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Characterization and Detection of N-Nitrosodimethylamine Precursors during Ozonation and Chloramination in Drinking Water Treatment / 浄水処理におけるオゾン処理およびクロラミン処理でのN-ニトロソジメチルアミン前駆体の特性評価と検出Hinneh, Klon D. C. 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第24601号 / 工博第5107号 / 新制||工||1977(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 伊藤 禎彦, 准教授 西村 文武, 教授 越後 信哉 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
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Agrotóxicos em doces de frutas em pasta: determinação de resíduos por μlc-qtrap-ms/ms e estudo de estabilidade / Pesticides in fruit jams: residues determination by μlc-qtrap-ms/ms and stability studyReichert, Bárbara 24 July 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents multi-method for pesticide residues determination in fruit
jams. Slurries of the fruit jams and ultrapure (u.p.) water were prepared to yield
homogeneous samples and to facilitate the sample handling. The modified
QuEChERS method was used for the sample preparation. Due the high detectability
of the micro flow liquid chromatography triple quadrupole-linear ion trap mass
spectrometry equipment (μLC-QTRAP-MS/MS) and to minimize the matrix effect (%)
the acetonitrile extracts were diluted 30-fold before analysis. The method validation
was performed analyzing spiked samples at the concentrations of 9 and 45 μg kg-1
(n=5). The method met validation criteria of 70 120% recovery and relative standard
deviation (RSD) ≤ 20% for 93% (99) of the 107 pesticides evaluated. The reporting
limit (RL) was 9 and 45 μg kg-1 for, respectively, 66% and 26% of the analytes, 5% of
the compounds did not fulfill the requirements for validation and 3% were not
detected at the studied concentrations. The validated method was applied to the
analysis of 51 different fruit jam samples from Brazil and from Spain. Pesticide
residues were detected in 80% of the samples, 51% of which contained at least one
pesticide at concentration higher than 10 μg kg-1. Moreover, the stability of five
pesticides was evaluated in the preparation of home-made fruit jams from spiked
fruits. Thereunto, five types of fruits (orange, apple, strawberry, pear and peach, with
n=2 for each type of fruit) were grinded and spiked at 500 μg kg-1 with a mixture of
carbendazim, chlorpyrifos, imidacloprid, iprodione and propargite. Home-made jams
were prepared with these spiked samples by cooking, over medium heat, the grinded
spiked fruit with sugar and u.p. water (ratio, 5:5:2, w/w/w), in an open pan for 30 min.
The modified QuEChERS extraction method was applied either to blank fruits, to the
fruits spiked at 500 μg kg-1 and to the home-made jams (prepared from spiked fruits
at 500 μg kg-1). The extracts of home-made jams and blank fruits were analyzed by
liquid chromatography quadrupole-time of flight mass spectrometry (LC-QTOF-MS)
to ascertain the occurrence of the known metabolites of the spiked pesticides and to
determine the number of co-extracted matrix components from the fruits and from the
jams. All samples were also analyzed by μLC-QTRAP-MS/MS for estimation of the
pesticides processing factors. So the pesticide concentrations found in the spiked
fruits were compared to the concentrations found in the home-made jams (pesticide
concentration measured in the jams/pesticide concentration measured in the raw
fruits). / Este trabalho apresenta um método multirresidual para determinação de resíduos de
agrotóxicos em doces de fruta em pasta. Para obter-se amostras homogêneas e de fácil
manipulação preparou-se uma mistura (slurry) dos doces de frutas e água ultrapura (u.p.). O
preparo das amostras foi feito utilizando o método QuEChERS modificado. Com o objetivo
de diminuir o efeito matriz (%) das amostras e pela alta detectabilidade do equipamento de
cromatografia de micro vazão a líquido acoplada à espectrometria de massas híbrida triplo
quadrupolo-armadilha de íons linear (μLC-QTRAP-MS/MS) os extratos de acetonitrila foram
diluídos na razão de 1:30 (v/v) antes da análise. A validação do método analítico foi feita
pela análise de amostras de doces de uva fortificadas nas concentrações de 9 e 45 μg kg-1
(n=5). Dos 107 agrotóxicos avaliados 93% (99) obtiveram recuperações de 70 a 120% e
desvio padrão relativo (RSD) ≤ 20%. Os limites de notificação (RL) foram de 9 e 45 μg kg-1
para, respectivamente, 66% e 26% dos agrotóxicos avaliados, 5% dos compostos não
alcançaram os pré-requisitos necessários para a validação e 3% não foram detectados nas
concentrações estudadas. Após a validação do método, foram analisadas 51 amostras de
doces de frutas provenientes do Brasil e da Espanha. Em 80% amostras foram detectados
resíduos de agrotóxicos, 51% destas continham no mínimo um agrotóxico em concentração
maior que 10 μg kg-1. Além disso, avaliou-se a estabilidade de cinco agrotóxicos no preparo
de doces de frutas caseiros. Para isso, cinco tipos de frutas (laranja, maçã, morango, pera e
pêssego, com n=2 para cada tipo de fruta) foram trituradas e fortificadas com uma mistura
de carbendazim, clorpirifós, imidacloprido, iprodiona e propargito a 500 μg kg-1. Essas
amostras foram utilizadas no preparo de doces de frutas caseiros. Para isso, as frutas
trituradas e fortificadas foram cozidas com açúcar e água u.p. (proporção de 5:5:2, m/m/m)
em panela aberta sob fogo médio durante 30 min. O método QuEChERS modificado foi
aplicado às frutas não fortificadas, às frutas fortificadas (500 μg kg-1) e aos doces de frutas
caseiros (preparados com frutas fortificadas a 500 μg kg-1). Os extratos dessas amostras
foram analisados por cromatografia a líquido acoplada à espectrometria de massas híbrida
quadrupolo-de tempo de voo (LC-QTOF-MS), com o objetivo de verificar a presença dos
metabólitos conhecidos dos agrotóxicos e determinar o número de componentes coextraídos
das matrizes. Todas as amostras foram analisadas também por μLC-QTRAPMS/
MS com o objetivo de comparar a concentração dos agrotóxicos nas frutas fortificadas
com as concentrações nos doces de frutas correspondentes. A partir dessa relação foi
possível estimar um fator de processamento (FP) para os agrotóxicos no preparo dos doces
de frutas caseiros (concentração do agrotóxico no doce de fruta/concentração do agrotóxico
na fruta fortificada).
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Aufbau und Anwendung einer Methode zur Identifizierung und Quantifizierung von Giften und deren Metaboliten in Blut und Haaren in der Systematischen Toxikologischen Analyse mittels Flüssigchromatographie-Quadrupol-Flugzeitmassenspektrometrie-Kopplung (LC-QTOF-MS)Broecker, Sebastian 15 February 2012 (has links)
Die Systematische Toxikologische Analyse (STA) stellt auf Grund der großen Vielfalt und der ständigen Zunahme an toxikologisch relevanten Substanzen eine der größten Herausforderungen in der chemischen Analyse dar. In der vorliegenden Arbeit wurde daher die Eignung der Flüssigchromatographie in Kombination mit der Hybrid-Quadrupol-Flugzeitmassenspektrometrie (LC-QTOF-MS) für diesen Zweck untersucht. Dazu wurden eine Datenbank mit über 7360 und eine CID-Spektrenbibliothek mit mehr als 2720 toxikologisch relevanten Substanzen erstellt und geeignete Probenvorbereitungsmethoden entwickelt. Die Erprobung der Methoden erfolgte an dotierten Blut- und Haarproben. Hierbei zeigte sich, dass die Analyse im Auto-MS/MS-Modus (Messzyklen von MS- und MS/MS-Spektren) eine Identifizierung basischer Substanzen mittels CID-Spektren zwischen 0,5 und 2 ng/ml im Blut ermöglichte. Die Nachweisgrenzen der für 24 Wirkstoffe validierten Methode in Haaren lagen bei 3 bis 15 pg/mg. Die Eignung der LC-QTOF-MS zur STA von Haarproben wurde an 30 Drogentodesfällen und 60 Todesfällen mit bekannter chronischer Medikamenteneinnahme zu Lebzeiten sowie an 77 Blutproben nachgewiesen. Für die Suche nach Metaboliten wurde ein Metaboliten-Tool entwickelt. In der praktischen Anwendung auf Datenfiles von Blut- und Haarproben erwies sich das Tool als wertvolles Hilfsmittel zur Identifizierung unbekannter Peaks und zur Bestätigung von Suchergebnissen in der Datenbank. Zur automatischen Konzentrationsabschätzung identifizierter Substanzen wurde ein Tool „Estimate Concentration“ geschaffen. Die Überprüfung des Verfahrens an realen Blut- und Haarproben durch Vergleich mit HPLC-DAD- und GC-MS-Ergebnissen wies eine gute Übereinstimmung der Konzentrationen auf. Insgesamt zeigten die Untersuchungen, dass die LC-QTOF-MS zurzeit die am besten geeignete Methode für die STA darstellt. Auch bei einem erst später aufkommenden Verdacht kann eine gezielte Suche in dem bereits gemessenen Datenfile durchgeführt werden. / Due to the large variety and the steady increase of toxicologically relevant substances, systematic toxicological analysis (STA) is one of the most difficult tasks in analytical chemistry and, therefore, a steady topic of research and methodical improvement. For this reason, the suitability of liquid chromatography in combination with hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) for STA was investigated. For this purpose, a database of more than 7360 and a CID spectra library of more than 2720 toxicologically relevant substances and suitable methods for sample preparation were developed. The application was evaluated at spiked blood and hair samples. It was found that the analysis in Auto-MS/MS mode (alternating measurement cycles of MS and MS/MS spectra) allowed substance identification in blood using CID spectra between 0.5 and 2 ng/ml for basic substances. The detection limits of the validated method in hair ranged from 3 to 15 pg/mg for 24 drugs. The suitability of LC-QTOF-MS for STA was tested for hair samples from 30 drug-related death cases and from 60 death cases with known chronic medication as well as for 77 blood samples. For the search of metabolites, a metabolite tool was developed. In the practical application to data files from blood and hair samples, the tool proved to be very helpful for identification of unknown peaks and for confirmation of results obtained only from the database without CID spectra. A tool "Estimate Concentration" was created for automatic estimation of concentrations of identified substances. The application to real blood and hair samples and the comparison of the concentrations with results from HPLC-DAD and GC-MS showed good agreement. Overall, these investigations showed that LC-QTOF-MS is currently the most favorable method for STA. Because of the comprehensive registration of all substances in a sample, the data files can be checked for the presence of certain poisons even later without new measurements.
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