11 research outputs found
ChemInform Abstract: Regioselective Removal of the Anomeric O-Benzyl from Differentially Protected Carbohydrates.
Perceptions of Chemical Safety in Laboratories
This study investigates the state of the perceptions of chemical safety in laboratories among undergraduate students of the Biomedical Engineering and Pharmaceutical and Chemical Engineering departments at the German Jordanian University in Jordan. A cross-sectional survey was conducted anonymously with a random sample size of 174 students. A questionnaire of 32 questions was designed with five sections: demographic data, familiarity of chemical hazard signs, attitude towards chemical laboratory safety, safety practices, and familiarity with emergency equipment and procedure. The descriptive statistics showed that students demonstrated fair to good familiarity and understanding of chemical hazard warning signs. Most students had poor to fair attitudes towards chemical laboratory safety; but the assessment of students’ chemical laboratory safety practices revealed fair to good practices. While students safety awareness and practices, but not attitude, at this university were acceptable, safety procedures need to be implemented within a more professional safety education and coherent risk and safety climate management
Ceric ammonium nitrate/acetic anhydride: A tunable system for the <i>O</i>-acetylation and mononitration of diversely protected carbohydrates
<p>Esterification of a wide range of partially protected carbohydrate derivatives was achieved using acetic anhydride and a catalytic amount of ceric ammonium nitrate (CAN). Compatibility with the commonly used protecting groups was demonstrated, with the esterified products being furnished in good yields. Apart from affording the <i>O</i>-acetylated products, their mononitrated counterparts were also produced depending upon the reactivity of the starting material. Decreasing the molar equivalents of CAN afforded the <i>O</i>-acetylated products exclusively, while increasing it favored the mononitrated derivatives.</p
Multistage extraction and purification of waste Sargassum natans to produce sodium alginate: an optimization approach
Sargassum in the Caribbean region has affected the livelihood of several coastal communities due to the influx of large quantities of the seaweed in recent times. This article seeks to explore how waste Sargassum natans can be utilized to produce sodium alginate. The novelty in this research lies in the optimization process, whereby multistage extraction and precipitation were investigated over commonly used single stage processing, in an effort to maximize both yield and purity. The results showed that a maximum yield of 19% was observed after 1 stage, while the purity was 74% after 4 stages. In addition, optimization of the multistage precipitation process using the Global Optimization Toolbox in MATLAB R2017b provided a novel model which indicated that a compromise between the maximum purity and yield can be obtained at 3 stages; 71–74% and 12–16% respectively. Furthermore, characterization was done using FTIR and NMR, with results comparable to a commercial sodium alginate brand, giving absorption bands at 1610 cm−1and 1395 cm-1and an M/G ratio of 0.51 respectively