NCJ Number
218702
Date Published
October 2004
Length
3 pages
Annotation
This study examined whether compounds commonly used to decontaminate surfaces that might have been exposed to toxic chemical and biological materials might interact with chemicals used in tests for blood on the same surfaces to produce false positives for the presence of blood.
Abstract
The study found that Oxone in aqueous concentrations, which is typically used to decontaminate surfaces, would react with the tetramethylbenzidine reagent commonly used to detect the presence of blood on surfaces. The initial colored compound and the color of the ultimate reaction solution, however, were unlike those found with authentic blood samples. The phenolphthalin reagent used in testing for the presence of blood reacted slowly with the decontaminating compound, but not in the manner characteristic of an actual blood stain. Sodium percarbonate, a decontamination compound, gave a positive-color test for blood when blood was present without the addition of the usual developer peroxide. The tests were performed in a two-step process. The blood test reagent was added first, followed by a notation of the color of the solution. The oxidizing reagent (decontamination compound) was then added. The influence of blood in contact with the oxidizing agents was also investigated. 8 references