Academic literature on the topic 'High Performance liquid chromatography coupled with mass spectrometry (LC-MS)'
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Journal articles on the topic "High Performance liquid chromatography coupled with mass spectrometry (LC-MS)"
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Neuhof, Torsten, Robert Köppen, Matthias Koch, and Irene Nehls. "Letter: High-Performance Liquid Chromatography/Electrospray Mass Spectrometry Analysis of the Mycotoxin Aurofusarin." European Journal of Mass Spectrometry 14, no. 5 (April 1, 2008): 329–33. http://dx.doi.org/10.1255/ejms.935.
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High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) can be used for simultaneous quantification of various mycotoxins in contaminated food samples. Therefore, multi-mycotoxin methods have been developed in the last couple of years. To enlarge these methods for further analytes, we have developed a LC-MS/MS method for the quantification of the mycotoxin aurofusarin. Additionally, further LC-MS n experiments were performed to demonstrate the fragmentation pattern of aurofusarin. Applicable multiple reaction monitoring (MRM) transitions of aurofusarin were found and optimized by parameter variation of the tandem mass spectrometer. The applicability of the developed method was tested by analysis of naturally contaminated wheat.
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Zhang, Feng, Mingping La, Xiaobin Gong, Shouhong Gao, Zhijun Wu, Lianna Sun, Xia Tao, and Wansheng Chen. "Metabolite identification and pharmacokinetic study of Lamiophlomis rotata in rats." RSC Advances 6, no. 29 (2016): 24331–39. http://dx.doi.org/10.1039/c5ra25264d.
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An ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry technique and a subsequent LC-MS/MS method were developed for metabolite profile study of Lamiophlomis rotata extract after its oral administration.
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Gao, Mengyuan, Xiaohua Jia, Xuhua Huang, Wei Wang, Guangzhe Yao, Yanxu Chang, Huizi Ouyang, Tianxiang Li, and Jun He. "Correlation between Quality and Geographical Origins of Cortex Periplocae, Based on the Qualitative and Quantitative Determination of Chemical Markers Combined with Chemical Pattern Recognition." Molecules 24, no. 19 (October 8, 2019): 3621. http://dx.doi.org/10.3390/molecules24193621.
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Quality assessment of Cortex Periplocae remains a challenge, due to its complex chemical profile. This study aims to investigate the chemical components of Cortex Periplocae, including its non-volatile and volatile constituents, via liquid chromatograph–mass spectrometry (LC-MS/MS) and gas chromatography–mass spectrometry (GC-MS) assays. The established strategy manifested that Cortex Periplocae from different producing areas was determined by identifying 27 chemical markers with ultra-high-performance liquid chromatography, coupled with quadrupole tandem time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS), including four main groups of cardiac glycosides, organic acids, aldehydes, and oligosaccharides. These groups’ variable importance in the projection (VIP) were greater than 1. Simultaneously, the samples were divided into four categories, combined with multivariate statistical analysis. In addition, in order to further understand the difference in the content of samples from different producing areas, nine chemical markers of Cortex Periplocae from 14 different producing areas were determined by high performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS), and results indicated that the main effective constituents of Cortex Periplocae varied with places of origin. Furthermore, in GC-MS analysis, samples were divided into three groups with multivariate statistical analysis; in addition, 22 differential components whose VIP were greater than 1 were identified, which were principally volatile oils and fatty acids. Finally, the relative contents of seven main volatile constituents were obtained, which varied extremely with the producing areas. The results showed that the LC-MS/MS and GC-MS assays, combined with multivariate statistical analysis for Cortex Periplocae, provided a comprehensive and effective means for its quality evaluation.
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Sosa-Ferrera, Zoraida, Cristina Mahugo-Santana, and José Juan Santana-Rodríguez. "New Developments in Liquid Chromatography Mass Spectrometry for the Determination of Micropollutants." Chromatography Research International 2012 (December 17, 2012): 1–18. http://dx.doi.org/10.1155/2012/748989.
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The combination of liquid chromatography (LC) with mass spectrometry (MS) in the environmental field has appeared as a valuable tool for the determination of micropollutants. Several groups of compounds have been considered as particularly relevant (e.g., pharmaceuticals, hormones and other endocrine-disrupting, personal care products and their metabolites, flame retardants, surfactants, and plasticizers, among others) since the same ones are continuously being released in the environment mainly as a result of the manufacturing processes, the disposal of unused or expired products, and the excreta. Because these micropollutants are not completely removed in the environment, very specific and sensitive analytical procedures are needed for their identification and quantification. High performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) (or LC-MS2) and especially time-of-flight mass spectrometry (TOF/MS), has allowed that many environmental contaminants that are highly polar or nonvolatile or have a high molecular weight to be analyzed or identified. In this work we present an overview focused on the developments of liquid chromatography mass spectrometry applied to the analysis of the main classes of micropollutants in aqueous and solid environmental samples. Various aspects of methodologies based on these techniques, including sample preparation (extraction/preconcentration) and matrix effects, are discussed.
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Roy, Shikha M. N., Kiran V. Mangaonkar, Santosh M. Yetal, and Santosh S. Joshi. "LC-MS-MS Method for Determination of Metolazone in Human Plasma." E-Journal of Chemistry 5, no. 3 (2008): 634–40. http://dx.doi.org/10.1155/2008/425974.
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A rapid, sensitive and specific method for quantification of metolazone in human plasma using metaxalone as internal standard is described. Sample preparation involved a simple liquid-liquid extraction procedure. The extract was analyzed by high performance liquid chromatography coupled to electrospray tandem mass spectrometry (LC–MS–MS). Chromatography was performed isocratically on a 5 μm C18analytical column (50 mm × 4.6 mmi.d.) with buffer–acetonitrile 20:80 (v/v) as mobile phase. The response to metolazone was a linear function of concentration over the range 1.00 to 2000.00 ng mL-1. The lower limit of quantification in plasma was 1.0 ng mL-1. The method was successfully applied in a bioequivalence study of a metolazone formulation after administration as a single oral dose.
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Chadwick, Carrie Ann, and Brian Keevil. "Measurement of cotinine in urine by liquid chromatography tandem mass spectrometry." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 44, no. 5 (September 1, 2007): 455–62. http://dx.doi.org/10.1258/000456307781645996.
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Background: Cotinine is the major metabolite of nicotine. It is also a specific biomarker for nicotine exposure in cigarette smokers. The measurement of urine cotinine concentration will enable: (1) the assessment of the smoking status of lung transplant patients and (2) tobacco abstinence to be studied in patients during treatment under smoking cessation programmes. Methods: We have developed and validated a method for the measurement of urinary cotinine using reversed phase high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (LC-MS/MS). This technique utilizes online ion exchange coupled with an analytical column to eliminate ion suppression effects. The chromatography was performed using a WatersTM 2795 Alliance HT LC system. Results: Cotinine and d3-cotinine had a retention time of 2.5 min and the cycle time from injection to injection was 4 min. The transition identified for cotinine was m/z 177.1>79.6 and for d3-cotinine m/z 180.2>79.6. This method was linear up to 1000 μg/L. Mean recovery of the assay was 112% with a range of 107-117% ( n=9). The limit of quantitation for this assay was 2.5 µg/L and the limit of detection was 0.156 µg/L. The intra- and inter-assay imprecision was <12% and <10% respectively over a concentration range of 22-660 μg/L. Conclusions: We have developed a robust and rapid assay for measuring and analysing urine cotinine by LC-MS/MS, by utilizing a technique, which has reduced ion suppression effects. Ultimately, the method will facilitate the assessment of lung transplant patients' smoking status.
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Pezzatti, Julian, Víctor González-Ruiz, Julien Boccard, Davy Guillarme, and Serge Rudaz. "Evaluation of Different Tandem MS Acquisition Modes to Support Metabolite Annotation in Human Plasma Using Ultra High-Performance Liquid Chromatography High-Resolution Mass Spectrometry for Untargeted Metabolomics." Metabolites 10, no. 11 (November 15, 2020): 464. http://dx.doi.org/10.3390/metabo10110464.
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Ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) is a powerful and essential technique for metabolite annotation in untargeted metabolomic applications. The aim of this study was to evaluate the performance of diverse tandem MS (MS/MS) acquisition modes, i.e., all ion fragmentation (AIF) and data-dependent analysis (DDA), with and without ion mobility spectrometry (IM), to annotate metabolites in human plasma. The influence of the LC separation was also evaluated by comparing the performance of MS/MS acquisition in combination with three complementary chromatographic separation modes: reversed-phase chromatography (RPLC) and hydrophilic interaction chromatography (HILIC) with either an amide (aHILIC) or a zwitterionic (zHILIC) stationary phase. RPLC conditions were first chosen to investigate all the tandem MS modes, and we found out that DDA did not provide a significant additional amount of chemical coverage and that cleaner MS/MS spectra can be obtained by performing AIF acquisitions in combination with IM. Finally, we were able to annotate 338 unique metabolites and demonstrated that zHILIC was a powerful complementary approach to both the RPLC and aHILIC chromatographic modes. Moreover, a better analytical throughput was reached for an almost negligible loss of metabolite coverage when IM-AIF and AIF using ramped instead of fixed collision energies were used.
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Wojtanowski, Krzysztof Kamil, and Tomasz Mroczek. "Detection, Identification and Structural Elucidation of Flavonoids using Liquid Chromatography Coupled to Mass Spectrometry." Current Organic Chemistry 24, no. 1 (April 15, 2020): 104–12. http://dx.doi.org/10.2174/1385272824666200123104815.
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Flavonoids are one of the most common secondary metabolites occurring in plants. Their activity in the Central Nervous System (CNS) including sedative, anxiolytic, anti-convulsive, anti-depressant and neuro-protective actions is well known and documented. The most popular methods for detection, identification and structural elucidation of flavonoids are these based on Nuclear Magnetic Resonance (NMR) and mass spectrometry (MS). NMR allows rapid, high throughput analysis of crude extracts and also gives stereochemical details about identified substances. However, these methods are expensive and less sensitive than MS-based techniques. Combining High Performance Liquid Chromatography (HPLC) with MS detection gives the most powerful tool for analysis of flavonoids occurring in plants. There is a lot of different approaches to use LC/MS based techniques for identification of flavonoids and this short review shows the most important.
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Roy, Shikha M. N., Santos H. M. Yetal, Sangita V. Chavan, Vara D. R. Pradhan, and Santosh S. Joshi. "Determination of Free Levels of Cinitipride in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry." E-Journal of Chemistry 5, no. 3 (2008): 453–60. http://dx.doi.org/10.1155/2008/242986.
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A rapid, sensitive and specific method to quantify cinitapride in human plasma using risperidone as the internal standard is described. Sample preparation involved simple solid phase extraction procedure. The extract was analyzed by high performance liquid chromatography coupled to electrospray tandem mass spectrometry API-4000 (LC-MS/MS). Chromatography was performed isocratically on Thermo Hypurity C18analytical column, (50 mm x 4.6 mm, 5µm i.d.). The assay of cinitapride was linear calibration curve over the range 20.118 pg mL−1to 2011.797 pg mL−1. Plasma concentrations of cinitapride were determined by LC-MS/MS with a limit of quantification of 20.118 pg mL−1that allowed an appropriate characterization of the pharmacokinetic profile of cinitapride at the therapeutic dose. The method was successfully applied to the bioequivalence study of cinitapride tablet (1.0 mg) administered as a single oral dose.
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Khedr, Alaa, Soad El-Hay, and Ahmed Kammoun. "Multi-Steps Fragmentation-Ion Trap Mass Spectrometry Coupled to Liquid Chromatography Diode Array System for Investigation of Olaparib Related Substances." Molecules 24, no. 5 (February 27, 2019): 843. http://dx.doi.org/10.3390/molecules24050843.
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A high-performance liquid chromatography-diode array-mass spectrometric (LC-DAD-MS) method was developed and validated to investigate the related substances of olaparib (OLA) in bulk form. OLA was exposed to acid–base hydrolysis, boiling, oxidation with hydrogen peroxide, and UV light followed by LC-DAD-MS analysis. OLA and OLA-related substances were simultaneously and quantitatively monitored by DAD at 278 nm and triple quadrupole mass spectrometry (QQQ-MS). The investigated compounds were auto-scanned by an ion trap MS which applied positive and negative modes separately. The fragmentation pathway was confirmed by applying multi-steps fragmentation to identify the resulted cleaved ions and their parent ion. OLA was found to be sensitive to the alkaline hydrolysis and less sensitive to UV light. Two major hydrolytic degradation products, including the protonated molar ions m/z 299 and m/z 367, were identified. Three potential impurities were also characterized. The LC-MS limit of detection (LOD) and limit of quantification (LOQ) were 0.01 and 0.05 ng/µL, respectively. The quantitative results obtained by LC-DAD was comparable with that of LC-QQQ-MS. The proposed method shows good intra-day and inter-day precision with relative standard deviation (RSD) <2%.
Dissertations / Theses on the topic "High Performance liquid chromatography coupled with mass spectrometry (LC-MS)"
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Nascimento, DemÃtrius Fernandes do. "Nimodipine determination in human plasma by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS-MS)." Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=31.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoA rapid, specific and highly sensitive liquid chromatography-tandem mass spectrometry method was developed to determine nimodipine in human plasma using dibucaine as the internal standard (IS) is described. The analyte (m/z 418,6 > 342,6) and IS (m/z 344,2 > 271,0) were extracted from plasma samples by liquid-liquid extraction using hexane-ethyl acetate (1:1v/v). Chromatography was performed on a Varian Polaris C18 analytical column (3 micrometer, 50 x 2,0 mm) and pre-column SecurityguardTM C18 (4,0 x 3,0 mm). The phase mobile consisted of Acetonitrile-Ammonium acetate 0.02 ml/L (80:20v/v). The method had a chromatographic run time of 4.5 min and linear calibration curve over the range 0.1- 40 ng/mL (r2 > 0.9938). The limit of quantification (LQ) was 0.1 ng/mL. The intra-day precision for the limit quantification was 0.00% (batch 01), 5.71% (batch 02) and 5.27% (batch 03); for the quality controls low (QCL), middle (QCM) and high (QCH) the results were respectively 8.57, 0.81 and 1.37%. The inter-day precision for LQ and QCL, QCM and QCH were respectively: 7% and 5.46, 4.12 and 3.37%. The intra-day accuracy for LQ was 110, 96 and 104%; for QCL, QCM and QCH the results were100.67, 109.09 and 109.72% respectively. The results of the inter-day accuracy for LQ, QCL, QCM and QCH were respectively and 110.0, 96.0, 104.0% for the limit of quantification and 8.57, 0.81, 1.37% and 100.67, 109.09, 109.72% respectively: 103% e 102.89, 106.60, 109.69%. This validated method was successfully applied for the pharmacokinetic profiles of nimodipine tablets administered to 24 healthy volunteerâs participant of bioavailability comparative study. Geometric mean of Test formulation/Refernce formulation individual percent ratio was 104,56% for AUC0-48h and 55,73% for Cmax. The 90% for the confidence intervals (CI) were 94,80-115,32% e 44,73-69,42%, respectively. The values of half-life and Cmax for test formulation and reference formulation were 27,83;32,78h and 9,48;18,76ng/mL, respectively. The values of Tmax were 2,34;0,98h for the formulations test and reference respectively. Since the 90% CI for Cmax and AUC0-48h, were within the 80-125% interval proposed by the âFood and Drug Administrationâ and ANVISA, it was concluded that the two formulations of nimodipine 30mg tablets were not bioequivalent, according to the rate of absorption after single dose administration.
Um mÃtodo rÃpido, sensÃvel e especÃfico de Cromatografia LÃquida de Alta EficiÃncia acoplada à Espectrometria de Massa (LC-MS-MS) foi desenvolvido para determinar nimodipino (analito) em plasma humano usando dibucaÃna como padrÃo interno (PI). O analito (m/z 418,6 > 342,6) e o PI (m/z 344,2 > 271,0) foram extraÃdos de amostras de plasma atravÃs de extraÃÃo lÃquido-lÃquido utilizando hexano-acetato de etila (1:1v/v). As corridas cromatogrÃficas foram executadas utilizando-se uma coluna analÃtica Varian Polaris C18 (3 micrÃmetros, 50 x 2,0 mm) e uma prÃ-coluna SecurityguardTM C18 (4,0 x 3,0 mm). A fase mÃvel consistiu de acetonitrila-soluÃÃo de acetato de amÃnio 0,02 mol/L (80:20v/v). O mÃtodo teve um tempo total de corrida de 4,5 min e uma curva de calibraÃÃo linear que variou de 0,1-40 ng/mL. O limite de quantificaÃÃo de 0,1 ng/mL. A precisÃo intra-ensaio para o limite de quantificaÃÃo (LQ) foi 0,00% (lote 01), 5,71% (lote 02) e 5,27% (lote 03); para os controles de qualidade baixo (CQB), mÃdio (CQM) e alto (CQA) os resultados foram respectivamente: 8,57, 0,81 e 1,37%. A precisÃo interensaio para o LQ e os CQB, CQM e CQA foram respectivamente de: 7% e 5,46, 4,12 e 3,37%. A exatidÃo intra-ensaio para o LQ foi 110, 96 e 104%; para CQB, CQM e CQA os resultados foram 100,67, 109,09 e 109,72% respectivamente. Os resultados da exatidÃo interensaio para o LQ, CQB, CQM e CQA foram respectivamente de: 103% e 102,89, 106,6, 109,69%. Este mÃtodo foi aplicado para a avaliaÃÃo do perfil farmacocinÃtico do nimodipino administrado em 24 voluntÃrios sadios participantes de um estudo de biodisponibilidade comparativa. A mÃdia geomÃtrica da FormulaÃÃo teste/FormulaÃÃo referÃncia para as porcentagens individuais foi 104,56% para ASC0-48h e 55,73% para Cmax. Os intervalos obtidos a partir do intervalo de confianÃa (IC) de 90% foram 94,80-115,32% e 44,73-69,42% respectivamente. Os valores de meia-vida e Cmax para as formulaÃÃes teste e referÃncia foram de 27,83;32,78h e 9,48;18,76ng/mL, respectivamente. Os valores de Tmax foram de 2,34;0,98h para as formulaÃÃes teste e referÃncia, respectivamente. Considerando o IC de 90% para Cmax e ASC0-48h dentro da variaÃÃo de 80-125% proposto pelo Food and Drug Administration e ANVISA, as duas formulaÃÃes de nimodipino 30mg nÃo sÃo bioequivalentes quanto à taxa de absorÃÃo (Cmax) apÃs uma Ãnica administraÃÃo.
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Nascimento, DemÃtrius Fernandes do. "Quantification of drugs with antimicrobial activity by high performance liquid chromatography coupled to mass spectrometry (LC-MS/MS): application in studies of comparative pharmacokinetics." Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=7045.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoTwo robust, fast and sensitive methods for quantification of sulfamethoxazole (SMX), trimethoprim (TMP) and sulfadiazine (SDZ) in plasma using high performance liquid chromatography coupled to mass spectrometry (LC-MS/MS) was developed and validated. The methods involved liquid-liquid extraction with ethyl acetate using metoprolol and sulfamethoxazole as internal standards (PI). The chromatographic separations were performed using Genesis C18 column 100 x 2.1 mm, 4 microns (sulfadiazine) and Genesis C18 150 x 4.6 mm, 4 microns (SMX+TMP), with elution systems consisting of solutions of methanol/water (35/65, v/v) + 0.5% Formic Acid (sulfadiazine) and methanol/water (45/55, v/v) + 0.5% Formic Acid (SMX+TMP). Calibration curves were linear in the range from 0.05 to 25 mg/mL (sulfadiazine); 0.5 to 100 mg/mL (SMX) and 0.02 to 3.5 mg/mL (TMP). The recoveries corresponding to the analysis of quality controls were 66.8, 59 and 63.4% for sulfadiazine; 67.7, 63.3 and 74.4% for SMX; 74.5, 70.5 and 78.1% for TMP. The recovery values relating to internal standards sulfamethoxazole and metoprolol were 66.2% and 76.8% respectively. The validated bioanalytical methods included evaluation of precision and accuracy being the results within the required limits. The methods were successfully applied in studies of comparative bioavailability of formulations containing a combination of sulfamethoxazole-trimethoprim (suspension containing 40mg of SMX and TMP 8mg per milliliter) and formulations containing sulfadiazine (tablets 500 mg) in healthy volunteers of both sexes
Foram desenvolvidos e validados dois mÃtodos robustos, rÃpidos e sensÃveis para a quantificaÃÃo de sulfametoxazol (SMX), trimetoprima (TMP) e sulfadazina (SDZ) em plasma, utilizando cromatografia lÃquida de alta eficiÃncia acoplada à espectrometria de massa (LC-MS/MS). Os mÃtodos envolveram extraÃÃo lÃquido-lÃquido, com acetato de etila utilizando metoprolol e sulfametoxazol como padrÃes internos (PI). As separaÃÃes cromatogrÃficas foram realizadas utilizando colunas Genesis C18 100 x 2.1 mm, 4 (sulfadiazina) e Genesis C18 150 x 4,6mm, 4 (SMX + TMP), com sistemas de eluiÃÃo constituÃdos por soluÃÃes de Metanol/Ãgua (35/65, v/v) + 0,5 % Ãcido FÃrmico (sulfadiazina) e Metanol/Ãgua (45/55; v/v) + 0,5% Ãcido FÃrmico (SMX + TMP). As curvas de calibraÃÃo foram lineares, nas faixas de 0,05 a 25 Âg/mL (sulfadiazina), 0,5 a 100 Âg/mL (SMX) e 0,02 a 3,5 Âg/mL (TMP). As recuperaÃÃes correspondentes Ãs anÃlises dos controles de qualidade foram de 66,8, 59 e 63,4 % para sulfadiazina; 67,7, 63,3 e 74,4% para SMX; 74,5, 70,5 e 78,1% para TMP. Os valores da recuperaÃÃo referentes aos padrÃes internos sulfametoxazol e metoprolol foram de 66,2% e 76,8% respectivamente. As metodologias bioanalÃticas validadas incluÃram avaliaÃÃo de precisÃo e exatidÃo intra e interlote, assegurando que estas estavam dentro de limites admissÃveis. Os mÃtodos foram aplicados com sucesso em estudos de biodisponibilidade comparativa de formulaÃÃes contendo a associaÃÃo de sulfametoxazol + trimetoprima (suspensÃo contendo 40 mg de SMX e 8 mg de TMP por mililitro) e de formulaÃÃes contendo sulfadiazina (comprimidos de 500 mg) em voluntÃrios sadios de ambos os sexos.
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Oshita, Daniele 1981. "Desenvolvimento e validação de método analítico para determinação de multirresíduos de agrotóxicos em morango por LC-MS/MS e comparação com UHPLC." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250530.
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Orientador: Isabel Cristina Sales Fontes JardimTese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: Este trabalho envolve o desenvolvimento, a otimização e a validação de um método analítico para determinação de multirresíduos de agrotóxicos em amostras de morango, por cromatografia líquida acoplada à espectrometria de massas sequencial (LC-MS/MS). No preparo de amostra utilizou o método QuEChERS (quick, easy, cheap, effective, rugged and safe), que foi testado nas três versões, Original, AOAC Official Method e European Committee for Standardization (CEN) Standard Method EN 15662, além da versão CEN 15662 modificada. Também foram otimizados os solventes de extração, massas do agente secante e, na etapa de clean-up por extração em fase sólida dispersiva (d-SPE), o sorvente comercial PSA (primary secondary amine), alguns preparados no laboratório à base de polímeros de siloxano, como octadecil, octil, amino, fenil, e a mistura PSA e octadecil. As avaliações dos métodos foram baseadas, principalmente, nos valores de recuperação e nos estudos sobre o uso de diferentes sorventes, outros parâmetros que estimam a eficiência do clean-up também foram utilizados, como aspecto físico do extrato final, quantidade de coextratos da matriz, obtida por medidas gravimétricas, e efeito matriz. O método desenvolvido foi validado por meio dos parâmetros analíticos de seletividade, limite de detecção (LOD), limite de quantificação (LOQ), linearidade, exatidão e precisão, conforme o guia Sanco para análises de resíduos de agrotóxicos em alimentos e, posteriormente, amostras comerciais de morango da região de Campinas foram analisadas. O método validado por LC-MS/MS apresentou-se seletivo, preciso, exato e atingiu concentrações abaixo dos respectivos limites máximos de resíduos (LMR) para determinação de agrotóxicos em morango. Este método foi transferido para cromatografia líquida de ultra eficiência (UHPLC), que mostrou redução no tempo de análise, na vazão da fase móvel (FM) e no volume de injeção de amostra e da FM, e similaridade na detectabilidade dos analitos
Abstract: This work involves the development, optimization and validation of an analytical method for multiresidue determination of pesticides in strawberry samples by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Sample preparation used the QuEChERS (quick, easy, cheap, effective, rugged and safe) method, which was tested in three versions, Original, AOAC Official Method and European Committee for Standardization (CEN) Standard Method EN 15662, and also CEN 15662 modified version. The factores optimized were extraction solvents, amount of drying agent and in the clean-up step by dispersive solid phase extraction (d-SPE), the commercial sorbent PSA (primary secondary amine), several prepared in the laboratory based on siloxane polymers, such as octadecyl, octyl, amine, phenyl, and the mixture PSA and octadecyl. The evaluation of the methods was based mainly on the recovery values and for the study of different sorbents, other parameters that estimate the efficiency of the clean-up were also used such as the physical aspect of the final extract, the amount of interference matrix obtained using gravimetric measurements, and the matrix effect. The developed method was validated by the analytical parameters of selectivity, limit of detection (LOD), limit of quantification (LOQ), linearity, accuracy and precision, as described in the Sanco guide for analysis of pesticide residues in foods. After, commercial strawberry samples from the Campinas region were analyzed. The validated method by LC-MS/MS was selective, precise, accurate and reached levels below the respective maximum residue limits (MRLs) for the determination of pesticides in strawberries. This method was transferred to ultra high performance liquid chromatography (UHPLC), which showed a reduction in analysis time, the mobile phase (MP) flow rate and the injection volume of the sample and MP, and similarity in the detectability of the analytes
Doutorado
Quimica Analitica
Doutora em Ciências
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Stuart, Orville Dean. "Investigation of Phosphorylated Proteins and Peptides in Human Cerebrospinal Fluid via High-Performance Liquid Chromatography Coupled to Elemental and Molecular Mass Spectrometry." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1245823953.
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Van, Wyk Pieter-Hugo. "Novel methods of chemical speciation of Pt(IV/II) complexes in acid halide-rich solutions by ion-pair RP-HPLC coupled to ICP-OES/MS in conjunction with 195Pt NMR." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80099.
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Thesis (PhD)--Stellenbosch University, 2013.ENGLISH ABSTRACT: In this work a robust reversed phase ion-pairing high performance liquid chromatographic (RP-HPLC) method has been developed for the separation, characterization and quantification of all possible [PtCl6-nBrn]2- (n = 0 – 6) and [PtCl4-nBrn]2- (n = 0 – 4) complex anions using UV-Vis detection. High resolution 195Pt NMR of more concentrated PtII/IV solutions served to validate the relevant species assignments, particularly those of the stereoisomer species, cis- and trans- [PtCl4Br2]2-, [PtCl2Br4]2- and mer- and fac-[PtCl3Br3]2-. Quantification of the PtII/IV species was achieved by means of IP-RP-HPLC coupled to either ICP-MS or ICP-OES, and together with the UV-Vis absorption spectra obtained by photodiode array (PDA) recording of all eluted species, allowed for the determination of the photometric characteristics (λmax and ε) of all the PtII/IV species. This data enables practical speciation studies of such PtII/IV complex anions using standard analytical equipment. The hyphenation of ion-pairing RP-HPLC to ICP-OES allows for the successful determination of the Pt to halide mole ratios of individually separated species in order to characterize these species in a novel manner. The Pt to chloride and/or Pt to bromide mole ratio of the [PtCl4]2- and the series of [PtCl6-nBrn]2- (n = 0 – 6) complexes were determined using HPLC-ICP-OES based on the 177.708 nm Pt, 134.724 nm Cl and 148.845 nm Br emission lines and served as a technique for the unambiguous chemical speciation of such complexes. An increase in sensitivity of the developed method was achieved by the use of an ion-pairing reversed phase ultra high performance liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-Q-TOF-MS) method. This method proved capable of separating and characterizing the homoleptic and heteroleptic [PtIVCl6-nBrn]2- (n = 0 – 6) and mono-aquated [PtIVCl5-nBrn(H2O)]- (n = 0 – 5) complex anions in well defined acidic aqueous solutions. Ion-pairing ultra high performance liquid chromatography separation based on the volatile ion-pairing reagent, tributylamine, provided adequate chromatographic resolution as well as sufficiently low background noise for high resolution ESI-Q-TOF-MS detection. The wealth of structural information contained in the mass spectra obtained for each PtIV species simplified the identification of individual species. Moreover, the general fragmentation trends encompassing a constant incremental change of 44 Da (79/81Br - 35/37Cl) resulting from the successive substitution of Cl- by Br-, in combination with the observed elution order, facilitated the relevant species assignments. The developed method enabled the relative rapid (<13 min) characterization of all 22 [PtCl6-nBrn]2- (n = 0 – 6) and mono-aquated [PtCl5-nBrn(H2O)]- (n = 0 – 5) species. Quantification of each individual [PtCl6-nBrn]2- (n = 0 – 6) species by means of ion-paring HPLC-UV-Vis allowed for the determination of all 17 stability constants for the PtIV chloridobromido halide exchange reaction network. Determination of the associated Gibbs free energies for each ligand exchange reaction step, o rxnK ΔG n (n = 1 - 17), together with energy conservation relationships, served to validate the accuracy of the experimentally calculated stability constants. The experimentally determined overall formation constant, or ΔGo rxn, and those calculated using the standard reaction half cell reduction potentials of [PtCl6]2- and [PtBr6]2- were in good agreement, further confirming the experimentally obtained thermodynamic parameters. The thermodynamic driving force for the PtIV chloride-bromido exchange reactions is attributed to the hydration of the halide ligands, which drives the reaction towards the bromido PtIV species in aqueous solutions, even though the chlorido PtIV complexes are energetically favoured in this reaction network. Evaluation of other metal cation halido exchange reactions shows that all metal halido complexes exhibit the F- >> Cl- > Br- > I- order of thermodynamic stability and is only inverted due to the solvation of the relevant halide ligands. Furthermore, density functional theory (DFT) was used to predict the thermodynamic stabilities with respect to the isodesmic reactions involving chlorido-bromido PtIV stereoisomer pairs and chlorido-bromido PtIV ligand exchange reactions of the [PtCl6-nBrn]2- (n = 0 – 6) species and confirm the F- >> Cl- > Br- > I- order of thermodynamic stability as well as determining the ΔΔGo rxn within the range of 8 - 20 kJ.mol-1 to the experimentally determined ΔΔGo rxn.
AFRIKAANSE OPSOMMING: Tydens hierdie studie is „n robuuste “reverse-phase” ioonparing hoë-verrigting vloeistof chromatografie, RP-IP-HPLC, metode ontwikkel vir die skeiding, karakterisering en kwantifisering van alle moontlike [PtCl6-nBrn]2- (n = 0 – 6) en [PtCl4-nBrn]2- (n = 0 – 4) kompleks anione waar UV-Vis as detektor gebruik word. Die relavante spesies toedelings wat gemaak is, veral ten opsigte van die cis- en trans-[PtCl4Br2]2-, [PtCl2Br4]2- en mer- en fac-[PtCl3Br3]2- stereo-isomeerpare, is deur middel van hoë-resolusie 195Pt KMR van meer gekonsentreerde PtII/IV oplossings bevestig. Die PtII/IV spesies was gekwantifiseer deur die IP-RP-HPLC aan of „n ICPMS of „n ICP-OES te koppel. Daarenbowe was dit moontlik om die fotometriese eienskappe (λmax en ε) van elke individuele PtII/IV komplex anion te bepaal deur die UV-Vis absorpsie spektrum van elke elueerende spesies met PDA op te neem. Die nuwe metode wat tydens hierdie studie ontwikkel is het dit dus moontlik gemaak om sulke PtII/IV komplek sanione met standaard analitiese toerusting prakties te skei. Verder is gevind dat deur IP-RP-HPLC aan ICP-OES te koppel dit moontlik is om die Pt tot halied mol verhoudings van elke individueel geskeide spesies te bepaal en dus hierdie spesies op „n oorspronklike, nuwe manier te karakteriseer. Die Pt tot chloried en/of Pt tot bromied mol verhoudings van die [PtCl4]2- en die reeks van [PtCl6-nBrn]2- (n = 0 – 6) kompleks anione, soos bepaal deur gebruik te maak van HPLC-ICP-OES, is gebasseer op die 177.708 nm Pt, 134.724 nm Cl en 148.845 nm Br emissie lyne. Hierdie metode kan gebruik word vir die eenduidige chemiese skeiding van hierdie komplekse. Die sensitiwiteit van hierdie metode was egter verder verbeter deur gebruik te maak van ioonparing “reverse-phase” ultra hoë-verrigting vloeistof chromatografie gekoppel met elektrosprei ionisasie quadropool “time-of-flight” massa spektrometrie (UHPLC-ESI-Q-TOFMS). Deur dit te doen is dit nou selfs moontlik om die homoleptiese en heteroleptiese [PtIVCl6-nBrn]2- (n = 0 – 6) spesies, asook die “mono-aqauted” [PtIVCl5-nBrnH2O]- (n = 0 – 5) spesies in „n goed gedefinieërde aangesuurde waterige oplossings te skei en te karakteriseer. Die vlugtige ioon-paringsreagent, tributielamien, is vir die skeidingsproses op die IP-UHPLC gebruik om te verseker dat voldoende chromatografiese resolusie, so wel as lae genoeg agtergrondgeraas, verkry word vir hoë-resolusie ESI-Q-TOF-MS deteksie. Die rykdom informasie vervat in die massaspektrum van elke PtIV spesies het die indentifikasie van elke spesies vergemaklik. Daarenbowe het die fragmentasie tendens, aanduidend van „n konstante inkrementele verandering van 44 amu (71/81Br – 35/37Cl) weens die opeenvolgende substitusie van Cl- met Br-, tesame met die elusie volgorde, die spesies-toedelings gefasiliteer. Met hierdie nuut ontwikkelde metode is dit nou moontlik om al 22 [PtCl6-nBrn]2- (n = 0 – 6) en “mono-aquated” [PtCl5-nBrnH2O]- (n = 0 – 5) spesies in „n relatiewe kort tydperk (< 13 min) te karakteriseer. Deurdat elke [PtCl6-nBrn]2- (n = 0 – 6) spesies nou individueel met IP-HPLC-UV-Vis gekwantifiseer kan word, is dit moontlik om al 17 stabiliteitskonstantes vir die PtIV chloridobromido halied uitruilingsreaksienetwerk te bepaal. Die geassosieerde Gibbs vrye energie, ΔG°rxnKn (n = 0 – 17), wat vir elke stap in die uitruilingsreaksienetwerk bepaal is, tesame met die energiebewaring verhoudings, was gebruik om die akkuraatheid van die eksperimenteel bepaalde stabiliteitskonstantes te bekragtig. Verdermeer was die waarde van die algehele formasie konstante wat eksperimenteel bepaal is, ΔG°rxn, in goeie ooreenstemming met dit wat bereken is deur die standaard reaksie halfsel reduksie potensiale van [PtCl6]2- en [PtBr6]2-. Dus is die eksperimenteel verkrygde termodinamiese parameters bevestig. Die termodinamiese dryfkrag vir die PtIV chloried-bromied uitruilingsreaksies is toegereken aan die hidrasie van die halied ligande, wat in waterige oplossings die reaksie na die bromied PtIV spesies dryf, al is die chloried PtIV spesies energeties bevoordeel in hierdie reaksienetwerk. Evaluering van ander metaalkatioon- halied-uitruilreaksies wys dat alle metaal-halied komplekse die F- >> Cl- > Br- > I- orde van termodinamiese stabiliteit volg en dat hierdie volgorde slegs omgekeer sal word weens solvasie van hierdie halied ligande. Darenbowe digtheids funksionele teorie (DFT) gebruik om die termodinamiese stabiliteit met betrekking tot isodesmiese reaksies wat chloried-bromied PtIV stereoisomeer pare behels te voorspel, sowel as van chloried-bromied PtIV liganduitruilingsreaksies van die [PtCl6-nBrn]2- (n = 0 – 6) spesies, en bevestig die F- >> Cl- > Br- > I- volgorde van termodinamiese stabiliteit. Verder was dit ook moontlik om met DFT die ΔΔG°rxn tot so naby as 8 – 20 kJ.mol-1 te bereken.
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Ameline, Alice. "Aspects analytiques, cliniques et médico-judiciaires des nouvelles substances psychoactives." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAJ018/document.
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En raison de la diffusion incontrôlée sur le e-commerce, la sécurité et l’alternative légale aux stupéfiants habituels, les nouvelles substances psychoactives (NPS), d’apparition récente (2008), sont au cœur des phénomènes récents d’addiction et de décès mal expliqués. Au-delà des différents défis dans nos sociétés (prévention, législation), la capacité d’identifier les NPS dans des échantillons biologiques pour caractériser leur utilisation, présente de nombreux challenges analytiques. L’objectif principal de cette thèse a été de collecter des échantillons biologiques (sang, urine, cheveux) provenant de cas d’exposition à des NPS et d’y caractériser les substances présentes à l’aide de méthodes analytiques originales, dans le but d’enrichir les librairies de spectres de masse et d’améliorer, en conséquence, la détection de la consommation de NPS. En particulier, il s’agissait d’augmenter la fenêtre de détection de la prise de NPS en se focalisant sur les métabolites qui sont, le plus souvent, les produits majeurs d’élimination. Le développement analytique, par chromatographie liquide ultra haute performance couplée à la spectrométrie de masse en tandem (UHPLC-MS/MS), a demandé plusieurs mois d’optimisation afin d’obtenir une méthode robuste, exhaustive et sensible. Actuellement, la librairie de spectres MS comporte 114 NPS et est mise à jour régulièrement. A la suite de ce développement, ma thèse a porté sur l’étude de cas d’intoxication vus au service des urgences du CHU de Strasbourg, mais aussi en médecine légale, avec des situations de décès et d’identification de produits inconnus provenant de saisies (poudres et cristaux). Il a également été nécessaire de développer des outils analytiques complémentaires, tels que la caractérisation de métabolite(s) par étude sur microsomes hépatiques humains (HLMs), et l’utilisation de la spectroscopie par résonance magnétique nucléaire (RMN) afin d’identifier avec certitude certains composés et de déterminer leur degré de pureté. Les outils analytiques développés et la stratégie mise en place ont permis la rédaction de 18 publications, ainsi que l’agencement de nombreuses collaborationsDue to the uncontrolled spread on the Internet and their legal alternative to usual drugs, the new psychoactive substances (NPS), recently appeared (2008), are at the center of recent phenomena of addiction and badly explained deaths. Beyond different challenges in our societies (prevention, legislation), the ability to identify NPS in biological samples, in order to characterize their use, presents many analytical challenges. The main objective of this thesis was to collect biological samples (blood, urine, hair) from cases of exposure to NPS and to characterize the substances present using original analytical methods, in order to enlarge the libraries of mass spectra and improve, as a result, the detection of NPS consumption. In particular, it was intended to increase the detection sensitivity of NPS intake by focusing on the metabolites that are often the major products of elimination. This analytical development, by ultra-high liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS), required several months of optimization in order to obtain a robust, exhaustive and sensitive method. At present, the mass spectra database has 114 NPS and is regularly updated. Thereafter, ma thesis focused on the study of cases of intoxication observed in the emergency department of Strasbourg, but also in legal medicine with situations of deaths and identification of unknown products collected from seizures (powders and crystals). It has also been necessary to implement complementary analytical tools, such as the characterization of metabolites by human liver microsomes (HLMs), and the use of nuclear magnetic resonance (NMR) spectroscopy to accurately identify the compounds and establish their purity degrees. The analytical tools developed, and the strategy adopted, allowed the writing of 18 publications, as well as the setting up of numerous collaborations
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Tang, Jianhua. "Development of a Novel Gradient Chromatofocusing Tandem Mass Spectrometry Technique for the Determination of Cationic Compounds in Biofluids; Identification of Caspase 3 Cleavage Sites of NHE-1 by High Performance Liquid Chromatography-Mass Spectrometry." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1247344073.
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Sismotto, Marcela. "Desenvolvimento e validação de método analítico utilizando LC-MS/MS para determinação de macrolídeos em carne de tilápia do Nilo (Oreochomis niloticus)." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256289.
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Orientador: Felix Guillermo Reyes ReyesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Mestre em Ciência de Alimentos
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Costa, Ana Carolina de Oliveira. "Metodologias para determinação de fármacos, metabólitos e disruptores endócrinos em água de abastecimento público utilizando técnicas de separação em meio líquido (CE/UV, CE-MS, LC-MS/MS)." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-08112010-143525/.
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Este trabalho apresenta o desenvolvimento e validação de métodos analíticos para investigar a presença de fármacos e seus metabólitos, assim como disruptores endócrinos, em amostras de águas superficiais, utilizando estratégias de \"clean up\" e enriquecimento de amostra no modo \"on line\" (\"stacking\") e \"off line\" (extração em fase sólida, SPE), em junção com técnicas de separação avançadas em meio líquido (eletroforese capilar, CE, e cromatografia a líquido, LC, com detecção UV, e seus acoplamentos com espectrometria de massas). No primeiro Capítulo são discutidos aspectos gerais sobre os produtos farmacêuticos, produtos de higiene pessoal e disruptores endócrinos, bem como a origem e ocorrência destas substâncias no meio ambiente. O segundo Capítulo aborda o desenvolvimento de um método de separação capaz de determinar oito substâncias entre fármacos de caráter ácido e metabólitos (diclofenaco, bezafibrato, fenoprofeno, ibuprofeno, cetoprofeno, naproxeno e ácidos gentísico e salicílico) numa única corrida, utilizando eletroforese capilar com enriquecimento em linha da amostra (stacking do analito baseado em grande volume de injeção da amostra) utilizando eletrólito de corrida constituído por 30 mmol L-1 de tetraborato de sódio e 5 mmol L-1 de Brij 35, pH 9,3. O método proposto alcançou limites de detecção que variaram de 2 µg L-1 para o fármaco naproxeno até 80 µg L-1 para o ibuprofeno. No terceiro capítulo é explorado um método de separação por CE para nove substâncias entre fármacos e hormônios (fluoxetina, trimetoprima, diazepam, carbamazepina, propranolol, clofibrato, fenofibrato, etinilestradiol e estrona). Utilizou-se como estratégia de pré-concentração dos analitos, o modo \"stacking\" de micelas com grande volume de injeção de amostra. Este método chegou a limites de detecção na ordem de 9 µg L-1 com eletrólito de corrida composto por 30 mmol L-1 de ácido fosfórico, 40 mmol L-1 de dodecilsulfato de sódio, 20% (v,v) de acetonitrila e 0,1% (v,v) de trietilamina. No quarto capítulo, foi realizado o estudo de parâmetros físico-químicos que estão relacionados à técnica de extração em fase sólida, tais como tipo do sorvente, volume de capacidade, volume de eluição, lavagem do cartucho de extração, entre outros. As condições ótimas de \"clean up\" e pré-concentração \"off line\" da amostra obtidas foram combinadas com as condições ótimas de pré-concentração \"on line\" e separação descritas nos Capítulos 2 e 3, para todas as substâncias abordadas ali, com o intuito de analisar amostras reais de água superficial coletadas no reservatório Billings (Estado de São Paulo). O método combinado permitiu alcançar concentrações da ordem de 500 ng L-1, com valores de recuperação satisfatórios (58 - 88%), quando levada em consideração a origem complexa da matriz ambiental. No quinto capítulo, desenvolveu-se um método de análise de p-hidroxibenzoatos de alquila, substâncias utilizadas como conservantes em diversos produtos de uso diário, utilizando eletroforese capilar associada a estratégias de concentração \"on line\" (stacking com injeção de grande volume de amostra) e \"off line\" (SPE). O método proposto, utilizando eletrólito constituído por 40 mmol L-1 de glicina e 40 mmol L-1 de trietilamina, foi aplicado na análise destas substâncias em amostras de água superficial, alcançando níveis de concentração da ordem de 4 6 µg L-1. O sexto capítulo aborda o desenvolvimento de um método por eletroforese capilar destinada à análise de alquilbenzeno sulfonato linear (LAS) e homólogos, tensoativo comumente utilizado na composição de detergentes de uso doméstico e industrial. O eletrólito de separação era composto de 60 mmol L-1 TRIS, 30 mmol L-1 HIBA, 15 mmol L-1 Brij 35 e 40% (v,v) acetonitrila. Foi realizada uma etapa de extração em fase sólida (C18), e uma concentração total de LAS na ordem de 1,09 mg L-1 foi encontrada em uma amostra de efluente de estação de tratamento de esgoto. No capítulo 7 foi desenvolvido um método utilizando eletroforese capilar acoplada a um espectrômetro de massas, com analisador \" ion trap\", para a análise dos fármacos cimetidina, propranolol, salbutamol, trimetoprima e metoclopramida. Amostras de água coletadas no reservatório Billings foi fortificada com os fármacos em estudo e submetida a procedimento de extração em fase sólida em cartuchos de poliestireno divinilbenzeno (PS-DVB). O método permitiu a análise das substâncias estudadas na concentração aproximada de 40 µg L-1. Finalmente, no oitavo capítulo foi explorado um método envolvendo cromatografia líquida de alta eficiência, hifenada a dois tipos de espectrômetros de massas: um triplo quadrupolo e um triplo quadrupolo com \"ion trap\" linear. Foram investigados fármacos de diversas classes em amostras de água coletadas no reservatório Billings, sendo possível encontrar carbamazepina na concentração de 20 ng L-1, com apenas uma etapa de filtração da amostra antecedendo a análise, utilizando o triplo quadrupolo. Cabe destacar que o LOD para este analito foi de 400 fg L-1, sem nenhum tratamento da amostra visando préconcentração.This work presents the development and validation of analytical methods to investigate the presence of pharmaceutical compounds, their metabolites and endocrine disruptors in surface water using on line (stacking) and off line (solid phase extraction) sample clean up and enrichment strategies coupled to advanced separation techniques in liquid medium (capillary electrophoresis and liquid chromatography with UV detection and their hyphenation with mass spectrometry). In the first Chapter, general aspects on pharmaceuticals, products of personal care and endocrine disruptors are discussed as well as their origin and means of entry to the environment. Chapter 2 describes the development of a separation method for the determination of eight pharmaceuticals and endocrine disruptors substances with acidic character (diclofenac, bezafibrate, fenoprofen, ibuprofen, ketoprofen, naproxen, gentisic and salicylic acids) in a single run using capillary electrophoresis with on line sample enrichment (analyte stacking with large sample volume injection) in electrolytes composed of 30 mmol L-1 sodium tetraborate at pH 9.3 and 5 mmol L-1 Brij 35. The proposed method reached limits of detection between 2 µg L-1 (naproxen) and 80 µg mL-1 (ibuprofen). In Chapter 3, a CE separation method for the determination of nine pharmaceuticals and hormones with neutral and basic character (fluoxetin, trimethoprim, diazepam, carbamazepine, propranolol, clofibrate, fenofibrate, ethynylestradiol and estrone) was exploited. As preconcentration strategy, micelle stacking with large sample volume injection was performed. Limits of detection in the order of 9 µg L-1 were reached with electrolytes composed of 30 mmol L-1 phosphoric acid, 40 mmol L-1 sodium dodecylsulfate, 20% (v,v) acetonitrile and 0.1% (v,v) triethylamine. In Chapter 4, the physicochemical parameters associated with the solid phase extraction technique, such as sorbent type, breakthrough volume, elution volume, extraction cartridge rinse, among others, were evaluated. Optimum sample clean up and off line preconcentration conditions combined with the optimum on line preconcentration and separation conditions described in Chapters 2 and 3, for all substances under consideration, were applied to the analysis of real surface water samples collected at the Reservoir Billings (Sao Paulo state, Brazil). The combined method reached concentrations in the order of 500 ng L-1, with satisfactory recoveries (58 88%) for complex environmental matrices. In Chapter 5, a method for the analysis of alkyl p-hydroxybenzoates, substances used as preservatives in several products of personal care, was developed using capillary electrophoresis associated with on line (stacking with large volume injection) and off line (SPE) preconcentration strategies. The proposed method, which used 40 mmol L-1 glycine and 40 mmol L-1 triethylamine as electrolyte, was applied to the analysis of alkyl p-hydroxybenzoates in surface water, reaching 4 - 6 µg L-1 concentrations. Chapter 6 describes the development of a CE method for de analysis of linear alkylbenzene sulfonates (LAS) and homologues, surfactants commonly used in the composition of detergents of industrial and domestic use. As separation electrolyte, 60 mmol L-1 TRIS, 30 mmol L-1 HIBA, 15 mmol L-1 Brij 35 and 40% (v,v) acetonitrile was used. A solid phase preconcentration extraction step in C18 was employed and a total LAS concentration of 1.09 mg L-1 was found in a sample obtained from the effluent of a sewage treatment plant. In Chapter 7, a CE-MS (ion trap) method was developed for the analysis of cimetidine, propranolol, salbutamol, trimethoprim and methoclopramide in fortified surface water samples collected in the Reservoir Billings (Sao Paulo state, Brazil) and previously enriched by SPE (PS-DVB). The method reached concentrations of c.a. 40 µg L-1. Finally, in Chapter 8, a method based on high-performance liquid chromatography coupled with two different mass spectrometers: a triple quadrupole and a triple quadrupole with linear ion trap). Several pharmaceuticals were investigated in surface water samples collected from the Reservoir Billings (Sao Paulo state, Brazil). With the LC-MS/MS (triple quadrupole) system, carbamazepine was found in a non treated sample (just a filtration step prior to injection was performed) in a concentration level of 20 ng L-1. It is worth mentioning that for carbamazepine, a LOD of 400 fg L-1 was found, without any preconcentration sample treatment
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Pouech, Charlene. "Développement de méthodologies analytiques pour l'étude de la migration depuis des contenants en matière plastique prévus pour des applications pharmaceutiques vers des solutions aqueuses et des fluides biologiques." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10118.
Full textBooks on the topic "High Performance liquid chromatography coupled with mass spectrometry (LC-MS)"
Book chapters on the topic "High Performance liquid chromatography coupled with mass spectrometry (LC-MS)"
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Hansen, Steen Honoré, and Leon Reubsaet. "High-Performance Liquid Chromatography (HPLC) and High-Performance Liquid Chromatography-Mass Spectrometry (LC-MS)." In Bioanalysis of Pharmaceuticals, 123–72. Chichester, UK: John Wiley & Sons, Ltd, 2015. http://dx.doi.org/10.1002/9781118716830.ch7.
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Munar, Ada, Clint Frazee, Bridgette Jones, and Uttam Garg. "Cetirizine Quantification by High-Performance Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)." In Methods in Molecular Biology, 115–20. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3252-8_13.
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Vicente, Faye B., Gina Vespa, Alan Miller, and Shannon Haymond. "Quantification of Iohexol in Serum by High-Performance Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)." In Methods in Molecular Biology, 185–93. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3252-8_20.
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Vicente, Faye B., Gina Vespa, Alan Miller, and Shannon Haymond. "Quantification of Arginine and Its Methylated Derivatives in Plasma by High-Performance Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)." In Clinical Applications of Mass Spectrometry in Biomolecular Analysis, 21–30. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3182-8_3.
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Tian, H., Z. Bao, X. Chen, C. Wei, and Z. Tang. "A rapid analytical method for selenium species by high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS)." In Global Advances in Selenium Research from Theory to Application, 37–38. CRC Press, 2015. http://dx.doi.org/10.1201/b19240-20.
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Marchetti, Nicola, Annalisa Maietti, Luisa Pasti, and Alberto Cavazzini. "New Trends in Chiral High-Performance Liquid Chromatography-Tandem Mass Spectrometry." In Advances in the Use of Liquid Chromatography Mass Spectrometry (LC-MS) - Instrumentation Developments and Applications, 53–79. Elsevier, 2018. http://dx.doi.org/10.1016/bs.coac.2017.09.001.
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Salameh, WA, BX Holmquist, G. Lee, A. Caston-Balderama, X. Huang, NJ Clarke, K. Zhang, E. Reitz, and MF Holick. "Quantification of Serum 25-Hydroxyvitamin D2and 25-Hydroxyvitamin D3Using High-Performance Liquid Chromatography, Tandem Mass Spectrometry (LC-MS/MS): Correlation with PTH and Other Assay Methods." In The Endocrine Society's 92nd Annual Meeting, June 19–22, 2010 - San Diego, P1–181—P1–181. Endocrine Society, 2010. http://dx.doi.org/10.1210/endo-meetings.2010.part1.p4.p1-181.
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Wallace, Mike. "Measurement of hormones." In Oxford Textbook of Endocrinology and Diabetes, 45–53. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199235292.003.1040.
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The role of accurate and reliable laboratory testing is particularly important for patients with potential endocrine disorders. The revolution which has taken place in the past 50 years in the methodology of hormone measurement is thus of considerable significance to this patient group. It is difficult to imagine that not too long ago common hormone measurements, such as thyroid function tests, took more than a week to produce. Now we live in a world where same day turnaround is the norm for the high throughput commonly requested tests. This is largely due to advances in the way hormones are measured and results delivered to the practising clinical endocrinologist. Measuring hormones has always been a challenge as most circulate at extremely low concentrations, typically in the pico- (10–12) or nanomolar (10–9) range, and often in a milieu of closely related and potentially interfering compounds making great demands on method sensitivity and specificity. The most common procedures currently used are immuno- and immunometric assays but gas chromatography mass spectrometry (GCMS) and high-performance liquid chromatography (HPLC) also have a place. Liquid chromatography mass spectrometry (LC-MS/MS) is rapidly gaining acceptance for a limited number of hormone measurements. It is not the aim of this chapter to provide precise detail on hormone measurement methodology but rather to overview general principles and applications of methods in current use. Attention is drawn to preanalytical and analytical problems which could have significant clinical consequences if not recognized.
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Abbas, Mateen. "Chromatographic Techniques for Estimation of Aflatoxins in Food Commodities." In Aflatoxins [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98508.
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Aflatoxins, produced mainly by Aspergillus flavus Aspergillus parasiticus, have been documented as one of the major food contaminants throughout the world. Because of their toxic nature, these food contaminants have acknowledged considerable attention in recent years. Among the different types of Aflatoxins, the most prevalent and predominant Aflatoxins are AFB1, AFB2, AFG1, AFG2, AFM1, AFM2 which are considered the more lethal as compared to others. Several analytical and immunological methods are available for testing and estimating aflatoxins in different food commodities. However, chromatographic techniques have been considered superior regarding the estimation of aflatoxins both qualitatively and quantitatively. Chromatographic techniques have numerous applications for the separation and identification of chemical and biological compounds in food industry. It has grown to be the most popular and versatile of all analytical techniques in laboratories used for the analysis of multiple components in different matrices. For preliminary qualitative detection of Aflatoxins, Thin layer chromatography (TLC) is considered the best analytical technique which is being used broadly in food industry. However, liquid chromatographic techniques including High Performance Liquid Chromatography (HPLC) and Liquid chromatography-mass Spectrometry (LC–MS) are the best analytical techniques developed so far for the quantification of Aflatoxins in food commodities.
Conference papers on the topic "High Performance liquid chromatography coupled with mass spectrometry (LC-MS)"
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Guo, Zhongxian, Qiantao Cai, and Zhaoguang Yang. "Determination of Water-Soluble Organophosphorus Herbicides by Ion Chromatography With Inductively Coupled Plasma Mass Spectrometry Detection." In 1st Water Quality, Drought, Human Health and Engineering Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/water2006-20024.
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There is a high risk for human exposure to organophosphorus pesticides through contaminated drinking water. Glyphosate, glufosinate, fosamine and ethephon are among the water-soluble herbicides used currently. Sensitive and rapid analytical methodologies are critical for evaluating their residuals in a broad variety of samples, including environmental waters. However, challenges arise from the inherent chemical properties of the herbicides: strong polarity, high solubility in water, insolubility in organic solvent (except ethephon), absence of chromophore or fluorophore in their molecular structures. So far very rare analytical methods are available for ethephon [1] and fosamine [2], while glyphosate and glufosinate are often determined by gas chromatography [3], high performance liquid chromatography (HPLC) [4] and capillary electrophoresis (CE) [5]. Inductively coupled plasma mass spectrometry (ICP-MS) is sensitive, rapid, selective, and is more powerful when hyphenated with appropriate separation. For the analysis of glufosinate, glyphosate and its metabolite aminomethylphosphonic acid (AMPA), ICP-MS was recently coupled to CE [6] or ion-pairing reversed-phase LC [7].
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Sheng, Chenguang, A. G. Agwu Nnanna, Yanghe Liu, and John D. Vargo. "Removal of Pharmaceutical Contaminants in Water." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-53240.
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Pharmaceutical contaminants in drinking water could potentially lead to increasing risks of heart attacks, organ damage, mental health and even cancer. Because their presence, frequency of occurrence, or source may not be known, the chemicals being discovered in water that previously had not been detected or are being detected at levels that may be significantly different than expected. Removal of emerging contaminants is considered recently to be one of the most important processes within advanced Waste Water Treatment Plants (WWTPs) system. EPA is working to improve its understanding of a number of emerging contaminants, particularly pharmaceuticals and personal care products (PPCPs). The objectives of this research are: 1) to identify the presence of selected emerging contaminants (Acetaminophen, Bezafibrate, Caffeine, Carbamazepine, Cotinine, Diclofenac, Gemfibrozil, Ibuprofen, Metoprolol, Naproxen, Sulfadimethoxine, Sulfamethazine, Sulfamethoxazole, Sulfathiazole, Triclosan and Trimethoprim). These contaminants were selected based on analyte selection criteria such as occurrence and availability of analytical standards, chronological ecotoxicity and environment relevance concentration, volume of use, and priority ranking, as well as literature survey on environmental occurrence studies in local WWTPs; 2) to estimate the corresponding WWTPs’ removal efficiency; and the third objective is to evaluate the feasibility of applying ultra-filtration (UF) membrane combined with pretreatments — powder activated carbon (PAC), coagulation, and sand filtration to remove the above emerging contaminants. This paper appraises the efficacy of ultra-filtration membrane coupled pretreatments to mitigate the presence of pharmaceutical contaminants in water. This work is a sequel to an earlier work, Liu et al., published in 2014 ASME-IMECE conference proceedings. In this study, water samples were analyzed using direct aqueous injection High Performance Liquid Chromatography with Tandem Quadrupole Mass Spectrometric (LC/MS/MS) detection. Through the project research period, both historical concentrations from WWTPs and experimental removal efficiency data were obtained. Results showed that conventional WWTP failed to remove Carbamazepine, Diclofenac and Trimethoprim, and in some cases, the concentration of these contaminants at the effluent were higher than influent concentration. Secondly, the ultrafiltration membrane system by itself was insufficient to remove the selected contaminants. However, the use of PAC as a pretreatment to the UF system was effective in removing most of the contaminants, and the removal efficiency was a function of PAC dosage. Results indicated that there is an optimum dosage where the removal efficiency must be balanced with the cost of PAC. Unlike PAC, coagulation coupled with filtration process, was not able to increase the contaminants removal efficiency significantly. Additionally, the historical data indicated there was no dramatic fluctuation of the target contaminants level during the 12-month monitoring period.
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Blebea, Nicoleta Mirela, and Simona Negreș. "METHODS FOR QUANTIFICATION OF THE MAIN CANNABINOIDS IN CBD OIL." In GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/13.
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Cannabidiol (CBD) is an alkaloid present in Cannabis sativa, together with tetrahydrocannabinol (THC) and more than 120 other substances belonging to a group of compounds named cannabinoids. Due to the continuous increased usage of CBD oils, it became necessary to be developed efficient methods for the identification of its compounds and especially for the characterization of the cannabinoids from the commercial specimens. Cannabinoids may be detected by many and different analytical methods, including immunoassays (EMIT®, Elisa, fluorescent polarization, radioimmunotest), techniques of flat chromatography: classic thin layer chromatography (TLC), optimum performance laminar chromatography (OPLC) and multiple development automatization (AMD), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography-mass spectrometry (HPLC-MS). Ultraviolet signal (UV) is used for the quantification of major cannabinoids and the mass spectrometer is used for the quantification of minor cannabinoids. The purpose of this study was to compare the performances of TLC, Ultra High-Performance Liquid chromatography with Photodiode Array Detection (UHPLC with PDA) and LC-MS/ MS technique for the qualitative and quantitative determination of cannabinoids in 3 commercial oils with CBD. Having in view that CBD may be found in many forms of oils, on the legal market of the internet, we believe that the development of a method for the qualitative and quantitative determination may be an interesting subject for the pharmaceutical professional persons.
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Chen, Hsieh, Sehoon Chang, Gawain Thomas, Wei Wang, Afnan Mashat, and Hussain Shateeb. "Comparison of Water and Gas Tracers Field Breakthrough." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205863-ms.
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Abstract We are developing new classes of barcoded advanced tracers, which, compared to present commercial offerings, can be optically detected in an automated fashion. The eventual goal for the advanced tracers is to deploy cost-effective, ubiquitous, long-term, and full-field tracer tests in supporting large-scale waterflooding optimization for improved oil recovery. In this paper, we compare model predictions to breakthrough data from two field tests of advanced tracers in a pilot during water alternating gas (WAG) cycles, where gas tracer tests have recently been performed as well. Two advanced tracer injections were performed at the test site. For the first injection, only a dipicolinic acid based advanced tracer (DPA) was injected. For the second injection, DPA and a phenanthroline- based advanced tracer, 4,7-bis(sulfonatophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BSPPDA), was injected in conjunction with a commercially available fluorobenzoic acid-based tracer (FBA) to benchmark their performance. Produced water samples were collected weekly for tracer analysis. Both newly developed 2D-high performance liquid chromatography/time-resolved fluorescence optical detection method (2D-HPLC/TRF) and liquid chromatography-mass spectrometry (LC-MS) were used to construct the breakthrough curves for the advanced tracers. In parallel, gas chromatography-mass spectrometry (GC-MS) was used to detect FBA tracer. Gas tracer tests have been performed on the same field. Since DPA, BSPPDA and FBA tracers were water tracers as designed, they were expected to appear in between gas tracer breakthroughs, and we observed exactly that for BSPPDA and FBA. Unexpectedly, the DPA predominantly appeared along with gas tracer breakthroughs, suggesting its favorable compatibility with the gas phase. We suspect the presence of some gas components rendered the medium more acidic, which likely protonates DPA molecules, thereby alters its hydrophilicity. A wealth of information could be gathered from the field tests. First, all tracers survived not only the harsh reservoir conditions but also the irregular WAG injections. Their successful detection from the producers suggested robustness of these materials for reservoir applications. Second, the breakthrough curves of the BSPPDA tracers using optical detection method were very similar to those of FBA tracers detected by GC-MS, substantiating the competency of our in-house materials and detection methods to the present commercial offerings. Finally, even though DPA has passed prior lab tests as a good water tracer, its high solubility to gas phase warrants further investigation. This paper summarizes key results from two field trials of the novel barcoded advanced tracers, of which both the tracer materials and detection methods are new to the industry. Importantly, the two co- injected advanced tracers showed opposite correlations to the gas tracers, highlighting the complex physicochemical interactions in reservoir conditions. Nevertheless, the information collected from the field trials is invaluable in enabling further design and utilization of the advanced tracers in fulfilling their wonderful promises.