In a method of formaldehyde determination by measuring the fluorescence of a fluorescent substance formed by allowing a formaldehyde-containing solution to react with a reagent capable of forming said fluorescent substance from formaldehyde, the improvement comprising measuring the fluorescence in the presence of a serum albumin.
In a method of formaldehyde determination by measuring the fluorescence of a fluorescent substance formed by the reaction of a formaldehyde-containing solution with a fluorescent reagent capable of forming said fluorescent substance by the reaction with formaldehyde, the improvement which comprises using as said fluorescence reagent a compound represented by the general formula CH.sub.3 C(NH.sub.2).dbd.CHCO.sub.2 R, wherein R represents an alkyl group having 1 to 4 carbon atoms.
A sensitive colorimetric detector for formaldehyde vapor is prepared by applying a ketone solution of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (AHMT) to a support coated with a stable metal bicarbonate to form a compound from which the ketone can be displaced by formaldehyde to yield a chromogen developing a purple color proportional to the amount of formaldehyde. The detector is sensitive to gaseous formaldehyde in air at concentrations below 2 ppm.
A composition, method, and device for quantitatively determining the concentration of an aldehyde in a sample are disclosed. The device includes a test pad having a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with the aldehyde to produce a detectable and measurable response for aldehyde concentration over a range of 0% to over 4%, by weight of the sample. An indicator reagent composition contains: (a) a protein, (b) an amine, (c) a color indicator, (d) preferably a neutral, nonionic polymer, such as a water-soluble cellulose polymer, and (e) a carrier. An indicator reagent composition is incorporated into a carrier matrix, like filter paper, to provide a test pad useful in a dry phase aldehyde assay of a sample, especially for samples containing a high concentration of glutaraldehyde or formaldehyde.
A test strip, methods for making and using the test strip, and a kit are described, which allow for the simple and efficient determination of the acetaldehyde content in a polyester polymer. The strip and methods have application, for example, in the manufacture of polyethylene terephthalate preforms and containers, where existing methods for testing for acetaldehyde are cumbersome and time consuming.
An apparatus for measuring the concentration of formaldehyde in an exhaust stream from turbines, internal combustion engines and the like, which apparatus includes a portable housing having a sample gas inlet through which a sample gas for analysis is introduced into the portable housing and an analysis system disposed in the portable housing suitable for analyzing the sample gas for the presence of formaldehyde in the sample gas.