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Mass spectrometry is an indispensable tool in lipidomics research. Current advances and progress in the technology of mass spectrometry have allowed for the identification, quantification and characterization of lipid molecular species to further our understanding of their biological roles. In this thesis, I assessed the influence post-mortem times have on quantitative lipidomics. Using liquid chromatography - electrospray ionization tandem mass spectrometry (LC-ESIMS/MS) on a triple-quadrupole mass spectrometer and multiple-reaction-monitoring (MRM) mode, the glycerophosphocholine (GPC) metabolites and second messengers in the hippocampus of N3 & N4 C57BL/6 x 129/SV were profiled at various post-mortem interval (PMI). I found that disruption to the GPC metabolite and second messengers lipidome occured as early as 1 hour postmortem and fluctuate up till at least 12 hours post-mortem. Therefore, PMI is a variable in lipidomic studies that must be controlled for, and brain samples which are collected with PMI variations must be matched to avoid misinterpretation. Subsequently, I developed a working protocol to visualize the location and distribution of different classes of glycerophospholipids, ceramides, and sphingomyelin in whole mouse brain sections. This visualization technique is novel because it does not require tissue staining or immunohistochemistry; instead, it was performed using an atmospheric-pressure matrix-assisted laser desorption/ionization (AP-MALDI) source coupled to an orbitrap mass spectrometer. As part of this lipid visualization technique, I also developed a protocol for sublimation as a simple, effective and reproducible matrix application method for brain tissue. The lipid-compatible matrix, 2,5-dihydroxybenzoic acid (DHB), was assessed and optimized for imaging lipid targets. The high mass-resolution and accuracy characteristics of the orbitrap mass spectrometer and its capability to perform tandem mass spectrometry via high-collision dissociation allowed for the identification of approximately 200 different lipid species directly from brain tissue using the visualization technique I developed. Altogether, the work in this thesis has showed that post-mortem changes in the lipidome are quantifiable and has provided a novel avenue to further assess these changes by means of imaging mass spectrometry.

Phospholipids are dominant components of bacterial cell membranes, where they create double layers. Bacteria differ in their phospholipid composition determination of which can help in identification of important groups of microorganisms. Phospholipid composition of bacteria is influenced by many environmental factors, therefore its variation can be observed within one bacterial stem also. Because of its simplicity, thin layer chromatography is usually applied to identification and determination of bacterial phospholipids. Disadvantage of this method are the high demands of time, carefulness and skills of the analytical personnel. The increasing interest in the phospholipid double-layer promotes the detailed investigation of their fatty acid composition because the more detailed analyses allows for more information yield about bacteria. Gas chromatography hyphenated with mass spectrometry seems to be the best choice for these purposes. Fatty acid identity and total fatty acid content in phospholipid molecules could be determined by this method. Additionally, number, position and isomerism of double bonds and presence of other functional groups on hydrocarbon chain could be determined. Whereas a suitable and...

Para um composto químico exercer seu efeito bioativo é necessário que ele atravesse várias barreiras biológicas até alcançar seu sitio de ação. Propriedades farmacocinéticas insatisfatórias (como absorção, distribuição, metabolismo e excreção) são reconhecidamente as principais causas na descontinuidade de pesquisas na busca por novos fármacos. Neste trabalho, modelos biofísicos foram utilizados para o estudo de absorção de uma série de flavonóides naturais com atividade tripanossomicida. O coeficiente cromatográfico de partição, kw, foi determinado através da cromatografia líquida de alta eficiência em fase reversa, RP-HPLC, utilizando-se de colunas cromatográficas empacotadas com constituintes básicos da membrana biológica (fosfatidilcolina e colesterol). Os resultados obtidos demonstraram que nas colunas compostas por fosfatidilcolina a retenção de flavonóides hidroxilados é determinada por interações secundárias, além da partição, e no caso da coluna de colesterol, a partição é o principal mecanismo que rege a retenção. Uma série de descritores físico-químicos foi gerada pelos campos moleculares de interações (MIFs) entre os flavonóides naturais e algumas sondas químicas virtuais, utilizando o programa GRID. Os descritores físico-químicos gerados foram correlacionados com os log kw por análise dos mínimos múltiplos parciais (PLS), utilizando o programa VolSurf, com a finalidade de gerar um modelo quantitativo entre estrutura e propriedade (QSPR) para esta classe de compostos. O modelo produzido por este estudo, ao utilizar os dados de partição em colesterol, log kwCol, apresentou elevada consistência interna, com bom poder de correlação (R2 = 0, 97) e predição (Q2 = 0,86) para a partição destas moléculas / In order to a chemical compound exert its bioactive effect it is necessary that it crosses some biological barriers until reaching its site of action. Unfavorable pharmacokinetics properties (absorption, distribution, metabolism and excretion) are admittedly one of the main causes in the discontinuity of research in the search for new drugs. In this work, biophysics models were used for the study of absorption of a series of natural flavonoids with trypanocide activity. The chromatographic retention indices (log kw) were determined on immobilized artificial membranes columns (IAM.PC.DD, IAM.PC.DD2, Cholesteryl 10-Undecetonoato) obtained by the extrapolation method. The results demonstrated that in the composed columns for fosfatidilcolina the retention of hydroxil flavonoids is determined by secondary interactions, beyond the partition. In the case of the retention for the cholesterol column, the partition is the main mechanism that drives the retention. A series of physico-chemical descriptors were generated by the molecular interaction fields (MIF) between the flavonoids and some virtual chemical probes, using the program GRID. The descriptors were correlated with log kw by the partial least squares regression (PLS), using the VolSurf program, with the purpose to generate a quantitative model between the structure and the retention (QSRR) for this compounds class. The model produced for this study, when using the data of partition in cholesterol, log kwCol, presented high internal consistency, with good correlation power (R2 = 0, 97) and prediction (Q2 = 0,86) for the partition of these molecules

O objetivo desta pesquisa foi desenvolver e validar métodos analíticos para o fármaco besilato de anlodipino (ABC) em comprimidos. O método espectrofotométrico no ultra violeta e o método por cromatografia líquida de alta eficiência (CLAE) desenvolvidos foram considerados simples, exatos e precisos. Foram analisadas amostras contendo 5 mg,10 mg e uma amostra formulada de 5mg de ABC/comprimido. Para o método espectrofotométrico, a primeira diluição das amostras foi feita em metanol e as subseqüentes em água. A leitura foi efetuada a 364,4 nm. A linearidade para ABC foi estabelecida na faixa de 41,0-61,0 mg/mL e o coeficiente de correlação foi R= 0,9996. O limite de detecção e o de quantificação foram respectivamente 0,54 e 1,8 mcg/mL. A exatidão e a precisão foram 98,99% e 0,37%, respectivamente. Nas análises por cromatografia líquida de alta eficiência (CLAE), foram utilizadas as seguintes condições: coluna LiChrospher ® 100 RP-18 Merck ® (250 mm x 4,6 mm, 5µm), fase móvel constituída por metanol: água: (35:65) com 1% de TEA e pH ajustado para 5.0 com ácido fosfórico; fluxo de 1,0 mL/min; detecção UV a 238 nm e temperatura de 22 ±1°C.Tempo de retenção (RT) ABC foi de 3,7 min. Foi obtida linearidade no intervalo de 50 a 350 mcg/mL e coeficiente de correlação = 0,9999. O limite de detecção e o de quantificação foram respectivamente de 2,26 mcg/mL e 7,52 mcg/mL. A exatidão foi de 100,18% e a precisão foi de 0,37% para a CLAE. Ambos os métodos podem ser usados na rotina de análise para o controle de qualidade de comprimidos contendo ABC. / The objective of this research was to develop and validate analytical methods for the amlodipine besylate (ABC) determination in tablets. Simple, accurate and precise spectrophotometric and HPLC methods were validate for ABC determination in samples containing 5.0 and 10.0 mg of ABC / tablet. For the spectrophotometric method, the first dilutions of samples were made in methanol and the consecutive in distilled water. Determination was made at 364.4 nm. Linearity was in the range of 41.0-61.0 µg/mL and r= 0.9996. The detection and quantitation limits were respectively, 0.54 µg/mL and 1.80 µg/mL. Accuracy and precision were respectively, 98.99% and 0.37%. For HPLC analysis, the following conditions were used: a LiChrospher ® 100 RP-18 Merck® (250 mm x 4,6 mm, 5µm) column; methanol: water with 1% of triethylamine adjusted to pH 5.0 with phosphoric acid (35:65), as mobile phase; a flow rate of 1.0 mL /min; UV detection at 238 nm and temperature of 22 ±1 °C . Retention time was 3.7 min. Linearity was in the range of 50.0 - 350.0 µg/mL and r = 0.9999. The detection and quantitation limits were respectively, 2.26 µg/mL and 7.52 µg/mL. Accuracy and precision were respectively, 100.18% and 0.37%. Both methods can be used in routine analysis for quality control of tablets containing ABC.

O difosfato de cloroquina é um fármaco antimalárico, de conhecida fotossensibilidade. O presente trabalho teve como objetivo desenvolver, caracterizar e avaliar a fotodegradação de complexos binários e ternários de difosfato cloroquina. Para tanto, foi desenvolvida uma metodologia analítica que permitiu identificar e quantificar o fármaco por CLAE com detecção UV, que mostrou seletividade, além de adequada especificidade, sensibilidade, linearidade, precisão exatidão, frente a seus respectivos produtos de degradação e fotodegradação. Os complexos com β-ciclodextrina e HP-β-ciclodextrina obtidos não foram capazes proteger o fármaco da degradação promovida pela luz nos meios água, HCI 0,1N e tampão fosfato pH 6,8. Em HCI 0,1N verificou-se que alguns complexos capazes, inclusive, de acelerar a degradação promovida pela luz. Foram também realizados estudos de recristalização do fármaco em diferentes solventes para avaliar o impacto sobre suas características físico-químicas, os quais resultaram possíveis modificações cristalinas observadas mediante técnica de DSC quando foram utilizados etanol e clorofórmio como solventes para o processo. / The chloroquine diphosphate is an antimalarial drug of know photosensibility. The present work had as objective to development, characterize and evaluate photodegradation of binary and ternary complex of chloroquine diphosphate. For such a way, an analytical methodology was developed that allowed to identify and quantify the drug for CLAE with detection UV, that showed good selectivity, beyond adjusted specificity, sensitivity, linearity, precision and accuracy, front its respective products of degradation and photodegradation. The complexes with &#946-ciclodextrin and HP-&#946-ciclodextrin had not been capable to protect the drug of the degradation promoted by the light in solvent water, HCl 0,1N and buffer phosphate pH 6,8. In HCl 0,1N is verified that some complex are capable to speed up the degradation promoted by the light. Also studies of recrystallization of the drug in different solvents were carried trough to evaluate the impact on its physical-chemistry characteristics, which had resulted in possible observed by DSC crystalline modifications technique when ethanol and chloroform had been used as solvent for the process.

A ocorrência de fármacos residuais no meio ambiente pode levar a efeitos adversos, tanto em organismos aquáticos como em terrestres. Os fármacos, tanto humanos como de uso veterinário, são absorvidos pelo organismo e estão sujeitos a reações metabólicas e, uma quantidade significativa dessas substâncias, tanto a original como seus metabólitos, são excretadas. Por não serem facilmente biodegradáveis, terem propriedades farmacológicas danosas quando administrados indevidamente, através de água contaminada, é crescente a preocupação com o destino destes fármacos residuais, principalmente com relação à avaliação de risco ambiental. A ocorrência destes resíduos, principalmente em águas superficiais e sistemas de abastecimento, vem sendo objeto de estudos em diversos países, principalmente na Europa. Por isso, a detecção, a eliminação e a investigação do destino destes compostos estrógenos em ecossistemas aquáticos têm tido prioridade na química ambiental. Estes produtos são encontrados nos corpos d\'água em baixas concentrações, de \'mü\'g L-1 a \'eta\'g L-1 e, mesmo assim, podem afetar os organismos por meio da bioacumulação. Estudos toxicológicos relacionados a efeitos crônicos em organismos expostos, são escassos. O objetivo do projeto foi adaptar e validar a metodologia analítica, e monitorar a presença de resíduos de hormônios nas águas dos Rios Corumbataí e Piracicaba e amostras de água de abastecimento da cidade de Piracicaba, SP, Brasil. Foram coletadas amostras de água bruta dos Rios Piracicaba e Corumbataí e água de abastecimento residencial da cidade de Piracicaba, SP, no período de novembro de 2007 a abril de 2009. Dentre os hormônios estudados estão o 17\'alfa\'-etinilestradiol (17\'alfa\'-EE2), 17\'beta\'-estradiol (17\'beta\'-E2) e estriol (E3). O método foi baseado na extração em fase sólida (SPE) e cromatografia líquida de alta eficiência (HPLC-DAD) / The occurrence of drug residues in the environment may lead to adverse effects, both on land and aquatic organisms. The drugs, for human and veterinary use, are absorbed by the organism and are subjected to metabolic reactions and a significant amount of these substances, both the original and its metabolites are excreted. By being not easily biodegradable and by having harmful pharmacological properties when administered through contaminated water, there is a growing concern about the fate of these residual drugs, especially in respect to the assessment of environmental risks. The occurrence of these residues, especially in surface Waters and water supplies has been the subject of studies in several countries, mainly in Europe. Therefore, detection, investigation and disposal of the fate of these estrogens compounds in aquatic ecosystems have a high priority in the field of environmental chemistry. These products are found in water bodies in low concentrations, from \'mü\'g L-1 a \'eta\'g L-1 and can still affect the organisms due to bioaccumulation. Toxicological studies related to chronic effects in the exposed organisms are scarce. The goals of this project was to adapt and validate the analytical methodology, and monitor the presence of hormone residues in the Waters of the Corumbataí and Piracicaba rivers and samples of water supply from the city of Piracicaba, SP, Brazil. We collected samples of raw water from the rivers of Piracicaba and Corumbataí and residential water supply from the city of Piracicaba in the period November 2007 to April 2009. Among the hormones studied are the 17\'alfa\'-ethinylestradiol (17\'alfa\'-EE2), 17\'beta\'-estradiol (17\'beta\'-E2) and estriol (E3). The method is based on solid phase extraction (SPE) and high performance liquid chromatography (HPLC-DAD)

<p>Insekticidi novije generacije, neonikotinoidi, odlikuju se specifičnim načinom &nbsp;delovanja na&nbsp;nervni sistem insekata. Radi dobijanja &scaron;to brže i kvalitetnije informacije o izloženosti životne sredine&nbsp;ovim insekticidima i količinama njihovih ostataka u hrani potrebno je raspolagati odgovarajućim&nbsp;instrumentalnim metodama za njihovo određivanje. Razvijene su i optimizovane analitičke metode&nbsp;zasnovane na tečnoj hromatografiji za određivanje sedam odabranih neonikotinoida (dinotefurana,&nbsp;nitenpirama, tiametoksama, klotianidina, imidakloprida, acetamiprida &nbsp;i tiakloprida) u medu i likeru od&nbsp;meda. Ispitivana je mogućnost određivanja klotianidina pomoću tečne hromatografije visoke efikasnosti&nbsp;sa detektrorom od niza dioda (HPLC-DAD) primenom kombinacije tečno-tečne i ekstrakcije na čvrstoj&nbsp;fazi iz uzoraka meda. Na osnovu preliminarnih rezultata može se zaključiti da kori&scaron;ćenje &nbsp;faznih-čvrsto&nbsp;kolona u kombinaciji sa tečno-tečnom ekstrakcijom dihlormetanom rezultira prihvatljivim prinosom&nbsp;klotianidina u uzorcima meda pri koncentraciji od oko 0,5 &micro;g g^-1&nbsp;klotianidina. Radi dobijanja većih&nbsp;prinosa odabrana je disperzna tečno-tečna mikroekstrakcija (DLLME) kao tehnika pripreme uzoraka&nbsp;meda. Testirana je upotreba acetonitrila kao disperznog sredstva. Pored hloroforma, kori&scaron;ćen je i&nbsp;dihlormetan kao drugo ekstrakciono sredstvo, kako bi se &nbsp;uporedila efikasnost ekstrakcije. Zabeleženi su&nbsp;prinosi klotianidina od 69,7 i 68,3% &nbsp;u zavisnosti da li je kori&scaron;ćen hloroform, odnosno DHM kao rastvor&nbsp;za ekstrakciju. Može se zaključiti da je prinos ekstrakcije bio povoljniji pri odnosu 0,5 mL ACN i 2,0&nbsp;mL DHM. Prinosi su se kretali od 68,4% do 92,1%, &scaron;to je ukazalo da su parametri DLLME ekstrakcije optimalni. Kako bi se detaljnije ispitali ključni parametri DLLME tehnike, kori&scaron;ćena je metodologija povr&scaron;ine odziva (RSM), kao i detekcija na osetljivijem kuplovanom masenom detektoru (MS/MS). Optimizovani su HPLC-MS/MS &nbsp;parametri kako bi se obezbedilo zadovoljavajuće hromatografsko &nbsp;razdvajanje i niske granice detekcije (GD, 0,5&ndash;1,0 &mu;g kg^-1) i određivanja (GO, 1,0&ndash;2,5 &mu;g kg^-1) ispitivanih neonikotinoida u medu. Upotrebom centralno kompozitnog dizajna konstruisani su kvadratni modeli ispitivanih faktora: zapremine ekstrakcionog (DHM, 1,0&ndash;3,0 mL) i disperznog (ACN, 0,0&ndash;1,0 mL) sredstva, izračunati statistički parametri i optimizovan proces DLLME upotrebom <em>Derringer</em>-ove funkcije poželjnih odgovora. Upotrebom MMC i SC krivih u opsegu GO&ndash;100,0 &mu;g kg^-1&nbsp;ispitan je uticaj matriksa pri čemu zaključeno je da je najveći uticaj matriksa bio na odziv analitičkog signala nitenpirama, dinotefurana i klotianidina. Ispitani su prinosi odabranih neonikotinoida (R, 74,3&ndash;113,9%), kao i preciznost metode u uslovima ponovljivosti (RSD, 2,74&ndash; 11,8%) i intermedijerne reproduktivnosti (RSD, 6,64&ndash;16,2%). Brza (retenciona vremena 1,5&ndash;9,9 min) i osetljiva metoda, koja tro&scaron;i malu količinu rastvarača, primenjena je za ispitivanje 15 realnih uzoraka meda različitog cvetnog porekla. Rezultati su pokazali da ispitivani med nije sadržao ostatke ispitivanih neonikotinoida u koncentracijama iznad GD. Dalje istraživanje je bilo usmereno ka&nbsp; razvijanju i optimizaciji HPLC-DAD analitičke metode upotrebom DLLME i QuEChERS tehnika za &nbsp;pripremu uzoraka za određivanje 7 neonikotinoida u uzorcima meda. U ovom delu istraživanja optimizovani su i hromatografski parametri, upotrebom RSM sa Box-Behnken-ovim dizajnom i Derringer-ovom funkcijom poželjnih odgovora. Od &nbsp;ispitivanih neonikotinoida dinotefuran i imidakloprid su bili u najvećoj meri izloženi uticaju matriksa, bez obzira na proceduru pripreme uzoraka. Može se istaći da je uticaj matriksa na analitički signal dinotefurana bio izraženiji u slučaju MS/MS, apostrofirajući manju robusnost ove metode određivanja. Prinosi neonikotinoida su &nbsp;bili (R, 73,1&ndash;118,3%), preciznost u uslovima ponovljivosti (RSD, 3,28&ndash;10,40%) i intermedijerne reproduktivnosti (RSD, 6,45&ndash;17,70%), a granice detekcije (GD, 1,5&ndash;2,5 &micro;g kg^-1) i određivanja (GO, 5,0&ndash;10,0 &micro;g kg^-1). Metoda je primenjena za ispitivanje 7 neonikotinoida u 104 uzorkameda različitog cvetnog porekla sa &nbsp;teritorije Autonomne Pokrajine Vojvodine. Detektovano je prisustvo tiakloprida, imidakloprida i tiametoksama u količinama koje su bile ispod MDK RS i EU. Analizirani su uzorci likera od meda - medice. Upoređivane su dve tehnike pripreme uzoraka, DLLME i QuEChERS i primenjeni optimizovani hromatografski &nbsp;uslovi i MS/MS parametri. U slučaju nitenpirama, dinotefurana i tiametoksama uticaj matriksa bio je najizraženiji. Metoda je validovana određivanjem prinosa neonikotinoida (R, 69,2&ndash;113,4%), preciznosti u uslovima ponovljivosti (RSD, 3,21&ndash;12,81%) i intermedijerne reproduktivnosti (RSD, 9,11&ndash;16,63%), kao i granice detekcije (GD, 0,5&ndash;2,5 &micro;g kg^-1) i određivanja (GO, 1,0&ndash;10,0 &micro;g kg^-1). Analizom 10 komercijalno dostupnih likera od meda otkriveno je&nbsp;prisustvo klotianidina i tiakloprida, evčzokinot&scaron; z&nbsp; na neophodnost daljeg kontrolisanja ovog proizvoda na&nbsp;prisustvo neonikotinoida. Ispitana je mogućnost uklanjanja odabranih neonikotinoida (dinotefurana,&nbsp;klotianidina i tiakloprida) iz vodene sredine (reke Dunav). Ispitivanje efikasnosti 6 različitih vrsta&nbsp;uklanjanja odabranih neonikotinoida (u prisustvu prirodne insolacije u laboratorijskim uslovima, sa&nbsp;dodatkom H2O2, sa dodatkom MWCNT, sa dodatkom MWCN+H&nbsp;₂O₂, sa dodatkom Fe-MWCNT, sa dodatkom Fe-MWCNT+H₂O₂) vr&scaron;eno je upotrebom prethodno razvijene HPLC-MS/MS metode. Krive uklanjanja odabranih neonikotinoida, pokazale su da tokom 60 minuta pri prirodnoj insolaciji&nbsp; u laboratorijskim uslovima koncentracija smanjenje oko 25%. Analitički signal dinotefurana dobijen u prisustvu H₂O_2&nbsp;pod istim uslovima ukazuje na uklanjanje ciljnog analita od oko 40%, tiakloprida od oko 70%, a klotianidina u potpunosti. Testirana je adsorpcija ciljnog analita na vi&scaron;ezidnim ugljeničnim nanocevima (MWCNT). Ovim postupkom može da se ukloni oko 30% dinotefurana, oko 50% klotianidina i 60% tiakloprida. U kombinaciji sa H₂O_2&nbsp;, MWCNT pokazuju bolju sposobnost uklanjanja za 15&ndash;50% u zavisnosti od ispitivanog neonikotinoida. Upotreba Fe-MWCNT i njihova kombinacija sa H₂O₂ otvorila je mogućnost za dalja &nbsp;ispitivanja mehanizma uklanjanja. Ustanovljeno je nastajanje intermedijera kojima odgovaraju m/z od 117,5 i 140,6 u slučaju razgradnje dinotefurana u sistemima sa H₂O₂, MWCNT+H₂O₂, Fe-MWCNT+H₂O_2&nbsp;i klotianidina u sistemu Fe-MWCNT+H₂O₂.</p> / <p>Neonicotinoid insecticides, as one of the fastest growing new generation of insecticides, have&nbsp;contributed to a significant reduction of toxicity for the environment; therefore, monitoring and&nbsp;determination of trace levels of the neonicotinoids in honey are necessary and demands highly efficient,&nbsp;selective and sensitive analytical techniques. The objective of the present work was to develop a rapid,&nbsp;sensitive, optimized and accurate analytical method based on liquid chromatography for determining&nbsp;seven neonicotinoid insecticides, dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid,&nbsp;acetamiprid and thiacloprid in honey and honey liqueur samples. The possibility for determination of&nbsp;clothianidin in honey samples was investigated by HPLC with a diode array detector (HPLC-DAD).&nbsp;Based on preliminary results, it can be concluded that the use of a solid-phase column in combination&nbsp;with a liquid-liquid extraction with dichloromethane results in an acceptable recovery of clothianidin in&nbsp;the samples with a clothianidin concentration of about 0.5 &micro;g g^-1. After obtaining low recovery of&nbsp;clothianidin, dispersed liquid-liquid microextraction (DLLME) was selected as a technique for the&nbsp;preparation of honey samples.. The adequacy of acetonitrile as a dispersing agent was investigated.&nbsp;Besides the chloroform, a dichloromethane was used as a second extracting agent , in order to compare&nbsp;the relative efficiency of the extraction solvents. It can be concluded that the extraction recovery (68.4&ndash;92.1%) was more favorable with the use of 0.5 mL ACN and 2.0 mL DHM. Furthermore, LC-MS/MS&nbsp;parameters were optimized to unequivocally provide good chromatographic separation, low detection&nbsp;(LOD, 0.5&ndash;1.0 &mu;g L^&minus;1) and quantification (LOQ, 1.0&ndash;2.5 &mu;g L^&minus;1) limits for acetamiprid, clothianidin,&nbsp;thiamethoxam, imidacloprid, dinotefuran, thiacloprid and nitenpyram in honey samples. Using different&nbsp;<br />types (chloroform, dichloromethane) and volumes of extraction (1.0&ndash;3.0 mL) and dispersive&nbsp;(acetonitrile; 0.0&ndash;1.0 mL) solvent and by mathematical modeling it was possible to establish the optimal&nbsp;sample preparation procedure. Matrix-matched calibration and blank honey sample spiked in the&nbsp;<span style="font-size: 12px;">concentration range of LOQ&ndash;100.0 &mu;g kg</span>^{<span style="font-size: 12px;">&minus;1&nbsp;</span>}<span style="font-size: 12px;">were used to compensate the matrix effect and to fulfill the&nbsp;</span><span style="font-size: 12px;">requirements of SANCO/12495/2011 for the accuracy (R 74.3&ndash;113.9%) and precision (expressed in&nbsp;</span><span style="font-size: 12px;">terms of repeatability (RSD 2.74&ndash;11.8%) and within-laboratory reproducibility (RSDs &nbsp;6.64&ndash;16.2%)) of&nbsp;</span><span style="font-size: 12px;">the proposed method. The rapid (retention times 1.5&ndash;9.9 min), sensitive and low solvent consumption&nbsp;</span><span style="font-size: 12px;">procedure described in this work provides reliable, simultaneous, and quantitative method applicable for&nbsp;</span><span style="font-size: 12px;">the routine laboratory analysis of seven neonicotinoid residues in 15 real honey samples. Neonicotinoid &nbsp;</span><span style="font-size: 12px;">residues were not detected in any of the investigated samples. The objective of next study was to&nbsp;</span><span style="font-size: 12px;">develop and optimize HPLC-DAD analytical method with dispersive liquid-liquid microextraction&nbsp;</span><span style="font-size: 12px;">(DLLME) and QuEChERS sample preparation procedures for the simultaneously analysis of seven&nbsp;</span><span style="font-size: 12px;">neonicotinoids in honey samples. The liquid chromatographic conditions were optimized by response&nbsp;</span><span style="font-size: 12px;">surface methodology with <em>Box-Behnken</em> design and the global <em>Derringer</em>&acute;s desirability. The optimized&nbsp;</span><span style="font-size: 12px;">method was &nbsp;validated to fulfill the requirements of SANCO/12495/2011 standard for both sample&nbsp;</span><span style="font-size: 12px;">pretreatment procedures providing results for accuracy (R, 73.1&ndash;118.3%), repeatability (RSD, 3.28&ndash;</span><span style="font-size: 12px;">10.40%) and within-laboratory reproducibility (RSD, 6.45&ndash;17.70%), limits of detection (LOD, 1.5&ndash;2.5&nbsp;</span><span style="font-size: 12px;">g&micro; kg</span>^{<span style="font-size: 12px;">-1</span>}<span style="font-size: 12px;">) and quantification (LOQ, 5.0&ndash;10.0 &micro;g kg</span>^{<span style="font-size: 12px;">-1</span>}<span style="font-size: 12px;">). For the first time, more than 100 honey samples&nbsp;</span><span style="font-size: 12px;">collected from all 7 counties of Autonomous Province of Vojvodina were analyzed. The presence of&nbsp;</span><span style="font-size: 12px;">thiacloprid, imidacloprid and thiametoxam was discovered in a small number of samples. The objective&nbsp;</span><span style="font-size: 12px;">of next study was to develop an optimized LC-MS/MS analytical method with DLLME and QuEChERS&nbsp;</span><span style="font-size: 12px;">procedures for analysis of 7 neonicotinoids in honey liqueur. The method was validated to fulfill the&nbsp;</span><span style="font-size: 12px;">requirements of SANCO/12495/2011 for both sample pretreatment procedures providing results for&nbsp;</span><span style="font-size: 12px;">accuracy (R, 69.2&ndash;113.4% for DLLME; 71.8&ndash;94.9% for QuEChERS), precision (RSD expressed in&nbsp;</span><span style="font-size: 12px;">terms of repeatability (3.21&ndash;10.20% for DLLME; 4.19&ndash;12.81% for QuEChERS) and within-laboratory&nbsp;</span><span style="font-size: 12px;">reproducibility (9.11&ndash;16.63% for DLLME; 11.32&ndash;16.40% for QuEChERS)), limits of detection (LOD,&nbsp;</span><span style="font-size: 12px;">0.5&ndash;1.5 g&micro; L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for DLLME; 1.0&ndash;2.5 g&micro; L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for QuEChERS) and quantification (LOQ, 1.0&ndash;5.0 g&micro; L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for&nbsp;</span><span style="font-size: 12px;">DLLME; 2.5&ndash;10.0 &micro;g L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for QuEChERS). Analysis of real honey liqueur samples obtained from local&nbsp;</span><span style="font-size: 12px;">markets showed the presence of clothianidin or thiacloprid in four of the analyzed samples, therefore&nbsp;</span><span style="font-size: 12px;">implicating the necessity of ongoing control of this type of traditional product. &nbsp;Removal of selected&nbsp;</span><span style="font-size: 12px;">neonicitinoid insecticides - dinotefuran, clothianidin and thiacloprid using MWCNT and H</span><span style="font-size: 12px;">₂O_2&nbsp;</span><span style="font-size: 12px;">from&nbsp;</span><span style="font-size: 12px;">Danube water matrix was investigated. &nbsp;Efficiency of different systems for neonicotinoids removal&nbsp;</span><span style="font-size: 12px;">(under natural insolation in laboratory, with H</span><span style="font-size: 12px;">₂O₂, with MWCNT, with MWCNT+ H</span><span style="font-size: 12px;">₂O₂, with Fe-MWCNT, with Fe-MWCNT+H₂O₂) was evaluated with developed LC-MS/MS method. Analysis of&nbsp;</span><span style="font-size: 12px;">degradation rates revealed loss of 25% of the initial neonicotinoid concentration under natural insolation in&nbsp;</span><span style="font-size: 12px;">the laboratory conditions during 60 min. Addition of chemical agent H₂O_2&nbsp;promoted loss of 40% of the&nbsp;</span><span style="font-size: 12px;">initial dinotefuran, 70% of thiacloprid concentration and total removal of clothianidin under same&nbsp;</span><span style="font-size: 12px;">conditions. With the addition &nbsp;of MWCNT concentration of dinotefuran, clothianidin and thiacloprid&nbsp;</span><span style="font-size: 12px;">decayed for 30, 50 and 60%, respectively. Iron modification of MWCNT in combination with H</span><span style="font-size: 12px;">₂O_2&nbsp;</span><span style="font-size: 12px;">increased the removal rate of selected neonicotinoid for 15&ndash;50%. Presence of intermediates was&nbsp;</span><span style="font-size: 12px;">discovered in systems of dinotefuran with H₂O₂, MWCNT+H</span><span style="font-size: 12px;">₂O₂, e-MWCNT+H₂O_2&nbsp;</span><span style="font-size: 12px;">and of&nbsp;</span><span style="font-size: 12px;">clothianidin in systems with Fe-MWCNT+H₂O_2&nbsp;</span><span style="font-size: 12px;">with m/z of 117,5 and 140,6.&nbsp;</span></p>