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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analysis of benzofury compounds in blood using different sample preparation methods and ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS)

Dye, Katherine 03 November 2015 (has links)
"Benzo Fury" compounds and derivatives are enactogens similar to 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) in various aspects. These compounds are similar in structure to MDMA and MDA, as well as, elicit similar effects such as elevated mood, euphoria and hallucinations. This similarity in effect increases the potential for abuse as MDMA has become less prevalent in some regions as the use of these new psychoactive substances (NPSs) has increased. The benzofury compounds are used as legal alternatives to MDMA because of their marketing as “not for human consumption”. With the relative ease in obtaining NPSs via the Internet, it is possible that these drugs may soon be prevalent in the United States. The project’s goal was to separate, detect, and quantitate the benzofury compounds and derivatives as well as MDA and MDMA in one method of analysis using ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS). The project also examined which method of sample preparation is more effective for these compounds. Six benzofury compounds were researched: 5-(2-aminopropyl)benzofuran) (5-APB), 6-(2-aminopropyl)benzofuran) (6-APB), 5-(2-aminopropyl)-2,3-dihydrobenzofuran (5-APDB), 6-(2-aminopropyl)-2,3-dihydrobenzofuran (6-APDB), 1-(benzofuran-5-yl)-N-methylpropan-2-amine (5-MAPB) and 1-(benzofuran-6-yl)-N-methylpropan-2-amine (6-MAPB) as well as MDMA and MDA. These drugs were analyzed in blood. A liquid-liquid extraction (LLE) method and solid phase extraction (SPE) method were examined to determine which would be better for the separation, detection and quantitation of the benzofury compounds. For the development of the overall method, accuracy, precision, calibration curve, carryover, limit of detection, limit of quantitation, analyte stability, and recovery were examined. The accuracy of the methods examined was greater than +/- 20%. For most analytes, the precision within-run and between-run did not exceed 20%, regardless of the sample preparation method used. A weighting of 1/x was applied to the calibration curve regardless of sample preparation method utilized. The carryover was less than 2% with the SPE method having less carryover (0.02% to 0.50%) than the LLE method (0.05% to 1.56%). The limit of quantitation was determined to be greater than 10 ng/mL. While this was unexpected, the limit of detection calculations determined that this was correct. Using the LLE method in combination with the UFLC-MS/MS method developed, the limit of detection was determined to be at least 9.98 ng/mL. Compared to the LLE method, the SPE limit of detection was lower and calculated to be 3.75 ng/mL. The percent recovery was examined for each of the analytes. It was determined that the SPE was capable of recovering 80% or more of the benzofury compounds and derivatives regardless of the concentration level. The LLE was not as successful in the recovering the benzofury compounds, the best recovery occurred at the 200 ng/mL level with only 65% or less recovered. Analyte stability exhibited a general decrease with variation prior to day 7 and then remains relatively stable until day 14. It was anticipated that the quantitation of the drugs might be complicated due to the similarity in structure between the isomers as well as the similarity of structure between all of the compounds. While this may still be the case, the difficult separation resulted in a re-evaluation and alterations to the UFLC-MS/MS method to correct for these issues. With the change in the UFLC-MS/MS method, further method optimization is required to achieve the appropriate accuracy and limit of quantitation. It was found that the best combination of sample preparation and detection of the benzofury compounds and derivatives is to use SPE followed by an UFLC-MS/MS method.

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