Dual layer solid phase extraction based on molecular imprinting technology: Seeking a route to enhance selectivity for trace analysis of pesticide residues in olive oil.

Aiming to introduce a multiresidue analysis for the trace detection of pesticide residues belonging to organophosphorus and triazine classes from olive oil samples, a new sample preparation methodology comprising the use of a dual layer of “tailor-made” molecularly imprinted polymers (MIPs) SPE for the simultaneous extraction of both pesticides in a single procedure has been attempted. This work has focused on the implementation of a dual MIP-layer SPE procedure (DL-MISPE) encompassing the use of two MIP layers as specific sorbents. In order to achieve higher recovery rates, the amount of MIP layers has been optimized as well as the influence of MIP packaging order. The optimized DL-MISPE approach has been used in the preconcentration of spiked organic olive oil samples with concentrations of dimethoate and terbuthylazine similar to the maximum residue limits and further quantification by HPLC. High recovery rates for dimethoate (95%) and terbuthylazine (94%) have been achieved with good accuracy and precision. Overall, this work constitutes the first attempt on the development of a dual pesticide residue methodology for the trace analysis of pesticide residues based on molecular imprinting technology. Thus, DL-MISPE constitutes a reliable, robust, and sensitive sample preparation methodology that enables preconcentration of the target pesticides in complex olive oil samples, even at levels similar to the maximum residue limits enforced by the legislation.

Combined Use of NMR, LC-ESIMS and Antifungal Tests for Rapid Detection of Bioactive Lipopeptides Produced by Bacillus

The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. Many microorganisms influenced by environmental conditions are the main responsible for biological contamination in built heritage. Biocides based on chemical compounds have been used to mitigate this problem. Thus, it is vitally important to develop proper remediation actions based on environmentally innocuous alternative. Bacillus specie is emerging as an optimistic alternative for built heritage treatment due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens. Therefore, the intent of this work was to access a rapid evaluation of antifungal potential of bioactive metabolites produced by Bacillus strains and simultaneously their characterization using spectroscopic (NMR) and chromatographic techniques (LCESI- MS). The high antifungal activity obtained for Bacillus sp. active compounds produced in this study confirms the great potential to suppress biodeteriogenic fungi growth on historical artworks. Additionally, the proposed methodology allowed to access bioactive metabolites produced without need of the laborious total previous isolation and could be used as a viable alternative to be employed for screening and production of new green biocides.

Does partial privatisation improve performance? Evidence from a chain of hotels in Portugal

This article contributes to the literature by testing six research hypotheses regarding the impact of partial privatisation on firms' performance. We measure performance using Data Envelopment Analysis (DEA), the Malmquist Index and ratios related to labour productivity, profitability and capacity utilisation. We use the Wilcoxon Signed Rank test to compare the performance after privatisation with that before privatisation. The hypotheses are tested with data from a chain of Portuguese heritage hotels, partially privatised in 2003. We conclude that productivity growth after privatisation is superior to productivity growth before privatisation due to technological progress. However, due to a frontier regress observed in the privatisation year, total factor productivity and profitability deteriorated after privatisation. This suggests that both efficiency changes and frontier shifts should be taken into account in order to accurately assess the impact of privatisation.