Investigations into the Performance of Travelling Wave-Enabled Conventional and Cyclic Ion Mobility Systems to Characterise Protomers of Fluoroquinolone Antibiotic Residues.

Abstract

Fluoroquinolones (FLQs) are a class of antimicrobial agents which have been administered to livestock for infection prevention/control and growth promotion. In this work blank porcine muscle extract (fortified with FLQs) has been screened for the FLQ protomer species (resulting from different sites of protonation) using the cumulative specificity of Ultra High Performance Liquid Chromatography coupled with Ion Mobility - Mass Spectrometry (UHPLC-IM-MS) and collision induced dissociation (CID). Collision cross sections (CCSs) and product ion spectra have been generated for the protomeric species with ΔCCS values between protomers ranging between 10-15 Å2 . CCSs of singly/doubly charged species were determined in a single assay, providing information about the sites of protonation being formed during the electrospray ionisation process. Fluctuations in the relative intensity and number of protomer species formed have also been observed, which ultimately impact the composite product ion spectra observed. Three protomeric species have been observed for danofloxacin and two protomers for the majority of FLQs analysed. Long term reproducibility and cross-platform travelling wave (T-wave) IM studies have demonstrated CCS differences of <1.5 % when compared to a FLQ protomer reference CCS library (in house). A comparison of FLQ protomer separation has been undertaken on a standard, linear, T-wave IM (TWIM) separator in both N2 /CO2 and on a novel, high resolution cyclic TWIM (cIM) device in N2 . Protomer peak-to-peak resolution ranged from Rs=1 to Rs=6 for the different IM strategies utilised. With increased resolution from cIM, deconvolution of FLQ protomers and pre-IM fragments has been achieved.
 

Rapid Commun Mass Spectrom. 2018 Dec 14. doi: 10.1002/rcm.8371. [Epub ahead of print]
McCullagh M1, Giles K1, Richardson K1, Stead S1, Palmer M1.
Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK.
 

https://onlinelibrary.wiley.com/doi/10.1002/rcm.8371