A comprehensive experimental study of industrial, domestic and environmental interferences with the forensic luminol test for blood

Abstract

This paper presents the fi rst comprehensive and quantitative study of substances that interfere with the forensic luminol test for blood. Two hundred and fifty substances have been selected on the basis of modern lifestyles and of contiguity with crime scenes. The intensity of the chemiluminescence produced by each substance has been measured relative to that of haemoglobin and the peak wavelength shift has also been determined. The following is a short list of nine substances that produce chemiluminescence intensities comparable with that of haemoglobin: turnips, parsnips, horseradishes, commercial bleach (NaClO), copper metal, some furniture polishes, some enamel paints, and some interior fabrics in motor vehicles. Care needs to be taken when the luminol test for blood is used in the presence of these substances.

History of the Early Biodetection Development

“…After a few years of environmental testing in a variety of locations, the US Army rejected the XM19 for the task of biological detection [76]. Currently, luminol has found acceptance in forensic applications for detection of blood splatter in crime scenes where the occasional false positives can be mitigated by other technologies [77]. By present day standards, the reagents are relatively inexpensive and in forensic applications, its high sensitivity compensates for its other deficiencies.…”

Chemiluminescence of 5-(azo-para-phenylene-N-aza-15-crown-5)-phthalhydrazide

“…38 We investigated the possibility of using similarly 1 for determining either Cu 2+ or Fe 3+ concentrations. It is known that luminol emits light in the presence of blood 11,39 or ferricyanide. 40 On applying the same equation (3) …”

“…[1][2][3][4][5][6][7] In alkaline medium, in the presence of oxygen, [2][3][4]8 hydrogen peroxide, and transitional metal ions such as Fe 3+ , its CL intensity (I CL ) is enhanced. [9][10][11] Based on its CL, luminol is being used for the bioanalytical determination of enzymatically-formed oxidizing species such as the superoxide anion and the hydroxyl radical. [12][13] It is also possible to determine cholesterol via the H 2 O 2 concentration formed by enzymatic oxidation.…”

The efficacy of luminol in detecting bloodstains that have been washed with sodium percarbonate and exposed to environmental conditions

“…While luminol is highly sensitive, previous research acknowledges that there are a number of environmental domestic and industrial substances that can induce a false--positive chemiluminescent reaction in the pres--ence of luminol. Such substances include soils, bleaches and vegetable compounds [11][12][13][14][15][16][17] . Only a few studies have explored substances that can suppress the luminol reaction and generate a false--negative result.…”