Non-target screening with high-resolution mass spectrometry: critical review using a collaborative trial on water analysis.

In this article, a dataset from a collaborative non-target screening trial organised by the NORMAN Association is used to review the state-of-the-art and discuss future perspectives of non-target screening using high-resolution mass spectrometry in water analysis. A total of 18 institutes from 12 European countries analysed an extract of the same water sample collected from the River Danube with either one or both of liquid and gas chromatography coupled with mass spectrometry detection. This article focuses mainly on the use of high resolution screening techniques with target, suspect, and non-target workflows to identify substances in environmental samples. Specific examples are given to emphasise major challenges including isobaric and co-eluting substances, dependence on target and suspect lists, formula assignment, the use of retention information, and the confidence of identification. Approaches and methods applicable to unit resolution data are also discussed. Although most substances were identified using high resolution data with target and suspect-screening approaches, some participants proposed tentative non-target identifications. This comprehensive dataset revealed that non-target analytical techniques are already substantially harmonised between the participants, but the data processing remains time-consuming. Although the objective of a "fully-automated identification workflow" remains elusive in the short term, important steps in this direction have been taken, exemplified by the growing popularity of suspect screening approaches. Major recommendations to improve non-target screening include better integration and connection of desired features into software packages, the exchange of target and suspect lists, and the contribution of more spectra from standard substances into (openly accessible) databases. Graphical Abstract Matrix of identification approach versus identification confidence.

Airborne mycotoxins in waste recycling and recovery facilities: Occupational exposure and health risk assessment.

Mycotoxins are metabolites secreted by certain types of moulds, and some of them can be harmful to health. The objective of this study was to estimate the level of exposure to airborne aflatoxin B1, ochratoxin A, gliotoxin and sterigmatocystin in waste recycling and recovery facilities. An additional goal was to assess the related health risks for workers. Targeted mycotoxins were analysed quantitatively in 94 air samples collected in five sites using ultra-performance liquid chromatography coupled with high resolution mass spectrometry. The level of exposure to mycotoxin during working day scenarios was compared to benchmark values, either health-based guidelines when available or the concentration of no toxicological concern (CoNTC) when not. Eleven per cent of samples showed quantifiable measurement results. Aflatoxin B1 and sterigmatocystin were quantified at the mechanical separation area in mechanical-biological treatment (MBT) facilities and in the materials recovery facility (MRF), but not in composting plants and composting units in MBT facilities. The levels of exposure were all below 1 ng m-3. This is the first time exposure to sterigmatocystin in waste management facilities is reported and quantified. Ochratoxin A and gliotoxin were not quantified in any of the air samples. Health risk assessment approaches did not suggest a significant threat to workers' health. These data do not suggest the need for specific prevention measures in addition to those against other airborne biological agents.