Alkylation of Aromatic Compounds in the Presence of Catalysts Based on Mesoporous Phenol–Formaldehyde Polymers

A catalyst based on a mesoporous phenol–formaldehyde polymer (MPF) as an organic support modified with the IMHSO₄ ionic liquid has been synthesized. The catalytic activity of the sample has been studied in the alkylation of aromatic compounds with octene-1. It has been found that the use of the catalyst in phenol alkylation leads to the formation of both alkylphenols (C-alkylates) and alkyl phenyl ethers (O-alkylates) with a total yield of up to 60%. In the case of alkylation of benzene and benzene derivatives, significant conversion values (45–50%) are achieved only for toluene and anisole.     

Selective Removal of H2S from Petroleum Refinery Gases. III. A Study on the Corrosion in Desulfurizer–H2S–CO2–H2O System

Abstract

Corrosion in desulfurizer–H₂S–CO₂–H₂O system was investigated by static weight loss test. The corrosion data for JPE-7 system were compared with those for MDEA and MEA system under the same conditions. The results indicated that the new desulfurizer JPE-7 system was generally less corrosion to carbon steel than MDEA and MEA system. The order of corrosivity of the desulfurizer system is JPE-7<MDEA<MEA. With the acid gas loading, especially the CO₂ loading increase, the corrosion rate increases. The chloride anion in desulfurizer solution contributes greatly to corrosion. The higher the solution temperature, the more the corrosivity of desulfurizers.     

Development and validation of an LC–MS/MS/MS method for the quantification of fluoroquinolones in several matrices from treated turkeys

The study presents a sensitive and reliable confirmatory method for the extraction, identification, quantification of five fluoroquinolones (FQ) namely enrofloxacin, ciprofloxacin, difloxacin, sarafloxacin and flumequine, in plasma, liver, kidney, muscle, skin + fat, lung and intestinal content from turkeys.For the extraction and matrix clean-up of FQ residues from all biological matrices, the Quick Easy Cheap Effective Rugged Safe (QuEChERS) methodology was adopted; only for plasma samples acetonitrile was used.The analyses were performed by liquid chromatography with mass spectrometry detection (LC–MS). LC separation was performed on a C18 Kinetex column (100 × 2.1 mm, 2.6 μm, Phenomenex, CA, USA) with gradient elution using ammonium acetate solution (10 mM, pH 2.5) and methanol containing 0.1% formic acid. Mass spectrometric identification was done using an LTQ XL ion trap (Thermo Fisher Scientific, CA, USA), with a heated electrospray ionization probe, in positive ion mode.The method was validated according to the European Legislation (decision 2002/657/EC) and EMA guideline (EMA/CVMP/VICH/463202/2009); selectivity, linearity response, trueness (in terms of recovery), precision (within-day repeatability and within-laboratory reproducibility), limit of detection, limit of quantification, decision limits, detection capability, absolute recovery and robustness were evaluated using turkey blank matrices. All data were within the required limits established for confirmatory methods except for flumequine which presented a recovery value slightly higher than 110% in muscle and intestinal content. For all FQs, all the extraction rates were greater than 70% and limits of quantification ranged from 1.2 μg kg⁻¹ to 118.8 μg kg⁻¹.This fast and robust method was suitable for the identification and quantification of FQ residues in tissues, plasma and intestinal content as confirmed by data obtained from incurred samples of turkeys treated at farm for therapeutic purposes.     

Olefin Synthesis from Dimethyl Ether in the Presence of a Hydrothermally Treated Mg–HZSM-5/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Catalyst: Effect of Reaction Conditions on the Product Composition and Ratio

Systematic studies of olefin synthesis from dimethyl ether (DME) in the presence of a hydrothermally treated HZSM-5 zeolite catalyst modified with magnesium have been conducted. Dependences of DME conversion, product yield and selectivity, and lower olefin ratio on space time in the temperature range of 320–360°C have been analyzed. The type of the resulting products has been determined, and assumptions about the reaction chemistry have been made to reveal the role of methylation and hydrogen-transfer reactions in the products formation.