sample, the test kit comprising:

a reagent pad on which an aromatic primary amine is disposed that is capable of reacting with a nitrite or nitrite derivative in the urine test sample to form a diazonium ion; and

a lateral flow device that is in fluid communication with the reagent pad and comprises:

a porous membrane defining a discrete detection zone that is separate and distinct from the reagent pad and within which is contained a nucleophilic aromatic amine detection reagent, the detection reagent being capable of reacting with the diazonium ion to form an azo indicator, the azo indicator exhibiting a color that is different than the color of the detection reagent; and

an absorbent material that receives the urine test sample after flowing through the porous membrane.

2. The diagnostic test kit of claim 1 , wherein the aromatic primary amine is p-arsalinic acid, sulfanilamide, or a derivative thereof.

3. The diagnostic test kit of claim 1 , wherein the detection reagent comprises N-1-naphthylethylene diamine or a derivative thereof.

4. The diagnostic test kit of claim 1 , wherein the detection reagent comprises a macromolecular moiety and an aromatic amine moiety.

5. The diagnostic test kit of claim 4 , wherein the macromolecular moiety is formed from a polymer.

6. The diagnostic test kit of claim 5 , wherein the polymer is a polysaccharide.

7. The diagnostic test kit of claim 4 , wherein the macromolecular moiety is formed from a particle.

8. The diagnostic test kit of claim 4 , wherein the aromatic amine moiety is formed from N-1-naphthylethylene diamine or a derivative thereof.

9. The diagnostic test kit of claim 1 , wherein the aromatic primary amine is disposed on the lateral flow assay device.

10. The diagnostic test kit of claim 1 , wherein the aromatic primary amine comprises aniline; 4-chloroaniline; 4-bromoaniline; 2,4,6-tribromoaniline; 2,4,6-trichloroaniline; α-trifluoro-m-toluidene; ortho-toluidine; m- and p-aminophenol; ortho-tolidine; sulfanilamide, p-aminobenzoic acid; 1-amino-8-hydroxynaphthalene-3 , 6-disulphonic acid; aminoacetoanilide; aminophenyl ether, p-arsalinic acid; 4-amino-1-naphthalenecarbonitrile, or derivatives thereof.

11. The diagnostic test kit of claim 1 , wherein the detection reagent comprises 8-hydroxyjulolidine, N,N-dimethylaniline; methylenedianiline; benzidine; benzoquinoline; aminoquinoline; m-phenylenediamine; α-trifluoro-m-toluidene; ortho-toluidine; m-aminophenol; ortho-tolidine; N-1-naphthylethylene diamine, or a derivative thereof.

12. The diagnostic test kit of claim 7 , wherein the particle is a carboxylated latex particle.

13. The diagnostic test kit of claim 1 , wherein the indicator is an aromatic azo compound.

14. The diagnostic test kit of claim 1 , wherein the lateral flow device further comprises a sample pad configured to receive the test sample.

15. The diagnostic test kit of claim 14 , wherein the sample pad also defines a quenching zone that contains an agent capable of reacting with a contaminant in the test sample.

16. The diagnostic test kit of claim 1 , wherein the absorbent material includes nitrocellulose, a cellulosic material, a porous polyethylene pad, glass fiber filter paper, or a combination thereof.

17. The diagnostic test kit of claim 1 , wherein the nitrite derivative is nitrous acid.

18. The diagnostic test kit of claim 1 , wherein the detection zone is located laterally downstream from the reagent zone.