Human breast milk is a biofluid produced by a woman’s body during pregnancy. Breast milk contains necessary nutrition to a growing infant as well as xenobiotics--including drugs of abuse-- consumed by the woman which diffuse into the breast milk from the bloodstream. Since breast milk is recommended to be part of all infants’ diets, being able to detect any toxic components--such as drugs--in the matrix is critical. However, despite the ease and noninvasive nature of collection, human breast milk is a difficult matrix to analyze due to its high fat and protein content. Thus far, no literature has been published on the analysis of breast milk through direct analysis in real time mass spectrometry (DART-MS). Adapting DART-MS to detect drugs of abuse in human breast milk will allow for quick and timely identification of drugs present in an individual’s breast milk, as well as aid in research regarding the potential harmful effects of drugs--both licit and illicit--on an infant who is breastfeeding. Forensically, this method could potentially allow toxicologists to use breast milk as a matrix to determine if drugs played a role in a woman’s or breastfed child’s death. Using both C18 biocompatible solid-phase microextraction (BIO-SPME) fibers and QuickStrip™ cards, a DART-MS method was developed to be able to detect drugs of abuse in human breast milk. Four drugs of abuse (cocaine, codeine, morphine, and delta-9-tetrahydrocannabinol (Δ9-THC))--all of which are either commonly abused during the postpartum period or are of particular danger to breastfeeding women--were chosen to be studied. The drugs of abuse were extracted from either whole or pre-filtered human breast milk using either liquid-liquid extraction or C18 BIO-SPME fibers and detected with DART-MS using parameters suggested by IonSense, Incorporation (Inc.). Mass spectral results indicated that macromolecules in whole breast milk did not hinder extraction or detection and that a larger amount of the analytes were ionized/desorbed when using the BIO-SPME fibers. Thus, a BIO-SPME method adopted from IonSense, Inc. utilizing C18 fibers and SPME DART-MS parameters (with temperature and rail time adjustments) can be used to quickly detect cocaine, codeine, morphine, and Δ9-THC in human breast milk, indicating that this method may be used for the detection of other drugs of abuse in breast milk. In addition, BIO-SPME fibers can be used to quantify the concentration of cocaine in breast milk between a range of 50 and 200 nanograms per milliliter as demonstrated by a matrix-matched calibration curve created using various concentrations of cocaine. Despite its benefits, the BIO-SPME and DART method cannot be used on samples containing more than one drug of abuse (based upon the drug concentrations utilized in this study) due to competitive adsorption and competitive ionization, respectively, as not all drugs could be detected when this method was applied to breast milk samples containing numerous drugs.

Since 2011, toxicology labs across the United States have faced an ever-increasing caseload, with backlogs and analytical turn-around times that continue to grow despite efforts to increase sample throughput. Sample preparation is often the more time-consuming, labor-intensive, and error-prone portion of the analytical process. Biocompatible Solid Phase Microextraction (Bio-SPME) is a single-step sample preparation technique that is rapid, simple, and amenable to automation. Direct Analysis in Real Time (DART) is an ambient ionization technique that can be paired with mass spectrometry (MS) to rapidly detect, identify, and quantitate drugs of abuse in urine samples. When these methods are combined, the entire analytical process, from start to finish, can be completed manually in just over 2 minutes per sample. By increasing sample throughput and decreasing human labor, toxicology labs would benefit greatly by adopting such a rapid analytical technique. This project focused on optimization of the Bio-SPME sample preparation process to maximize signal intensity and minimize preparation time per sample. 11-nor-9-carboxy-9-tetrahydrocannabinol (THC-COOH), benzoylecgonine, norfentanyl, and methamphetamine were selected as target analytes for detection and quantitation in specialty matrix urine (SMx urine). To prepare samples, octadecyl (C18) Bio-SPME fibers were subjected to a conditioning and extracting process prior to analysis via DART-MS. It was determined that a 15 minute conditioning period was sufficient to prepare the fibers for extraction. The extraction period was analyte-dependent with ideal analytes adsorbing to the fibers in as little as 15 minutes. Under ideal conditions, the entire sample preparation process was found to take as little as 30 minutes. Multiple Reaction Monitoring (MRM) methods were built for each target analyte and their deuterated analog. For qualitative purposes, two to three transitions were included for each analyte, whereas the quantitative methods included only one transition per analyte. The limit of detection (LOD) for benzoylecgonine and methamphetamine was found to be 50ng/mL in urine. The LOD for norfentanyl was 75ng/mL in urine, and the LOD for THC-COOH was 250ng/mL in urine. Three of the four analytes were successfully quantitated using DART-MS when only a single analyte is present in the sample: benzoylecgonine and methamphetamine can be reliably quantitated between 50ng/mL and 1000ng/mL, while norfentanyl can be quantitated between 75ng/mL and 1000ng/mL. Data collected from the optimized sample preparation and targeted analytical process demonstrates that rapid detection, identification, and quantitation of metabolites from various drug classes are possible via DART-MS.

Esta tese foi dividida em três capítulos. O capítulo I descreve o desenvolvimento do método Column switching UHPLC-MS/MS para a determinação simultaneamente de fármacos psicotrópicos em amostras de plasma de pacientes esquizofrênicos. A politerapia é uma prática comum no tratamento da esquizofrenia. Portanto, a monitorização terapêutica destes fármacos tem sido realizada para o ajuste das doses e individualização da terapia farmacológica. O método Column switching UHPLC-MS/MS apresentou linearidade na faixa de concentração de 0,025 a 1,25 ng mL-1 com R2 acima de 0,9950 e a falta de teste de ajuste (p > 0,05); precisão com coeficientes de variação inferiores a 12% e exatidão com erro padrão relativo inferior a 14%. Este método foi aplicado com sucesso para determinação de fármacos em amostras de plasma de pacientes esquizofrênicos para fins de monitorização terapêutica. No capítulo II, o desempenho cromatográfico de colunas C18 superficialmente e totalmente porosas com diferentes tamanhos de partícula foi avaliado para a análise de fármacos psicotrópicos por LC-MS/MS e LC-DAD. Com o sistema LC-MS/MS foram avaliados os seguintes parâmetros cromatográficos: altura do prato reduzido vs velocidade linear reduzida, impedância vs velocidade linear reduzida, tempo da corrida cromatográfica vs vazão, pressão vs vazão, resolução, capacidade de pico, assimetria e fator de retenção. Já com o sistema LC-DAD foram avaliados a hidrofobicidade, atividade silanol e impurezas metálicas também foram avaliadas. As colunas com superfície carregada apresentaram maior eficiência cromatográfica para os fármacos em sua forma ionizada. Já as colunas com partículas menores que 2 µm (Cortecs 1,6 µm, Acquity 1,7 µm, e Kinetex 1,7 µm) apresentaram maior eficiência cromatográfica para os fármacos na forma parcialmente ionizada. Os modelos matemáticos gerados foram capazes de prever a pressão e o tempo da corrida cromatográfica em diferentes vazões para todas as colunas. Considerando a eficiência, impedância, resolução, capacidade de pico, fator de retenção e hidrofobicidade, as colunas Cortecs 1,6 µm e Acquity 1,7 µm apresentaram melhor desempenho durante a análise dos fármacos em amostra de plasma. O capítulo III descreve o desenvolvimento e validação dos métodos SPME-UHPLC-MS/MS e Bio-SPME-Nano-ESI-MS/MS para a determinação dos endocanabinóides (AEA e 2-AG) em amostras biológicas. Para a otimização do processo SPME foram avaliadas as fases SPME (C18, C30 e HLB) e os solventes para dessorção (metanol, acetonitrila e isopropanol). Os aditivos modificadores de matriz, como cloridrato de guanidina, ácido trifluoroacético e acetonitrila foram avaliados por planejamento experimental. Os métodos SPME-UHPLC-MS/MS e Bio-SPME-Nano-ESI-MS/MS, com a fase HLB biocompatível, apresentaram para ambos endocanabinóides valores de LOQs de 1 ng mL-1 e 50 ng mL-1, respectivamente. O método Bio-SPME-Nano-ESI-MS/MS permitiu o direto acoplamento da fibra SPME ao espectrômetro de massas via dessorção/ionização nanoeletrospray que resultou em rápida determinação quantitativa dos endocanabinóides em amostras biológicas. / This thesis is divided into three chapters. Chapter I describes the development of a column switching UHPLCMS/MS method to determine psychotropic drugs in schizophrenic patients plasma samples simultaneously. Polytherapy is a common practice in schizophrenia treatment. Therefore, therapeutic drug monitoring has been applied to adjust doses and to customize pharmacological therapy. The column switching UHPLCMS/MS method developed here is linear at concentrations ranging from 0.025 to 1.25 ng mL-1 with R2 above 0.9950 and presents lack of fit test (p > 0.05), precision with coefficients of variation lower than 12%, and accuracy with relative standard error lower than 14%. This method was successfully applied to determine drugs in schizophrenic patients plasma samples for therapeutic drug monitoring. In chapter II, the chromatographic performance of C18 superficially porous columns and of C18 fully porous columns with different particle sizes were evaluated for analysis of psychotropic drugs by LC-MS/MS and LC-DAD. Within the LC-MS/MS system, the following chromatographic parameters were assessed: reduced plate height vs reduced linear velocity, impedance vs reduced linear velocity, chromatographic run time vs flow rate, backpressure vs flow rate, resolution, peak capacity, asymmetry, and retention factor. Within the LC-DAD system, hydrophobicity, silanol activity, and metal impurities were also examined. Columns with charged surface displayed improved chromatographic efficiency for drugs in the ionized form. Columns with particles smaller than 2 µm (Cortecs 1.6 µm, Acquity 1.7 µm, and Kinetex 1.7 µm) presented higher chromatographic efficiency for the drugs, which were in their partially ionized form. The generated mathematical models were able to predict the backpressure and the chromatographic run time at different flow rates for all the columns. Considering efficiency, impedance, resolution, peak capacity, retention factor, and hydrophobicity, columns Cortecs 1.6 µm and Acquity 1.7 µm provided the best performance during analysis of drugs in plasma samples. Chapter III describes the development and validation of the SPME-UHPLC-MS/MS and the Bio-SPME-Nano-ESI-MS/MS methods for determination of endocannabinoids (AEA and 2-AG) in biological samples. To optimize the SPME process, SPME coatings (C18, C30, and HLB) and solvents for desorption (methanol, acetonitrile, and isopropanol) were evaluated. Matrix modifier additives, such as guanidine hydrochloride, trifluoroacetic acid, and acetonitrile, were assessed by experimental design. The SPME-UHPC-MS/MS and the Bio-SPME-Nano-ESI-MS/MS methods with HLB biocompatible coating provided LOQ values of 1 ng mL-1 and 50 ng mL-1, respectively, for both endocannabinoids. The Bio-SPME-Nano-ESI-MS/MS method allowed direct coupling of SPME fibers to the mass spectrometer by desorption/ionization nanoelectrospray, which resulted in rapid quantitative determinations of endocannabinoids in biological samples.

Esta tese foi dividida em três capítulos. O capítulo I descreve o desenvolvimento do método Column switching UHPLC-MS/MS para a determinação simultaneamente de fármacos psicotrópicos em amostras de plasma de pacientes esquizofrênicos. A politerapia é uma prática comum no tratamento da esquizofrenia. Portanto, a monitorização terapêutica destes fármacos tem sido realizada para o ajuste das doses e individualização da terapia farmacológica. O método Column switching UHPLC-MS/MS apresentou linearidade na faixa de concentração de 0,025 a 1,25 ng mL-1 com R2 acima de 0,9950 e a falta de teste de ajuste (p > 0,05); precisão com coeficientes de variação inferiores a 12% e exatidão com erro padrão relativo inferior a 14%. Este método foi aplicado com sucesso para determinação de fármacos em amostras de plasma de pacientes esquizofrênicos para fins de monitorização terapêutica. No capítulo II, o desempenho cromatográfico de colunas C18 superficialmente e totalmente porosas com diferentes tamanhos de partícula foi avaliado para a análise de fármacos psicotrópicos por LC-MS/MS e LC-DAD. Com o sistema LC-MS/MS foram avaliados os seguintes parâmetros cromatográficos: altura do prato reduzido vs velocidade linear reduzida, impedância vs velocidade linear reduzida, tempo da corrida cromatográfica vs vazão, pressão vs vazão, resolução, capacidade de pico, assimetria e fator de retenção. Já com o sistema LC-DAD foram avaliados a hidrofobicidade, atividade silanol e impurezas metálicas também foram avaliadas. As colunas com superfície carregada apresentaram maior eficiência cromatográfica para os fármacos em sua forma ionizada. Já as colunas com partículas menores que 2 µm (Cortecs 1,6 µm, Acquity 1,7 µm, e Kinetex 1,7 µm) apresentaram maior eficiência cromatográfica para os fármacos na forma parcialmente ionizada. Os modelos matemáticos gerados foram capazes de prever a pressão e o tempo da corrida cromatográfica em diferentes vazões para todas as colunas. Considerando a eficiência, impedância, resolução, capacidade de pico, fator de retenção e hidrofobicidade, as colunas Cortecs 1,6 µm e Acquity 1,7 µm apresentaram melhor desempenho durante a análise dos fármacos em amostra de plasma. O capítulo III descreve o desenvolvimento e validação dos métodos SPME-UHPLC-MS/MS e Bio-SPME-Nano-ESI-MS/MS para a determinação dos endocanabinóides (AEA e 2-AG) em amostras biológicas. Para a otimização do processo SPME foram avaliadas as fases SPME (C18, C30 e HLB) e os solventes para dessorção (metanol, acetonitrila e isopropanol). Os aditivos modificadores de matriz, como cloridrato de guanidina, ácido trifluoroacético e acetonitrila foram avaliados por planejamento experimental. Os métodos SPME-UHPLC-MS/MS e Bio-SPME-Nano-ESI-MS/MS, com a fase HLB biocompatível, apresentaram para ambos endocanabinóides valores de LOQs de 1 ng mL-1 e 50 ng mL-1, respectivamente. O método Bio-SPME-Nano-ESI-MS/MS permitiu o direto acoplamento da fibra SPME ao espectrômetro de massas via dessorção/ionização nanoeletrospray que resultou em rápida determinação quantitativa dos endocanabinóides em amostras biológicas. / This thesis is divided into three chapters. Chapter I describes the development of a column switching UHPLCMS/MS method to determine psychotropic drugs in schizophrenic patients plasma samples simultaneously. Polytherapy is a common practice in schizophrenia treatment. Therefore, therapeutic drug monitoring has been applied to adjust doses and to customize pharmacological therapy. The column switching UHPLCMS/MS method developed here is linear at concentrations ranging from 0.025 to 1.25 ng mL-1 with R2 above 0.9950 and presents lack of fit test (p > 0.05), precision with coefficients of variation lower than 12%, and accuracy with relative standard error lower than 14%. This method was successfully applied to determine drugs in schizophrenic patients plasma samples for therapeutic drug monitoring. In chapter II, the chromatographic performance of C18 superficially porous columns and of C18 fully porous columns with different particle sizes were evaluated for analysis of psychotropic drugs by LC-MS/MS and LC-DAD. Within the LC-MS/MS system, the following chromatographic parameters were assessed: reduced plate height vs reduced linear velocity, impedance vs reduced linear velocity, chromatographic run time vs flow rate, backpressure vs flow rate, resolution, peak capacity, asymmetry, and retention factor. Within the LC-DAD system, hydrophobicity, silanol activity, and metal impurities were also examined. Columns with charged surface displayed improved chromatographic efficiency for drugs in the ionized form. Columns with particles smaller than 2 µm (Cortecs 1.6 µm, Acquity 1.7 µm, and Kinetex 1.7 µm) presented higher chromatographic efficiency for the drugs, which were in their partially ionized form. The generated mathematical models were able to predict the backpressure and the chromatographic run time at different flow rates for all the columns. Considering efficiency, impedance, resolution, peak capacity, retention factor, and hydrophobicity, columns Cortecs 1.6 µm and Acquity 1.7 µm provided the best performance during analysis of drugs in plasma samples. Chapter III describes the development and validation of the SPME-UHPLC-MS/MS and the Bio-SPME-Nano-ESI-MS/MS methods for determination of endocannabinoids (AEA and 2-AG) in biological samples. To optimize the SPME process, SPME coatings (C18, C30, and HLB) and solvents for desorption (methanol, acetonitrile, and isopropanol) were evaluated. Matrix modifier additives, such as guanidine hydrochloride, trifluoroacetic acid, and acetonitrile, were assessed by experimental design. The SPME-UHPC-MS/MS and the Bio-SPME-Nano-ESI-MS/MS methods with HLB biocompatible coating provided LOQ values of 1 ng mL-1 and 50 ng mL-1, respectively, for both endocannabinoids. The Bio-SPME-Nano-ESI-MS/MS method allowed direct coupling of SPME fibers to the mass spectrometer by desorption/ionization nanoelectrospray, which resulted in rapid quantitative determinations of endocannabinoids in biological samples.