• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1294
  • 1070
  • 199
  • 160
  • 141
  • 29
  • 29
  • 29
  • 29
  • 29
  • 29
  • 28
  • 26
  • 22
  • 18
  • Tagged with
  • 3840
  • 1612
  • 1026
  • 1008
  • 996
  • 896
  • 763
  • 666
  • 569
  • 473
  • 363
  • 317
  • 313
  • 261
  • 240
  • 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.
541

Purificacao de hormonio de crescimento humano recombinante obtido no espaco periplasmico de ESCHERICHIA COLI, visando sua aplicacao clinica

OLIVEIRA, JOAO E. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:43:39Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:47Z (GMT). No. of bitstreams: 1 06652.pdf: 3582362 bytes, checksum: acb423f59896fb445118557871bc22b3 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
542

Estratégia de purificação por IMAC de fragmento Fab de IgG humana adicionado a extrato proteico de soja / IMAC purification strategy of human IgG Fab fragments added to soy protein extract

Serracchiani, Marcel Mafei, 1986- 23 August 2018 (has links)
Orientador: Sonia Maria Alves Bueno / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-23T20:44:35Z (GMT). No. of bitstreams: 1 Serracchiani_MarcelMafei_M.pdf: 2065791 bytes, checksum: 04a95a39ac0691a669c45efc9e3fc435 (MD5) Previous issue date: 2013 / Resumo: A produção de proteínas recombinantes em plantas transgênicas tem se mostrado uma forma segura, eficiente e barata de obtenção em grande escala de várias proteínas de interesse, tais como vacinas, enzimas industriais, bioativos, biofarmacos e anticorpos e seus fragmentos. Contudo, para que a produção de proteínas recombinantes em plantas se torne viável é necessário o desenvolvimento de um processo de recuperação e separação da molécula alvo que seja eficiente e reprodutivo, pois a produção de biomoléculas em plantas transgênicas, assim como os métodos tradicionais de produção, apresentam componentes indesejáveis que devem ser removidos. Neste trabalho, avaliou-se a purificação de fragmentos Fab de IgG humana adicionados artificialmente (spiking) a extrato protéico de soja não transgênica utilizando-se a técnica de cromatografia de afinidade por íons metálicos imobilizados (IMAC). Estudou-se o efeito dos quelatos IDA-Ni(II) e TREN-Ni(II), dos sistemas tamponantes Tris-HCl, fosfato de sódio e Mes, na presença e na ausência de sal (NaCl) na purificação de fragmentos Fab. Primeiramente foram realizados experimentos cromatográficos com as proteínas nativas do extrato proteico do grão de soja. Dos resultados obtidos, selecionou-se, para o adsorvente agarose-TREN-Ni(II), o sistema tamponante Tris-HCl/Tris-HCl na ausência de NaCl, e para o adsorvente agarose-IDA-Ni(II), selecionou-se o sistema tamponante fosfato de sódio/acetato de sódio contendo NaCl. Estes sistemas tamponantes e adsorventes foram utilizados para purificação dos fragmentos Fab adicionados (spiking) ao extrato proteico de grãos de soja. Em agarose-TREN-Ni(II), os fragmentos Fab foram purificados por cromatografia negativa, obtendo-se 66% dos fragmentos Fab na etapa de flowthrough e lavagem, com um grau de pureza de 91% e fator de purificação de 1,4. Para o adsorvente agarose-IDA-Ni(II), os fragmentos Fab foram purificados por cromatografia tradicional (eluição a pH 5,8), obtendo-se alto grau de pureza do fragmento Fab purificados, com um fator de purificação de 2,5. Este estudo contribuiu para obter conhecimento de base para posterior aplicação da técnica de IMAC na purificação de proteínas recombinantes produzidas em sementes de plantas transgênicas / Abstract: The recombinant proteins production using transgenic plants have been considered a safe, efficient and cheap way of producing on large scale innumerous proteins of interest, such as vaccines, industrial enzymes, bioactives, biopharmaceuticals and antibody and it fragments. However, for the production of recombinant proteins in plants become viable is necessary to develop a process for recovery and separation of the target molecule that is efficient and reproductive, because the production of biomolecules in transgenic plants, as well as traditional production methods, have components reactions which must be removed. In this work, the purification of Fab fragments of human IgG added artificially (spiking) to extract non-transgenic soy protein, using the technique of affinity chromatography on immobilized metal ions (IMAC), was evaluated. The effect of chelating agents IDA-Ni(II) and TREN-Ni(II), and the buffers Tris, sodium phosphate and Mes, in presence and the absent of NaCl, was studied for the Fab purification. First, the chromatographic experiments with the native proteins of soybean extract were performed. From the results obtained, it was selected, for the adsorbent TREN-Ni(II), the buffers system Tris-HCl/Tris-HCl without NaCl, and for the adsorbent IDA-Ni(II), the buffer system sodium phosphate/ sodium acetate with NaCl was selected. These adsorbents and buffer systems were used for purification of Fab fragments added (spiking) to soybean extract proteins. In the agarose adsorbent TREN-Ni (II), Fab fragments were purified by negative chromatography, obtaining 66% of Fab fragments in flowthrough and wash steps with a purity of 91% and purification factor of 1.4. For the adsorbent agarose-IDA-Ni (II), Fab fragments were purified by traditional chromatography (elution at pH 5.8), obtaining a high purity of the purified FAB, with a purification factor of 2.5. This study contributed to obtain knowledge base for application of the technique on the IMAC purification of recombinant proteins produced in transgenic plant seeds / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestre em Engenharia Química
543

Estudo dos modos batelada e reciclo externo estacionário para a separação do ácido hialurônico por cromatografia de exclusão por tamanho / Study of batch and steady state recycling modes for hyaluronic acid separation by size exclusion chromatography

Sousa, Anayla dos Santos 19 August 2018 (has links)
Orientador: Cesar Costapinto Santana / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T00:34:49Z (GMT). No. of bitstreams: 1 Sousa_AnayladosSantos_D.pdf: 1255579 bytes, checksum: 2c0a223e27891ba584d4f621ffa8e2bd (MD5) Previous issue date: 2011 / Resumo: O Ácido hialurônico (AH) é um polissacarídeo linear com importantes aplicações na indústria farmacêutica, médica e cosmética, fazendo-se necessária sua purificação por ser oriundo de uma variedade de fontes, animal e não animal. Assim sendo, o presente trabalho discorre sobre a separação do AH produzido por fermentação em meio de cultura sintético, utilizando a técnica cromatográfica de exclusão por tamanho. Determinaram-se as melhores condições de separação utilizando, inicialmente, uma coluna de exclusão por tamanho operando em batelada. Estas condições foram mantidas em todos os ensaios e serviram de modelo para a obtenção dos parâmetros para o escalonamento do processo. Ainda em batelada, avaliou-se a inserção da técnica cromatográfica de troca iônica acoplada à exclusão por tamanho, com o intuito de aprimorar a separação do AH, averiguando resinas de caráter catiônico e aniônico. Realizou-se um estudo comparativo entre o processo em batelada, com e sem a inserção da troca iônica, e o semicontínuo operado com reciclo externo estacionário (REE), visando a obtenção de frações de AH e proteínas com elevado grau de pureza. Considerando-se o processo semicontínuo operado em REE foram avaliados diferentes volumes de reciclo, sendo eles 1,0; 1,5; 2,25 e 3,0 mL. Os resultados obtidos com o processo semicontínuo em REE alcançaram um percentual de purificação entre 92% e 97% para o AH, trabalhando-se com volumes de reciclo de 1,0 a 3,0 mL, enquanto que para as proteínas mostrou-se inviável. A inserção da cromatografia de troca iônica mostrou-se promissora com o uso da resina catiônica, apresentando 98% de pureza com um rendimento de 99% para o AH; ao contrário da resina aniônica que exibiu uma perda mássica de AH em torno de 50%. O escalonamento do processo cromatográfico de exclusão por tamanho mostrou-se possível, apresentando resultados semelhantes à operação em batelada / Abstract: The hyaluronic acid (HA) is a linear polysaccharide with important applications in the pharmaceutical, medical and cosmetics industry. Its purification is necessary because it is in a mixture coming from a variety of sources, animal and non-animal. The aim of this work is the separation of HA obtained by fermentation in synthetic medium, using the technique of size exclusion chromatography. The best conditions for HA separation were determined using, initially, a batch operation size exclusion column. These conditions were maintained in all trials and served to obtain the parameters for the large scale process. The batch operation also evaluated the ion exchange chromatography technique coupled to size exclusion, in order to enhance the separation of HA by examining cationic and anionic resins. A comparative study was carried out between the batch process, with and without the inclusion of ion exchange, and the semi-batch process with steady state recycling (SSR), in order to obtain fractions of HA and proteins with high purity. The semi-batch process operated with SSR assessed in differents volumes of recycle (1.0, 1.5, 2.25 and 3.0 mL). The results obtained with the semi-batch process with SSR achieved a purification percentage between 92 % and 97% for HA, working with recycle volumes from 1.0 to 3.0 mL, showing to be feasible for HA, while for the proteins proved to be unfeasible, with a maximum of 60 % purity. The ion-exchange chromatography obtained good results with the use of cationic resin, with 98% of purity and a yield of 99 % for HA, unlike the anionic resin which exhibited a mass loss of HA around 50 %. The scale-up process for size exclusion chromatography proved to be possible, with similar results to batch operation / Doutorado / Desenvolvimento de Processos Biotecnologicos / Doutor em Engenharia Química
544

Microextração em fase sólida e cromatografia gasosa convencional e bidimensional para classificação de méis / Solid phase microextraction and conventional and comprehensive gas chromatography for the classification of honeys

Marques, Sandra Regina Rivellino, 1975- 19 August 2018 (has links)
Orientador: Fabio Augusto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-19T18:08:24Z (GMT). No. of bitstreams: 1 Marques_SandraReginaRivellino_D.pdf: 2317302 bytes, checksum: fe68941a7328088e8aaba96b46928a24 (MD5) Previous issue date: 2011 / Resumo: A técnica de microextração em fase sólida através do headspace (HS-SPME) combinada com a cromatografia gasosa bidimensional abrangente e detecção por ionização em chama (GCxGCxFID) foi empregada para detectar artefatos formados durante o preparo da amostra de méis, que poderiam ser prejudiciais ao processo de identificação de sua origem floral. O método foi otimizado utilizando-se planejamento multivariado. Para isso, uma mistura de diferentes tipos de méis brasileiros foi usada como modelo. Os artefatos de extração identificados foram classificados como resultantes da manipulação através do HS. A influência da temperatura e do tempo de exposição ao tratamento térmico também foi avaliada. A identificação da fração volátil da mistura de mel foi realizada por GCxGCxFID e cromatografia gasosa acoplada à espectrometria de massas com analisador quadrupolar (GC-QMS) comparando-se o índice de retenção linear com programação de temperatura obtido na primeira dimensão (D-LTPRI), calculado a partir dos cromatogramas obtidos por GCxGCxFID, e os índices obtidos por GC-QMS para as mesmas amostras. Esta identificação foi confirmada por cromatografia gasosa bidimensional abrangente combinada a um espectrômetro de massas por tempo de vôo (GCxGCxTOFMS). Portanto, a identificação e detecção de artefatos de extração previamente desconhecidos é atribuída às vantagens da GCxGC. A GCxGCxFID combinada com ferramentas quimiométricas foi empregada para classificar algumas amostras de méis de diferentes origens do Piauí-Brasil. A GCxGCxQMS foi empregada para identificação dos voláteis de algumas destas amostras. A combinação de HS-SPME - (GCxGC ou GC) com o poder de identificação do detector MS, juntamente com índices de retenção e de métodos quimiométricos forneceram informações valiosas sobre a classificação química dos méis / Abstract: Solid phase microextraction through headspace (HS-SPME) was otimizated by a multivariate design. This technique combined with comprehensive two-dimensional gas chromatography with flame ionization detection (GCxGC-FID) was employed to detect potential artifacts formed during preparation of honey samples, that could possibly be relevant to the identification of its floral origin. A mixture of different types of brazilian honeys was used as the model sample. The extraction artifacts identified were classified as resulting from HS manipulation. The influence of temperature and time exposure of the thermal treatment was also evaluated. The identification of the volatile fraction of the honey blend was performed through combination of GCxGC-FID and GC coupled to quadrupole mass spectrometry (GC-QMS) by comparing the one dimensional linear temperature programmed retention index (D-LTPRI) calculated from GCxGCxFID chromatograms to that of chromatograms of the same samples obtained on GC-QMS. This identification was confirmed by GCxGC combined with a time-of-flight mass analyzer (GCxGC-TOFMS). Therefore, the identification and detection of previously unknown extraction artifacts is attributed to advantages of GCxGC. GCxGCxFID in combination with chemometric tools was employed to classify some honey samples from different origins from Piauí-Brazil. GCxGCxQMS was employed for the identification of the volatiles from some one of these samples. The combination of HS-SPME - (GCxGC or GC) and the qualitative information of MS, retention index and chemometric methods may be able to provide valuable information on the chemical classification of honeys / Doutorado / Quimica Analitica / Doutor em Ciências
545

Detector Comparison for Simultaneous Determination of Organic Acids and Inorganic Anions

Pannell, Daniel K. (Daniel Kirk) 08 1900 (has links)
The research reported here is a study of detector systems to determine those most suited for simultaneous organic acid, inorganic anion determination. Comparisons are made on the basis of detection limits and sensitivities for conductivity, UV/Vis, photoconductivity, and derivative conductivity detection systems. The investigation was made using a constant chromatographic system with the only variable component being the detector system. Eluant optimization conditions for each detector are reported along with tables reporting detection limits and sensitivities for each detector system. Various chromatograms are also shown to provide a visual comparison between detector results.
546

Desenvolvimento e validação de método analítico empregando DLLME e HPLC/UV para determinação de benzodiazepínicos em amostra de água / Development and validation of analytical method employing DLLME and HPLC/UV for the determination of benzodiazepines in water sample

Marques, Tamires Valim, 1987- 02 December 2014 (has links)
Orientador: Rodnei Bertazzoli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T13:08:38Z (GMT). No. of bitstreams: 1 Marques_TamiresValim_M.pdf: 6834346 bytes, checksum: 5eb1bc6d88a438ca9002c92109a6c660 (MD5) Previous issue date: 2014 / Resumo: A crescente preocupação com a poluição das águas por novos poluentes denominados emergentes tem se intensificado, visto que aumentou o número destes compostos detectados em água. Dentre estes compostos encontram-se os fármacos e produtos de higiene pessoal, usados cotidianamente pela população. O presente trabalho teve como objetivo o desenvolvimento de um método simples, rápido e sensível utilizando a microextração líquido líquido (DLLME) combinada com a cromatografia líquida de ultra eficiência (HPLC) com detecção ultravioleta (UV) para a determinação de alguns benzodiazepínicos (bromazepam, clonazepam e diazepam) em amostras de água. A determinação foi realizada em uma coluna C18 de acordo com as condições cromatográficas ótimas (fase móvel acetonitrila:água (60:40, v/v); vazão 1,2 mL min-1; detecção 225 nm). No método de extração, uma mistura apropriada de solvente extrator e dispersor foi injetada rapidamente na amostra aquosa (10 mL) com auxílio de uma seringa. De modo que uma solução turva foi formada, esta solução é caracterizada por conter pequenas partículas do solvente extrator que se dispersa na fase aquosa. Os parâmetros da extração, tais como natureza e volume dos solventes extrator e dispersor, tempo de extração, pH da amostra, força iônica, velocidade e tempo de centrifugação, foram estudados para a otimização. Com as condições ótimas definidas (solvente extrator: clorofórmio, 200 ?L; solvente dispersor: metanol, 700 ?L; pH da amostra 9,0; velocidade e tempo de extração: 5000 rpm, 1 minuto; força iônica: adição de 1% (p/v) de (NH4)2SO4) o método proposto foi validado seguindo as figuras de método preconizadas pela ANVISA na Resolução N° 899 de 2003. A faixa linear para cada fármaco foram 8,0 - 96 ?g L-1 para bromazepam, 4,0 - 48 ?g L-1 para clonazepam e 1,0 - 12 ?g L-1 para diazepam. Todas as curvas obtiveram valores de (r) superiores a 0,999. Os limites de detecção e quantificação obtidos foram 2,4 e 8,0 ?g L-1 para bromazepam, 1,2 e 4,0 ?g L-1 para clonazepam, 0,2 e 1,0 ?g L-1 para diazepam, respectivamente. As recuperações variaram de 50 a 110% com RSD (Desvio Padrão Relativo) inferiores a 12,7 %. Finalmente, o método proposto foi aplicado em amostras coletadas na represa Billings localizada no município de Diadema-SP. / Abstract: The growing concern over water pollution caused by so-called new emerging pollutants has intensified since increased the number of these compounds detected in water. Among these compounds are pharmaceuticals and personal care products used daily by the population. This study aimed to develop a simple, rapid and sensitive liquid using liquid micro extraction (DLLME) combined with ultra-performance liquid chromatography (HPLC ) with ultraviolet detection (UV) for the determination of some benzodiazepines (bromazepam, clonazepam and diazepam) in water samples . The determination was performed on a C18 column in accordance with the optimal chromatographic conditions (mobile phase acetonitrile: water (60:40, v/v), flow rate 1.2 mL min-1, detection 225 nm). In the extraction method, a suitable mixture of extractant and dispersing solvent was injected rapidly into the aqueous sample (10 ml) with a syringe. So that a cloudy solution was formed, this solution is characterized by containing fine drops of the extractor solvent is dispersed in the aqueous phase. The parameters of the extraction, such as the nature and volume of the extractor and disperser solvents, extraction time, sample pH, ionic strength, speed and time of centrifugation, were studied for optimization. With the defined optimal conditions (extracting solvent: chloroform, 200 ?L; disperser solvent: methanol, 700 ?L, sample pH 9.0, extraction time and speed: 5000 rpm, 1 minute; ionic strength: adding 1% (p/v) (NH4)2SO4) the proposed method was validated following the figures of merit recommended by the ANVISA Resolution No. 899 of 2003. The linear ranges for each drug were 8.0 to 96 ?g L- 1 for bromazepam, 4.0 to 48 ?g L- 1 for clonazepam and 1.0 to 12 ?g L- 1 for diazepam. All curves obtained values (r) greater than 0.999. The limits of detection and quantification obtained were 2.4 and 8.0 ?g L- 1 to bromazepam, 1.2 and 4.0 ?g L- 1 to clonazepam, 0.2 and 1.0 ?g L- 1 for diazepam, respectively. Recoveries ranged from 50 to 110% with RSD (Relative Standard Deviation) of less than 12.7%. Finally, the proposed method was applied to samples collected in the Billings dam located in Diadema-SP. / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica
547

VÝVOJ METOD VYSOKOÚČINNÉ KAPALINOVÉ CHROMATOGRAFIE KE STANOVENÍ VÝZNAMNÝCH SLOŽEK TABÁKU / Development of high-performance liquid chromatography methods for determination of major components of tobacco

Rozkovcová, Lucie January 2016 (has links)
The aim of this work was development of high-performance liquid chromatography method with DAD detection for determination of nicotine in tobacco. Standard operating procedure used by World Health Organization was chosen as comparison of the developed method. Optimized high performance chromatography method is suitable for determining nicotine in tobacco. Limit of detection for this method was 0,0003 mg/ml and limit of quantification was 0,0010 mg/ml. Optimization of preparation of samples was significant part of this thesis. Sample preparation procedure was made substantially easier in comparison to other commonly used methods. Nicotine content was determined from real tobacco leaves samples, cigarette tobacco filler, nicotine cartridge for electronic cigarettes and pipe tobacco. Satisfactory relative standard deviation was achieved for all types of samples. Next part of this thesis focused on study of determining polyphenols using high-performance liquid chromatography with diode array detector. Chosen analytes were chlorogenic acid, caffeic acid, rutine, scopoletine and quercitrine. Among the five tested analytes, the highest sensitivity was achieved for chlorogenic acid and caffeic acid. All of the analytes achieved low limits of detection and quantification. Key words Liquid chromatography,...
548

Příprava a testování kapilárních monolitických kolon pro hydrofilní interakční chromatografii / Preparation and testing of capillary monolithic columns for hydrophobic interaction chromatography

Vlková, Michaela January 2015 (has links)
In frame work of this diploma thesis, monolithic stationary phases based on hydroxymethylmethacrylate were prepared in fused silica capillaries of 320 μm innerdiameter. Monolithic columns were synthesized by a simple procedure using a polymerization mixture, consisting of a monomer N-(hydroxymethyl) methacrylamide (HMMAA), a croslinking agent ethylene dimethacrylate (EDMA), porogenic solvents butane- 1,4-diol, propane-1-ol and an initiator α,α′-azobisisobutyronitrile (AIBN). Prepared HMMA monolithic columns were utilized for separation of mixtures of biologically active compounds, namely peptides with small number of amino acids. Mechanical strength and specific permeability were determined for selected monolithic columns. Keywords: HPLC, HILIC mechanism, hydroxymethyl methacrylate (HMMA) monolithic columns, amino acid, enkephalins.
549

Stanovení glukosinolátů v rostlinných materiálech / Determination of glucosinolates in plant materials

Holá, Veronika January 2020 (has links)
This diploma thesis deals with the determination of glucosinolates in plant material by capillary electrophoresis and high performance liquid chromatography. The chemical structure, biosynthesis, degradation, and also biological effects of glucosinolates are described. One part of this work also deals with the methods, which glucosinolates in plant materials were determined by. The experimental part describes the separation of intact glucosinolates by capillary electrophoresis and high performance liquid chromatography. Two plant materials were available for the determination of glucosinolates, namely lyophilized rapeseed leaves and broccoli juice. Micellar electrokinetic chromatography using a cationic surfactant was used to determine intact glucosinolates by capillary electrophoresis. After finding the optimal conditions for the separation of intact glucosinolates, it was found that it is impossible to determine these substances in plant samples. The reason was interference from the matrix, which interfered with this determination. While using high performance liquid chromatography under optimal conditions, some of the intact glucosinolates were identified in a rapeseed plant sample. Furthermore, the calibration dependencies of individual glucosinolates were obtained and the recovery and...
550

Analysis of synthetic cannabinoids in urine, plasma, and edibles utilizing multidimensional liquid chromatography tandem mass spectrometry

Benvenuto, Kayla 01 November 2017 (has links)
Synthetic cannabinoids (SCs), present a multitude of problems in terms of maintaining up-to-date, reliable, specific, and sensitive methods of detection. Synthetic cannabinoids are novel psychoactive substances originally synthesized for medical use and research purposes. Abuse of these compounds, however, has demonstrated a variety of effects ranging from euphoria to aggressive behavior and loss of consciousness. The most dangerous reported result of synthetic cannabinoids use has been death. The number of synthetic cannabinoid compounds detected drastically increased from two to over 80 compounds within six years. The marketing of these compounds, similar naming, and described pharmacological interactions, create the dangerous and very false perception that SCs are similar to, or the same as, tetrahydrocannabinol in cannabis products. This research focused on the development of a method to detect and quantify seven synthetic cannabinoids in urine, plasma, and gummy bears. The seven synthetic cannabinoids studied include XLR-11, AB-PINACA 5-pentanoic acid metabolite, UR-144 5-pentanoic acid metabolite, 5F-PB-22, AM-2201 4-hydroxypentyl metabolite, JWH-018, and JWH-018 5-hydroxypentyl metabolite. Sample preparation methods and a two dimensional liquid chromatography tandem mass spectrometry method were optimized and developed for analysis of the seven SCs in each matrix. The method was successfully applied to 17 authentic urine case samples previously screened positive for synthetic cannabinoids and a calibration curve for each matrix was generated from spiked samples at varying concentrations. Utilizing two-dimensional (2D) chromatography for the analysis of synthetic cannabinoids allowed for a novel approach to be employed. With this method, 100% organic samples were analyzed with improved resolution and increased sensitivity. The sample preparation method for the urine and plasma samples included a protein precipitation technique with acid followed by solid phase extraction (SPE) on a mixed-mode reversed phase strong anion exchange sorbent. The spiked gummy bear samples were prepared in 50% methanol in water, dissolved by heating, and extracted with SPE on the same sorbent used for the urine and plasma samples. A 200µL injection of the 100% MeOH extracts was injected into 2D-LC-MS/MS for analysis with a loading and diluting solvent consisting of water and 2% ammonium hydroxide and elution solvents containing water or methanol with 0.5% formic acid. These conditions were optimized with an automated method development protocol assessing various conditions such as mobile phase solvents, pH additives, and trap column chemistries. The final chromatography method utilized an ACQUITY ultra performance liquid chromatography (UPLC) ethylene bridged hybrid (BEH) C8 2.1 x 30mm, 10µm trap column and an ACQUITY UPLC high strength silica with tri-functional C18 bonding (HSS T3) analytical column 2.1 x 150mm, 1.7µm. The urine calibration curve produced had a linear dynamic range (LDR) of 0.05-2.5ng/mL for UR-144 5-COOH and AB-PINACA 5-COOH and 0.05-5ng/mL for the other five synthetic cannabinoids. R2 values included 0.992 and 0.993 for UR-144 5-COOH and AB-PINACA 5-COOH, respectively and 0.995 or above for the other five compounds. Synthetic cannabinoids were detected at varying concentrations in all 17 urine case samples. Analysis of plasma and gummy bear samples was also successfully carried out. Plasma calibration curves had a LDR 0.05-10ng/mL with all R2 values above 0.995. Gummy bear calibration curves produced a LDR of 0.05-10ng/mL or 0.05-2.5ng/mL with R2 values over 0.995. All extraction recovery values were greater than 80% with the exception of 63% recovery for AB-PINACA 5-COOH in the gummy bear matrix. Suppression effects of 8%, 19%, and 6.6% were observed for urine, plasma, and gummy bears, respectively. Relatively low recovery values, reduced linear dynamic ranges, and suppression matrix effects for the carboxylic acid analytes assessed in this research suggested an alternative approach may be more successful for the analysis of these particular compound types in all three matrices. Overall, a sensitive, specific, and reliable method was developed with low limits of detection and quantification for efficient and rapid analysis of compounds at trace levels utilizing 2D-LC-MS/MS.

Page generated in 0.409 seconds