The Sensitivity of Luminol to Common Household Produce Regarding Forensic Use


  • Jacey Freeman Texas A&M University


Abstract. 3-Aminophthalhydrazide, later coined luminol in 1934 by Ernest H. Huntress, is a well-known chemical used in the detection of blood at a crime scene. For almost a century, it has been utilized as a presumptive for blood in scenes of crimes and laboratories. While luminol is useful as it is extremely sensitive to the presence of hemoglobin and hematin, there are also known false positives that can skew the interpretation of a crime scene. As a result, an experiment was conducted in which common household fruits and vegetables were sprayed with a luminol mixture to test if they would result in a false positive identification for blood. In this study, the produce was separated into their individual parts: skin, leaves, and flesh, and juiced. Each of these parts were then sprayed independently with a luminol mixture and observed in darkness to check if chemiluminescence was present. The results indicated that out of the nine different types of produce tested (navel orange, lime, red grapefruit, beet, radish, kale, spinach, rainbow swiss chard, broccoli), only radishes reacted with the luminol mixture. However, since the duration of the luminescence and the intensity of the luminescence differed heavily from the duration and intensity of luminescence from a luminol and blood reaction, it is highly unlikely that radishes will result in a false positive identification for blood at the scene of a crime. Thus, none of the nine different types of produce tested were deemed likely to result in a false positive identification at the scene of a crime. This study is a foundation for the extent of false positives on household fruits and vegetables sprayed with luminol; however, several questions need a wider array of the Brassicaceae family to check if more than just radishes react to luminol.