Abstract:
of dwellings by methamphetamine smoke and or manufacture is stated to be a major concern to public health in New Zealand. Despite these concerns, few studies have investigated the interactions of methamphetamine with other contaminants that may be present within an indoor environment. Third-hand tobacco smoke has also been an increasingly discussed topic in recent years, and previous studies have reported the formation of carcinogenic nitrosamines from the reaction of nicotine deposits with atmospheric oxidants, such as nitrous acid (HONO) and ozone. Similar reactivity may occur with methamphetamine deposits, therefore this thesis aimed to investigate the fate of methamphetamine on indoor surfaces, with specific focus on the oxidation of methamphetamine by HONO. Since both nicotine and methamphetamine are amines that can undergo nitrosation, the nicotine nitrosamine reaction pathway was investigated as a surrogate for the formation of N-nitrosomethamphetamine (NMA). The methamphetamine and nicotine nitrosamines were successfully synthesized in solution via a reaction with sodium nitrite under acidic conditions, and these solutions were used in conjunction with a commercial N-nitrosonornicotine (NNN) standard, to develop GC-MS and LC-MS methods for nitrosamine analysis. Both nicotine and methamphetamine were exposed to gaseous HONO under laboratory conditions in an attempt to induce the formation of their respective nitrosamines. Although we could not confirm the production of nitrosamines under the laboratory conditions used, we did optimize the chromatographic methods used to detect nitrosamines. Using the NNN standard, the limit of detection determined for GC-MS in selected ion monitoring (SIM) mode was approximately 4 μg mL-1 while the LC-MS method had an estimated limit of detection of 0.5 ng mL-1 in multiple reaction monitoring (MRM) mode (m/z 178 to m/z 148). While the GC-MS method developed was suitable for separating each nitrosamine from its respective starting material, it was not suitable for the detection at low concentrations, and therefore the LC-MS method was used predominantly in this study. A selective MRM method for NMA analysis was also reported in this thesis, using the MRM transition of m/z 179 to m/z 91. The effect of tobacco third-hand smoke on the persistence of methamphetamine deposits was also investigated, by monitoring the partitioning of methamphetamine between two glass plates in a sandwich format, with one plate contaminated with tobacco third-hand smoke and the other being clean. It was discovered that tobacco third-hand smoke increases the retention of methamphetamine, relative to a clean glass plate, which suggests that dwellings containing tobacco third-hand smoke may have an increased risk of residual methamphetamine contamination.