Reversing microcrystalline tests--an analytical approach to recycling of microcrystals from drugs of abuse

A combined analysis of microcrystalline tests followed by LC-MS or GC-MS analysis is described. Microcrystalline tests are shown to be non-destructive as addition products formed were easily dissociated after the application of an appropriate solvent. Subsequent analysis of the sample was done to quantify the recovery of the drug. Examples were performed using the date rape drug γ-hydroxybutyrate (GHB) and the synthetic opioid methadone.     

Development of a GC-MS method for the simultaneous analysis of latent fingerprint components

Latent fingerprint residue is a complex mixture of organic and inorganic compounds. A full understanding of the composition of this mixture and how it changes after deposition is lacking. Three solvent systems were compared for the simultaneous extraction and derivatization with ethyl chloroformate of selected amino and fatty acids from a nonporous substrate (Mylar for subsequent analysis by gas chromatography-mass spectrometry. A solvent system comprised of sodium hydroxide, ethanol, and pyridine was found to be the most effective. This method was applied to the analysis of latent fingerprint residue deposited on Mylar and preliminary data are presented. Twelve amino acids (e.g., serine, glycine, and aspartic acid) and 10 fatty acids (e.g., tetradecanoic, hexadecanoic, and octadecanoic acids) were identified. The potential application of this method to further the understanding of latent fingerprint chemistry has been demonstrated.     

The effect of household corrosive substances on latent fingermark development in the context of deliberate corrosive substance attacks

Corrosive substance attacks (CSA) are a prevalent issue in the UK with 525 offenses involving a corrosive substance reported to the police in the year ending March 2022. Easy availability, low cost, and concealability in public are common reasons for choosing a corrosive substance as a weapon. The Metropolitan Police revealed that 68% of 1849 CSA cases resulted in no suspect identified or evidential difficulties. There is limited research into the effect of corrosive substances on latent fingermarks. This study aimed to determine the potential for fingermarks to be recovered from surfaces exposed to a household corrosive substance within the context of a deliberate CSA. Natural and sebaceous-loaded fingermarks were exposed to Domestos bleach, Harpic limescale remover (hydrochloric acid-based) and lemon juice. Harpic limescale remover had the most detrimental effect, with only 7.1% of fingermarks (n = 378) exposed being identifiable (defined as sufficient clear ridge detail for identification) after enhancement, followed by bleach with only 10.3% of fingermarks (n = 378) identifiable. Lemon juice had the least detrimental effect on fingermarks, with 40.5% fingermarks (n = 378) identifiable compared to 53.4% for the controls (not exposed to any substance; n = 378). Throughout the study, fewer natural fingermarks were identifiable after exposure to corrosive substances compared to sebaceous fingermarks which was as expected. Overall, this study demonstrated that there is potential to recover latent fingermarks, depending on their composition, following exposure to a household corrosive substance. This area warrants further research to establish best practice to maximize the potential to recover identifiable fingermarks.