Effects of Surface Temperature on Chemiluminescence

Luminol testing is used by forensic scientists as a presumptive blood test at crime scenes. Because Luminol can detect the presence of blood that has been diluted 10 million times, it is highly effective. The purpose of this investigation was to determine how surface temperature affects the reaction rate, as well as the ability of Luminol to detect the presence of hemoglobin. Test samples were treated with interstitial fluid, a hemoglobin source, and tested at surface temperatures of 50o C, 20o C, 10o C, and 0o C; untreated control samples were also tested at all temperatures. After analyzing the results of 15 trials, it was concluded that an inverse relationship exists between surface temperature and the reaction rate of the Luminol test. Treated samples with surface temperatures of 50o C, 20o C, 10o C, and 0o C all tested positive, while all control samples tested negative. Further testing was conducted to determine the point at which heat could destroy the hemoglobin molecules so they could not be detected by the Luminol test. It was determined that temperatures of 107o C and higher produced negative results. In conclusion, surface temperature does affect the reaction rate of the Luminol chemiluminescence test