Quantitative-qualitative data acquisition using a benchtop orbitrap mass spectrometer

Abstract

Current approaches to discovery-stage drug metabolism studies (pharmacokinetics, microsomal stability, etc.) typically use triple-quadrupole-based approaches for quantitative analysis. This necessitates the optimization of parameters such as Q1 and Q3 m/z values, collision energy, and interface voltages. These studies detect only the specified compound and information about other components, such as metabolites, is lost. The ability to perform full-scan acquisition for quantitative analysis would eliminate the need for compound optimization while enabling the detection of metabolites and other non-drug-related endogenous components. Such an instrument would have to provide sensitivity, selectivity, dynamic range, and scan speed suitable for discovery-stage quantitative studies. In this study, a prototype benchtop Orbitrap-based mass analyzer was used to collect both quantitative and qualitative data from human microsomal incubation samples as well as rat plasma from pharmacokinetic studies. Instrumental parameters such as scan speed, resolution, and mass accuracy are discussed in relation to the requirements for a quantitative-qualitative workflow. The ability to perform highly selective quantitative analysis while simultaneously characterizing metabolites from both in vitro and in vivo studies is discussed.

Simultaneous Screening of Glutathione and Cyanide Adducts Using Precursor Ion and Neutral Loss Scans-Dependent Product Ion Spectral Acquisition and Data Mining Tools

“…However, it is not practical to equip two or multiple LC/MS instruments in a small lab, each of which is dedicated to either quantitative or qualitative analysis. HR-MS is a preferred LC/MS platform for a drug metabolism lab where metabolite identification is its major task, while quantitative analysis in discovery pharmacokinetic and in vitro metabolism studies is performed occasionally [44,45].…”

A Survey of Orbitrap All Ion Fragmentation Analysis Assessed by an R MetaboList Package to Study Small-molecule Metabolites

“…The combination of MS 1 and AIF full-scans provides an opportunity to perform retrospective data analysis of additional compounds of interest based on hypotheses that arise later [11,12], thus providing dimensions of flexibility not achieved by other MS 2 analyses such as multiple reaction monitoring (MRM) [11]. As pointed out by Bateman et al (2009) [13], AIF analysis can provide improved mass accuracy and requires negligible time investment to develop methods in contrast to that required for traditional QQQ-based MRM analysis. Advances in Time of Flight (TOF) instrumentation, standalone or coupled to a quadrupole (Q-TOF), has also resulted in instruments capable of operating at high scan rate/mass resolution in a way similar to AIF conditions (i.e.…”

Design Study of an Atmospheric Pressure Photoionization Interface for GC-MS

“…For evaluation of the ion source performance, an Exactive Orbitrap MS, and additionally a modified Exactive MS with a compact, high-field Orbitrap analyzer (research-only), were employed [23]. The standard IonMax API housing and the ion sweep cone were removed and the electronic interlock was bridged with appropriate resistors to mimic an APPI/APCI operating mode.…”