No abstract

A method for extraction and fast gas chromatographic (GC) determination of twenty pesticide residues of different volatility and polarity at ultratrace concentration level in apples is presented. Apples as representatives of non-fatty food were chosen as a matrix; they are also a common raw material for baby food production. Under fast GC conditions employing a mass spectrometric detector (MSD), several parameters of the MSPD procedure were optimised. Samples were homogenised with sorbent Florisil, pesticides were eluted with the optimised volume of etylacetate. After solvent evaporation to dryness, reconstitution of the rest to toluene follow and the final extract was injected. Recoveries obtained at three selected concentration levels were determined. The optimised procedure led to recoveries ≥ 90 % for the majority of the studied pesticides and the limits of quantification (LOQs) < 5 µg.kg -1 . Repeatability of gas chromatography-mass spectrometry (GC-MS) measurements of the matrix matched standards, expressed as the relative standard deviation (RSD [ %]), was in most cases acceptable for ultratrace concentration levels of pesticide residues.

POM analysis and related approaches are significant tools based on calculating various physico-chemical properties and predicting biological activity, ADME parameters, and toxicity of a molecule. These methods are used to evaluate a molecule’s potential to become a drug candidate. Avenanthramides (AVNs) are promising secondary metabolites specific to Avena spp. (oat). They comprise the amides of anthranilic acid linked to various polyphenolic acids with or without post-condensation molecule transformation. These natural compounds have been reported to exert numerous biological effects, including antioxidant, anti-inflammatory, hepatoprotective, antiatherogenic, and antiproliferative properties. To date, almost 50 various AVNs have been identified. We performed a modified POM analysis of 42 AVNs using MOLINSPIRATION, SWISSADME, and OSIRIS software. The evaluation of primary in silico parameters revealed significant differences among individual AVNs, highlighting the most promising candidates. These preliminary results may help coordinate and initiate other research projects focused on particular AVNs, especially those with predicted bioactivity, low toxicity, optimal ADME parameters, and promising perspectives.

The analytical procedure based on stir-bar sorptive extraction technique, for the determination of selected pesticide residues (diazinon, malathion, cyprodinyl, penconazole, fludioxonyl, pyriproxyfen, boscalid, pyraclostrobin) is described. Analysis was performed using the commercial Twister TM stir bar for sorptive extraction. It consists of a 2.0-cm-long glass-encapsulated magnetic stir bar externally coated with PDMS. The extracts were off-line analyzed using fast GC-MS in SIM mode. Optimized conditions were established as follows concerning extraction time, stirring speed, aqueous medium characteristics (ionic strength and polarity) respectively: 120 min (700 rpm), addition of 4 g of sodium chloride, no addition of methanol as organic modifier, and 30 min ultrasonic desorption in acetonitrile. Recoveries ranged from 38 % to 58 % (RSD < 15 %, n = 6). Validated limits of quantification in matrix were between 1.6 ngL −1 and 548.8 ngL −1 , depending on the compound.