EURL-FV, Universidad de Almería-Edificio de Química is a European Reference Laboratory for pesticide residues in fruit and vegetables within the department of chemistry at the University of Almería in Spain.
Full scan MS in high resolution mass spectroscopy is a highly selective technique, suitable for pesticide screening. However, it is often necessary to utilize MS2 mode to avoid obtaining false positive results. In this poster presentation, Carmen Ferrer Amate, from the European Reference Laboratory for Fruits and Vegetables (EURL-FV), describes the variances in selectivity between different liquid chromatography – mass spectrometry (LC-MS) workflows.
In this interview, Carmen describes the research with the Pesticide Residue Research Group, at the University of Almería, where they used a Thermo Scientific™ Q Exactive™ Focus Hybrid Quadrupole-Orbitrap™ Mass Spectrometer to evaluate three different simultaneous MS and MS/MS workflows. She explains that the first workflow employed targeted data dependent MS/MS, while the second and third workflows were non-targeted, using all-ion fragmentation (AIF) and variable data-independent acquisition (vDIA) methods. The experiment involved spiking of 166 pesticides into 11 different fruit and vegetable matrices, before analysis to determine mass errors, matrix effects, linearity of results, repeatability and identification rates.
The EURL-FV’s research determined that the data dependent MS/MS workflow had the highest selectivity and identification rate. In addition, the system had good linearity and few matrix effects were observed, except for on the most complex matrices. However, false positives from difficult matrices are avoidable. Carmen concludes that “evaluation of the three different workflows proved to be very effective for obtaining further identification criteria”.