GC analysis of diisopropylnaphthalene (DIPN) isomers is presented. Naphthalene was repeatedly alkylated with propylene over an amorphous aluminosilicate catalyst under different preparation conditions, and then pure isomers or at least DIPN fractions enriched in individual isomers were isolated from the alkylates and analysed using GC-MS, IR and NMR techniques. Eight of the ten possible isomers appeared in the chromatograms; seven of them (1,3-, 1,4-, 1,5-, 1,6-, 1,7-, 2,6- and 2,7-) were separated and identified, while the eighth one was indirectly proved to be 2,3-DIPN. The remaining two isomers (1,2- and 1,8-DIPN) were not found in the products.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0021-9673(01)01571-0 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Mixed reality for preoperative planning and intraoperative assistance of surgical correction of complex congenital heart defects.
J Thorac Cardiovasc Surg
January 2025
Division of Cardiology, The Hospital for Sick Children, Toronto, ON, Canada; Center for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, Canada.
Objectives: Mixed reality (MixR) is an innovative visualization tool that presents virtual elements in a real-world environment, enabling real-time interaction between the user and the combined digital/physical reality. We aimed to explore the feasibility of MixR in enhancing preoperative planning and intraoperative guidance for the correction of various complex congenital heart defects (CHDs).
Methods: Patients underwent cardiac computed tomography or cardiac magnetic resonance and segmentation of digital imaging and communications in medicine (DICOM) images was performed.
Nitrosyl factors play a vital role in the ventilatory depressant effects of fentanyl in freely moving guinea pigs.
Biomed Pharmacother
January 2025
Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, USA.
An understanding of intracellular mechanisms by which fentanyl and other synthetic opioids exert adverse effects on breathing is needed. Using freely moving adult male guinea pigs, we administered the nitric oxide synthase (NOS) inhibitor, L-NAME (N-nitro-L-arginine methyl ester), to determine whether nitrosyl factors, such as nitric oxide and S-nitrosothiols, play a role in fentanyl-induced respiratory depression. Ventilatory parameters were recorded by whole body plethysmography to determine the effects of fentanyl (75 μg/kg, IV) in guinea pigs that had received a prior injection of vehicle (saline), L-NAME or the inactive D-isomer, D-NAME (both at 50 μmol/kg, IV), 15 min beforehand.
View Article and Find Full Text PDFAn unconventional separation method of α-Terpineol from its isomer 1,8-Cineole via in situ-association formation of deep eutectic solvent and machine learning.
J Chromatogr A
January 2025
College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, PR China. Electronic address:
α-Terpineol and 1,8-cineole are two important compounds in essential oils. This study developed an efficient method to recover α-terpineol from model oil (MO) based on association extraction by in situ formations of deep eutectic solvent (DES) between α-terpineol and some quaternary ammonium salts (QASs) by hydrogen-bond (HB) interaction. Such interaction could be broken almost completely by the introduction of water, due to the stronger HB interaction between water and QASs, which could release α-terpineol by liquid-liquid separation and save the organic solvents consumption.
View Article and Find Full Text PDFDevelopment of a novel HPLC-HRMS method for quantitative analysis of resorcinol in urine: Application to hairdressers' occupational exposure.
J Chromatogr B Analyt Technol Biomed Life Sci
January 2025
Resorcinol is a widespread substance used in a large variety of manufacturing industries, including cosmetics, with endocrine-disrupting activity on the thyroid function. The aim of the present study was to develop and validate a sensitive, selective and robust method to quantify resorcinol in urine and thereby assess hairdressers' occupational exposure. As resorcinol is mainly excreted in urine as glucuronide or sulfate forms, the first step consisted in hydrolyzing urine samples with a β-glucuronidase-arylsulfatase enzyme for 16 h.
View Article and Find Full Text PDFShared Pheromone Compounds in Neotropical Rice Stink Bugs: The Role of Zingiberenol and Sesquipiperitol.
J Chem Ecol
January 2025
Embrapa Recursos Genéticos e Biotecnologia, Laboratório de Semioquímicos, Brasília, DF, 70297-400, Brazil.
The small black stem bug, Paratibraca (= Glyphepomis) spinosa (Campos and Grazia 1998), is a rice pest in Brazil and is part of a complex of stink bugs that includes Oebalus poecilus (Dallas) and Tibraca limbativentris Stål. Together, these pentatomid species pose a serious threat to rice crops throughout South America. In this study, we identified the sex pheromone of P.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!