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Ionascu C.,West University of Timișoara | Ostafe V.,Advanced Research Environmental Laboratories
Studia Universitatis Babes-Bolyai Chemia | Year: 2014

Three sample preparation methods: solvent extraction, solidphase extraction (SPE) and stir bar sorptive extraction (SBSE) to assess the occurrence of 11 mycotoxins in beer (pale, dark and non-alchoolic) samples were compared. In order to select the best extraction procedure, the sample matrix effects and the effect of the dilution of the sample were investigated by addition of the analytes before and after the extraction procedure was carried out. The study revealed that SPE (with Oasis HLB cartridge) procedure offered the best results compared with the other two extraction methods: relative standard errors under 16% and recovery of the analytes better than 85%. An Ultrahigh Performance Liquid Chromatography coupled with Mass Spectrometry (UPLC-MS/MS) method was used to identify and confirm the mycotoxins. © 2014, Universitatea Babes-Bolyai, Catedra de Filosofie Sistematica. All rights reserved.


Preda E.,West University of Timișoara | Preda E.,Advanced Research Environmental Laboratories | Maria Mincea M.,West University of Timișoara | Maria Mincea M.,Advanced Research Environmental Laboratories | And 5 more authors.
Studia Universitatis Babes-Bolyai Chemia | Year: 2013

In this study, a new procedure, based on solid-phase extraction (SPE) and analysis by Ultrahigh Performance Liquid Chromatography coupled with Mass Spectrometry method (UPLC-MS/MS), has been developed for the simultaneous, multianalyte determination of 15 selected phenols in water. SPE was carried out on LiChrolut RP-18 and Oasis HLB cartridges by percolating 500 mL water samples. The analytical methods allowed the separation of the 15 phenols in less than 8 minutes, with a recovery higher than 70%, and a quantification limit between 3 - 5 ng/L. The developed UPLC-MS/MS method showed high precision, as it was confirmed by the low values of relative standard deviation (RSD) for water samples spiked with 10 and 100 ng/L analytes. In the optimized method, LOQ higher than 5 ng/L, satisfactory precision (relative standard deviations < 20%) and accuracies (recovery percentages between 70 and 95%) were obtained for most investigated compounds.


Negrulescu A.,West University of Timișoara | Negrulescu A.,Advanced Research Environmental Laboratories | Patrulea V.,West University of Timișoara | Patrulea V.,Advanced Research Environmental Laboratories | And 5 more authors.
Studia Universitatis Babes-Bolyai Chemia | Year: 2015

An UPLC method was developed to determine the concentrations of tartrazine (TAR), Congo red (CR), and methyl orange (MO) in aqueous mixtures. The chromatographic method was optimized considering the temperature of the column, the composition of mobile phases and the gradient program. The chosen method has allowed the separation and identification of TAR, CR, and MO from aqueous samples in 2 min. The calibration plots (R2> 0.991) were linear over the ranges 0.5 – 50 μg/mL. Accuracy of the method was investigated, by applying recovery tests, with average recovery higher than 99%. The precision analysis included an intra-day variation, for which RSD (%) had values lower than 0.94, and an inter-day variation with RSD (%) values lower than 1.07. The developed method was successfully tested on water samples collected from a river nearby a textile industry plant. © 2015, Universitatea Babes-Bolyai, Catedra de Filosofie Sistematica. All rights reserved.

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