, and sometimes dependent, to the Asia/Europe intermediates market. The dependence cited here has an incredible effect on the final manufacturing price but also on the choice of synthetic route. In this way, the choice of drug candidate for continuous
Authors:E. Radomińska, T. Znamierowska, and W. Szuszkiewicz
previously unknown phase equilibria in the Rb 3 PO 4 –Ba 3 (PO 4 ) 2 system were investigated in the entire composition range up to a temperature of 1800 °C. BaRbPO 4 appeared as an intermediate compound in the system. Due to the synthesis conditions of the
Authors:A. Czylkowska, D. Czakis-Sulikowska, A. Kaczmarek, and M. Markiewicz
derivatograph type Q-1500, samples of 100 mg, α-Al 2 O 3 served as reference material in air static atmosphere. From TG, DTA and DTG curves the solid intermediate products decomposition were determined and were confirmed by the IR spectra of sinters. In sinters
Authors:B. Ivković, J. Brborić, V. Dobričić, and O. Čudina
) equipped with quaternary pump, autosampler, and DAD detector. Intermediate precision was tested on chromatograph Agilent 1200 (Agilent Technologies, Palo Alto, CA, USA) equipped with binary pump, manual injector (20 μL loop), and DAD detector. The column
Authors:J. Skubiszewska-Zięba, B. Charmas, R. Leboda, V. A. Tertykh, and V. V. Yanishpolskii
of ST 1 and ST 15 the amount of weakly bound water is significantly smaller than that of strongly bound water desorbing at higher temperatures (above 110 °C). The intermediate properties with respect to the proportion of weakly and strongly bound
Authors:Daniel Blanco-Ania and Floris P. J. T. Rutjes
While continuous-flow chemistry is steadily increasing its footprint in academic research and in the manufacturing of pharmaceutical intermediates and fine chemicals, the attention for flow chemistry in educational programs is on average rather limited. This account is meant to provide a personal overview of the possibilities to address the involvement of flow chemistry in the various stages of chemical education.
Authors:Joanna Wiśniewska, Grzegorz Wrzeszcz, Stanisław Koter, and Tomasz Ligor
hazardous contaminants from the environment, we can use these safe processes to remove pharmaceuticals and pharmaceutical pollution. Chemical oxidation aims to selectively remove persistent components via the conversion to readily biodegradable intermediates
Authors:Sinan Zazoğlu, Beril Anilanmert, Muhammed Aydin, and Salih Cengiz
A fast, reliable, inexpensive, and practical method with a low determination limit and high recovery has been developed for the determination of the marijuana metabolite in routine analysis. THC-COOH in urine was validated using liquid chromatography—tandem mass spectrometry (LC—MS/MS). Before an easy single-step extraction with Toxi-Tubes, basic hydrolysis was performed at 60 °C for 30 min. LC—MS/MS analysis takes 2.5 min for each sample, and the retention time of the analyte is 1.75 min. Specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, repeatability, and intermediate precision (inter-day) system suitability parameters were determined in the validation study. The recovery of the extraction method was 88.67 (±5.91). LOD and LOQ values were 1.41 and 5.00 ng mL−1, respectively. The method showed linear response between the values 5.00 and 500.00 ng mL−1. The repeatability was 9.64% (relative standard deviation, RSD%), and the intermediate precisions (RSDR%) were 10.73%, 13.74%, and 8.11% at 10.00, 100.00, and 200.00 ng mL−1 concentration levels, respectively. No statistically significant difference was found in ANOVA analysis, between three consecutive days in intermediate precision study, for 90% confidence level. HorRat values were between 0.34 and 0.61. The method was applied to CEDIA positive samples, obtained from the Trabzon Group Presidency of Turkish Council of Forensic Medicine, successfully.
In this study, the influence of glycols on chemical structure and thermal stability of glycolysates as polyurethane intermediates were investigated. The intermediates were obtained by the glycolysis process of waste polyurethane foams in the reaction with different glycols ranging from ethylene glycol to hexane-1,6-diol. The used glycols were not separated from the product after the glycolysis process has been terminated. The effects of different weight ratio of glycols to polyurethane (PU) foam on chemical structure and thermal stability were investigated by FTIR, GPC, and TG/DTG. FTIR analysis of the glycolysates revealed their similar chemical architecture as manifested by the similarity of absorption peaks within the entire wavenumber range of spectra. This may indicate that the glycol has no influence on the chemical composition of glycolysates. GPC analysis showed that the glycolysates were characterized by polydispersity smaller than 2 which is lower as compared to some commercial polyols used for PU synthesis. GPC chromatograms showed that the applied glycols and the conditions of PU glycolysis allowed recreation of the original polyol as documented on the chromatograms by a single, well-formed peak at the beginning of retention time. Based on TG thermograms, it was established that glycol used in transesterification of PUs affected the temperature at which the loss of glycolysate mass by 5 and 10 % occurs. It was also observed that glycol affected the temperature at which the decomposition rate of glycolysates was the highest.