A method to distinguish the presence or absence of relationship between two cannabis seizures is required for forensic investigations. In this study, we focused on the chemical profile of the cannabis. We developed a method to discriminate whether the two cannabis seizures derived from a single organism or different ones (“individual” discrimination) and whether the two seizures had been seized in the same criminal investigation or not (“case” discrimination). Discrimination ability of these methods were evaluated statistically. For 21 cannabis seizures, gas chromatography/time-of-flight mass spectrometry analysis were conducted to obtain the comprehensive chemical profile. The contents of not only cannabinoids and terpenes but almost all detected compounds were used as variables to perform multivariate analysis. Using hierarchical cluster analysis, most of the cannabis seized in an identical case formed one group in the dendrogram. The cannabis cultivated outdoors and indoors belonged to different groups. 441 hierarchical cluster analysis were performed with a combination of all pair of cannabis seizures to calculate the Euclidean distance between specimens based on definite rules. Two thresholds were arbitrarily set for the distance to perform two types of cannabis discrimination. The equal error rate and the area under the receiver operating characteristic curve of “individual” discrimination were 0.024 and 0.997 and those of “case” discrimination were 0.220 and 0.867. By selecting an appropriate threshold, “individual” discrimination was achieved with sensitivity of 0.810, specificity of 0.998 and accuracy rate of 0.989. Similarly, “case” discrimination was with sensitivity of 0.627, specificity of 0.971 and accuracy rate of 0.925. These results suggested that the present method by using hierarchical cluster analysis of chemical profile would be effective for cannabis discrimination in forensic investigations.
Strange shaped fired bullets were found in a suicide case. While one fired casing was found in the cylinder of a Paltik revolver, one column-shaped fired bullet was found in the head of a dead man and one longer gourd-shaped fired bullet was found in the barrel of the Paltik revolver. As a result of the gunfire test with revolvers and round-nose-cartridges, firing the revolver with a lodged (first) bullet and propellant powder in the barrel, the first bullet became column-shaped and the next bullet became a longer gourd-shaped. We had carried out X-raying the bullet's collision in the barrel, and we found out that the bullets had deformed in the barrel within a very short time. In the gunfire test, the amount of propellant powder in the barrel was larger than that in the next cartridge, so by regulating the amount of propellant powder, the velocity of the next bullet was reduced.
Simultaneous analytical methods for 18 compounds of fentanyl and its analogues by thin-layer chromatography (TLC), gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) were developed. In TLC, fentanyl analogues were well separated by using toluene-acetone-28% aq. ammonia (20:10:0.3, by vol.) as a developing solvent. In GC/MS, fentanyl analogues, except for fentanyl and acetyl-α-methylfentanyl, could be separated on the extracted ion chromatograms (EIC) of the characteristic fragment ions of each compound. In LC/MS, fentanyl analogues could be separated on the EICs of the protonated molecule of each compound. All of the fentanyl analogues tested were identified correctly by using the combination of TLC, GC/MS and LC/MS.
A simple and low-cost chemical synthetic method for p-hydroxymethamphetamine glucuronide using Lewis acid catalyst has been developed. The formation of by-product was minimized by using methyl 1,2,3,4-tetra-O-acetyl-β-D-glucuronate and boron trifluoride as glucuronyl donor and Lewis acid catalyst, respectively. In this combination, the yield of desired product was improved with the usage of three equivalent of glucuronate donor. The yield of p-hydroxymethamphetamine glucuronide in an optimized condition was about 50%, and was comparable to that of the previous methods.