SWATH data independent acquisition mass spectrometry for screening of xenobiotics in biological fluids: Opportunities and challenges for data processing.

SWATH data independent acquisition (DIA) mass spectrometry (MS) has become an established technique in MS-based 'omics' research and is increasingly used for the screening of xenobiotics (e.g. drugs, drug metabolites, pesticides, toxicants).

Metabolic studies of the Amaryllidaceous alkaloids galantamine and lycorine based on electrochemical simulation in addition to in vivo and in vitro models.

Alkaloids from the plant family of Amaryllidaceae, such as galantamine (GAL) and lycorine (LYC), are known to exhibit numerous promising biological and pharmacological activities like antibacterial, antiviral or anti-inflammatory effects. Nonetheless, studies on the biotransformation pathway are rare for this substance class, unless approval for use as medication exists. While GAL has become a prescription drug used to alleviate and delay the symptoms of Alzheimer's disease, LYC exhibits potential antitumor properties.

Electrochemistry coupled to (liquid chromatography/) mass spectrometry--current state and future perspectives.

The coupling of electrochemistry (EC) to different mass spectrometric (MS) techniques in off-line and especially in on-line approaches is a quickly growing research field in analytical chemistry with numerous distinct objectives. Depending on the analytical problem, a separation step can be further integrated according to the instrumental set-up and, most frequently, liquid chromatography (LC) is selected for this purpose. In this review, various scientific areas of application for this EC/(LC/)MS hybrid method are presented and discussed in detail.

Electrochemistry/mass spectrometry as a tool in the investigation of the potent skin sensitizer p-phenylenediamine and its reactivity toward nucleophiles.

Rationale: Although para-phenylenediamine (PPD) is known to cause severe allergic contact dermatitis in consequence of autoxidation and/or skin metabolism pathways, it is commonly utilized as an ingredient in permanent hair dyes. The aim of this work was to simultaneously accelerate the autoxidation process and to simulate the metabolic activation of PPD using a purely instrumental system.

Methods: Electrochemistry (EC) in combination with electrospray ionization mass spectrometry (ESI-MS) was used in this study to assess the skin-sensitizing potential of PPD.

Electrochemistry/liquid chromatography/mass spectrometry to demonstrate irreversible binding of the skin allergen p-phenylenediamine to proteins.

Rationale: para-Phenylenediamine (PPD) is a potent and well-known allergen, which is commonly used in hair or fur dyes and can cause severe allergic contact dermatitis. In this work, the skin-sensitizing potential of PPD with respect to the conjugation of proteins was evaluated using an approach without animal testing.

Methods: Electrochemistry (EC) coupled offline to liquid chromatography (LC) and electrospray ionization mass spectrometry (ESI-MS) was employed to convert the pre-hapten PPD into its reactive hapten analogs.

Identification and quantification of potential metabolites of Gd-based contrast agents by electrochemistry/separations/mass spectrometry.

Oxidative and potentially metabolic pathways of the five most frequently used contrast agents for magnetic resonance imaging (MRI) based on gadolinium (Gd) are examined. The oxidation of gadopentetate (Gd-DTPA) was studied with a focus on electrochemical oxidation coupled to analytical separation methods and mass spectrometric detection. Mass voltammograms generated with online electrochemistry/electrospray ionization mass spectrometry (EC/ESI-MS) gave a first overview of oxidation products.

Investigation of the biotransformation pathway of verapamil using electrochemistry/liquid chromatography/mass spectrometry - a comparative study with liver cell microsomes.

The biotransformation pathway of verapamil, a widely prescribed calcium channel blocker, was investigated by electrochemistry (EC) coupled online to liquid chromatography (LC) and electrospray mass spectrometry (ESI-MS). Mimicry of the oxidative phase I metabolism was achieved in a simple amperometric thin-layer cell equipped with a boron-doped diamond (BDD) working electrode. Structures of the electrochemically generated metabolites were elucidated on the basis of accurate mass data and additional MS/MS experiments.

Electrochemistry/liquid chromatography/mass spectrometry as a tool in metabolism studies.

Electrochemistry/liquid chromatography/mass spectrometry is a powerful complementary tool for the simulation of the oxidative metabolism of drugs and other xenobiotics.

A ferrocene-based reagent for the conjugation and quantification of reactive metabolites.

In the present study, a method for the analysis of reactive metabolites via liquid chromatography (LC) with inductively coupled plasma-mass spectrometry (MS) was developed. A ferrocenyl-modified glutathione (GSH) reagent, consisting of GSH and succinimidyl-3-ferrocenylpropionate, was synthesized. Derivatization of the tripeptide was performed at the N-terminus, leaving the nucleophilic thiol group vacant for the attack of electrophilic compounds.