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dc.contributor.authorZhen, Linen_US
dc.date.accessioned2017-03-13T14:04:34Z
dc.date.available2017-03-13T14:04:34Z
dc.date.issued2017
dc.identifier.urihttps://hdl.handle.net/2144/20791
dc.description.abstractBenzodiazepines (Benzos) and ketamine (K) are compounds that have been encountered in Drug-Facilitated Sexual Assault (DFSA) cases. Due to the intimate nature of these crimes, evidence collection is often postponed due to delays and/or reluctance in reporting these crimes. Further delays in analysis may be encountered in laboratories with large caseloads and/or backlogs. Drug identification in biological samples is important to determine whether victims knowingly or unknowingly took an impairing substance, however, the results could be negative due to chemical degradation over a long storage period. The purpose of this project was to study if degradation could be prevented with a new preservation method at the time of collection. Urine samples were prepared by the addition of K and metabolites and selected benzos and metabolites that were subjected to different sample pre-treatment techniques, and were analyzed after storage at room temperature (25°C), refrigerator (4°C) and freezer (-20°). The samples were either pre-treated with preservative (0.5% toluene) or filtration sterilization (sterile filter kit) within two hours after sample collection, and a control group with no pre-treatment was incorporated into the study for comparison. The changes in concentrations over 50 days (Benzos group) and 210 days (K group) were evaluated between different pre-treated methods and different temperature conditions. Sample that were treated with 0.5% toluene showed the most degradation: 44% of oxazepam and 96% of diazepam degraded over 10 days, and 80% of dehydronorketamine degraded after storage of 150 days regardless the temperature conditions. Clonazepam and flunitrazepam concentrations were reduced by 80% of the original concentration when stored at room temperature for 10 days. The major benzodiazepines evaluated in this study were stable when stored in the freezer. In K group, ketamine and norketamine that were stored at room temperature and refrigerated over 210 days were stable, however, degradation was observed after 150 days when the samples were stored in the freezer. There was no statistically different change observed among the samples pre-treated with or without filtration sterilization. Each sample pH was measured and it was determined that those stored at room temperature had an average pH of 8.5, while samples stored in the refrigerator and freezer had an average pH of 6.7 and 6.5, respectively. This finding revealed that pH could be the major factor affecting compound degradation rather than the bacterial contamination with high pH contributing to degradation, and low pH potentially preventing sample lost.en_US
dc.language.isoen_US
dc.rightsAttribution 4.0 Internationalen_US
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/
dc.subjectToxicologyen_US
dc.subjectBenzodiazepinesen_US
dc.subjectCompound degradationen_US
dc.subjectFiltration sterilizationen_US
dc.subjectKetamineen_US
dc.subjectLCMSen_US
dc.subjectPreservationen_US
dc.titleEffects of filtration sterilization on the stability of ketamine, selected benzodiazepines and metabolites in female urineen_US
dc.typeThesis/Dissertationen_US
dc.date.updated2017-03-09T02:07:08Z
etd.degree.nameMaster of Scienceen_US
etd.degree.levelmastersen_US
etd.degree.disciplineBiomedical Forensic Sciencesen_US
etd.degree.grantorBoston Universityen_US


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Attribution 4.0 International
Except where otherwise noted, this item's license is described as Attribution 4.0 International