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An electrochemical sensor for the pesticide Pirimicarb (PMC) has been developed. A screen-printed electrode (SPCE) was used and modified with the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) and gold nanoparticles (AuNPs) to enhance electrochemical proprieties. Electrode characterizations were performed using scattering electron microscopy (SEM) and cyclic voltammetry (CV). With the SPCE/PEDOT:PSS/AuNPs modified electrode, a new peak at 1.0 V appeared in the presence of PMC related to the PMC oxidation. To elucidate the mechanism of PMC oxidation, Gas Chromatography-Mass Spectrometry (GC-MS), where two major peaks were identified, evidencing that the device can both detect and degrade PMC by an electro-oxidation process. Exploring this peak signal, it was possible the sensor development, performing detection from 93.81–750 µmol L−1, limits of quantification (LOQ) and detection (LOD) of 93.91 µmol L−1 and 28.34 µmol L−1, respectively. Thus, it was possible to study and optimization of PMC degradation, moreover, to perform detection at low concentrations and with good selectivity against different interferents using a low-cost printed electrode based on graphite modified with conductive polymer and AuNPs.

Pervaporation with a polydimethylsiloxane membrane (PDMS) has previously been used for the recovery of aroma compounds or to dealcoholise beer. This work considers two PDMS pervaporation processes and associated operating conditions. In addition to ethanol, two esters and one higher alcohol were chosen as key beer aroma compounds. The effects of feed flow rate and temperature on aroma recovery were studied, with feed temperature and permeate pressure evaluated with regard to beer dealcoholisation. The required membrane areas for a given alcoholic beer flow rate were simulated by mass balance to achieve a non‐alcoholic product. With aroma recovery, no concentration polarisation was observed with Reynolds numbers above 1520 and the optimal temperature was 10°C. For alcohol removal, the best operation conditions were 65°C and 1400 Pa. With such conditions, the required membrane surface to recover 50% of ethyl acetate from the original beer was 13.8 m2 in the first pervaporation unit, whereas 4.4 m2 was needed in the second one to achieve an alcohol content of 0.05% (v/v). The mixed final product was defined as an alcohol‐free beer with significant aroma compounds, showing the feasibility of pervaporation for both beer aroma recovery and dealcoholisation. © 2019 The Institute of Brewing & Distilling

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