A rare form of intoxication: acute methyl ethyl ketone peroxide poisoning

We report two suicidal cases of acute methyl ethyl ketone peroxide (MEKP) poisoning. A woman in her late 60s suffered from oral mucosal erosion, functional impairment of the heart, liver and other organs, pulmonary inflammation, elevated inflammatory markers, pleural effusion, hypoproteinemia and metabolic acidosis after oral administration of approximately 50 mL of MEKP. After admission, the patient was administered hemoperfusion four times, 8 mg of betamethasone for 6 days and symptomatic support. Hemoperfusion had an obvious effect on the treatment of oral MEKP poisoning. After discharge, the patient developed progressive dysphagia and secondary esophageal stenosis. Supplementary feeding was administered with a gastrostomy tube after the patient was completely unable to eat. A man in his mid-40s developed oropharyngeal mucosal erosion, bronchitis and esophageal wall thickening after oral administration of 40 ml MEKP. After receiving total gastrointestinal dispersal, 80 mg of methylprednisolone was administered for 7 days, and symptomatic supportive treatment was provided. Slight dysphagia was observed after discharge, and there was no major effect on the quality of life. Patients with acute oral MEKP poisoning should be followed up regularly to observe its long-term effects on digestive tract corrosion and stenosis.

Removal of Copper (II), Zinc (II), Cobalt (II), and Nickel (II) Ions by PIMs Doped 2-Alkylimidazoles

Polymer inclusion membranes (PIMs) are an attractive approach to the separation of metals from an aqueous solution. This study is concerned with the use of 2-alkylimidazoles (alkyl = methyl, ethyl, propyl, butyl) as ion carriers in PIMs. It investigates the separation of copper (II), zinc (II), cobalt (II), and nickel (II) from aqueous solutions with the use of polymer inclusion membranes. PIMs are formed by casting a solution containing a carrier (extractant), a plasticizer (o-NPPE), and a base polymer such as cellulose triacetate (CTA) to form a thin, flexible, and stable film. The topics discussed include transport parameters, such as the type of carrier, initial fluxes, separation coefficients of copper in relation to other metals, as well as transport recovery of metal ions. The membrane was characterized using AFM and SEM to obtain information on its composition.

A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones

A simple and efficient method for α-brominating lactones that affords α-bromolactones under mild conditions using tetraalkylammonium hydroxide (R4N+OH−) as a base was developed. Lactones are ring-opened with Br2 and a substoichiometric amount of PBr3, leading to good yields of the corresponding α-bromocarboxylic acids. Subsequent intramolecular cyclization over 1 h using a two-phase system (H2O/CHCl3) containing R4N+OH− afforded α-bromo lactones in good yields. This method can be applied at the 10 mmol scale using simple operations. α-Bromo-δ-valerolactone, which is extremely reactive and difficult to isolate, could be isolated and stored in a freezer for about one week using the developed method. Optimizing the solvent for environmentally friendly large-scale syntheses revealed that methyl ethyl ketone (MEK) was as effective. In addition, in situ-generated α-bromo-δ-valerolactone was directly converted into a sulfur-substituted functional lactone without difficulty by reacting it with a sulfur nucleophile in one pot without isolation. This new bromination system is expected to facilitate the industrial use of α-bromolactones as important intermediates.