Quantitative targeted and retrospective data analysis of relevant pesticides, antibiotics and mycotoxins in bakery products by liquid chromatography-single-stage Orbitrap mass spectrometry

Abstract

In addition to 'traditional' multi-residue and multi-contaminant multiple reaction monitoring (MRM) mass spectrometric techniques devoted to quantifying a list of targeted compounds, the global food industry requires non-targeted methods capable of detecting other possible potentially hazardous compounds. Ultra-high-performance liquid chromatography combined with a single-stage Orbitrap high-resolution mass spectrometer (UHPLC-HRMS Exactive™-Orbitrap Technology) was successfully exploited for the complete selective and quantitative determination of 33 target compounds within three major cross categories (pesticides, antibiotics and mycotoxins) in bakery matrices (specifically milk, wheat flour and mini-cakes). Resolution was set at 50 000 full width at half maximum (FWHM) to achieve the right compromise between an adequate scan speed and selectivity, allowing for the limitations related to the necessary generic sample preparation approach. An exact mass with tolerance of 5 ppm and minimum peak threshold of 10 000 units were fixed as the main identification conditions, including retention time and isotopic pattern as additional criteria devoted to greatly reducing the risk of false-positive findings. The full validation for all the target analytes was performed: linearity, intermediate repeatability and recovery (28 analytes within 70-120%) were positively assessed; furthermore, limits of quantification between 5 and 100 µg kg(-1) (with most of the analytes having a limit of detection below 6 µg kg(-1)) indicate good performance, which is compatible with almost all the regulatory needs. Naturally contaminated and fortified mini-cakes, prepared through combined use of industrial and pilot plant production lines, were analysed at two different concentration levels, obtaining good overall quantitative results and providing preliminary indications of the potential of full-scan HRMS cluster analysis. The effectiveness of this analytical approach was also tested in terms of the formulation of hypotheses for the identification of other analytes not initially targeted which can have toxicological implications (e.g. 3-acetyl-deoxynivalenol and deoxynivalenol-3-glucoside), opening a window on retrospective investigation perspectives in food safety laboratories.

Developments in mycotoxin analysis: an update for 2017-2018

“…The discussed data highlight the analytical potential of the high resolving power (>50.000 (full width at half maximum, FWHM), the accurate mass measurements (1-5 ppm) and the acquisition in full scan (with and without fragmentation), to perform target analysis and retrospective screening over a database of more than 400 compounds of interest. An example of quantitative targeted and retrospective data analysis of relevant pesticides, antibiotics and mycotoxins in bakery products by liquid chromatography-single-stage Orbitrap MS can be found in de Dominicis et al (2015). To prove the applicability of the method for quantitative analysis in finished products, mini-cake samples at two different contamination levels were prepared on an industrial pilot plant.…”

Mycotoxin testing: From Multi-toxin analysis to metabolomics

“…While those types of mass spectrometers are not as sensitive, they offer a virtually unlimited number of compounds to be analysed. For instance, a method for the analysis of mycotoxins (but also other analytes such as pesticides) in bakery products by LC-Orbitrap-MS was developed 22) . While good quantitative findings were obtained for the analysed mycotoxins, the limits of quantification were not suitable to verify the levels of OTA and aflatoxin B1 with respect to maximum permitted levels in the European Union.…”

Multiclass and multiresidue screening of veterinary drugs and pesticides in infant formula using Quadrupole‐Orbitrap MS with PRM scan mode

“…Screening analysis of multiclass residues based on high‐resolution mass spectrometry (HRMS) is popular because full mass scan mode of this type of instrument could conduct exhaustive monitoring with acceptable sensitivity . However, HRMS with full mass scan mode is not always a resort especially in dealing with complicated food matrix such as infant formula.…”

“…Screening analysis of multiclass residues based on high-resolution mass spectrometry (HRMS) is popular because full mass scan mode of this type of instrument could conduct exhaustive monitoring with acceptable sensitivity. [17][18][19][20][21] However, HRMS with full mass scan mode is not always a resort especially in dealing with complicated food matrix such as infant formula. Parallel reaction monitoring (PRM) is an alternative acquisition mode that depends on fragment ions with accurate mass and hence affords to higher selectivity than full mass scan mode.…”