Thesis (Ph.D.)--Ohio University, March, 2005. / Includes bibliographical references (p. 163-176)

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 137-143).

Thesis (Ph.D.)--Ohio University, March, 2005. / Title from PDF t.p. Includes bibliographical references (p. 163-176)

A cocaína (COC) é um alcaloide presente nas folhas de espécies do gênero Erytroxylum novagranatense e Erytroxylum coca. Possui grande efeito estimulante sobre o Sistema Nervoso Central (SNC) e por isso é utilizada como droga de abuso. Dentre os principais metabólitos estão a benzoilecgonina (BZE), éster metil anidroecgonina (EMA) e anidroegonina (AEC), sendo que os dois últimos são provenientes de pirólise (consumo do crack através do fumo ou inalação). Ainda, o cocaetileno (CE) é biotransformado após a ingestão conjunta de COC e etanol. O consumo de substâncias psicoativas (SPA), dentre elas a COC e seus derivados, traz diversos prejuízos à saúde dos usuários, principalmente quando se considera a interação causada pelos compostos adulterantes, adicionados à droga para aumentar lucros e mimetizar os efeitos desejados. Ainda, o uso associado ao trânsito, é uma preocupação crescente em toda a sociedade, pois eleva em números consideráveis a chance da ocorrência de acidentes de trânsito. A detecção de SPA pode ser feita em uma variedade de matrizes biológicas, sendo que cada uma possui suas particularidades, incluindo diferentes janelas de detecção. Análises realizadas em fluido oral (FO), urina e sangue são recomendadas por guias nacionais e internacionais para a detecção de SPA e se complementam pois identificam as drogas intactas e seus produtos de biotransformação em diferentes concentrações e períodos de tempo. A correlação de concentração entre essas matrizes não é bem estabelecida, sendo que diversos estudos reportados na literatura trazem resultados controversos. A validação de métodos analíticos ou bioanalíticos é etapa crucial para a realização de análises seguras e que não deixem margem de dúvida na interpretação dos resultados, caracterizando-se como de extrema importância em todas as áreas da toxicologia. Nesse sentido, foram desenvolvidos e validados métodos para a detecção simultânea de COC, BZE, CE, EMA e AEC em FO, urina e plasma, utilizando cromatografia líquida acoplada a detector de massas (CL-EM), além de três métodos para análise de COC e compostos adulterantes em amostras de apreensão, sendo dois deles qualitativos, utilizando cromatografia gasosa acoplada à detector de massas (CG-EM) e cromatografia gasosa portátil acoplada à detector de massas íon trap (CG-EM-IT) e um quantitativo utilizando cromatografia líquida acoplada à detector de massas sequencial (CL-EM/EM). Ainda, um estudo de correlação foi aplicado a fim de avaliar a concentração dos metabólitos entre as matrizes biológicas coletadas simultaneamente. As etapas de preparação das amostras nos métodos bioanalíticos compreenderam precipitação de proteínas com acetonitrila, seguida de filtração para urina e plasma e diluição em tampão seguida de filtração para FO. As curvas de calibração foram lineares entre 4,25 e 544,00 ng/mL para FO, e entre 5,00 e 320,00 ng/mL para urina e plasma. Os limites inferiores de quantificação foram iguais à menor concentração das curvas de calibração. Os limites de precisão e exatidão intra e inter-dias mantiveram-se dentro dos limites de ±20% para o limite de quantificação e ±15% para os demais controles preconizados pelas guias regulatórias. Os métodos desenvolvidos foram aplicados satisfatoriamente em 110, 116 e 113 amostras de FO, urina e plasma, respectivamente, coletadas de usuários de múltiplas drogas. Os resultados mostraram alta prevalência destes analitos nesta população, especialmente COC e BZE, presentes em 75,8 e 75,0% dos casos, respectivamente. Em relação ao método analítico quantitativo, este se mostrou preciso, exato e linear na faixa de 50 – 2000 ng/mL, todos os demais parâmetros se mantiveram dentro dos limites preconizados. Levamisol (LEV), fenacetina (FEN), cafeína (CAF), hidroxizina (HDZ) e benzocaína (BZC) foram os adulterantes mais encontrados dentre as 166 amostras de apreensão analisadas. O método qualitativo por CG-EM foi efetivo para ser utilizado como método de screening para todos os compostos, equanto que o método por CG-EM-IT apresentou restrições de aplicação para alguns compostos. Os capítulos apresentados nesse trabalho abrangem de uma maneira geral a análise de COC e seus derivados em amostras biológicas e material apreendido, assim como trazem uma abordagem em relação aos problemas relacionados ao uso e tráfico de drogas em diferentes cenários. Os métodos desenvolvidos neste trabalho podem ser aplicados, além da área de trânsito e controle de materias apreendidos, em diferentes áreas de conhecimento como laboratórios de toxicologia clínica, forense e no próprio meio científico. / Cocaine (COC) is an alkaloid which is found in the leaves of Erytroxylum novagranaense and Erytroxylum coca. COC has a strong stimulant effect on central nervous system (CNS) and this is the reason for its classification as drug of abuse. Benzoylecgonine (BZE), anhydroecgonine methyl ester (AEME) and anhydroecgonine (AEC) are among its main metabolites. AEME and AEC are pyrolysis products that forms as a result of crack-cocaine consumption through smoking or inhalation. Additionally, cocaethylene (CE) is biotransformed after the ingestion of cocaine and alcohol. The use of psychoactive substances (SP), including cocaine and its derivatives, can cause several issues to the health of its users specially when the interactions caused by cutting agents added to the drugs to increase the profits and mimic the effects are taken into consideration. Furthermore, the use of SP combined with driving is an emerging problem since it increases the chances of traffic accidents. The detection of SP can be done in a variety of biological matrices that each has their own particularities such as different windows of detection. The guidelines recommend analysis in oral fluid (OF), urine, and blood for the detection of SP. These three matrices complement each other because it is possible to identify drugs and the products of biotransformation in varying concentrations and periods of time. The coefficient of correlation between those three matrices is not very well established since many studies report conflicting results. The validation of analytical or bioanalytical methods is an important step to ensure accurate results and it is considered essential in every area of toxicology. Therefore, methods for the detection of COC, BZE, AEME, AEC and CE in OF, urine and plasma were developed and validated using liquid chromatography coupled to mass spectrometry (LC-MS). Likewise, three methods (two qualitative and one quantitative) for the detection of COC and known cutting agents in seized drugs were developed using gas chromatography coupled to mass spectrometry (GC-MS), portable gas chromatography toroidal ion trap mass spectrometry (GC-TMS), and liquid chromatography tandem mass spectrometry (LC-MS/MS). A correlation study was done to evaluate the drug concentrations in the three matrices collected simultaneously. OF was diluted in buffer while urine and plasma were precipitated using acetonitrile. Calibration curve ranges were prepared at 4.25 – 544 ng/mL for oral fluid, and 5 – 320 ng/mL for urine and plasma. The lowest concentration of the calibration curves were designated as the lower limit of quantification. The calculated precision and accuracy values were within the limits stipulated by the guidelines (±20% for the limit of quantification and ±15% for the rest of the quality controls). The methods were fully validated and proved to be suitable for analysis of 110, 116, and 113 samples of OF, urine, and plasma, respectively, that were collected from drug users. The results showed high prevalence of SP drugs in this population. Particularly of note, COC and BZE were found in 75.8 and 75.0% of the cases, respectively. The analytical quantitative method proved to be precise, accurate, and linear in the range of 50 – 2000 ng/mL; all the other parameters were within the limits stipulated. Levamisole (LEV), phenacetin (PHN), caffeine (CAF), hydroxyzine (HYDZ), and benzocaine (BZC) were the adulterants most prevalent in the 166 samples analyzed. The analytical qualitative method by GC-MS was shown to be effective as screening method for all the compounds, while the analytical method by GC-TMS was limited due to its incompatibility with certain target compounds. The chapters presented in this work comprise the analysis of cocaine and its derivatives in biological matrices and seized material, as well as an approach relating to the analysis of samples from impaired driving and similar scenarios. The methods developed in this work can be further applied to other areas of science and research including clinical toxicology, general laboratories and forensic laboratories.

A cocaína (COC) é um alcaloide presente nas folhas de espécies do gênero Erytroxylum novagranatense e Erytroxylum coca. Possui grande efeito estimulante sobre o Sistema Nervoso Central (SNC) e por isso é utilizada como droga de abuso. Dentre os principais metabólitos estão a benzoilecgonina (BZE), éster metil anidroecgonina (EMA) e anidroegonina (AEC), sendo que os dois últimos são provenientes de pirólise (consumo do crack através do fumo ou inalação). Ainda, o cocaetileno (CE) é biotransformado após a ingestão conjunta de COC e etanol. O consumo de substâncias psicoativas (SPA), dentre elas a COC e seus derivados, traz diversos prejuízos à saúde dos usuários, principalmente quando se considera a interação causada pelos compostos adulterantes, adicionados à droga para aumentar lucros e mimetizar os efeitos desejados. Ainda, o uso associado ao trânsito, é uma preocupação crescente em toda a sociedade, pois eleva em números consideráveis a chance da ocorrência de acidentes de trânsito. A detecção de SPA pode ser feita em uma variedade de matrizes biológicas, sendo que cada uma possui suas particularidades, incluindo diferentes janelas de detecção. Análises realizadas em fluido oral (FO), urina e sangue são recomendadas por guias nacionais e internacionais para a detecção de SPA e se complementam pois identificam as drogas intactas e seus produtos de biotransformação em diferentes concentrações e períodos de tempo. A correlação de concentração entre essas matrizes não é bem estabelecida, sendo que diversos estudos reportados na literatura trazem resultados controversos. A validação de métodos analíticos ou bioanalíticos é etapa crucial para a realização de análises seguras e que não deixem margem de dúvida na interpretação dos resultados, caracterizando-se como de extrema importância em todas as áreas da toxicologia. Nesse sentido, foram desenvolvidos e validados métodos para a detecção simultânea de COC, BZE, CE, EMA e AEC em FO, urina e plasma, utilizando cromatografia líquida acoplada a detector de massas (CL-EM), além de três métodos para análise de COC e compostos adulterantes em amostras de apreensão, sendo dois deles qualitativos, utilizando cromatografia gasosa acoplada à detector de massas (CG-EM) e cromatografia gasosa portátil acoplada à detector de massas íon trap (CG-EM-IT) e um quantitativo utilizando cromatografia líquida acoplada à detector de massas sequencial (CL-EM/EM). Ainda, um estudo de correlação foi aplicado a fim de avaliar a concentração dos metabólitos entre as matrizes biológicas coletadas simultaneamente. As etapas de preparação das amostras nos métodos bioanalíticos compreenderam precipitação de proteínas com acetonitrila, seguida de filtração para urina e plasma e diluição em tampão seguida de filtração para FO. As curvas de calibração foram lineares entre 4,25 e 544,00 ng/mL para FO, e entre 5,00 e 320,00 ng/mL para urina e plasma. Os limites inferiores de quantificação foram iguais à menor concentração das curvas de calibração. Os limites de precisão e exatidão intra e inter-dias mantiveram-se dentro dos limites de ±20% para o limite de quantificação e ±15% para os demais controles preconizados pelas guias regulatórias. Os métodos desenvolvidos foram aplicados satisfatoriamente em 110, 116 e 113 amostras de FO, urina e plasma, respectivamente, coletadas de usuários de múltiplas drogas. Os resultados mostraram alta prevalência destes analitos nesta população, especialmente COC e BZE, presentes em 75,8 e 75,0% dos casos, respectivamente. Em relação ao método analítico quantitativo, este se mostrou preciso, exato e linear na faixa de 50 – 2000 ng/mL, todos os demais parâmetros se mantiveram dentro dos limites preconizados. Levamisol (LEV), fenacetina (FEN), cafeína (CAF), hidroxizina (HDZ) e benzocaína (BZC) foram os adulterantes mais encontrados dentre as 166 amostras de apreensão analisadas. O método qualitativo por CG-EM foi efetivo para ser utilizado como método de screening para todos os compostos, equanto que o método por CG-EM-IT apresentou restrições de aplicação para alguns compostos. Os capítulos apresentados nesse trabalho abrangem de uma maneira geral a análise de COC e seus derivados em amostras biológicas e material apreendido, assim como trazem uma abordagem em relação aos problemas relacionados ao uso e tráfico de drogas em diferentes cenários. Os métodos desenvolvidos neste trabalho podem ser aplicados, além da área de trânsito e controle de materias apreendidos, em diferentes áreas de conhecimento como laboratórios de toxicologia clínica, forense e no próprio meio científico. / Cocaine (COC) is an alkaloid which is found in the leaves of Erytroxylum novagranaense and Erytroxylum coca. COC has a strong stimulant effect on central nervous system (CNS) and this is the reason for its classification as drug of abuse. Benzoylecgonine (BZE), anhydroecgonine methyl ester (AEME) and anhydroecgonine (AEC) are among its main metabolites. AEME and AEC are pyrolysis products that forms as a result of crack-cocaine consumption through smoking or inhalation. Additionally, cocaethylene (CE) is biotransformed after the ingestion of cocaine and alcohol. The use of psychoactive substances (SP), including cocaine and its derivatives, can cause several issues to the health of its users specially when the interactions caused by cutting agents added to the drugs to increase the profits and mimic the effects are taken into consideration. Furthermore, the use of SP combined with driving is an emerging problem since it increases the chances of traffic accidents. The detection of SP can be done in a variety of biological matrices that each has their own particularities such as different windows of detection. The guidelines recommend analysis in oral fluid (OF), urine, and blood for the detection of SP. These three matrices complement each other because it is possible to identify drugs and the products of biotransformation in varying concentrations and periods of time. The coefficient of correlation between those three matrices is not very well established since many studies report conflicting results. The validation of analytical or bioanalytical methods is an important step to ensure accurate results and it is considered essential in every area of toxicology. Therefore, methods for the detection of COC, BZE, AEME, AEC and CE in OF, urine and plasma were developed and validated using liquid chromatography coupled to mass spectrometry (LC-MS). Likewise, three methods (two qualitative and one quantitative) for the detection of COC and known cutting agents in seized drugs were developed using gas chromatography coupled to mass spectrometry (GC-MS), portable gas chromatography toroidal ion trap mass spectrometry (GC-TMS), and liquid chromatography tandem mass spectrometry (LC-MS/MS). A correlation study was done to evaluate the drug concentrations in the three matrices collected simultaneously. OF was diluted in buffer while urine and plasma were precipitated using acetonitrile. Calibration curve ranges were prepared at 4.25 – 544 ng/mL for oral fluid, and 5 – 320 ng/mL for urine and plasma. The lowest concentration of the calibration curves were designated as the lower limit of quantification. The calculated precision and accuracy values were within the limits stipulated by the guidelines (±20% for the limit of quantification and ±15% for the rest of the quality controls). The methods were fully validated and proved to be suitable for analysis of 110, 116, and 113 samples of OF, urine, and plasma, respectively, that were collected from drug users. The results showed high prevalence of SP drugs in this population. Particularly of note, COC and BZE were found in 75.8 and 75.0% of the cases, respectively. The analytical quantitative method proved to be precise, accurate, and linear in the range of 50 – 2000 ng/mL; all the other parameters were within the limits stipulated. Levamisole (LEV), phenacetin (PHN), caffeine (CAF), hydroxyzine (HYDZ), and benzocaine (BZC) were the adulterants most prevalent in the 166 samples analyzed. The analytical qualitative method by GC-MS was shown to be effective as screening method for all the compounds, while the analytical method by GC-TMS was limited due to its incompatibility with certain target compounds. The chapters presented in this work comprise the analysis of cocaine and its derivatives in biological matrices and seized material, as well as an approach relating to the analysis of samples from impaired driving and similar scenarios. The methods developed in this work can be further applied to other areas of science and research including clinical toxicology, general laboratories and forensic laboratories.

Secondary Ion Mass Spectrometry (SIMS) is a powerful technique for high spatial resolution chemical mapping and characterization of native surfaces. The use of massive cluster projectiles has been shown to extend the applicable mass range of SIMS and improve secondary ion yields 100 fold or beyond. These large projectiles however, present a challenge in terms of focusing due to the initial spatial and kinetic energy spreads inherent to their generation. In the present work, we describe the development and construction of a novel primary ion (PI) column employing a gold nanoparticle – liquid metal ion source (AuNP-LMIS) and the coupling to ultrahigh resolution mass spectrometers (e.g., Fourier Transform Ion Cyclotron Resonance Mass Spectrometer, FT-ICR MS) for accurate chemical characterization of complex biological surfaces. This work describes the ion dynamics, development and the experimental characterization of the AuNP-LMIS.

Presented in this thesis are two methods that are coupled to the instrumentation for the recovery and analysis of ultra-trace illicit drug residues. The electrostatic dust lifting process is coupled with nanomanipulation-nanospray ionization to retrieve drug particles off of hard surfaces for analysis. For the second method, drug residues from fingerprint impressions are extracted followed by analysis. The methodology of these hyphenated techniques toward forensic science applications is applied as to explore limits of detection, sensitivity, and selectivity of analytes as well as immediacy and efficiency of analysis. The application of nanomanipulation-coupled to nanospray ionization-mass spectrometry toward forensic science based applications is considered as future improvements to trace and ultra-trace analysis.

<p>Advancements in 3D printing technology have provided (1) easy access to low-cost, open- source robotics, and (2) a fast fabrication technique for analytical devices among others. Using the robotics of a 3D printer, a mass spectrometry-based reaction screening device was built as a low- cost, modest throughput alternative to expensive, very fast systems. Using the 3D printer for fabrication, ion mobility devices were fabricated. Fundamental studies of the motion of ions in these devices were performed in addition to applications of ion mobility-mass spectrometry using a 3D printed drift tube ion mobility spectrometer.</p><p><br></p><p>With only simple modification, 3D printer kits provide nearly all the necessary parts for a functional reaction screening device. Replacing the hotend assembly with custom parts to hold a syringe, precise volumes of reaction mixtures can be dispensed, and high voltage applied to the needle for direct analysis of solutions by mass spectrometry. Direct analysis of reaction mixtures in a 96-well microtiter plates was completed in approximately 105 minutes (~65 seconds per reaction mixture, including washing of syringe). Following analysis, product distributions derived from the electrospray mass spectra were represented as heatmaps and optimum reaction conditions were determined. Using low-cost, open-source hardware, a modest throughput for reaction screening could be achieved using electrospray ionization mass spectrometry.</p><p><br></p><p>The manipulation of ions at reduced pressures is very well understood, whereas the efficient manipulation of ions at atmospheric pressure is far less understood. Using 3D printing, multiple iterations of atmospheric pressure drift tube ion mobility spectrometers were fabricated with one and two turns in the drift path. Optimum electrode geometries for ion transmission and resolution were determined by both simulation and experiment. Racetrack effects, where ions on the inside of turns have a shorter path than ions on the outside, were determined to be highly detrimental to resolving power. Drift tubes with two turns in opposite directions (a chicane) corrected for racetrack effects and had only marginally poorer resolving power than a straight drift tube. Additionally, ion intensities were nearly identical between optimized straight and turned ion paths, showing that these manipulations can be done with high efficiency. The focusing of ions at reduced pressure using RF ion funnels at reduced pressure can have nearly 100 percent transmission. At atmospheric pressure, RF fields are not nearly as efficient at focusing ions. By using non-uniform DC fields at atmospheric pressure, ions can be focused, but not nearly to the extent as at reduced pressure.</p><p><br></p><div><div><div><p>The coupling of atmospheric pressure drift tube ion mobility with ion trap mass spectrometry is inefficient due to the mismatch in duty cycle between the two instruments. For this reason, increasing the amount of data collected from a single experiment is of high importance. Fourier transform ion mobility increases the duty cycle from less than 1% to 25%. When ions are fragmented in the mass spectrometer, they maintain the frequency characteristic of the precursor. Therefore, ions can be fragmented without isolation in the ion trap (reducing duty cycle further) and related precursors and product ions identified through their drift time. Two-dimensional tandem mass spectrometry is a method to collect all tandem mass spectrometry information in a single scan. When coupled with ion mobility, this data can be used to generate functional group- specific ion mobility spectra where ion intensity is measured along a precursor or neutral loss scan line. This was demonstrated for a lipid sample in which head-group specific ion mobility spectra were obtained using head-group specific precursor and neutral loss scan lines.</p></div></div></div>

<div>Mass spectrometry (MS) is a powerful and versatile analytical tool that is extensively used for the identification and analysis of complex mixtures. The ability to couple MS to atmospheric pressure ionization techniques and high-performance liquid chromatography (HPLC) or gas chromatography (GC) provides a high degree of experimental flexibility. MS is based on the analysis of gas-phase ions. Gas-phase ions are manipulated within the mass spectrometer and separated for detection based on their mass-to-charge (m/z) ratio.</div><div>One of the most commonly used techniques for complex mixture analysis is tandem mass spectrometry (MSⁿ). MSⁿ involves the isolation of the desired ion and allowing it to undergo reactions, such as collision-activated dissociation (CAD) or ion-molecule reactions. Based on the generated product ions, structural information can be obtained for unknown analytes in complex mixtures. In addition, MSⁿ methods based on diagnostic gas-phase ion-molecule reactions have been demonstrated to provide a general and predictable tool to identify specific functional groups in unknown ionized analytes and to classify unknown analytes into different compound classes depending on their functionalities.</div><div>The research described in this dissertation mainly focuses on the development of tandem mass spectrometric methods based on gas-phase ion-molecule reactions and/or CAD for the identification of the <i>N</i>-nitroso functionality, which is present in some potentially mutagenic drug impurities. Furthermore, the dissertation discusses combining machine learning and MSⁿexperiments based on diagnostic ion-molecule reactions of 2-methoxypropene to predict reaction outcomes in a semiautomated fashion for protonated analytes containing specific functional groups. Lastly, chemical characterization and gas-phase reactivity of the boron-centered radical dianion [B₁₂I₁₁]^2-• toward some organic molecules are discussed.</div>

Tocopheryl Polyethylene Glycol Succinate 1000 (TPGS 1000) can inhibit P-glycoprotein (P-gp); TPGS 1000 was not originally designed to inhibit an efflux pump. Recent work from our laboratories demonstrated that TPGS activity has a rational PEG chain length dependency. In other recent work, inhibition mechanism was investigated and appears to be specific to the ATPase providing P-gp energy. Based on these observations, we commenced rational surface-active design. The current work summarizes new materials tested in a validated Caco-2 cell monolayer model; rhodamine 123 (10 μM) was used as the P-gp substrate. These results demonstrate that one may logically construct non-ionic surfactants with enhanced propensity to inhibit in vitro efflux. One new surfactant based inhibitor, Tocopheryl Polypropylene Glycol Succinate 1000 (TPPG 1000), approached cyclosporine (CsA) in its in vitro efflux inhibitory potency. Subsequently, TPPG 1000 was tested for its ability to enhance the bioavailability of raloxifene - an established P-gp substrate - in fasted male rats. Animals dosed with raloxifene and TPPG 1000 experienced an increase in raloxifene oral bioavailability versus a control group which received no inhibitor. These preliminary results demonstrate that one may prepare TPGS analogs that possess enhanced inhibitory potency in vitro and in vivo.