On-line electrochemistry/liquid chromatography/mass spectrometry for the simulation of pesticide metabolism

Lohmann, Wiebke; Dötzer, Reinhard; Gütter, Gerald; Leeuwen, S.M. van; Kärst, Uwe

doi:10.1016/j.jasms.2008.09.003

Cited by 53 publications

(29 citation statements)

References 21 publications

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“…We refer the interested reader to a selection of published reviews pertaining to electrospray ionization and/or EC/ESI coupling available elsewhere . The focus in the current paper is kept on features of electrochemistry/ electrospray that have been largely neglected but might be important for analytical practice, especially if one considers how the development of electrochemical derivatization of analytes has become an established and fruitful method [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

mentioning

confidence: 99%

Perspective on Electrospray Ionization and Its Relation to Electrochemistry

Pozniak

Cole

2015

J. Am. Soc. Mass Spectrom.

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A VAbstract. The phenomenon of electrospraying of liquids is presented from the perspective of the electrochemistry involved. Basics of current and liquid flow in the capillary and spray tip are discussed, followed by specifics of charging and discharging of the sprayed liquid surface. Fundamental theories and numerical modeling relating electrospray current to solution and spray parameters are described and then compared with our own experimentally obtained data. The method of mapping potentials and currents inside the electrospray capillary by using an inserted electrically-isolated small wire probe electrode is discussed in detail with illustrations from new and published data. Based on these experimentally obtained results, a new mathematical model is derived. The introduced "nonlinear resistor electrospray capillary model" divides the electrospray capillary into small sections, adds their contributions, and then, by transition to infinitely small section thickness, produces analytical formulas that relate current and potential maps to other properties of the electrospraying liquid: primarily conductivity and current density. The presentation of the model is undertaken from an elementary standpoint, and it offers the possibility to obtain quantitative information regarding operating parameters from typical analytical systems subjected to electrospray. The model stresses simplicity and ease of use; examples applying experimental data are shown and some predictions of the model are also presented. The developed nonlinear resistor electrospray capillary model is intended to provide a new quantitative basis for improving the understanding of electrochemical transformations occurring in the electrospray emitter. A supplemental material section gives full derivation of the model and discusses other consequences.

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confidence: 99%

Perspective on Electrospray Ionization and Its Relation to Electrochemistry

Pozniak

Cole

2015

J. Am. Soc. Mass Spectrom.

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“…Unfortunately, the method fails when isomeric degradation products of the test drug are formed. Then, it is necessary to obtain the separation of metabolites using liquid chromatography [35][36][37]. On the other hand, the method allows the direct detection of reactive metabolites when coupled with liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS).…”

Section: Methods Used In Drug Metabolism Studiesmentioning

confidence: 99%

Photocatalysis combined with chromatographic methods as a new promising tool in drug metabolism studies – a review

Gawlik

Skibiński

Trawiński

et al. 2018

Acta Chromatographica

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The number of new drugs launched to the market is constantly increasing; however, the metabolism of many of them is still not fully established. The knowledge of drug metabolism pathways is crucial for the efficacy and safety of therapies and, in classical approach, requires the use of animals as well as human volunteers, but this kind of research is expensive and time-consuming. Therefore, nowadays, more and more biological and chemical in vitro methods are developed for the drug metabolism study. This review is focused on the photocatalytic degradation of chemicals and the application of this process in chromatographic methods of drug metabolism research. A theoretical background of photocatalysis and all its applications in a drug metabolism study were reviewed, and other in vitro methods that are actually used were summarized and discussed. Other analytical methods used in this area were also discussed and compared.

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“…Due to presence of one hydroxyl group in product 1a, we suggest that its position should be identical as in product 1b and that the hydroxylation of the benzene ring occurs primarily to the N-dealkylation, with product 1b as a substrate. Hydroxylation of a benzene ring has already been performed by different EC/ESI-MS setups [7,[9][10][11].…”

Section: Lc/ec/esi-qqtofmentioning

confidence: 99%

“…Guanosine derivatives are also known to self-assembly into different aggregates [43]. However, some substances, such as boscolide (2-chloro-N-(4'-chloro(1,1'-biphenyl)-2-yl)-3-pyridinecarboxamide), show no dimer formation in in vitro assays in contrast to their formation in the EC cell [10]. The proposed structure and the site of dimerisation was based on the report by Pitterl et al [36].…”

Section: Lc/ec/esi-qqtofmentioning

confidence: 99%

“…Several studies, utilizing electrochemical (EC) flow cells online with MS, have demonstrated that electrochemically derived products can often accurately predict biological metabolites and chemical degradants [7]. Some of the typical metabolism reactions simulated by an EC system include N-dealkylation [7][8], aromatic hydroxylation [7,[9][10][11], benzylic hydroxylation [7], alcohol oxidation [7,12] or dehydrogenation [9,[13][14][15].…”

Section: Introductionmentioning

confidence: 99%

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High Performance Liquid Chromatography‐Electrochemistry‐Electrospray Ionization Mass Spectrometry (HPLC/EC/ESI‐MS) for Detection and Characterization of Roscovitine Oxidation Products

Karády¹,

Novák²,

Horna³

et al. 2011

Electroanalysis

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On-line LC-EC/ESI-MS has been established as a fast and simple method to mimic some types of oxidation reaction of various drugs and to study the formation and structure of the resulting products. This technique has been applied to a 2,6,9-trisubstituted purine, R-roscovitine, which is known to be an inhibitor of some cyclin-dependent kinases (CDKs) and a potential anticancer drug. Oxidation of R-roscovitine in an electrochemical cell (EC), operated under various conditions, resulted in appearance of 6 major products. These were further analyzed by high-resolution mass spectrometry, their structures were elucidated by accurate mass measurement and compared to previously identified R-roscovitine in vitro/in vivo metabolites. Although none of the observed products was structurally identical to those identified previously in vitro/in vivo, all of them, except for the methoxylated products, resembled similarity due to appearing through the same reaction type. R-roscovitine in the EC cell underwent N-dealkylation of the isopropyl moiety, hydroxylation of the aromatic side-chain, dihydroxylation, methoxylation and dimer formation. The hydroxylation product was identified as Olomoucine II, a R-roscovitine derivative, which displays 10-times higher CDK-inhibiting activity than R-roscovitine and the occurrence of which, as R-roscovitine product, has not yet been observed in vitro/in vivo.

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On-line electrochemistry/liquid chromatography/mass spectrometry for the simulation of pesticide metabolism

Cited by 53 publications

References 21 publications

Perspective on Electrospray Ionization and Its Relation to Electrochemistry

Perspective on Electrospray Ionization and Its Relation to Electrochemistry

Photocatalysis combined with chromatographic methods as a new promising tool in drug metabolism studies – a review

High Performance Liquid Chromatography‐Electrochemistry‐Electrospray Ionization Mass Spectrometry (HPLC/EC/ESI‐MS) for Detection and Characterization of Roscovitine Oxidation Products

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