Multiple Reaction Monitoring with Multistage Fragmentation (MRM3) Detection Enhances Selectivity for LC-MS/MS Analysis of Plasma Free Metanephrines

Abstract

BACKGROUND: LC-MS/MS with multiple reaction monitoring (MRM) is a powerful tool for quantifying target analytes in complex matrices. However, the technique lacks selectivity when plasma free metanephrines are measured. We propose the use of multistage fragmentation (MRM 3 ) to improve the analytical selectivity of plasma free metanephrine measurement.

Tandem mass spectrometric analysis of novel caffeine scaffold‐based bifunctional compounds for Parkinson's disease

“…Additionally, the fragmentation of each of these bifunctional compounds gave rise to MS 3 product ions (Figure S2, supporting information) which can be used to improve analytical selectivity through MRM with multistage fragmentation (MS 3 ) for the quantification of these bifunctional compounds in complex biological matrices where there is an increased possibility of matrix interference with conventional MRM transitions. For example, poor analytical selectivity for quantitation of plasma normetanephrine and metanephrine by LC‐MRM was improved using MRM with multistage fragmentation (MS 3 ) …”

“…31 . [32][33][34][35][36] The detailed tandem mass spectrometric fragmentation of these bifunctional compounds is described below.…”

A simple and robust liquid chromatography tandem mass spectrometry assay for determination of plasma free metanephrines and its application to routine clinical testing for diagnosis of pheochromocytoma

“…High‐performance liquid chromatography coupled with electrochemical detection (HPLC–ECD) is the most promising and widely used technique for quantification of PFMs (Hickman, Leong, Chang, Wilson, & McWhinney, ; Lenders et al, ; Rosano, Swift, & Hayes, ). However, with the development of analytical techniques, liquid chromatography tandem mass spectrometry (LC–MS/MS), as a powerful analytical system which typically requires smaller sample volumes, allows shorter run times and offers increased analytical selectivity and sensitivity, has become popular for PFM determination (Marney, Laha, Baird, Rainey, & Hoofnagle, ; Lagerstedt, ƠKane, & Singh, ; Gabler, Yuan, Woroniecki, Liu, & Wang, ; Petteys, Graham, Parnás, Holt, & Frank, ; Peitzsch et al, ; Lee et al, ; Wright, Thomas, Stanford, & Horvath, ; Heideloff, Payto, & Wang, ; Woo et al, ), although LC–MS/MS equipment is expensive (Singh & Eisenhofer, ). In these studies, protein precipitation and solid‐phase extraction (SPE), which usually require extract evaporation for concentration or use buffers containing salts, such as nonvolatile ammonium phosphate, were always used for sample pretreatment.…”

Interference from 3-O-Methyldopa with Ultra–High Performance LC-MS/MS Measurements of Plasma Metanephrines: Chromatographic Separation Remains Important

“…Suspicion that 3-O-methyldopa might cause interference with ultrahigh performance LC-MS/MS (UHPLC-MS/MS) 1 with the latter was possible, particularly in patients treated with L-dopa or with renal insufficiency. We therefore set out to eliminate this source of interference, which we determined was associated with cochromatography of 3-Omethyldopa with methoxytyramine (Fig.…”

“…Additional measurements of 3-O-methyldopa were incorporated into the method. Differences in plasma methoxytyramine [mean (SD)] using the revised compared to the original method were more pronounced for patients with renal failure [8 (5) The mass spectrometric instrument (5500 Q-trap) we use is the same as that enabling the MRM 3 approach for minimizing interferences described by Wright et al (1 ). However, that approach does not provide a solution for the interference described here.…”