Method and apparatus for the identification of aldehydes

Abstract

An apparatus for estimating the concentration of an aldehyde comprising a solid medium; a nucleophilic aromatic compound held on the medium; and an acid held on the medium and a method for detecting the presence of an aldehyde in a sample with the apparatus in which the sample is exposed at room temperature to a test medium to catalyze the formation of optically detectable quantities of a product within a time period of no more than 60 minutes and without applying any external heat to the sample or test medium, the test medium comprising a indicator that is a nucleophilic compound having acidic protons at the nucleophilic center and at least one acid, and measuring the optical changes that occur as a result of the catalysis.

What is claimed is: 
     
         1 . An apparatus for estimating the concentration of an aldehyde comprising:
 a solid medium;   a nucleophilic aromatic compound held on the medium; and,   an acid held on the medium.   
     
     
         2 . The apparatus of  claim 1 , wherein the solid medium comprises a matrix of fibers made from one or more of polymers or glass, wherein the nucleophilic aromatic compound comprises an activated methylene group, and wherein optical changes of the solid medium are measured to estimate the aldehyde concentration. 
     
     
         3 . The apparatus of  claim 1 , wherein the nucleophilic aromatic compound comprises one of 2-thiobarbituric acid and 1-methyl-2-phenylindole. 
     
     
         4 . The apparatus of  claim 1 , wherein the nucleophilic aromatic compound comprises one of an aromatic amine and a Schiff reagent. 
     
     
         5 . The apparatus of  claim 1  in which the nucleophilic aromatic compound is an aromatic amine selected from the group of aniline, 4′-aminoacetophenone, ethyl p-aminobenzoate, 4,4′-sulfonyldianiline, and p-nitroaniline. 
     
     
         6 . The apparatus of  claim 1 , wherein the acid is solid phase and is a substituted sulfonic acid. 
     
     
         7 . The apparatus of  claim 1 , wherein the acid is one or more of para-toluene sulfonic acid or benzene sulfonic acid, and the nucleophilic aromatic compound has a nitrogen nucleophilic center. 
     
     
         8 . The apparatus of  claim 1 , wherein
 the nucleophilic compound comprises 2-thiobarbituric acid;   the acid comprises para-toluene sulfonic acid;   the aldehyde is malondialdehyde; and,   the optical properties comprise changes that occur on the solid medium through the reaction of the nucleophilic aromatic compound and the acid with a solution containing the aldehyde when the solid medium is exposed to the solution at room temperature in a time period of no more than about 60 minutes and without application of external heat, and wherein the aldehyde concentration can be estimated by measuring the degree of optical changes.   
     
     
         9 . The apparatus of  claim 1  and further comprising a fluorescent whitener.