3 research outputs found
The role of sample preparation in suspect and non-target screening for exposome analysis using human urine
The use of suspect and non-target screening (SNTS) for the characterization of the chemical exposome employing human biofluids is gaining attention. Among the biofluids, urine is one of the preferred matrices since organic xenobiotics are excreted through it after metabolization. However, achieving a consensus between selectivity (i.e. preserving as many compounds as possible) and sensitivity (i.e. minimizing matrix effects by removing interferences) at the sample preparation step is challenging. Within this context, several sample preparation approaches, including solid-phase extraction (SPE), liquid-liquid extraction (LLE), salt-assisted LLE (SALLE) and dilute-and-shoot (DS) were tested to screen not only exogenous compounds in human urine but also their phase II metabolites using liquid-chromatography coupled to high-resolution tandem mass spectrometry (LC-HRMS/MS). Additionally, enzymatic hydrolysis of phase II metabolites was evaluated. Under optimal conditions, SPE resulted in the best sample preparation approach in terms of the number of detected xenobiotics and metabolites since 97.1% of the total annotated suspects were present in samples extracted by SPE. In LLE and SALLE, pure ethyl acetate turned out to be the best extractant but fewer suspects than with SPE (80.7%) were screened. Lastly, only 52.5% of the suspects were annotated in the DS approach, showing that it could only be used to detect compounds at high concentration levels. Using pure standards, the presence of diverse xenobiotics such as parabens, industrial chemicals (benzophenone-3, caprolactam and mono-2-ethyl-5-hydroxyhexyl phthalate) and chemicals related to daily habits (caffeine, cotinine or triclosan) was confirmed. Regarding enzymatic hydrolysis, only 10 parent compounds of the 44 glucuronides were successfully annotated in the hydrolysed samples. Therefore, the screening of metabolites in non-hydrolysed samples through SNTS is the most suitable approach for exposome characterization.Authors gratefully acknowledge financial support from the State Research Agency of the Ministry of Science and Innovation (Government of Spain) through project PID 2020-117686RB-C31 and the Basque Government as a consolidated group of the Basque Research System (IT-1446-22). M. Musatadi also acknowledges the Basque Government for his predoctoral grant
Síntesis estereocontrolada de alcaloides isoquinolínicos asistida por beta-aminoalcoholes quirales
ΤΑΚΤΙΚΗ ΣΥΝΕΔΡΙΑΣΗ ΔΗΜΟΤΙΚΟΥ ΣΥΜΒΟΥΛΙΟΥ ΤΟΜΟΣ 50/ 15_9_1949 (έναρξη συνεδρίασης 8:00μ.μ.)
"Prestige" ontziak zeraman hondakin fuel-olioa, petrolioaren eraldaketan sortutako osagai pisu tsuen hidrokarburo-nahastea da. Horregatik, isurketa honen ondorioak ulertu ahal izateko, beronen jatorria eta eraldaketa aztertu behar dira lehenik, hau da, hidrokarburoen ezaugarri kimiko nagusiak, petrolioaren kimika eta petrolioaren industri eraldaketak eta ondoren hondakin fuel-olioaren ezaugarriak eta toxikotasuna