Drug screening by using the Toxtyper™ LC-ion trap MS: Optimization of its application on serum samples in a DUID context.

The toxicological approach for monitoring Driving Under Influence of Drugs (DUID) requires analytical techniques with a broad spectrum of identification coupled to a high analytical sensitivity. In this context immunological methods are generally used, while GC or LC-MS are applied for the confirmation step. A different approach for drug screening is represented by the Toxtyper™ instrumentation, an LC-MS platform equipped with a high-speed ion trap mass analyzer, provided with ready-to-use protocols and a database of as many as 4500 therapeutic, toxic/illicit drugs and metabolites. The aim of the present work was to verify its performances in real conditions of drug screening of human serum in the context of DUID. To test and compare its analytical performances, four pooled serum samples were fortified with a selected panel of 47 drugs and metabolites. The agreement between the results from the ToxtyperTM and from the confirmatory techniques currently in use at the University of Verona (GC and LC-MS) was investigated by analyzing 90 real samples chosen from those routinely analyzed. The present study highlights the suitability of the ToxtyperTM for drug screening in serum with a sensitivity compatible with the needs of the DUID for all the tested compounds, with the only exception of cannabinoids.

Morphological analysis of the seeds of three pseudocereals by using light microscopy and ESEM-EDS.

The seed morphology of three Pseudocereal Grains (PSCg), i.e. quinoa (Chenopodium quinoa Willd, Chenopodiaceae), buckwheat (Fagopyrum esculentum Moench, Polygonaceae) and amaranth (Amaranthus caudatus L., Amaranthaceae) was studied by light microscopy (LM) and Environmental Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (ESEM-EDS). LM was used with visible light to evaluate either unstained sections or sections stained with Azan mixture and with fluorescent light. The aim of the study was to compare the architecture of the three seeds in order to connect their morphology with nutrient localization. The Azan staining allowed for the visualization of the seed coat, the embryo - with its shoot apical meristem - and the radicle cell layers, whereas the use of fluorescent microscopy identified the cells rich in phenolic compounds. Finally, the ESEM-EDS analysis revealed that the seed coat of the quinoa was thinner than that of amaranth or buckwheat. In all PSCg, starch granules appeared to be located in large polygonal cells, surrounded by a thin cell wall. Several globoids of proteins were observed in the embryo cells. In the radicle section, the vascular bundles of the procambium were evident, while Amaranth only showed a consistent layer of calcium crystals, located between the embryo and the perysperm. The morphological differences of the three PSCg were discussed in the context of their structural resistance to processing technologies which impact on nutritional value of derived foods.