Precision Laboratories, Inc.

Eva Hrboticka

James A Bertsch

A colorimetric dry-reagent test strip for direct detection of the presence of hydrogen peroxide in strongly acidic solutions without the necessity of a pH neutralization step comprises a chromogen responsive to hydrogen peroxide, an enzyme peroxidase catalyst and at least one complexing agent chosen to protect an active site of the catalyst for an amount of time sufficient to allow for the catalytic oxidation of the chromogen. The test strip has particular value in the determination of peroxide-based explosive compounds, such as hexamethylene triperoxide diamine (HMTD) or triacetone triperoxide (TATP), which require a treatment with a strong organic acid to release the hydrogen peroxide to be detected, and typically requires neutralization of the acid before a conventional test strip can be employed. The invention dispenses with the need for such a neutralization step.

Stabilized test strip for the detection of hydrogen peroxide

An apparatus and a method for the colorimetric detection testing of peroxide-based compositions is disclosed. The apparatus comprises a first carrier having an acidic compound in dry form for hydrolysis of peroxide-based compounds and a second carrier having a colorimetric detection reagent composition in dry form. The carriers are positioned with respect to a support member to facilitate transfer of a solution containing a peroxide-based compound hydrolyzed by the acidic compound when activated into contact with the reagent composition of the second carrier for observation of any resulting color indication. The method comprises steps of applying the acidic compound and colorimetric detection reagent composition is liquid forms to the respective carriers and allowing the applied formulations to dry. The carriers are then positioned with respect to a tester support member to facilitate transfer of a solution containing a peroxide-based compound hydrolyzed by the acidic compound when activated into contact with the reagent composition of the second carrier for observation of any resulting color indication. When a test is to be performed the formulations are activated by water, and a composition to be tested is placed in contact with the carriers and any color change of the colorimetric detection reagent is observed.

Tester for peroxide-based compounds

A test strip construction includes a test strip having a testing region bearing a chromogenic reagent to detect the presence of a substance in a fluid test sample. A supporting member is attached to one end of the test strip in a manner such that the testing region is remote form the attachment point and is free from any contact with supporting member. When dipped into the test sample the test strip can flutter away from the supporting member to allow for full contact between that the testing region and the test sample. When removed from the test sample the supporting member provides a consistent background for observation of color changes of the reagent.

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Brno, Czechia

Eva Hrboticka