Application of Microgel as a Sorbent for Bisphenol Analysis in Liquid Food Samples

Bisphenols are well-known endocrine disruptors that can easily migrate from plastic and can containers to food. Due to the complicated matrix and ultra-low concentrations of bisphenols in food, samples require extensive preparation before instrumental analysis. In this paper, an environmental sensitive microgel was employed as a sorbent for the preconcentration of four bisphenols, bisphenol A (BPA), bisphenol B (BPB), bisphenol E (BPE) and bisphenol F (BPF), from liquid food samples. Liquid chromatography with fluorescence detection (LC-FLD) was used for the quantification of bisphenols. By applying microgel solid-phase extraction procedure, the limits of detections achieved in liquid food samples can be lowered to 0.9 µg·L−1 for BPF and BPA, 2.3 µg·L−1 for BPE and 2.9 µg·L−1 for BPB. Only 5 mg of microgel was sufficient to achieve good recoveries (70.5–109%) with precision (RSD 0.21–5.01%, n = 3) for different analyzed liquid food samples spiked at concentration levels of 50 µg·L−1. In five out of twelve of the analyzed samples (pineapple, mandarin, peach, mushroom and pickles), they were contaminated with BPA, and the determined concentration was in the range of 6.2–22 µg·L−1; however, these results are below the specific migration limit (SML) set for BPA (50 µg·kg−1).

Solid phase extraction procedure coupled with the chiral LC-ESI-MS/MS method for the enantioseparation and determination of butoconazole enantiomers in rat plasma and tissues: application to the enantioselective study on pharmacokinetics and tissue distribution

A significant enantioselective difference between (−)- and (+)-butoconazole existed in the stage of not only pharmacokinetics but also tissue distribution.

Separation of aniline from water and wastewater samples based on activated carbon nanoparticles and dispersive solid phase extraction procedure

The water, wastewater and air are the main sources of aniline in environment. Aniline has a toxic effect in the human body and environment and so, must be determined by novel techniques. In this study, the activated carbon with microwave heating methods (MHM-ACNPs) were used for extraction aniline from waters by dispersive ionic liquid solid phase extraction procedure (D-IL-SPE) and compared to the activated carbon (AC). For this purpose, the mixture of acetone, ionic liquid and 30 mg of MHM-ACNPs/AC added to 100 mL of water samples at pH=8. After sonication for 10 min, the benzene ring in aniline as electron acceptor was chemically adsorbed on carboxylic groups of MHM-ACNPs as electron donors (MHM-ACNPs-COO─……C6H5-NH2) and then, the adsorbent was collected by IL phase in bottom of conical centrifuging tube. Finally, the aniline was released from MHM-ACNPs in remained solution by changing pH and the concentration of aniline determined by GC-FID.

Suspect and Target Screening of Natural Toxins in the Ter River Catchment Area in NE Spain and Prioritisation by Their Toxicity

This study presents the application of a suspect screening approach to screen a wide range of natural toxins, including mycotoxins, bacterial toxins, and plant toxins, in surface waters. The method is based on a generic solid-phase extraction procedure, using three sorbent phases in two cartridges that are connected in series, hence covering a wide range of polarities, followed by liquid chromatography coupled to high-resolution mass spectrometry. The acquisition was performed in the full-scan and data-dependent modes while working under positive and negative ionisation conditions. This method was applied in order to assess the natural toxins in the Ter River water reservoirs, which are used to produce drinking water for Barcelona city (Spain). The study was carried out during a period of seven months, covering the expected prior, during, and post-peak blooming periods of the natural toxins. Fifty-three (53) compounds were tentatively identified, and nine of these were confirmed and quantified. Phytotoxins were identified as the most frequent group of natural toxins in the water, particularly the alkaloids group. Finally, the toxins identified to levels 2 and 1 were prioritised according to their bioaccumulation factor, biodegradability, frequency of detection, and toxicity. This screening and prioritisation approach resulted in different natural toxins that should be further assessed for their ecotoxicological effects and considered in future studies.

High-Silica Zeolites as Sorbent Media for Adsorption and Pre-Concentration of Pharmaceuticals in Aqueous Solutions

The present work focused on the use of high-silica commercial zeolites as sorbent media for pharmaceuticals in an aqueous matrix. As drug probes, ketoprofen, hydrochlorothiazide, and atenolol were selected, because of their occurrence in surface waters and effluents from wastewater treatment plants. Pharmaceuticals adsorption was evaluated for two Faujasite topology zeolites with Silica/Alumina Ratio 30 and 200. The selected zeolites were demonstrated to be efficient sorbents towards all investigated pharmaceuticals, thanks to their high saturation capacities (from 12 to 32% w/w) and binding constants. These results were corroborated by thermal and structural analyses, which revealed that adsorption occurred inside zeolite’s porosities, causing lattice modifications. Finally, zeolites have been tested as a pre-concentration media in the dispersive-solid phase extraction procedure. Recoveries higher than 95% were gained for ketoprofen and hydrochlorothiazide and approximately 85% for atenolol, at conditions that promoted the dissolution of the neutral solute into a phase mainly organic. The results were obtained by using a short contact time (5 min) and reduced volume of extraction (500 µL), without halogenated solvents. These appealing features make the proposed procedure a cost and time saving method for sample enrichment as well as for the regeneration of exhausted sorbent, rather than the more energetically expensive thermal treatment.