On the inter‐instrument and inter‐laboratory transferability of a tandem mass spectral reference library: 1. Results of an Austrian multicenter study

Abstract

The inter-instrument and inter-laboratory transferability of a tandem mass spectral reference library originally built on a quadrupole-quadrupole-time-of-flight instrument was examined. The library consisted of 3759 MS/MS spectra collected from 402 reference compounds applying several different collision-energy values for fragmentation. In the course of the multicenter study, 22 test compounds were sent to three different laboratories, where 418 tandem mass spectra were acquired using four different instruments from two manufacturers. The study covered the following types of tandem mass spectrometers: quadrupole-quadrupole-time-of-flight, quadrupole-quadrupole-linear ion trap, quadrupole-quadrupole-quadrupole, and linear ion trap-Fourier transform ion cyclotron resonance mass spectrometer. In each participating laboratory, optimized instrumental parameters were gathered solely from routinely applied workflows. No standardization procedure was applied to increase the inter-instrument comparability of MS/MS spectra. The acquired tandem mass spectra were matched against the established reference library using a sophisticated matching algorithm, which is presented in detail in a companion paper. Correct answers, meaning that the correct compound was retrieved as top hit, were obtained in 98.1% of cases. For the remaining 1.9% of spectra, the correct compound was matched at second rank. The observed high percentage of correct assignments clearly suggests that the developed mass spectral library search approach is to a large extent platform independent.

Analytical Validation of a Portable Mass Spectrometer Featuring Interchangeable, Ambient Ionization Sources for High Throughput Forensic Evidence Screening

“…It has been asserted that the addition of the N-(2-methoxy)benzyl group to the 2C-phenethylamine structure (another electron donating aromatic ring, as seen in Supplementary Figure S-8C) creates more favorable sites for dissociation that can occur along the -C-C-N-C-linkage chain, specifically C-C bond cleavage between the α-and β-carbon atoms on the ethylene bridge [68,69]. The complexity and intensity to which these fragmentation patterns are seen is highly dependent on the MS/MS conditions utilized [44], which leads to the inter-instrument variations reported [66,70]. While NBOMe derivatives may represent a special case due to the number of low abundance transitions seen, instrument-specific spectral databases [71] may be more prudent in scenarios where automated chemical identification is needed, but variability is a concern.…”

Applications of liquid chromatography coupled to mass spectrometry-based metabolomics in clinical chemistry and toxicology: A review

“…For instance, Palit et al proposed a fragmentation energy index for the normalization of collision energy [125] which is nevertheless restricted to ion trap instruments. Oberacher et al designed a multicenter study in which 22 test compounds (drug standards) were sent to three different laboratories, where 418 tandem mass spectra were acquired using four different instruments from two manufacturers including Q-TOF, triple quadrupole, Q-Trap and FTICR mass spectrometers [126]. CID mass spectra were recorded without any standardization of experimental conditions and they were matched against a reference library using a sophisticated matching algorithm [127].…”

Pitfalls Associated with the Use of Liquid Chromatography–Tandem Mass Spectrometry in the Clinical Laboratory

“…Besides the fact that, for many analytes, collision-induced dissociation generates only a single product ion of sufficient intensity to be detected, this technique is not widely used, mainly because of the practical reasons described below. Quantitative fragmentation patterns, which determine branching ratios, are a result of complex individual instrument characteristics (45)(46)(47). These patterns typically differ between instruments and even can show distinct matrix effects (48 ).…”