The issue with maintaining stability of compounds during storage and transportation has been universal across many fields such as clinical, pharmaceutical, food industry and especially in forensic laboratories where case backlogs hinder immediate analysis of samples upon collection. This study compares various storage conditions and analyzes changes in compound stability over 28 days. The various storage conditions compared in this study are temperature (+4 °C and -20 °C); water sample and urine sample and solid state (loading onto Solid Phase Extraction cartridges) and storing in its liquid state (present in the urine or water sample). 51 compounds were analyzed in this study belonging to pharmaceutical and hormone classes. Two Dimensional Liquid Chromatography was used for separation allowing the analysis of varied compounds in terms of chemistry. Mass Spectrometry was used for detection of these compounds. This study conclusively helped determine that there is no significant difference in stability of 42 out of 51 of these compounds on comparing them in solid versus liquid state over a period of 28 days. This helps determine that Solid Phase Extraction (SPE) cartridges can be used as an alternative for storage and transportation of these compounds. 46 compounds showed no significant difference in +4 and -20 °C temperature storage conditions as well. Despite not including a wash step during sample preparation between loading and elution, 11 out of 51 compounds did not show suppression or enhancement due to matrix effect. This study not only highlights the importance of sample preparation prior to analysis but also shows how SPE technique could help maintain stability of compounds during storage. In future studies, stability changes using SPE for long term storage could provide beneficial results to conclude if SPE techniques can provide an advantage over liquid state for a period longer than a month.
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/38621 |
| Date | 09 October 2019 |
| Creators | Bhandari, Devyani |
| Contributors | Botch-Jones, Sabra |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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